GH-101520: Move tracemalloc functionality into core, leaving interface in Modules. (#104508)

11 files changed, 1621 insertions, 1545 deletions

diff --git a/Include/internal/pycore_pylifecycle.h b/Include/internal/pycore_pylifecycle.h
index 7f8cc643ec..7cd998a704 100644
--- a/Include/internal/pycore_pylifecycle.h
+++ b/Include/internal/pycore_pylifecycle.h
@@ -31,7 +31,6 @@ PyAPI_FUNC(int) _Py_IsLocaleCoercionTarget(const char *ctype_loc);
 
 extern void _Py_InitVersion(void);
 extern PyStatus _PyFaulthandler_Init(int enable);
-extern int _PyTraceMalloc_Init(int enable);
 extern PyObject * _PyBuiltin_Init(PyInterpreterState *interp);
 extern PyStatus _PySys_Create(
     PyThreadState *tstate,
diff --git a/Include/tracemalloc.h b/Include/tracemalloc.h
index bd14217c19..580027a8e3 100644
--- a/Include/tracemalloc.h
+++ b/Include/tracemalloc.h
@@ -33,6 +33,40 @@ PyAPI_FUNC(int) PyTraceMalloc_Untrack(
 PyAPI_FUNC(PyObject*) _PyTraceMalloc_GetTraceback(
     unsigned int domain,
     uintptr_t ptr);
+
+/* Return non-zero if tracemalloc is tracing */
+PyAPI_FUNC(int) _PyTraceMalloc_IsTracing(void);
+
+/* Clear the tracemalloc traces */
+PyAPI_FUNC(void) _PyTraceMalloc_ClearTraces(void);
+
+/* Clear the tracemalloc traces */
+PyAPI_FUNC(PyObject *) _PyTraceMalloc_GetTraces(void);
+
+/* Clear tracemalloc traceback for an object */
+PyAPI_FUNC(PyObject *) _PyTraceMalloc_GetObjectTraceback(PyObject *obj);
+
+/* Initialize tracemalloc */
+PyAPI_FUNC(int) _PyTraceMalloc_Init(void);
+
+/* Start tracemalloc */
+PyAPI_FUNC(int) _PyTraceMalloc_Start(int max_nframe);
+
+/* Stop tracemalloc */
+PyAPI_FUNC(void) _PyTraceMalloc_Stop(void);
+
+/* Get the tracemalloc traceback limit */
+PyAPI_FUNC(int) _PyTraceMalloc_GetTracebackLimit(void);
+
+/* Get the memory usage of tracemalloc in bytes */
+PyAPI_FUNC(size_t) _PyTraceMalloc_GetMemory(void);
+
+/* Get the current size and peak size of traced memory blocks as a 2-tuple */
+PyAPI_FUNC(PyObject *) _PyTraceMalloc_GetTracedMemory(void);
+
+/* Set the peak size of traced memory blocks to the current size */
+PyAPI_FUNC(void) _PyTraceMalloc_ResetPeak(void);
+
 #endif
 
 #endif /* !Py_TRACEMALLOC_H */
diff --git a/Makefile.pre.in b/Makefile.pre.in
index 8f43def305..da3a8f6c13 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -421,6 +421,7 @@ PYTHON_OBJS=	\
 		Python/sysmodule.o \
 		Python/thread.o \
 		Python/traceback.o \
+		Python/tracemalloc.o \
 		Python/getopt.o \
 		Python/pystrcmp.o \
 		Python/pystrtod.o \
diff --git a/Misc/NEWS.d/next/Library/2023-05-11-21-32-18.gh-issue-101520.l9MjRE.rst b/Misc/NEWS.d/next/Library/2023-05-11-21-32-18.gh-issue-101520.l9MjRE.rst
new file mode 100644
index 0000000000..5e8bf967bf
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-05-11-21-32-18.gh-issue-101520.l9MjRE.rst
@@ -0,0 +1,2 @@
+Move the core functionality of the ``tracemalloc`` module in the ``Python/``
+folder, leaving just the module wrapper in ``Modules/``.
diff --git a/Modules/_tracemalloc.c b/Modules/_tracemalloc.c
index c5714d5e7d..f3f4af9aba 100644
--- a/Modules/_tracemalloc.c
+++ b/Modules/_tracemalloc.c
@@ -1,988 +1,13 @@
 #include "Python.h"
-#include "pycore_fileutils.h"     // _Py_write_noraise()
-#include "pycore_gc.h"            // PyGC_Head
-#include "pycore_hashtable.h"     // _Py_hashtable_t
-#include "pycore_object.h"        // _PyType_PreHeaderSize
-#include "pycore_pymem.h"         // _Py_tracemalloc_config
-#include "pycore_runtime.h"       // _Py_ID()
-#include "pycore_traceback.h"
-#include <pycore_frame.h>
-#include "frameobject.h"          // _PyInterpreterFrame_GetLine
-
-#include <stdlib.h>               // malloc()
 
 #include "clinic/_tracemalloc.c.h"
 
+
 /*[clinic input]
 module _tracemalloc
 [clinic start generated code]*/
 /*[clinic end generated code: output=da39a3ee5e6b4b0d input=708a98302fc46e5f]*/
 
-#define tracemalloc_config _PyRuntime.tracemalloc.config
-
-_Py_DECLARE_STR(anon_unknown, "<unknown>");
-
-/* Forward declaration */
-static void tracemalloc_stop(void);
-static void* raw_malloc(size_t size);
-static void raw_free(void *ptr);
-
-#ifdef Py_DEBUG
-#  define TRACE_DEBUG
-#endif
-
-#define TO_PTR(key) ((const void *)(uintptr_t)(key))
-#define FROM_PTR(key) ((uintptr_t)(key))
-
-#define allocators _PyRuntime.tracemalloc.allocators
-
-
-#if defined(TRACE_RAW_MALLOC)
-/* This lock is needed because tracemalloc_free() is called without
-   the GIL held from PyMem_RawFree(). It cannot acquire the lock because it
-   would introduce a deadlock in _PyThreadState_DeleteCurrent(). */
-#  define tables_lock _PyRuntime.tracemalloc.tables_lock
-#  define TABLES_LOCK() PyThread_acquire_lock(tables_lock, 1)
-#  define TABLES_UNLOCK() PyThread_release_lock(tables_lock)
-#else
-   /* variables are protected by the GIL */
-#  define TABLES_LOCK()
-#  define TABLES_UNLOCK()
-#endif
-
-
-#define DEFAULT_DOMAIN 0
-
-typedef struct tracemalloc_frame frame_t;
-typedef struct tracemalloc_traceback traceback_t;
-
-#define TRACEBACK_SIZE(NFRAME) \
-        (sizeof(traceback_t) + sizeof(frame_t) * (NFRAME - 1))
-
-/* The maximum number of frames is either:
- - The maximum number of frames we can store in `traceback_t.nframe`
- - The maximum memory size_t we can allocate */
-static const unsigned long MAX_NFRAME = Py_MIN(UINT16_MAX, ((SIZE_MAX - sizeof(traceback_t)) / sizeof(frame_t) + 1));
-
-
-#define tracemalloc_empty_traceback _PyRuntime.tracemalloc.empty_traceback
-
-
-/* Trace of a memory block */
-typedef struct {
-    /* Size of the memory block in bytes */
-    size_t size;
-
-    /* Traceback where the memory block was allocated */
-    traceback_t *traceback;
-} trace_t;
-
-
-#define tracemalloc_traced_memory _PyRuntime.tracemalloc.traced_memory
-#define tracemalloc_peak_traced_memory _PyRuntime.tracemalloc.peak_traced_memory
-#define tracemalloc_filenames _PyRuntime.tracemalloc.filenames
-#define tracemalloc_traceback _PyRuntime.tracemalloc.traceback
-#define tracemalloc_tracebacks _PyRuntime.tracemalloc.tracebacks
-#define tracemalloc_traces _PyRuntime.tracemalloc.traces
-#define tracemalloc_domains _PyRuntime.tracemalloc.domains
-
-
-#ifdef TRACE_DEBUG
-static void
-tracemalloc_error(const char *format, ...)
-{
-    va_list ap;
-    fprintf(stderr, "tracemalloc: ");
-    va_start(ap, format);
-    vfprintf(stderr, format, ap);
-    va_end(ap);
-    fprintf(stderr, "\n");
-    fflush(stderr);
-}
-#endif
-
-
-#if defined(TRACE_RAW_MALLOC)
-#define REENTRANT_THREADLOCAL
-
-#define tracemalloc_reentrant_key _PyRuntime.tracemalloc.reentrant_key
-
-/* Any non-NULL pointer can be used */
-#define REENTRANT Py_True
-
-static int
-get_reentrant(void)
-{
-    void *ptr;
-
-    assert(PyThread_tss_is_created(&tracemalloc_reentrant_key));
-    ptr = PyThread_tss_get(&tracemalloc_reentrant_key);
-    if (ptr != NULL) {
-        assert(ptr == REENTRANT);
-        return 1;
-    }
-    else
-        return 0;
-}
-
-static void
-set_reentrant(int reentrant)
-{
-    assert(reentrant == 0 || reentrant == 1);
-    assert(PyThread_tss_is_created(&tracemalloc_reentrant_key));
-
-    if (reentrant) {
-        assert(!get_reentrant());
-        PyThread_tss_set(&tracemalloc_reentrant_key, REENTRANT);
-    }
-    else {
-        assert(get_reentrant());
-        PyThread_tss_set(&tracemalloc_reentrant_key, NULL);
-    }
-}
-
-#else
-
-/* TRACE_RAW_MALLOC not defined: variable protected by the GIL */
-static int tracemalloc_reentrant = 0;
-
-static int
-get_reentrant(void)
-{
-    return tracemalloc_reentrant;
-}
-
-static void
-set_reentrant(int reentrant)
-{
-    assert(reentrant != tracemalloc_reentrant);
-    tracemalloc_reentrant = reentrant;
-}
-#endif
-
-
-static Py_uhash_t
-hashtable_hash_pyobject(const void *key)
-{
-    PyObject *obj = (PyObject *)key;
-    return PyObject_Hash(obj);
-}
-
-
-static int
-hashtable_compare_unicode(const void *key1, const void *key2)
-{
-    PyObject *obj1 = (PyObject *)key1;
-    PyObject *obj2 = (PyObject *)key2;
-    if (obj1 != NULL && obj2 != NULL) {
-        return (PyUnicode_Compare(obj1, obj2) == 0);
-    }
-    else {
-        return obj1 == obj2;
-    }
-}
-
-
-static Py_uhash_t
-hashtable_hash_uint(const void *key_raw)
-{
-    unsigned int key = (unsigned int)FROM_PTR(key_raw);
-    return (Py_uhash_t)key;
-}
-
-
-static _Py_hashtable_t *
-hashtable_new(_Py_hashtable_hash_func hash_func,
-              _Py_hashtable_compare_func compare_func,
-              _Py_hashtable_destroy_func key_destroy_func,
-              _Py_hashtable_destroy_func value_destroy_func)
-{
-    _Py_hashtable_allocator_t hashtable_alloc = {malloc, free};
-    return _Py_hashtable_new_full(hash_func, compare_func,
-                                  key_destroy_func, value_destroy_func,
-                                  &hashtable_alloc);
-}
-
-
-static void*
-raw_malloc(size_t size)
-{
-    return allocators.raw.malloc(allocators.raw.ctx, size);
-}
-
-static void
-raw_free(void *ptr)
-{
-    allocators.raw.free(allocators.raw.ctx, ptr);
-}
-
-
-static Py_uhash_t
-hashtable_hash_traceback(const void *key)
-{
-    const traceback_t *traceback = (const traceback_t *)key;
-    return traceback->hash;
-}
-
-
-static int
-hashtable_compare_traceback(const void *key1, const void *key2)
-{
-    const traceback_t *traceback1 = (const traceback_t *)key1;
-    const traceback_t *traceback2 = (const traceback_t *)key2;
-
-    if (traceback1->nframe != traceback2->nframe) {
-        return 0;
-    }
-    if (traceback1->total_nframe != traceback2->total_nframe) {
-        return 0;
-    }
-
-    for (int i=0; i < traceback1->nframe; i++) {
-        const frame_t *frame1 = &traceback1->frames[i];
-        const frame_t *frame2 = &traceback2->frames[i];
-
-        if (frame1->lineno != frame2->lineno) {
-            return 0;
-        }
-        if (frame1->filename != frame2->filename) {
-            assert(PyUnicode_Compare(frame1->filename, frame2->filename) != 0);
-            return 0;
-        }
-    }
-    return 1;
-}
-
-
-static void
-tracemalloc_get_frame(_PyInterpreterFrame *pyframe, frame_t *frame)
-{
-    frame->filename = &_Py_STR(anon_unknown);
-    int lineno = PyUnstable_InterpreterFrame_GetLine(pyframe);
-    if (lineno < 0) {
-        lineno = 0;
-    }
-    frame->lineno = (unsigned int)lineno;
-
-    PyObject *filename = pyframe->f_code->co_filename;
-
-    if (filename == NULL) {
-#ifdef TRACE_DEBUG
-        tracemalloc_error("failed to get the filename of the code object");
-#endif
-        return;
-    }
-
-    if (!PyUnicode_Check(filename)) {
-#ifdef TRACE_DEBUG
-        tracemalloc_error("filename is not a unicode string");
-#endif
-        return;
-    }
-    if (!PyUnicode_IS_READY(filename)) {
-        /* Don't make a Unicode string ready to avoid reentrant calls
-           to tracemalloc_malloc() or tracemalloc_realloc() */
-#ifdef TRACE_DEBUG
-        tracemalloc_error("filename is not a ready unicode string");
-#endif
-        return;
-    }
-
-    /* intern the filename */
-    _Py_hashtable_entry_t *entry;
-    entry = _Py_hashtable_get_entry(tracemalloc_filenames, filename);
-    if (entry != NULL) {
-        filename = (PyObject *)entry->key;
-    }
-    else {
-        /* tracemalloc_filenames is responsible to keep a reference
-           to the filename */
-        if (_Py_hashtable_set(tracemalloc_filenames, Py_NewRef(filename),
-                              NULL) < 0) {
-            Py_DECREF(filename);
-#ifdef TRACE_DEBUG
-            tracemalloc_error("failed to intern the filename");
-#endif
-            return;
-        }
-    }
-
-    /* the tracemalloc_filenames table keeps a reference to the filename */
-    frame->filename = filename;
-}
-
-
-static Py_uhash_t
-traceback_hash(traceback_t *traceback)
-{
-    /* code based on tuplehash() of Objects/tupleobject.c */
-    Py_uhash_t x, y;  /* Unsigned for defined overflow behavior. */
-    int len = traceback->nframe;
-    Py_uhash_t mult = _PyHASH_MULTIPLIER;
-    frame_t *frame;
-
-    x = 0x345678UL;
-    frame = traceback->frames;
-    while (--len >= 0) {
-        y = (Py_uhash_t)PyObject_Hash(frame->filename);
-        y ^= (Py_uhash_t)frame->lineno;
-        frame++;
-
-        x = (x ^ y) * mult;
-        /* the cast might truncate len; that doesn't change hash stability */
-        mult += (Py_uhash_t)(82520UL + len + len);
-    }
-    x ^= traceback->total_nframe;
-    x += 97531UL;
-    return x;
-}
-
-
-static void
-traceback_get_frames(traceback_t *traceback)
-{
-    PyThreadState *tstate = PyGILState_GetThisThreadState();
-    if (tstate == NULL) {
-#ifdef TRACE_DEBUG
-        tracemalloc_error("failed to get the current thread state");
-#endif
-        return;
-    }
-
-    _PyInterpreterFrame *pyframe = _PyThreadState_GetFrame(tstate);
-    while (pyframe) {
-        if (traceback->nframe < tracemalloc_config.max_nframe) {
-            tracemalloc_get_frame(pyframe, &traceback->frames[traceback->nframe]);
-            assert(traceback->frames[traceback->nframe].filename != NULL);
-            traceback->nframe++;
-        }
-        if (traceback->total_nframe < UINT16_MAX) {
-            traceback->total_nframe++;
-        }
-        pyframe = _PyFrame_GetFirstComplete(pyframe->previous);
-    }
-}
-
-
-static traceback_t *
-traceback_new(void)
-{
-    traceback_t *traceback;
-    _Py_hashtable_entry_t *entry;
-
-    assert(PyGILState_Check());
-
-    /* get frames */
-    traceback = tracemalloc_traceback;
-    traceback->nframe = 0;
-    traceback->total_nframe = 0;
-    traceback_get_frames(traceback);
-    if (traceback->nframe == 0)
-        return &tracemalloc_empty_traceback;
-    traceback->hash = traceback_hash(traceback);
-
-    /* intern the traceback */
-    entry = _Py_hashtable_get_entry(tracemalloc_tracebacks, traceback);
-    if (entry != NULL) {
-        traceback = (traceback_t *)entry->key;
-    }
-    else {
-        traceback_t *copy;
-        size_t traceback_size;
-
-        traceback_size = TRACEBACK_SIZE(traceback->nframe);
-
-        copy = raw_malloc(traceback_size);
-        if (copy == NULL) {
-#ifdef TRACE_DEBUG
-            tracemalloc_error("failed to intern the traceback: malloc failed");
-#endif
-            return NULL;
-        }
-        memcpy(copy, traceback, traceback_size);
-
-        if (_Py_hashtable_set(tracemalloc_tracebacks, copy, NULL) < 0) {
-            raw_free(copy);
-#ifdef TRACE_DEBUG
-            tracemalloc_error("failed to intern the traceback: putdata failed");
-#endif
-            return NULL;
-        }
-        traceback = copy;
-    }
-    return traceback;
-}
-
-
-static _Py_hashtable_t*
-tracemalloc_create_traces_table(void)
-{
-    return hashtable_new(_Py_hashtable_hash_ptr,
-                         _Py_hashtable_compare_direct,
-                         NULL, raw_free);
-}
-
-
-static _Py_hashtable_t*
-tracemalloc_create_domains_table(void)
-{
-    return hashtable_new(hashtable_hash_uint,
-                         _Py_hashtable_compare_direct,
-                         NULL,
-                         (_Py_hashtable_destroy_func)_Py_hashtable_destroy);
-}
-
-
-static _Py_hashtable_t*
-tracemalloc_get_traces_table(unsigned int domain)
-{
-    if (domain == DEFAULT_DOMAIN) {
-        return tracemalloc_traces;
-    }
-    else {
-        return _Py_hashtable_get(tracemalloc_domains, TO_PTR(domain));
-    }
-}
-
-
-static void
-tracemalloc_remove_trace(unsigned int domain, uintptr_t ptr)
-{
-    assert(tracemalloc_config.tracing);
-
-    _Py_hashtable_t *traces = tracemalloc_get_traces_table(domain);
-    if (!traces) {
-        return;
-    }
-
-    trace_t *trace = _Py_hashtable_steal(traces, TO_PTR(ptr));
-    if (!trace) {
-        return;
-    }
-    assert(tracemalloc_traced_memory >= trace->size);
-    tracemalloc_traced_memory -= trace->size;
-    raw_free(trace);
-}
-
-#define REMOVE_TRACE(ptr) \
-            tracemalloc_remove_trace(DEFAULT_DOMAIN, (uintptr_t)(ptr))
-
-
-static int
-tracemalloc_add_trace(unsigned int domain, uintptr_t ptr,
-                      size_t size)
-{
-    assert(tracemalloc_config.tracing);
-
-    traceback_t *traceback = traceback_new();
-    if (traceback == NULL) {
-        return -1;
-    }
-
-    _Py_hashtable_t *traces = tracemalloc_get_traces_table(domain);
-    if (traces == NULL) {
-        traces = tracemalloc_create_traces_table();
-        if (traces == NULL) {
-            return -1;
-        }
-
-        if (_Py_hashtable_set(tracemalloc_domains, TO_PTR(domain), traces) < 0) {
-            _Py_hashtable_destroy(traces);
-            return -1;
-        }
-    }
-
-    trace_t *trace = _Py_hashtable_get(traces, TO_PTR(ptr));
-    if (trace != NULL) {
-        /* the memory block is already tracked */
-        assert(tracemalloc_traced_memory >= trace->size);
-        tracemalloc_traced_memory -= trace->size;
-
-        trace->size = size;
-        trace->traceback = traceback;
-    }
-    else {
-        trace = raw_malloc(sizeof(trace_t));
-        if (trace == NULL) {
-            return -1;
-        }
-        trace->size = size;
-        trace->traceback = traceback;
-
-        int res = _Py_hashtable_set(traces, TO_PTR(ptr), trace);
-        if (res != 0) {
-            raw_free(trace);
-            return res;
-        }
-    }
-
-    assert(tracemalloc_traced_memory <= SIZE_MAX - size);
-    tracemalloc_traced_memory += size;
-    if (tracemalloc_traced_memory > tracemalloc_peak_traced_memory) {
-        tracemalloc_peak_traced_memory = tracemalloc_traced_memory;
-    }
-    return 0;
-}
-
-#define ADD_TRACE(ptr, size) \
-            tracemalloc_add_trace(DEFAULT_DOMAIN, (uintptr_t)(ptr), size)
-
-
-static void*
-tracemalloc_alloc(int use_calloc, void *ctx, size_t nelem, size_t elsize)
-{
-    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-    void *ptr;
-
-    assert(elsize == 0 || nelem <= SIZE_MAX / elsize);
-
-    if (use_calloc)
-        ptr = alloc->calloc(alloc->ctx, nelem, elsize);
-    else
-        ptr = alloc->malloc(alloc->ctx, nelem * elsize);
-    if (ptr == NULL)
-        return NULL;
-
-    TABLES_LOCK();
-    if (ADD_TRACE(ptr, nelem * elsize) < 0) {
-        /* Failed to allocate a trace for the new memory block */
-        TABLES_UNLOCK();
-        alloc->free(alloc->ctx, ptr);
-        return NULL;
-    }
-    TABLES_UNLOCK();
-    return ptr;
-}
-
-
-static void*
-tracemalloc_realloc(void *ctx, void *ptr, size_t new_size)
-{
-    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-    void *ptr2;
-
-    ptr2 = alloc->realloc(alloc->ctx, ptr, new_size);
-    if (ptr2 == NULL)
-        return NULL;
-
-    if (ptr != NULL) {
-        /* an existing memory block has been resized */
-
-        TABLES_LOCK();
-
-        /* tracemalloc_add_trace() updates the trace if there is already
-           a trace at address ptr2 */
-        if (ptr2 != ptr) {
-            REMOVE_TRACE(ptr);
-        }
-
-        if (ADD_TRACE(ptr2, new_size) < 0) {
-            /* Memory allocation failed. The error cannot be reported to
-               the caller, because realloc() may already have shrunk the
-               memory block and so removed bytes.
-
-               This case is very unlikely: a hash entry has just been
-               released, so the hash table should have at least one free entry.
-
-               The GIL and the table lock ensures that only one thread is
-               allocating memory. */
-            Py_FatalError("tracemalloc_realloc() failed to allocate a trace");
-        }
-        TABLES_UNLOCK();
-    }
-    else {
-        /* new allocation */
-
-        TABLES_LOCK();
-        if (ADD_TRACE(ptr2, new_size) < 0) {
-            /* Failed to allocate a trace for the new memory block */
-            TABLES_UNLOCK();
-            alloc->free(alloc->ctx, ptr2);
-            return NULL;
-        }
-        TABLES_UNLOCK();
-    }
-    return ptr2;
-}
-
-
-static void
-tracemalloc_free(void *ctx, void *ptr)
-{
-    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-
-    if (ptr == NULL)
-        return;
-
-     /* GIL cannot be locked in PyMem_RawFree() because it would introduce
-        a deadlock in _PyThreadState_DeleteCurrent(). */
-
-    alloc->free(alloc->ctx, ptr);
-
-    TABLES_LOCK();
-    REMOVE_TRACE(ptr);
-    TABLES_UNLOCK();
-}
-
-
-static void*
-tracemalloc_alloc_gil(int use_calloc, void *ctx, size_t nelem, size_t elsize)
-{
-    void *ptr;
-
-    if (get_reentrant()) {
-        PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-        if (use_calloc)
-            return alloc->calloc(alloc->ctx, nelem, elsize);
-        else
-            return alloc->malloc(alloc->ctx, nelem * elsize);
-    }
-
-    /* Ignore reentrant call. PyObjet_Malloc() calls PyMem_Malloc() for
-       allocations larger than 512 bytes, don't trace the same memory
-       allocation twice. */
-    set_reentrant(1);
-
-    ptr = tracemalloc_alloc(use_calloc, ctx, nelem, elsize);
-
-    set_reentrant(0);
-    return ptr;
-}
-
-
-static void*
-tracemalloc_malloc_gil(void *ctx, size_t size)
-{
-    return tracemalloc_alloc_gil(0, ctx, 1, size);
-}
-
-
-static void*
-tracemalloc_calloc_gil(void *ctx, size_t nelem, size_t elsize)
-{
-    return tracemalloc_alloc_gil(1, ctx, nelem, elsize);
-}
-
-
-static void*
-tracemalloc_realloc_gil(void *ctx, void *ptr, size_t new_size)
-{
-    void *ptr2;
-
-    if (get_reentrant()) {
-        /* Reentrant call to PyMem_Realloc() and PyMem_RawRealloc().
-           Example: PyMem_RawRealloc() is called internally by pymalloc
-           (_PyObject_Malloc() and  _PyObject_Realloc()) to allocate a new
-           arena (new_arena()). */
-        PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-
-        ptr2 = alloc->realloc(alloc->ctx, ptr, new_size);
-        if (ptr2 != NULL && ptr != NULL) {
-            TABLES_LOCK();
-            REMOVE_TRACE(ptr);
-            TABLES_UNLOCK();
-        }
-        return ptr2;
-    }
-
-    /* Ignore reentrant call. PyObjet_Realloc() calls PyMem_Realloc() for
-       allocations larger than 512 bytes. Don't trace the same memory
-       allocation twice. */
-    set_reentrant(1);
-
-    ptr2 = tracemalloc_realloc(ctx, ptr, new_size);
-
-    set_reentrant(0);
-    return ptr2;
-}
-
-
-#ifdef TRACE_RAW_MALLOC
-static void*
-tracemalloc_raw_alloc(int use_calloc, void *ctx, size_t nelem, size_t elsize)
-{
-    PyGILState_STATE gil_state;
-    void *ptr;
-
-    if (get_reentrant()) {
-        PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-        if (use_calloc)
-            return alloc->calloc(alloc->ctx, nelem, elsize);
-        else
-            return alloc->malloc(alloc->ctx, nelem * elsize);
-    }
-
-    /* Ignore reentrant call. PyGILState_Ensure() may call PyMem_RawMalloc()
-       indirectly which would call PyGILState_Ensure() if reentrant are not
-       disabled. */
-    set_reentrant(1);
-
-    gil_state = PyGILState_Ensure();
-    ptr = tracemalloc_alloc(use_calloc, ctx, nelem, elsize);
-    PyGILState_Release(gil_state);
-
-    set_reentrant(0);
-    return ptr;
-}
-
-
-static void*
-tracemalloc_raw_malloc(void *ctx, size_t size)
-{
-    return tracemalloc_raw_alloc(0, ctx, 1, size);
-}
-
-
-static void*
-tracemalloc_raw_calloc(void *ctx, size_t nelem, size_t elsize)
-{
-    return tracemalloc_raw_alloc(1, ctx, nelem, elsize);
-}
-
-
-static void*
-tracemalloc_raw_realloc(void *ctx, void *ptr, size_t new_size)
-{
-    PyGILState_STATE gil_state;
-    void *ptr2;
-
-    if (get_reentrant()) {
-        /* Reentrant call to PyMem_RawRealloc(). */
-        PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
-
-        ptr2 = alloc->realloc(alloc->ctx, ptr, new_size);
-
-        if (ptr2 != NULL && ptr != NULL) {
-            TABLES_LOCK();
-            REMOVE_TRACE(ptr);
-            TABLES_UNLOCK();
-        }
-        return ptr2;
-    }
-
-    /* Ignore reentrant call. PyGILState_Ensure() may call PyMem_RawMalloc()
-       indirectly which would call PyGILState_Ensure() if reentrant calls are
-       not disabled. */
-    set_reentrant(1);
-
-    gil_state = PyGILState_Ensure();
-    ptr2 = tracemalloc_realloc(ctx, ptr, new_size);
-    PyGILState_Release(gil_state);
-
-    set_reentrant(0);
-    return ptr2;
-}
-#endif   /* TRACE_RAW_MALLOC */
-
-
-static void
-tracemalloc_clear_filename(void *value)
-{
-    PyObject *filename = (PyObject *)value;
-    Py_DECREF(filename);
-}
-
-
-/* reentrant flag must be set to call this function and GIL must be held */
-static void
-tracemalloc_clear_traces(void)
-{
-    /* The GIL protects variables against concurrent access */
-    assert(PyGILState_Check());
-
-    TABLES_LOCK();
-    _Py_hashtable_clear(tracemalloc_traces);
-    _Py_hashtable_clear(tracemalloc_domains);
-    tracemalloc_traced_memory = 0;
-    tracemalloc_peak_traced_memory = 0;
-    TABLES_UNLOCK();
-
-    _Py_hashtable_clear(tracemalloc_tracebacks);
-
-    _Py_hashtable_clear(tracemalloc_filenames);
-}
-
-
-static int
-tracemalloc_init(void)
-{
-    if (tracemalloc_config.initialized == TRACEMALLOC_FINALIZED) {
-        PyErr_SetString(PyExc_RuntimeError,
-                        "the tracemalloc module has been unloaded");
-        return -1;
-    }
-
-    if (tracemalloc_config.initialized == TRACEMALLOC_INITIALIZED)
-        return 0;
-
-    PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &allocators.raw);
-
-#ifdef REENTRANT_THREADLOCAL
-    if (PyThread_tss_create(&tracemalloc_reentrant_key) != 0) {
-#ifdef MS_WINDOWS
-        PyErr_SetFromWindowsErr(0);
-#else
-        PyErr_SetFromErrno(PyExc_OSError);
-#endif
-        return -1;
-    }
-#endif
-
-#if defined(TRACE_RAW_MALLOC)
-    if (tables_lock == NULL) {
-        tables_lock = PyThread_allocate_lock();
-        if (tables_lock == NULL) {
-            PyErr_SetString(PyExc_RuntimeError, "cannot allocate lock");
-            return -1;
-        }
-    }
-#endif
-
-    tracemalloc_filenames = hashtable_new(hashtable_hash_pyobject,
-                                          hashtable_compare_unicode,
-                                          tracemalloc_clear_filename, NULL);
-
-    tracemalloc_tracebacks = hashtable_new(hashtable_hash_traceback,
-                                           hashtable_compare_traceback,
-                                           NULL, raw_free);
-
-    tracemalloc_traces = tracemalloc_create_traces_table();
-    tracemalloc_domains = tracemalloc_create_domains_table();
-
-    if (tracemalloc_filenames == NULL || tracemalloc_tracebacks == NULL
-       || tracemalloc_traces == NULL || tracemalloc_domains == NULL) {
-        PyErr_NoMemory();
-        return -1;
-    }
-
-    tracemalloc_empty_traceback.nframe = 1;
-    tracemalloc_empty_traceback.total_nframe = 1;
-    /* borrowed reference */
-    tracemalloc_empty_traceback.frames[0].filename = &_Py_STR(anon_unknown);
-    tracemalloc_empty_traceback.frames[0].lineno = 0;
-    tracemalloc_empty_traceback.hash = traceback_hash(&tracemalloc_empty_traceback);
-
-    tracemalloc_config.initialized = TRACEMALLOC_INITIALIZED;
-    return 0;
-}
-
-
-static void
-tracemalloc_deinit(void)
-{
-    if (tracemalloc_config.initialized != TRACEMALLOC_INITIALIZED)
-        return;
-    tracemalloc_config.initialized = TRACEMALLOC_FINALIZED;
-
-    tracemalloc_stop();
-
-    /* destroy hash tables */
-    _Py_hashtable_destroy(tracemalloc_domains);
-    _Py_hashtable_destroy(tracemalloc_traces);
-    _Py_hashtable_destroy(tracemalloc_tracebacks);
-    _Py_hashtable_destroy(tracemalloc_filenames);
-
-#if defined(TRACE_RAW_MALLOC)
-    if (tables_lock != NULL) {
-        PyThread_free_lock(tables_lock);
-        tables_lock = NULL;
-    }
-#endif
-
-#ifdef REENTRANT_THREADLOCAL
-    PyThread_tss_delete(&tracemalloc_reentrant_key);
-#endif
-}
-
-
-static int
-tracemalloc_start(int max_nframe)
-{
-    PyMemAllocatorEx alloc;
-    size_t size;
-
-    if (max_nframe < 1 || (unsigned long) max_nframe > MAX_NFRAME) {
-        PyErr_Format(PyExc_ValueError,
-                     "the number of frames must be in range [1; %lu]",
-                     MAX_NFRAME);
-        return -1;
-    }
-
-    if (tracemalloc_init() < 0) {
-        return -1;
-    }
-
-    if (tracemalloc_config.tracing) {
-        /* hook already installed: do nothing */
-        return 0;
-    }
-
-    tracemalloc_config.max_nframe = max_nframe;
-
-    /* allocate a buffer to store a new traceback */
-    size = TRACEBACK_SIZE(max_nframe);
-    assert(tracemalloc_traceback == NULL);
-    tracemalloc_traceback = raw_malloc(size);
-    if (tracemalloc_traceback == NULL) {
-        PyErr_NoMemory();
-        return -1;
-    }
-
-#ifdef TRACE_RAW_MALLOC
-    alloc.malloc = tracemalloc_raw_malloc;
-    alloc.calloc = tracemalloc_raw_calloc;
-    alloc.realloc = tracemalloc_raw_realloc;
-    alloc.free = tracemalloc_free;
-
-    alloc.ctx = &allocators.raw;
-    PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &allocators.raw);
-    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &alloc);
-#endif
-
-    alloc.malloc = tracemalloc_malloc_gil;
-    alloc.calloc = tracemalloc_calloc_gil;
-    alloc.realloc = tracemalloc_realloc_gil;
-    alloc.free = tracemalloc_free;
-
-    alloc.ctx = &allocators.mem;
-    PyMem_GetAllocator(PYMEM_DOMAIN_MEM, &allocators.mem);
-    PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &alloc);
-
-    alloc.ctx = &allocators.obj;
-    PyMem_GetAllocator(PYMEM_DOMAIN_OBJ, &allocators.obj);
-    PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &alloc);
-
-    /* everything is ready: start tracing Python memory allocations */
-    tracemalloc_config.tracing = 1;
-
-    return 0;
-}
-
-
-static void
-tracemalloc_stop(void)
-{
-    if (!tracemalloc_config.tracing)
-        return;
-
-    /* stop tracing Python memory allocations */
-    tracemalloc_config.tracing = 0;
-
-    /* unregister the hook on memory allocators */
-#ifdef TRACE_RAW_MALLOC
-    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &allocators.raw);
-#endif
-    PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &allocators.mem);
-    PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &allocators.obj);
-
-    tracemalloc_clear_traces();
-
-    /* release memory */
-    raw_free(tracemalloc_traceback);
-    tracemalloc_traceback = NULL;
-}
-
-
 
 /*[clinic input]
 _tracemalloc.is_tracing
@@ -994,7 +19,7 @@ static PyObject *
 _tracemalloc_is_tracing_impl(PyObject *module)
 /*[clinic end generated code: output=2d763b42601cd3ef input=af104b0a00192f63]*/
 {
-    return PyBool_FromLong(tracemalloc_config.tracing);
+    return PyBool_FromLong(_PyTraceMalloc_IsTracing());
 }
 
 
@@ -1008,262 +33,11 @@ static PyObject *
 _tracemalloc_clear_traces_impl(PyObject *module)
 /*[clinic end generated code: output=a86080ee41b84197 input=0dab5b6c785183a5]*/
 {
-    if (!tracemalloc_config.tracing)
-        Py_RETURN_NONE;
-
-    set_reentrant(1);
-    tracemalloc_clear_traces();
-    set_reentrant(0);
-
+    _PyTraceMalloc_ClearTraces();
     Py_RETURN_NONE;
 }
 
 
-static PyObject*
-frame_to_pyobject(frame_t *frame)
-{
-    PyObject *frame_obj, *lineno_obj;
-
-    frame_obj = PyTuple_New(2);
-    if (frame_obj == NULL)
-        return NULL;
-
-    PyTuple_SET_ITEM(frame_obj, 0, Py_NewRef(frame->filename));
-
-    lineno_obj = PyLong_FromUnsignedLong(frame->lineno);
-    if (lineno_obj == NULL) {
-        Py_DECREF(frame_obj);
-        return NULL;
-    }
-    PyTuple_SET_ITEM(frame_obj, 1, lineno_obj);
-
-    return frame_obj;
-}
-
-
-static PyObject*
-traceback_to_pyobject(traceback_t *traceback, _Py_hashtable_t *intern_table)
-{
-    PyObject *frames;
-
-    if (intern_table != NULL) {
-        frames = _Py_hashtable_get(intern_table, (const void *)traceback);
-        if (frames) {
-            return Py_NewRef(frames);
-        }
-    }
-
-    frames = PyTuple_New(traceback->nframe);
-    if (frames == NULL)
-        return NULL;
-
-    for (int i=0; i < traceback->nframe; i++) {
-        PyObject *frame = frame_to_pyobject(&traceback->frames[i]);
-        if (frame == NULL) {
-            Py_DECREF(frames);
-            return NULL;
-        }
-        PyTuple_SET_ITEM(frames, i, frame);
-    }
-
-    if (intern_table != NULL) {
-        if (_Py_hashtable_set(intern_table, traceback, frames) < 0) {
-            Py_DECREF(frames);
-            PyErr_NoMemory();
-            return NULL;
-        }
-        /* intern_table keeps a new reference to frames */
-        Py_INCREF(frames);
-    }
-    return frames;
-}
-
-
-static PyObject*
-trace_to_pyobject(unsigned int domain, const trace_t *trace,
-                  _Py_hashtable_t *intern_tracebacks)
-{
-    PyObject *trace_obj = NULL;
-    PyObject *obj;
-
-    trace_obj = PyTuple_New(4);
-    if (trace_obj == NULL)
-        return NULL;
-
-    obj = PyLong_FromSize_t(domain);
-    if (obj == NULL) {
-        Py_DECREF(trace_obj);
-        return NULL;
-    }
-    PyTuple_SET_ITEM(trace_obj, 0, obj);
-
-    obj = PyLong_FromSize_t(trace->size);
-    if (obj == NULL) {
-        Py_DECREF(trace_obj);
-        return NULL;
-    }
-    PyTuple_SET_ITEM(trace_obj, 1, obj);
-
-    obj = traceback_to_pyobject(trace->traceback, intern_tracebacks);
-    if (obj == NULL) {
-        Py_DECREF(trace_obj);
-        return NULL;
-    }
-    PyTuple_SET_ITEM(trace_obj, 2, obj);
-
-    obj = PyLong_FromUnsignedLong(trace->traceback->total_nframe);
-    if (obj == NULL) {
-        Py_DECREF(trace_obj);
-        return NULL;
-    }
-    PyTuple_SET_ITEM(trace_obj, 3, obj);
-
-    return trace_obj;
-}
-
-
-typedef struct {
-    _Py_hashtable_t *traces;
-    _Py_hashtable_t *domains;
-    _Py_hashtable_t *tracebacks;
-    PyObject *list;
-    unsigned int domain;
-} get_traces_t;
-
-
-static int
-tracemalloc_copy_trace(_Py_hashtable_t *traces,
-                       const void *key, const void *value,
-                       void *user_data)
-{
-    _Py_hashtable_t *traces2 = (_Py_hashtable_t *)user_data;
-
-    trace_t *trace = (trace_t *)value;
-
-    trace_t *trace2 = raw_malloc(sizeof(trace_t));
-    if (trace2 == NULL) {
-        return -1;
-    }
-    *trace2 = *trace;
-    if (_Py_hashtable_set(traces2, key, trace2) < 0) {
-        raw_free(trace2);
-        return -1;
-    }
-    return 0;
-}
-
-
-static _Py_hashtable_t*
-tracemalloc_copy_traces(_Py_hashtable_t *traces)
-{
-    _Py_hashtable_t *traces2 = tracemalloc_create_traces_table();
-    if (traces2 == NULL) {
-        return NULL;
-    }
-
-    int err = _Py_hashtable_foreach(traces,
-                                    tracemalloc_copy_trace,
-                                    traces2);
-    if (err) {
-        _Py_hashtable_destroy(traces2);
-        return NULL;
-    }
-    return traces2;
-}
-
-
-static int
-tracemalloc_copy_domain(_Py_hashtable_t *domains,
-                        const void *key, const void *value,
-                        void *user_data)
-{
-    _Py_hashtable_t *domains2 = (_Py_hashtable_t *)user_data;
-
-    unsigned int domain = (unsigned int)FROM_PTR(key);
-    _Py_hashtable_t *traces = (_Py_hashtable_t *)value;
-
-    _Py_hashtable_t *traces2 = tracemalloc_copy_traces(traces);
-    if (traces2 == NULL) {
-        return -1;
-    }
-    if (_Py_hashtable_set(domains2, TO_PTR(domain), traces2) < 0) {
-        _Py_hashtable_destroy(traces2);
-        return -1;
-    }
-    return 0;
-}
-
-
-static _Py_hashtable_t*
-tracemalloc_copy_domains(_Py_hashtable_t *domains)
-{
-    _Py_hashtable_t *domains2 = tracemalloc_create_domains_table();
-    if (domains2 == NULL) {
-        return NULL;
-    }
-
-    int err = _Py_hashtable_foreach(domains,
-                                    tracemalloc_copy_domain,
-                                    domains2);
-    if (err) {
-        _Py_hashtable_destroy(domains2);
-        return NULL;
-    }
-    return domains2;
-}
-
-
-static int
-tracemalloc_get_traces_fill(_Py_hashtable_t *traces,
-                            const void *key, const void *value,
-                            void *user_data)
-{
-    get_traces_t *get_traces = user_data;
-
-    const trace_t *trace = (const trace_t *)value;
-
-    PyObject *tuple = trace_to_pyobject(get_traces->domain, trace,
-                                        get_traces->tracebacks);
-    if (tuple == NULL) {
-        return 1;
-    }
-
-    int res = PyList_Append(get_traces->list, tuple);
-    Py_DECREF(tuple);
-    if (res < 0) {
-        return 1;
-    }
-
-    return 0;
-}
-
-
-static int
-tracemalloc_get_traces_domain(_Py_hashtable_t *domains,
-                              const void *key, const void *value,
-                              void *user_data)
-{
-    get_traces_t *get_traces = user_data;
-
-    unsigned int domain = (unsigned int)FROM_PTR(key);
-    _Py_hashtable_t *traces = (_Py_hashtable_t *)value;
-
-    get_traces->domain = domain;
-    return _Py_hashtable_foreach(traces,
-                                 tracemalloc_get_traces_fill,
-                                 get_traces);
-}
-
-
-static void
-tracemalloc_pyobject_decref(void *value)
-{
-    PyObject *obj = (PyObject *)value;
-    Py_DECREF(obj);
-}
-
-
-
 /*[clinic input]
 _tracemalloc._get_traces
 
@@ -1279,107 +53,7 @@ static PyObject *
 _tracemalloc__get_traces_impl(PyObject *module)
 /*[clinic end generated code: output=e9929876ced4b5cc input=6c7d2230b24255aa]*/
 {
-    get_traces_t get_traces;
-    get_traces.domain = DEFAULT_DOMAIN;
-    get_traces.traces = NULL;
-    get_traces.domains = NULL;
-    get_traces.tracebacks = NULL;
-    get_traces.list = PyList_New(0);
-    if (get_traces.list == NULL)
-        goto error;
-
-    if (!tracemalloc_config.tracing)
-        return get_traces.list;
-
-    /* the traceback hash table is used temporarily to intern traceback tuple
-       of (filename, lineno) tuples */
-    get_traces.tracebacks = hashtable_new(_Py_hashtable_hash_ptr,
-                                          _Py_hashtable_compare_direct,
-                                          NULL, tracemalloc_pyobject_decref);
-    if (get_traces.tracebacks == NULL) {
-        goto no_memory;
-    }
-
-    // Copy all traces so tracemalloc_get_traces_fill() doesn't have to disable
-    // temporarily tracemalloc which would impact other threads and so would
-    // miss allocations while get_traces() is called.
-    TABLES_LOCK();
-    get_traces.traces = tracemalloc_copy_traces(tracemalloc_traces);
-    TABLES_UNLOCK();
-
-    if (get_traces.traces == NULL) {
-        goto no_memory;
-    }
-
-    TABLES_LOCK();
-    get_traces.domains = tracemalloc_copy_domains(tracemalloc_domains);
-    TABLES_UNLOCK();
-
-    if (get_traces.domains == NULL) {
-        goto no_memory;
-    }
-
-    // Convert traces to a list of tuples
-    set_reentrant(1);
-    int err = _Py_hashtable_foreach(get_traces.traces,
-                                    tracemalloc_get_traces_fill,
-                                    &get_traces);
-    if (!err) {
-        err = _Py_hashtable_foreach(get_traces.domains,
-                                    tracemalloc_get_traces_domain,
-                                    &get_traces);
-    }
-    set_reentrant(0);
-    if (err) {
-        goto error;
-    }
-
-    goto finally;
-
-no_memory:
-    PyErr_NoMemory();
-
-error:
-    Py_CLEAR(get_traces.list);
-
-finally:
-    if (get_traces.tracebacks != NULL) {
-        _Py_hashtable_destroy(get_traces.tracebacks);
-    }
-    if (get_traces.traces != NULL) {
-        _Py_hashtable_destroy(get_traces.traces);
-    }
-    if (get_traces.domains != NULL) {
-        _Py_hashtable_destroy(get_traces.domains);
-    }
-
-    return get_traces.list;
-}
-
-
-static traceback_t*
-tracemalloc_get_traceback(unsigned int domain, uintptr_t ptr)
-{
-
-    if (!tracemalloc_config.tracing)
-        return NULL;
-
-    trace_t *trace;
-    TABLES_LOCK();
-    _Py_hashtable_t *traces = tracemalloc_get_traces_table(domain);
-    if (traces) {
-        trace = _Py_hashtable_get(traces, TO_PTR(ptr));
-    }
-    else {
-        trace = NULL;
-    }
-    TABLES_UNLOCK();
-
-    if (!trace) {
-        return NULL;
-    }
-
-    return trace->traceback;
+    return _PyTraceMalloc_GetTraces();
 }
 
 
@@ -1401,62 +75,9 @@ static PyObject *
 _tracemalloc__get_object_traceback(PyObject *module, PyObject *obj)
 /*[clinic end generated code: output=41ee0553a658b0aa input=29495f1b21c53212]*/
 {
-    PyTypeObject *type;
-    traceback_t *traceback;
-
-    type = Py_TYPE(obj);
-    const size_t presize = _PyType_PreHeaderSize(type);
-    uintptr_t ptr = (uintptr_t)((char *)obj - presize);
-
-    traceback = tracemalloc_get_traceback(DEFAULT_DOMAIN, ptr);
-    if (traceback == NULL) {
-        Py_RETURN_NONE;
-    }
-
-    return traceback_to_pyobject(traceback, NULL);
-}
-
-
-#define PUTS(fd, str) _Py_write_noraise(fd, str, (int)strlen(str))
-
-static void
-_PyMem_DumpFrame(int fd, frame_t * frame)
-{
-    PUTS(fd, "  File \"");
-    _Py_DumpASCII(fd, frame->filename);
-    PUTS(fd, "\", line ");
-    _Py_DumpDecimal(fd, frame->lineno);
-    PUTS(fd, "\n");
+    return _PyTraceMalloc_GetObjectTraceback(obj);
 }
 
-/* Dump the traceback where a memory block was allocated into file descriptor
-   fd. The function may block on TABLES_LOCK() but it is unlikely. */
-void
-_PyMem_DumpTraceback(int fd, const void *ptr)
-{
-    traceback_t *traceback;
-    int i;
-
-    if (!tracemalloc_config.tracing) {
-        PUTS(fd, "Enable tracemalloc to get the memory block "
-                 "allocation traceback\n\n");
-        return;
-    }
-
-    traceback = tracemalloc_get_traceback(DEFAULT_DOMAIN, (uintptr_t)ptr);
-    if (traceback == NULL)
-        return;
-
-    PUTS(fd, "Memory block allocated at (most recent call first):\n");
-    for (i=0; i < traceback->nframe; i++) {
-        _PyMem_DumpFrame(fd, &traceback->frames[i]);
-    }
-    PUTS(fd, "\n");
-}
-
-#undef PUTS
-
-
 
 /*[clinic input]
 _tracemalloc.start
@@ -1474,7 +95,7 @@ static PyObject *
 _tracemalloc_start_impl(PyObject *module, int nframe)
 /*[clinic end generated code: output=caae05c23c159d3c input=40d849b5b29d1933]*/
 {
-    if (tracemalloc_start(nframe) < 0) {
+    if (_PyTraceMalloc_Start(nframe) < 0) {
         return NULL;
     }
     Py_RETURN_NONE;
@@ -1493,7 +114,7 @@ static PyObject *
 _tracemalloc_stop_impl(PyObject *module)
 /*[clinic end generated code: output=c3c42ae03e3955cd input=7478f075e51dae18]*/
 {
-    tracemalloc_stop();
+    _PyTraceMalloc_Stop();
     Py_RETURN_NONE;
 }
 
@@ -1511,22 +132,9 @@ static PyObject *
 _tracemalloc_get_traceback_limit_impl(PyObject *module)
 /*[clinic end generated code: output=d556d9306ba95567 input=da3cd977fc68ae3b]*/
 {
-    return PyLong_FromLong(tracemalloc_config.max_nframe);
+    return PyLong_FromLong(_PyTraceMalloc_GetTracebackLimit());
 }
 
-
-static int
-tracemalloc_get_tracemalloc_memory_cb(_Py_hashtable_t *domains,
-                                      const void *key, const void *value,
-                                      void *user_data)
-{
-    const _Py_hashtable_t *traces = value;
-    size_t *size = (size_t*)user_data;
-    *size += _Py_hashtable_size(traces);
-    return 0;
-}
-
-
 /*[clinic input]
 _tracemalloc.get_tracemalloc_memory
 
@@ -1539,22 +147,10 @@ static PyObject *
 _tracemalloc_get_tracemalloc_memory_impl(PyObject *module)
 /*[clinic end generated code: output=e3f14e280a55f5aa input=5d919c0f4d5132ad]*/
 {
-    size_t size;
-
-    size = _Py_hashtable_size(tracemalloc_tracebacks);
-    size += _Py_hashtable_size(tracemalloc_filenames);
-
-    TABLES_LOCK();
-    size += _Py_hashtable_size(tracemalloc_traces);
-    _Py_hashtable_foreach(tracemalloc_domains,
-                          tracemalloc_get_tracemalloc_memory_cb, &size);
-    TABLES_UNLOCK();
-
-    return PyLong_FromSize_t(size);
+    return PyLong_FromSize_t(_PyTraceMalloc_GetMemory());
 }
 
 
-
 /*[clinic input]
 _tracemalloc.get_traced_memory
 
@@ -1567,17 +163,7 @@ static PyObject *
 _tracemalloc_get_traced_memory_impl(PyObject *module)
 /*[clinic end generated code: output=5b167189adb9e782 input=61ddb5478400ff66]*/
 {
-    Py_ssize_t size, peak_size;
-
-    if (!tracemalloc_config.tracing)
-        return Py_BuildValue("ii", 0, 0);
-
-    TABLES_LOCK();
-    size = tracemalloc_traced_memory;
-    peak_size = tracemalloc_peak_traced_memory;
-    TABLES_UNLOCK();
-
-    return Py_BuildValue("nn", size, peak_size);
+    return _PyTraceMalloc_GetTracedMemory();
 }
 
 /*[clinic input]
@@ -1593,14 +179,7 @@ static PyObject *
 _tracemalloc_reset_peak_impl(PyObject *module)
 /*[clinic end generated code: output=140c2870f691dbb2 input=18afd0635066e9ce]*/
 {
-    if (!tracemalloc_config.tracing) {
-        Py_RETURN_NONE;
-    }
-
-    TABLES_LOCK();
-    tracemalloc_peak_traced_memory = tracemalloc_traced_memory;
-    TABLES_UNLOCK();
-
+    _PyTraceMalloc_ResetPeak();
     Py_RETURN_NONE;
 }
 
@@ -1640,118 +219,10 @@ PyInit__tracemalloc(void)
     if (m == NULL)
         return NULL;
 
-    if (tracemalloc_init() < 0) {
+    if (_PyTraceMalloc_Init() < 0) {
         Py_DECREF(m);
         return NULL;
     }
 
     return m;
 }
-
-
-int
-_PyTraceMalloc_Init(int nframe)
-{
-    assert(PyGILState_Check());
-    if (nframe == 0) {
-        return 0;
-    }
-    return tracemalloc_start(nframe);
-}
-
-
-void
-_PyTraceMalloc_Fini(void)
-{
-    assert(PyGILState_Check());
-    tracemalloc_deinit();
-}
-
-int
-PyTraceMalloc_Track(unsigned int domain, uintptr_t ptr,
-                    size_t size)
-{
-    int res;
-    PyGILState_STATE gil_state;
-
-    if (!tracemalloc_config.tracing) {
-        /* tracemalloc is not tracing: do nothing */
-        return -2;
-    }
-
-    gil_state = PyGILState_Ensure();
-
-    TABLES_LOCK();
-    res = tracemalloc_add_trace(domain, ptr, size);
-    TABLES_UNLOCK();
-
-    PyGILState_Release(gil_state);
-    return res;
-}
-
-
-int
-PyTraceMalloc_Untrack(unsigned int domain, uintptr_t ptr)
-{
-    if (!tracemalloc_config.tracing) {
-        /* tracemalloc is not tracing: do nothing */
-        return -2;
-    }
-
-    TABLES_LOCK();
-    tracemalloc_remove_trace(domain, ptr);
-    TABLES_UNLOCK();
-
-    return 0;
-}
-
-
-/* If the object memory block is already traced, update its trace
-   with the current Python traceback.
-
-   Do nothing if tracemalloc is not tracing memory allocations
-   or if the object memory block is not already traced. */
-int
-_PyTraceMalloc_NewReference(PyObject *op)
-{
-    assert(PyGILState_Check());
-
-    if (!tracemalloc_config.tracing) {
-        /* tracemalloc is not tracing: do nothing */
-        return -1;
-    }
-
-    PyTypeObject *type = Py_TYPE(op);
-    const size_t presize = _PyType_PreHeaderSize(type);
-    uintptr_t ptr = (uintptr_t)((char *)op - presize);
-
-    int res = -1;
-
-    TABLES_LOCK();
-    trace_t *trace = _Py_hashtable_get(tracemalloc_traces, TO_PTR(ptr));
-    if (trace != NULL) {
-        /* update the traceback of the memory block */
-        traceback_t *traceback = traceback_new();
-        if (traceback != NULL) {
-            trace->traceback = traceback;
-            res = 0;
-        }
-    }
-    /* else: cannot track the object, its memory block size is unknown */
-    TABLES_UNLOCK();
-
-    return res;
-}
-
-
-PyObject*
-_PyTraceMalloc_GetTraceback(unsigned int domain, uintptr_t ptr)
-{
-    traceback_t *traceback;
-
-    traceback = tracemalloc_get_traceback(domain, ptr);
-    if (traceback == NULL)
-        Py_RETURN_NONE;
-
-    return traceback_to_pyobject(traceback, NULL);
-}
diff --git a/PCbuild/_freeze_module.vcxproj b/PCbuild/_freeze_module.vcxproj
index c9dbe195d9..3df0a07204 100644
--- a/PCbuild/_freeze_module.vcxproj
+++ b/PCbuild/_freeze_module.vcxproj
@@ -242,6 +242,7 @@
     </ClCompile>
     <ClCompile Include="..\Python\thread.c" />
     <ClCompile Include="..\Python\traceback.c" />
+    <ClCompile Include="..\Python\tracemalloc.c" />
   </ItemGroup>
   <ItemGroup>
     <!-- BEGIN frozen modules -->
diff --git a/PCbuild/_freeze_module.vcxproj.filters b/PCbuild/_freeze_module.vcxproj.filters
index 176935a63c..d98a4c5ae4 100644
--- a/PCbuild/_freeze_module.vcxproj.filters
+++ b/PCbuild/_freeze_module.vcxproj.filters
@@ -394,6 +394,9 @@
     <ClCompile Include="..\Python\traceback.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\Python\tracemalloc.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\Objects\tupleobject.c">
       <Filter>Source Files</Filter>
     </ClCompile>
diff --git a/PCbuild/pythoncore.vcxproj b/PCbuild/pythoncore.vcxproj
index ca43404454..48cd4418f9 100644
--- a/PCbuild/pythoncore.vcxproj
+++ b/PCbuild/pythoncore.vcxproj
@@ -567,6 +567,7 @@
     </ClCompile>
     <ClCompile Include="..\Python\thread.c" />
     <ClCompile Include="..\Python\traceback.c" />
+    <ClCompile Include="..\Python\tracemalloc.c" />
   </ItemGroup>
   <ItemGroup>
     <!-- BEGIN deepfreeze -->
diff --git a/PCbuild/pythoncore.vcxproj.filters b/PCbuild/pythoncore.vcxproj.filters
index a3c2e2476d..5c8c1444e8 100644
--- a/PCbuild/pythoncore.vcxproj.filters
+++ b/PCbuild/pythoncore.vcxproj.filters
@@ -1268,6 +1268,9 @@
     <ClCompile Include="..\Python\traceback.c">
       <Filter>Python</Filter>
     </ClCompile>
+    <ClCompile Include="..\Python\tracemalloc.c">
+      <Filter>Python</Filter>
+    </ClCompile>
     <ClCompile Include="..\Python\bootstrap_hash.c">
       <Filter>Python</Filter>
     </ClCompile>
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 740901f53d..93ad1fe098 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -1129,11 +1129,12 @@ init_interp_main(PyThreadState *tstate)
             return _PyStatus_ERR("can't initialize signals");
         }
 
-        if (_PyTraceMalloc_Init(config->tracemalloc) < 0) {
-            return _PyStatus_ERR("can't initialize tracemalloc");
+        if (config->tracemalloc) {
+           if (_PyTraceMalloc_Start(config->tracemalloc) < 0) {
+                return _PyStatus_ERR("can't start tracemalloc");
+            }
         }
 
-
 #ifdef PY_HAVE_PERF_TRAMPOLINE
         if (config->perf_profiling) {
             if (_PyPerfTrampoline_SetCallbacks(&_Py_perfmap_callbacks) < 0 ||
diff --git a/Python/tracemalloc.c b/Python/tracemalloc.c
new file mode 100644
index 0000000000..bc76562352
--- /dev/null
+++ b/Python/tracemalloc.c
@@ -0,0 +1,1560 @@
+#include "Python.h"
+#include "pycore_fileutils.h"     // _Py_write_noraise()
+#include "pycore_gc.h"            // PyGC_Head
+#include "pycore_hashtable.h"     // _Py_hashtable_t
+#include "pycore_object.h"        // _PyType_PreHeaderSize
+#include "pycore_pymem.h"         // _Py_tracemalloc_config
+#include "pycore_runtime.h"       // _Py_ID()
+#include "pycore_traceback.h"
+#include <pycore_frame.h>
+#include "frameobject.h"          // _PyInterpreterFrame_GetLine
+
+#include <stdlib.h>               // malloc()
+
+#define tracemalloc_config _PyRuntime.tracemalloc.config
+
+_Py_DECLARE_STR(anon_unknown, "<unknown>");
+
+/* Forward declaration */
+static void* raw_malloc(size_t size);
+static void raw_free(void *ptr);
+
+#ifdef Py_DEBUG
+#  define TRACE_DEBUG
+#endif
+
+#define TO_PTR(key) ((const void *)(uintptr_t)(key))
+#define FROM_PTR(key) ((uintptr_t)(key))
+
+#define allocators _PyRuntime.tracemalloc.allocators
+
+
+#if defined(TRACE_RAW_MALLOC)
+/* This lock is needed because tracemalloc_free() is called without
+   the GIL held from PyMem_RawFree(). It cannot acquire the lock because it
+   would introduce a deadlock in _PyThreadState_DeleteCurrent(). */
+#  define tables_lock _PyRuntime.tracemalloc.tables_lock
+#  define TABLES_LOCK() PyThread_acquire_lock(tables_lock, 1)
+#  define TABLES_UNLOCK() PyThread_release_lock(tables_lock)
+#else
+   /* variables are protected by the GIL */
+#  define TABLES_LOCK()
+#  define TABLES_UNLOCK()
+#endif
+
+
+#define DEFAULT_DOMAIN 0
+
+typedef struct tracemalloc_frame frame_t;
+typedef struct tracemalloc_traceback traceback_t;
+
+#define TRACEBACK_SIZE(NFRAME) \
+        (sizeof(traceback_t) + sizeof(frame_t) * (NFRAME - 1))
+
+/* The maximum number of frames is either:
+ - The maximum number of frames we can store in `traceback_t.nframe`
+ - The maximum memory size_t we can allocate */
+static const unsigned long MAX_NFRAME = Py_MIN(UINT16_MAX, ((SIZE_MAX - sizeof(traceback_t)) / sizeof(frame_t) + 1));
+
+
+#define tracemalloc_empty_traceback _PyRuntime.tracemalloc.empty_traceback
+
+
+/* Trace of a memory block */
+typedef struct {
+    /* Size of the memory block in bytes */
+    size_t size;
+
+    /* Traceback where the memory block was allocated */
+    traceback_t *traceback;
+} trace_t;
+
+
+#define tracemalloc_traced_memory _PyRuntime.tracemalloc.traced_memory
+#define tracemalloc_peak_traced_memory _PyRuntime.tracemalloc.peak_traced_memory
+#define tracemalloc_filenames _PyRuntime.tracemalloc.filenames
+#define tracemalloc_traceback _PyRuntime.tracemalloc.traceback
+#define tracemalloc_tracebacks _PyRuntime.tracemalloc.tracebacks
+#define tracemalloc_traces _PyRuntime.tracemalloc.traces
+#define tracemalloc_domains _PyRuntime.tracemalloc.domains
+
+
+#ifdef TRACE_DEBUG
+static void
+tracemalloc_error(const char *format, ...)
+{
+    va_list ap;
+    fprintf(stderr, "tracemalloc: ");
+    va_start(ap, format);
+    vfprintf(stderr, format, ap);
+    va_end(ap);
+    fprintf(stderr, "\n");
+    fflush(stderr);
+}
+#endif
+
+
+#if defined(TRACE_RAW_MALLOC)
+#define REENTRANT_THREADLOCAL
+
+#define tracemalloc_reentrant_key _PyRuntime.tracemalloc.reentrant_key
+
+/* Any non-NULL pointer can be used */
+#define REENTRANT Py_True
+
+static int
+get_reentrant(void)
+{
+    void *ptr;
+
+    assert(PyThread_tss_is_created(&tracemalloc_reentrant_key));
+    ptr = PyThread_tss_get(&tracemalloc_reentrant_key);
+    if (ptr != NULL) {
+        assert(ptr == REENTRANT);
+        return 1;
+    }
+    else
+        return 0;
+}
+
+static void
+set_reentrant(int reentrant)
+{
+    assert(reentrant == 0 || reentrant == 1);
+    assert(PyThread_tss_is_created(&tracemalloc_reentrant_key));
+
+    if (reentrant) {
+        assert(!get_reentrant());
+        PyThread_tss_set(&tracemalloc_reentrant_key, REENTRANT);
+    }
+    else {
+        assert(get_reentrant());
+        PyThread_tss_set(&tracemalloc_reentrant_key, NULL);
+    }
+}
+
+#else
+
+/* TRACE_RAW_MALLOC not defined: variable protected by the GIL */
+static int tracemalloc_reentrant = 0;
+
+static int
+get_reentrant(void)
+{
+    return tracemalloc_reentrant;
+}
+
+static void
+set_reentrant(int reentrant)
+{
+    assert(reentrant != tracemalloc_reentrant);
+    tracemalloc_reentrant = reentrant;
+}
+#endif
+
+
+static Py_uhash_t
+hashtable_hash_pyobject(const void *key)
+{
+    PyObject *obj = (PyObject *)key;
+    return PyObject_Hash(obj);
+}
+
+
+static int
+hashtable_compare_unicode(const void *key1, const void *key2)
+{
+    PyObject *obj1 = (PyObject *)key1;
+    PyObject *obj2 = (PyObject *)key2;
+    if (obj1 != NULL && obj2 != NULL) {
+        return (PyUnicode_Compare(obj1, obj2) == 0);
+    }
+    else {
+        return obj1 == obj2;
+    }
+}
+
+
+static Py_uhash_t
+hashtable_hash_uint(const void *key_raw)
+{
+    unsigned int key = (unsigned int)FROM_PTR(key_raw);
+    return (Py_uhash_t)key;
+}
+
+
+static _Py_hashtable_t *
+hashtable_new(_Py_hashtable_hash_func hash_func,
+              _Py_hashtable_compare_func compare_func,
+              _Py_hashtable_destroy_func key_destroy_func,
+              _Py_hashtable_destroy_func value_destroy_func)
+{
+    _Py_hashtable_allocator_t hashtable_alloc = {malloc, free};
+    return _Py_hashtable_new_full(hash_func, compare_func,
+                                  key_destroy_func, value_destroy_func,
+                                  &hashtable_alloc);
+}
+
+
+static void*
+raw_malloc(size_t size)
+{
+    return allocators.raw.malloc(allocators.raw.ctx, size);
+}
+
+static void
+raw_free(void *ptr)
+{
+    allocators.raw.free(allocators.raw.ctx, ptr);
+}
+
+
+static Py_uhash_t
+hashtable_hash_traceback(const void *key)
+{
+    const traceback_t *traceback = (const traceback_t *)key;
+    return traceback->hash;
+}
+
+
+static int
+hashtable_compare_traceback(const void *key1, const void *key2)
+{
+    const traceback_t *traceback1 = (const traceback_t *)key1;
+    const traceback_t *traceback2 = (const traceback_t *)key2;
+
+    if (traceback1->nframe != traceback2->nframe) {
+        return 0;
+    }
+    if (traceback1->total_nframe != traceback2->total_nframe) {
+        return 0;
+    }
+
+    for (int i=0; i < traceback1->nframe; i++) {
+        const frame_t *frame1 = &traceback1->frames[i];
+        const frame_t *frame2 = &traceback2->frames[i];
+
+        if (frame1->lineno != frame2->lineno) {
+            return 0;
+        }
+        if (frame1->filename != frame2->filename) {
+            assert(PyUnicode_Compare(frame1->filename, frame2->filename) != 0);
+            return 0;
+        }
+    }
+    return 1;
+}
+
+
+static void
+tracemalloc_get_frame(_PyInterpreterFrame *pyframe, frame_t *frame)
+{
+    frame->filename = &_Py_STR(anon_unknown);
+    int lineno = PyUnstable_InterpreterFrame_GetLine(pyframe);
+    if (lineno < 0) {
+        lineno = 0;
+    }
+    frame->lineno = (unsigned int)lineno;
+
+    PyObject *filename = pyframe->f_code->co_filename;
+
+    if (filename == NULL) {
+#ifdef TRACE_DEBUG
+        tracemalloc_error("failed to get the filename of the code object");
+#endif
+        return;
+    }
+
+    if (!PyUnicode_Check(filename)) {
+#ifdef TRACE_DEBUG
+        tracemalloc_error("filename is not a unicode string");
+#endif
+        return;
+    }
+    if (!PyUnicode_IS_READY(filename)) {
+        /* Don't make a Unicode string ready to avoid reentrant calls
+           to tracemalloc_malloc() or tracemalloc_realloc() */
+#ifdef TRACE_DEBUG
+        tracemalloc_error("filename is not a ready unicode string");
+#endif
+        return;
+    }
+
+    /* intern the filename */
+    _Py_hashtable_entry_t *entry;
+    entry = _Py_hashtable_get_entry(tracemalloc_filenames, filename);
+    if (entry != NULL) {
+        filename = (PyObject *)entry->key;
+    }
+    else {
+        /* tracemalloc_filenames is responsible to keep a reference
+           to the filename */
+        if (_Py_hashtable_set(tracemalloc_filenames, Py_NewRef(filename),
+                              NULL) < 0) {
+            Py_DECREF(filename);
+#ifdef TRACE_DEBUG
+            tracemalloc_error("failed to intern the filename");
+#endif
+            return;
+        }
+    }
+
+    /* the tracemalloc_filenames table keeps a reference to the filename */
+    frame->filename = filename;
+}
+
+
+static Py_uhash_t
+traceback_hash(traceback_t *traceback)
+{
+    /* code based on tuplehash() of Objects/tupleobject.c */
+    Py_uhash_t x, y;  /* Unsigned for defined overflow behavior. */
+    int len = traceback->nframe;
+    Py_uhash_t mult = _PyHASH_MULTIPLIER;
+    frame_t *frame;
+
+    x = 0x345678UL;
+    frame = traceback->frames;
+    while (--len >= 0) {
+        y = (Py_uhash_t)PyObject_Hash(frame->filename);
+        y ^= (Py_uhash_t)frame->lineno;
+        frame++;
+
+        x = (x ^ y) * mult;
+        /* the cast might truncate len; that doesn't change hash stability */
+        mult += (Py_uhash_t)(82520UL + len + len);
+    }
+    x ^= traceback->total_nframe;
+    x += 97531UL;
+    return x;
+}
+
+
+static void
+traceback_get_frames(traceback_t *traceback)
+{
+    PyThreadState *tstate = PyGILState_GetThisThreadState();
+    if (tstate == NULL) {
+#ifdef TRACE_DEBUG
+        tracemalloc_error("failed to get the current thread state");
+#endif
+        return;
+    }
+
+    _PyInterpreterFrame *pyframe = _PyThreadState_GetFrame(tstate);
+    while (pyframe) {
+        if (traceback->nframe < tracemalloc_config.max_nframe) {
+            tracemalloc_get_frame(pyframe, &traceback->frames[traceback->nframe]);
+            assert(traceback->frames[traceback->nframe].filename != NULL);
+            traceback->nframe++;
+        }
+        if (traceback->total_nframe < UINT16_MAX) {
+            traceback->total_nframe++;
+        }
+        pyframe = _PyFrame_GetFirstComplete(pyframe->previous);
+    }
+}
+
+
+static traceback_t *
+traceback_new(void)
+{
+    traceback_t *traceback;
+    _Py_hashtable_entry_t *entry;
+
+    assert(PyGILState_Check());
+
+    /* get frames */
+    traceback = tracemalloc_traceback;
+    traceback->nframe = 0;
+    traceback->total_nframe = 0;
+    traceback_get_frames(traceback);
+    if (traceback->nframe == 0)
+        return &tracemalloc_empty_traceback;
+    traceback->hash = traceback_hash(traceback);
+
+    /* intern the traceback */
+    entry = _Py_hashtable_get_entry(tracemalloc_tracebacks, traceback);
+    if (entry != NULL) {
+        traceback = (traceback_t *)entry->key;
+    }
+    else {
+        traceback_t *copy;
+        size_t traceback_size;
+
+        traceback_size = TRACEBACK_SIZE(traceback->nframe);
+
+        copy = raw_malloc(traceback_size);
+        if (copy == NULL) {
+#ifdef TRACE_DEBUG
+            tracemalloc_error("failed to intern the traceback: malloc failed");
+#endif
+            return NULL;
+        }
+        memcpy(copy, traceback, traceback_size);
+
+        if (_Py_hashtable_set(tracemalloc_tracebacks, copy, NULL) < 0) {
+            raw_free(copy);
+#ifdef TRACE_DEBUG
+            tracemalloc_error("failed to intern the traceback: putdata failed");
+#endif
+            return NULL;
+        }
+        traceback = copy;
+    }
+    return traceback;
+}
+
+
+static _Py_hashtable_t*
+tracemalloc_create_traces_table(void)
+{
+    return hashtable_new(_Py_hashtable_hash_ptr,
+                         _Py_hashtable_compare_direct,
+                         NULL, raw_free);
+}
+
+
+static _Py_hashtable_t*
+tracemalloc_create_domains_table(void)
+{
+    return hashtable_new(hashtable_hash_uint,
+                         _Py_hashtable_compare_direct,
+                         NULL,
+                         (_Py_hashtable_destroy_func)_Py_hashtable_destroy);
+}
+
+
+static _Py_hashtable_t*
+tracemalloc_get_traces_table(unsigned int domain)
+{
+    if (domain == DEFAULT_DOMAIN) {
+        return tracemalloc_traces;
+    }
+    else {
+        return _Py_hashtable_get(tracemalloc_domains, TO_PTR(domain));
+    }
+}
+
+
+static void
+tracemalloc_remove_trace(unsigned int domain, uintptr_t ptr)
+{
+    assert(tracemalloc_config.tracing);
+
+    _Py_hashtable_t *traces = tracemalloc_get_traces_table(domain);
+    if (!traces) {
+        return;
+    }
+
+    trace_t *trace = _Py_hashtable_steal(traces, TO_PTR(ptr));
+    if (!trace) {
+        return;
+    }
+    assert(tracemalloc_traced_memory >= trace->size);
+    tracemalloc_traced_memory -= trace->size;
+    raw_free(trace);
+}
+
+#define REMOVE_TRACE(ptr) \
+            tracemalloc_remove_trace(DEFAULT_DOMAIN, (uintptr_t)(ptr))
+
+
+static int
+tracemalloc_add_trace(unsigned int domain, uintptr_t ptr,
+                      size_t size)
+{
+    assert(tracemalloc_config.tracing);
+
+    traceback_t *traceback = traceback_new();
+    if (traceback == NULL) {
+        return -1;
+    }
+
+    _Py_hashtable_t *traces = tracemalloc_get_traces_table(domain);
+    if (traces == NULL) {
+        traces = tracemalloc_create_traces_table();
+        if (traces == NULL) {
+            return -1;
+        }
+
+        if (_Py_hashtable_set(tracemalloc_domains, TO_PTR(domain), traces) < 0) {
+            _Py_hashtable_destroy(traces);
+            return -1;
+        }
+    }
+
+    trace_t *trace = _Py_hashtable_get(traces, TO_PTR(ptr));
+    if (trace != NULL) {
+        /* the memory block is already tracked */
+        assert(tracemalloc_traced_memory >= trace->size);
+        tracemalloc_traced_memory -= trace->size;
+
+        trace->size = size;
+        trace->traceback = traceback;
+    }
+    else {
+        trace = raw_malloc(sizeof(trace_t));
+        if (trace == NULL) {
+            return -1;
+        }
+        trace->size = size;
+        trace->traceback = traceback;
+
+        int res = _Py_hashtable_set(traces, TO_PTR(ptr), trace);
+        if (res != 0) {
+            raw_free(trace);
+            return res;
+        }
+    }
+
+    assert(tracemalloc_traced_memory <= SIZE_MAX - size);
+    tracemalloc_traced_memory += size;
+    if (tracemalloc_traced_memory > tracemalloc_peak_traced_memory) {
+        tracemalloc_peak_traced_memory = tracemalloc_traced_memory;
+    }
+    return 0;
+}
+
+#define ADD_TRACE(ptr, size) \
+            tracemalloc_add_trace(DEFAULT_DOMAIN, (uintptr_t)(ptr), size)
+
+
+static void*
+tracemalloc_alloc(int use_calloc, void *ctx, size_t nelem, size_t elsize)
+{
+    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+    void *ptr;
+
+    assert(elsize == 0 || nelem <= SIZE_MAX / elsize);
+
+    if (use_calloc)
+        ptr = alloc->calloc(alloc->ctx, nelem, elsize);
+    else
+        ptr = alloc->malloc(alloc->ctx, nelem * elsize);
+    if (ptr == NULL)
+        return NULL;
+
+    TABLES_LOCK();
+    if (ADD_TRACE(ptr, nelem * elsize) < 0) {
+        /* Failed to allocate a trace for the new memory block */
+        TABLES_UNLOCK();
+        alloc->free(alloc->ctx, ptr);
+        return NULL;
+    }
+    TABLES_UNLOCK();
+    return ptr;
+}
+
+
+static void*
+tracemalloc_realloc(void *ctx, void *ptr, size_t new_size)
+{
+    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+    void *ptr2;
+
+    ptr2 = alloc->realloc(alloc->ctx, ptr, new_size);
+    if (ptr2 == NULL)
+        return NULL;
+
+    if (ptr != NULL) {
+        /* an existing memory block has been resized */
+
+        TABLES_LOCK();
+
+        /* tracemalloc_add_trace() updates the trace if there is already
+           a trace at address ptr2 */
+        if (ptr2 != ptr) {
+            REMOVE_TRACE(ptr);
+        }
+
+        if (ADD_TRACE(ptr2, new_size) < 0) {
+            /* Memory allocation failed. The error cannot be reported to
+               the caller, because realloc() may already have shrunk the
+               memory block and so removed bytes.
+
+               This case is very unlikely: a hash entry has just been
+               released, so the hash table should have at least one free entry.
+
+               The GIL and the table lock ensures that only one thread is
+               allocating memory. */
+            Py_FatalError("tracemalloc_realloc() failed to allocate a trace");
+        }
+        TABLES_UNLOCK();
+    }
+    else {
+        /* new allocation */
+
+        TABLES_LOCK();
+        if (ADD_TRACE(ptr2, new_size) < 0) {
+            /* Failed to allocate a trace for the new memory block */
+            TABLES_UNLOCK();
+            alloc->free(alloc->ctx, ptr2);
+            return NULL;
+        }
+        TABLES_UNLOCK();
+    }
+    return ptr2;
+}
+
+
+static void
+tracemalloc_free(void *ctx, void *ptr)
+{
+    PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+
+    if (ptr == NULL)
+        return;
+
+     /* GIL cannot be locked in PyMem_RawFree() because it would introduce
+        a deadlock in _PyThreadState_DeleteCurrent(). */
+
+    alloc->free(alloc->ctx, ptr);
+
+    TABLES_LOCK();
+    REMOVE_TRACE(ptr);
+    TABLES_UNLOCK();
+}
+
+
+static void*
+tracemalloc_alloc_gil(int use_calloc, void *ctx, size_t nelem, size_t elsize)
+{
+    void *ptr;
+
+    if (get_reentrant()) {
+        PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+        if (use_calloc)
+            return alloc->calloc(alloc->ctx, nelem, elsize);
+        else
+            return alloc->malloc(alloc->ctx, nelem * elsize);
+    }
+
+    /* Ignore reentrant call. PyObjet_Malloc() calls PyMem_Malloc() for
+       allocations larger than 512 bytes, don't trace the same memory
+       allocation twice. */
+    set_reentrant(1);
+
+    ptr = tracemalloc_alloc(use_calloc, ctx, nelem, elsize);
+
+    set_reentrant(0);
+    return ptr;
+}
+
+
+static void*
+tracemalloc_malloc_gil(void *ctx, size_t size)
+{
+    return tracemalloc_alloc_gil(0, ctx, 1, size);
+}
+
+
+static void*
+tracemalloc_calloc_gil(void *ctx, size_t nelem, size_t elsize)
+{
+    return tracemalloc_alloc_gil(1, ctx, nelem, elsize);
+}
+
+
+static void*
+tracemalloc_realloc_gil(void *ctx, void *ptr, size_t new_size)
+{
+    void *ptr2;
+
+    if (get_reentrant()) {
+        /* Reentrant call to PyMem_Realloc() and PyMem_RawRealloc().
+           Example: PyMem_RawRealloc() is called internally by pymalloc
+           (_PyObject_Malloc() and  _PyObject_Realloc()) to allocate a new
+           arena (new_arena()). */
+        PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+
+        ptr2 = alloc->realloc(alloc->ctx, ptr, new_size);
+        if (ptr2 != NULL && ptr != NULL) {
+            TABLES_LOCK();
+            REMOVE_TRACE(ptr);
+            TABLES_UNLOCK();
+        }
+        return ptr2;
+    }
+
+    /* Ignore reentrant call. PyObjet_Realloc() calls PyMem_Realloc() for
+       allocations larger than 512 bytes. Don't trace the same memory
+       allocation twice. */
+    set_reentrant(1);
+
+    ptr2 = tracemalloc_realloc(ctx, ptr, new_size);
+
+    set_reentrant(0);
+    return ptr2;
+}
+
+
+#ifdef TRACE_RAW_MALLOC
+static void*
+tracemalloc_raw_alloc(int use_calloc, void *ctx, size_t nelem, size_t elsize)
+{
+    PyGILState_STATE gil_state;
+    void *ptr;
+
+    if (get_reentrant()) {
+        PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+        if (use_calloc)
+            return alloc->calloc(alloc->ctx, nelem, elsize);
+        else
+            return alloc->malloc(alloc->ctx, nelem * elsize);
+    }
+
+    /* Ignore reentrant call. PyGILState_Ensure() may call PyMem_RawMalloc()
+       indirectly which would call PyGILState_Ensure() if reentrant are not
+       disabled. */
+    set_reentrant(1);
+
+    gil_state = PyGILState_Ensure();
+    ptr = tracemalloc_alloc(use_calloc, ctx, nelem, elsize);
+    PyGILState_Release(gil_state);
+
+    set_reentrant(0);
+    return ptr;
+}
+
+
+static void*
+tracemalloc_raw_malloc(void *ctx, size_t size)
+{
+    return tracemalloc_raw_alloc(0, ctx, 1, size);
+}
+
+
+static void*
+tracemalloc_raw_calloc(void *ctx, size_t nelem, size_t elsize)
+{
+    return tracemalloc_raw_alloc(1, ctx, nelem, elsize);
+}
+
+
+static void*
+tracemalloc_raw_realloc(void *ctx, void *ptr, size_t new_size)
+{
+    PyGILState_STATE gil_state;
+    void *ptr2;
+
+    if (get_reentrant()) {
+        /* Reentrant call to PyMem_RawRealloc(). */
+        PyMemAllocatorEx *alloc = (PyMemAllocatorEx *)ctx;
+
+        ptr2 = alloc->realloc(alloc->ctx, ptr, new_size);
+
+        if (ptr2 != NULL && ptr != NULL) {
+            TABLES_LOCK();
+            REMOVE_TRACE(ptr);
+            TABLES_UNLOCK();
+        }
+        return ptr2;
+    }
+
+    /* Ignore reentrant call. PyGILState_Ensure() may call PyMem_RawMalloc()
+       indirectly which would call PyGILState_Ensure() if reentrant calls are
+       not disabled. */
+    set_reentrant(1);
+
+    gil_state = PyGILState_Ensure();
+    ptr2 = tracemalloc_realloc(ctx, ptr, new_size);
+    PyGILState_Release(gil_state);
+
+    set_reentrant(0);
+    return ptr2;
+}
+#endif   /* TRACE_RAW_MALLOC */
+
+
+static void
+tracemalloc_clear_filename(void *value)
+{
+    PyObject *filename = (PyObject *)value;
+    Py_DECREF(filename);
+}
+
+
+/* reentrant flag must be set to call this function and GIL must be held */
+static void
+tracemalloc_clear_traces(void)
+{
+    /* The GIL protects variables against concurrent access */
+    assert(PyGILState_Check());
+
+    TABLES_LOCK();
+    _Py_hashtable_clear(tracemalloc_traces);
+    _Py_hashtable_clear(tracemalloc_domains);
+    tracemalloc_traced_memory = 0;
+    tracemalloc_peak_traced_memory = 0;
+    TABLES_UNLOCK();
+
+    _Py_hashtable_clear(tracemalloc_tracebacks);
+
+    _Py_hashtable_clear(tracemalloc_filenames);
+}
+
+
+int
+_PyTraceMalloc_Init(void)
+{
+    if (tracemalloc_config.initialized == TRACEMALLOC_FINALIZED) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "the tracemalloc module has been unloaded");
+        return -1;
+    }
+
+    if (tracemalloc_config.initialized == TRACEMALLOC_INITIALIZED)
+        return 0;
+
+    PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &allocators.raw);
+
+#ifdef REENTRANT_THREADLOCAL
+    if (PyThread_tss_create(&tracemalloc_reentrant_key) != 0) {
+#ifdef MS_WINDOWS
+        PyErr_SetFromWindowsErr(0);
+#else
+        PyErr_SetFromErrno(PyExc_OSError);
+#endif
+        return -1;
+    }
+#endif
+
+#if defined(TRACE_RAW_MALLOC)
+    if (tables_lock == NULL) {
+        tables_lock = PyThread_allocate_lock();
+        if (tables_lock == NULL) {
+            PyErr_SetString(PyExc_RuntimeError, "cannot allocate lock");
+            return -1;
+        }
+    }
+#endif
+
+    tracemalloc_filenames = hashtable_new(hashtable_hash_pyobject,
+                                          hashtable_compare_unicode,
+                                          tracemalloc_clear_filename, NULL);
+
+    tracemalloc_tracebacks = hashtable_new(hashtable_hash_traceback,
+                                           hashtable_compare_traceback,
+                                           NULL, raw_free);
+
+    tracemalloc_traces = tracemalloc_create_traces_table();
+    tracemalloc_domains = tracemalloc_create_domains_table();
+
+    if (tracemalloc_filenames == NULL || tracemalloc_tracebacks == NULL
+       || tracemalloc_traces == NULL || tracemalloc_domains == NULL) {
+        PyErr_NoMemory();
+        return -1;
+    }
+
+    tracemalloc_empty_traceback.nframe = 1;
+    tracemalloc_empty_traceback.total_nframe = 1;
+    /* borrowed reference */
+    tracemalloc_empty_traceback.frames[0].filename = &_Py_STR(anon_unknown);
+    tracemalloc_empty_traceback.frames[0].lineno = 0;
+    tracemalloc_empty_traceback.hash = traceback_hash(&tracemalloc_empty_traceback);
+
+    tracemalloc_config.initialized = TRACEMALLOC_INITIALIZED;
+    return 0;
+}
+
+
+static void
+tracemalloc_deinit(void)
+{
+    if (tracemalloc_config.initialized != TRACEMALLOC_INITIALIZED)
+        return;
+    tracemalloc_config.initialized = TRACEMALLOC_FINALIZED;
+
+    _PyTraceMalloc_Stop();
+
+    /* destroy hash tables */
+    _Py_hashtable_destroy(tracemalloc_domains);
+    _Py_hashtable_destroy(tracemalloc_traces);
+    _Py_hashtable_destroy(tracemalloc_tracebacks);
+    _Py_hashtable_destroy(tracemalloc_filenames);
+
+#if defined(TRACE_RAW_MALLOC)
+    if (tables_lock != NULL) {
+        PyThread_free_lock(tables_lock);
+        tables_lock = NULL;
+    }
+#endif
+
+#ifdef REENTRANT_THREADLOCAL
+    PyThread_tss_delete(&tracemalloc_reentrant_key);
+#endif
+}
+
+
+int
+_PyTraceMalloc_Start(int max_nframe)
+{
+    PyMemAllocatorEx alloc;
+    size_t size;
+
+    if (max_nframe < 1 || (unsigned long) max_nframe > MAX_NFRAME) {
+        PyErr_Format(PyExc_ValueError,
+                     "the number of frames must be in range [1; %lu]",
+                     MAX_NFRAME);
+        return -1;
+    }
+
+    if (_PyTraceMalloc_Init() < 0) {
+        return -1;
+    }
+
+    if (tracemalloc_config.tracing) {
+        /* hook already installed: do nothing */
+        return 0;
+    }
+
+    tracemalloc_config.max_nframe = max_nframe;
+
+    /* allocate a buffer to store a new traceback */
+    size = TRACEBACK_SIZE(max_nframe);
+    assert(tracemalloc_traceback == NULL);
+    tracemalloc_traceback = raw_malloc(size);
+    if (tracemalloc_traceback == NULL) {
+        PyErr_NoMemory();
+        return -1;
+    }
+
+#ifdef TRACE_RAW_MALLOC
+    alloc.malloc = tracemalloc_raw_malloc;
+    alloc.calloc = tracemalloc_raw_calloc;
+    alloc.realloc = tracemalloc_raw_realloc;
+    alloc.free = tracemalloc_free;
+
+    alloc.ctx = &allocators.raw;
+    PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &allocators.raw);
+    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &alloc);
+#endif
+
+    alloc.malloc = tracemalloc_malloc_gil;
+    alloc.calloc = tracemalloc_calloc_gil;
+    alloc.realloc = tracemalloc_realloc_gil;
+    alloc.free = tracemalloc_free;
+
+    alloc.ctx = &allocators.mem;
+    PyMem_GetAllocator(PYMEM_DOMAIN_MEM, &allocators.mem);
+    PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &alloc);
+
+    alloc.ctx = &allocators.obj;
+    PyMem_GetAllocator(PYMEM_DOMAIN_OBJ, &allocators.obj);
+    PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &alloc);
+
+    /* everything is ready: start tracing Python memory allocations */
+    tracemalloc_config.tracing = 1;
+
+    return 0;
+}
+
+
+void
+_PyTraceMalloc_Stop(void)
+{
+    if (!tracemalloc_config.tracing)
+        return;
+
+    /* stop tracing Python memory allocations */
+    tracemalloc_config.tracing = 0;
+
+    /* unregister the hook on memory allocators */
+#ifdef TRACE_RAW_MALLOC
+    PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &allocators.raw);
+#endif
+    PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &allocators.mem);
+    PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &allocators.obj);
+
+    tracemalloc_clear_traces();
+
+    /* release memory */
+    raw_free(tracemalloc_traceback);
+    tracemalloc_traceback = NULL;
+}
+
+
+
+static PyObject*
+frame_to_pyobject(frame_t *frame)
+{
+    PyObject *frame_obj, *lineno_obj;
+
+    frame_obj = PyTuple_New(2);
+    if (frame_obj == NULL)
+        return NULL;
+
+    PyTuple_SET_ITEM(frame_obj, 0, Py_NewRef(frame->filename));
+
+    lineno_obj = PyLong_FromUnsignedLong(frame->lineno);
+    if (lineno_obj == NULL) {
+        Py_DECREF(frame_obj);
+        return NULL;
+    }
+    PyTuple_SET_ITEM(frame_obj, 1, lineno_obj);
+
+    return frame_obj;
+}
+
+
+static PyObject*
+traceback_to_pyobject(traceback_t *traceback, _Py_hashtable_t *intern_table)
+{
+    PyObject *frames;
+
+    if (intern_table != NULL) {
+        frames = _Py_hashtable_get(intern_table, (const void *)traceback);
+        if (frames) {
+            return Py_NewRef(frames);
+        }
+    }
+
+    frames = PyTuple_New(traceback->nframe);
+    if (frames == NULL)
+        return NULL;
+
+    for (int i=0; i < traceback->nframe; i++) {
+        PyObject *frame = frame_to_pyobject(&traceback->frames[i]);
+        if (frame == NULL) {
+            Py_DECREF(frames);
+            return NULL;
+        }
+        PyTuple_SET_ITEM(frames, i, frame);
+    }
+
+    if (intern_table != NULL) {
+        if (_Py_hashtable_set(intern_table, traceback, frames) < 0) {
+            Py_DECREF(frames);
+            PyErr_NoMemory();
+            return NULL;
+        }
+        /* intern_table keeps a new reference to frames */
+        Py_INCREF(frames);
+    }
+    return frames;
+}
+
+
+static PyObject*
+trace_to_pyobject(unsigned int domain, const trace_t *trace,
+                  _Py_hashtable_t *intern_tracebacks)
+{
+    PyObject *trace_obj = NULL;
+    PyObject *obj;
+
+    trace_obj = PyTuple_New(4);
+    if (trace_obj == NULL)
+        return NULL;
+
+    obj = PyLong_FromSize_t(domain);
+    if (obj == NULL) {
+        Py_DECREF(trace_obj);
+        return NULL;
+    }
+    PyTuple_SET_ITEM(trace_obj, 0, obj);
+
+    obj = PyLong_FromSize_t(trace->size);
+    if (obj == NULL) {
+        Py_DECREF(trace_obj);
+        return NULL;
+    }
+    PyTuple_SET_ITEM(trace_obj, 1, obj);
+
+    obj = traceback_to_pyobject(trace->traceback, intern_tracebacks);
+    if (obj == NULL) {
+        Py_DECREF(trace_obj);
+        return NULL;
+    }
+    PyTuple_SET_ITEM(trace_obj, 2, obj);
+
+    obj = PyLong_FromUnsignedLong(trace->traceback->total_nframe);
+    if (obj == NULL) {
+        Py_DECREF(trace_obj);
+        return NULL;
+    }
+    PyTuple_SET_ITEM(trace_obj, 3, obj);
+
+    return trace_obj;
+}
+
+
+typedef struct {
+    _Py_hashtable_t *traces;
+    _Py_hashtable_t *domains;
+    _Py_hashtable_t *tracebacks;
+    PyObject *list;
+    unsigned int domain;
+} get_traces_t;
+
+
+static int
+tracemalloc_copy_trace(_Py_hashtable_t *traces,
+                       const void *key, const void *value,
+                       void *user_data)
+{
+    _Py_hashtable_t *traces2 = (_Py_hashtable_t *)user_data;
+
+    trace_t *trace = (trace_t *)value;
+
+    trace_t *trace2 = raw_malloc(sizeof(trace_t));
+    if (trace2 == NULL) {
+        return -1;
+    }
+    *trace2 = *trace;
+    if (_Py_hashtable_set(traces2, key, trace2) < 0) {
+        raw_free(trace2);
+        return -1;
+    }
+    return 0;
+}
+
+
+static _Py_hashtable_t*
+tracemalloc_copy_traces(_Py_hashtable_t *traces)
+{
+    _Py_hashtable_t *traces2 = tracemalloc_create_traces_table();
+    if (traces2 == NULL) {
+        return NULL;
+    }
+
+    int err = _Py_hashtable_foreach(traces,
+                                    tracemalloc_copy_trace,
+                                    traces2);
+    if (err) {
+        _Py_hashtable_destroy(traces2);
+        return NULL;
+    }
+    return traces2;
+}
+
+
+static int
+tracemalloc_copy_domain(_Py_hashtable_t *domains,
+                        const void *key, const void *value,
+                        void *user_data)
+{
+    _Py_hashtable_t *domains2 = (_Py_hashtable_t *)user_data;
+
+    unsigned int domain = (unsigned int)FROM_PTR(key);
+    _Py_hashtable_t *traces = (_Py_hashtable_t *)value;
+
+    _Py_hashtable_t *traces2 = tracemalloc_copy_traces(traces);
+    if (traces2 == NULL) {
+        return -1;
+    }
+    if (_Py_hashtable_set(domains2, TO_PTR(domain), traces2) < 0) {
+        _Py_hashtable_destroy(traces2);
+        return -1;
+    }
+    return 0;
+}
+
+
+static _Py_hashtable_t*
+tracemalloc_copy_domains(_Py_hashtable_t *domains)
+{
+    _Py_hashtable_t *domains2 = tracemalloc_create_domains_table();
+    if (domains2 == NULL) {
+        return NULL;
+    }
+
+    int err = _Py_hashtable_foreach(domains,
+                                    tracemalloc_copy_domain,
+                                    domains2);
+    if (err) {
+        _Py_hashtable_destroy(domains2);
+        return NULL;
+    }
+    return domains2;
+}
+
+
+static int
+tracemalloc_get_traces_fill(_Py_hashtable_t *traces,
+                            const void *key, const void *value,
+                            void *user_data)
+{
+    get_traces_t *get_traces = user_data;
+
+    const trace_t *trace = (const trace_t *)value;
+
+    PyObject *tuple = trace_to_pyobject(get_traces->domain, trace,
+                                        get_traces->tracebacks);
+    if (tuple == NULL) {
+        return 1;
+    }
+
+    int res = PyList_Append(get_traces->list, tuple);
+    Py_DECREF(tuple);
+    if (res < 0) {
+        return 1;
+    }
+
+    return 0;
+}
+
+
+static int
+tracemalloc_get_traces_domain(_Py_hashtable_t *domains,
+                              const void *key, const void *value,
+                              void *user_data)
+{
+    get_traces_t *get_traces = user_data;
+
+    unsigned int domain = (unsigned int)FROM_PTR(key);
+    _Py_hashtable_t *traces = (_Py_hashtable_t *)value;
+
+    get_traces->domain = domain;
+    return _Py_hashtable_foreach(traces,
+                                 tracemalloc_get_traces_fill,
+                                 get_traces);
+}
+
+
+static void
+tracemalloc_pyobject_decref(void *value)
+{
+    PyObject *obj = (PyObject *)value;
+    Py_DECREF(obj);
+}
+
+
+static traceback_t*
+tracemalloc_get_traceback(unsigned int domain, uintptr_t ptr)
+{
+
+    if (!tracemalloc_config.tracing)
+        return NULL;
+
+    trace_t *trace;
+    TABLES_LOCK();
+    _Py_hashtable_t *traces = tracemalloc_get_traces_table(domain);
+    if (traces) {
+        trace = _Py_hashtable_get(traces, TO_PTR(ptr));
+    }
+    else {
+        trace = NULL;
+    }
+    TABLES_UNLOCK();
+
+    if (!trace) {
+        return NULL;
+    }
+
+    return trace->traceback;
+}
+
+
+#define PUTS(fd, str) _Py_write_noraise(fd, str, (int)strlen(str))
+
+static void
+_PyMem_DumpFrame(int fd, frame_t * frame)
+{
+    PUTS(fd, "  File \"");
+    _Py_DumpASCII(fd, frame->filename);
+    PUTS(fd, "\", line ");
+    _Py_DumpDecimal(fd, frame->lineno);
+    PUTS(fd, "\n");
+}
+
+/* Dump the traceback where a memory block was allocated into file descriptor
+   fd. The function may block on TABLES_LOCK() but it is unlikely. */
+void
+_PyMem_DumpTraceback(int fd, const void *ptr)
+{
+    traceback_t *traceback;
+    int i;
+
+    if (!tracemalloc_config.tracing) {
+        PUTS(fd, "Enable tracemalloc to get the memory block "
+                 "allocation traceback\n\n");
+        return;
+    }
+
+    traceback = tracemalloc_get_traceback(DEFAULT_DOMAIN, (uintptr_t)ptr);
+    if (traceback == NULL)
+        return;
+
+    PUTS(fd, "Memory block allocated at (most recent call first):\n");
+    for (i=0; i < traceback->nframe; i++) {
+        _PyMem_DumpFrame(fd, &traceback->frames[i]);
+    }
+    PUTS(fd, "\n");
+}
+
+#undef PUTS
+
+
+static int
+tracemalloc_get_tracemalloc_memory_cb(_Py_hashtable_t *domains,
+                                      const void *key, const void *value,
+                                      void *user_data)
+{
+    const _Py_hashtable_t *traces = value;
+    size_t *size = (size_t*)user_data;
+    *size += _Py_hashtable_size(traces);
+    return 0;
+}
+
+int
+PyTraceMalloc_Track(unsigned int domain, uintptr_t ptr,
+                    size_t size)
+{
+    int res;
+    PyGILState_STATE gil_state;
+
+    if (!tracemalloc_config.tracing) {
+        /* tracemalloc is not tracing: do nothing */
+        return -2;
+    }
+
+    gil_state = PyGILState_Ensure();
+
+    TABLES_LOCK();
+    res = tracemalloc_add_trace(domain, ptr, size);
+    TABLES_UNLOCK();
+
+    PyGILState_Release(gil_state);
+    return res;
+}
+
+
+int
+PyTraceMalloc_Untrack(unsigned int domain, uintptr_t ptr)
+{
+    if (!tracemalloc_config.tracing) {
+        /* tracemalloc is not tracing: do nothing */
+        return -2;
+    }
+
+    TABLES_LOCK();
+    tracemalloc_remove_trace(domain, ptr);
+    TABLES_UNLOCK();
+
+    return 0;
+}
+
+
+void
+_PyTraceMalloc_Fini(void)
+{
+    assert(PyGILState_Check());
+    tracemalloc_deinit();
+}
+
+
+/* If the object memory block is already traced, update its trace
+   with the current Python traceback.
+
+   Do nothing if tracemalloc is not tracing memory allocations
+   or if the object memory block is not already traced. */
+int
+_PyTraceMalloc_NewReference(PyObject *op)
+{
+    assert(PyGILState_Check());
+
+    if (!tracemalloc_config.tracing) {
+        /* tracemalloc is not tracing: do nothing */
+        return -1;
+    }
+
+    PyTypeObject *type = Py_TYPE(op);
+    const size_t presize = _PyType_PreHeaderSize(type);
+    uintptr_t ptr = (uintptr_t)((char *)op - presize);
+
+    int res = -1;
+
+    TABLES_LOCK();
+    trace_t *trace = _Py_hashtable_get(tracemalloc_traces, TO_PTR(ptr));
+    if (trace != NULL) {
+        /* update the traceback of the memory block */
+        traceback_t *traceback = traceback_new();
+        if (traceback != NULL) {
+            trace->traceback = traceback;
+            res = 0;
+        }
+    }
+    /* else: cannot track the object, its memory block size is unknown */
+    TABLES_UNLOCK();
+
+    return res;
+}
+
+
+PyObject*
+_PyTraceMalloc_GetTraceback(unsigned int domain, uintptr_t ptr)
+{
+    traceback_t *traceback;
+
+    traceback = tracemalloc_get_traceback(domain, ptr);
+    if (traceback == NULL)
+        Py_RETURN_NONE;
+
+    return traceback_to_pyobject(traceback, NULL);
+}
+
+int
+_PyTraceMalloc_IsTracing(void)
+{
+    return tracemalloc_config.tracing;
+}
+
+void
+_PyTraceMalloc_ClearTraces(void)
+{
+
+    if (!tracemalloc_config.tracing) {
+        return;
+    }
+    set_reentrant(1);
+    tracemalloc_clear_traces();
+    set_reentrant(0);
+}
+
+PyObject *
+_PyTraceMalloc_GetTraces(void)
+{
+    get_traces_t get_traces;
+    get_traces.domain = DEFAULT_DOMAIN;
+    get_traces.traces = NULL;
+    get_traces.domains = NULL;
+    get_traces.tracebacks = NULL;
+    get_traces.list = PyList_New(0);
+    if (get_traces.list == NULL)
+        goto error;
+
+    if (!tracemalloc_config.tracing)
+        return get_traces.list;
+
+    /* the traceback hash table is used temporarily to intern traceback tuple
+       of (filename, lineno) tuples */
+    get_traces.tracebacks = hashtable_new(_Py_hashtable_hash_ptr,
+                                          _Py_hashtable_compare_direct,
+                                          NULL, tracemalloc_pyobject_decref);
+    if (get_traces.tracebacks == NULL) {
+        goto no_memory;
+    }
+
+    // Copy all traces so tracemalloc_get_traces_fill() doesn't have to disable
+    // temporarily tracemalloc which would impact other threads and so would
+    // miss allocations while get_traces() is called.
+    TABLES_LOCK();
+    get_traces.traces = tracemalloc_copy_traces(tracemalloc_traces);
+    TABLES_UNLOCK();
+
+    if (get_traces.traces == NULL) {
+        goto no_memory;
+    }
+
+    TABLES_LOCK();
+    get_traces.domains = tracemalloc_copy_domains(tracemalloc_domains);
+    TABLES_UNLOCK();
+
+    if (get_traces.domains == NULL) {
+        goto no_memory;
+    }
+
+    // Convert traces to a list of tuples
+    set_reentrant(1);
+    int err = _Py_hashtable_foreach(get_traces.traces,
+                                    tracemalloc_get_traces_fill,
+                                    &get_traces);
+    if (!err) {
+        err = _Py_hashtable_foreach(get_traces.domains,
+                                    tracemalloc_get_traces_domain,
+                                    &get_traces);
+    }
+    set_reentrant(0);
+    if (err) {
+        goto error;
+    }
+
+    goto finally;
+
+no_memory:
+    PyErr_NoMemory();
+
+error:
+    Py_CLEAR(get_traces.list);
+
+finally:
+    if (get_traces.tracebacks != NULL) {
+        _Py_hashtable_destroy(get_traces.tracebacks);
+    }
+    if (get_traces.traces != NULL) {
+        _Py_hashtable_destroy(get_traces.traces);
+    }
+    if (get_traces.domains != NULL) {
+        _Py_hashtable_destroy(get_traces.domains);
+    }
+
+    return get_traces.list;
+}
+
+PyObject *
+_PyTraceMalloc_GetObjectTraceback(PyObject *obj)
+/*[clinic end generated code: output=41ee0553a658b0aa input=29495f1b21c53212]*/
+{
+    PyTypeObject *type;
+    traceback_t *traceback;
+
+    type = Py_TYPE(obj);
+    const size_t presize = _PyType_PreHeaderSize(type);
+    uintptr_t ptr = (uintptr_t)((char *)obj - presize);
+
+    traceback = tracemalloc_get_traceback(DEFAULT_DOMAIN, ptr);
+    if (traceback == NULL) {
+        Py_RETURN_NONE;
+    }
+
+    return traceback_to_pyobject(traceback, NULL);
+}
+
+int _PyTraceMalloc_GetTracebackLimit(void) {
+    return tracemalloc_config.max_nframe;
+}
+
+size_t
+_PyTraceMalloc_GetMemory(void) {
+
+    size_t size;
+
+    size = _Py_hashtable_size(tracemalloc_tracebacks);
+    size += _Py_hashtable_size(tracemalloc_filenames);
+
+    TABLES_LOCK();
+    size += _Py_hashtable_size(tracemalloc_traces);
+    _Py_hashtable_foreach(tracemalloc_domains,
+                          tracemalloc_get_tracemalloc_memory_cb, &size);
+    TABLES_UNLOCK();
+    return size;
+}
+
+
+PyObject *
+_PyTraceMalloc_GetTracedMemory(void)
+{
+    Py_ssize_t size, peak_size;
+
+    if (!tracemalloc_config.tracing)
+        return Py_BuildValue("ii", 0, 0);
+
+    TABLES_LOCK();
+    size = tracemalloc_traced_memory;
+    peak_size = tracemalloc_peak_traced_memory;
+    TABLES_UNLOCK();
+
+    return Py_BuildValue("nn", size, peak_size);
+}
+
+void
+_PyTraceMalloc_ResetPeak(void)
+{
+    if (!tracemalloc_config.tracing) {
+        return;
+    }
+    TABLES_LOCK();
+    tracemalloc_peak_traced_memory = tracemalloc_traced_memory;
+    TABLES_UNLOCK();
+}