summaryrefslogtreecommitdiff
path: root/Modules/_lsprof.c
blob: c5a6f4445872cad30b35b14f53c11aedc41623a7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
#include "Python.h"
#include "frameobject.h"
#include "rotatingtree.h"

/************************************************************/
/* Written by Brett Rosen and Ted Czotter */

struct _ProfilerEntry;

/* represents a function called from another function */
typedef struct _ProfilerSubEntry {
    rotating_node_t header;
    _PyTime_t tt;
    _PyTime_t it;
    long callcount;
    long recursivecallcount;
    long recursionLevel;
} ProfilerSubEntry;

/* represents a function or user defined block */
typedef struct _ProfilerEntry {
    rotating_node_t header;
    PyObject *userObj; /* PyCodeObject, or a descriptive str for builtins */
    _PyTime_t tt; /* total time in this entry */
    _PyTime_t it; /* inline time in this entry (not in subcalls) */
    long callcount; /* how many times this was called */
    long recursivecallcount; /* how many times called recursively */
    long recursionLevel;
    rotating_node_t *calls;
} ProfilerEntry;

typedef struct _ProfilerContext {
    _PyTime_t t0;
    _PyTime_t subt;
    struct _ProfilerContext *previous;
    ProfilerEntry *ctxEntry;
} ProfilerContext;

typedef struct {
    PyObject_HEAD
    rotating_node_t *profilerEntries;
    ProfilerContext *currentProfilerContext;
    ProfilerContext *freelistProfilerContext;
    int flags;
    PyObject *externalTimer;
    double externalTimerUnit;
} ProfilerObject;

#define POF_ENABLED     0x001
#define POF_SUBCALLS    0x002
#define POF_BUILTINS    0x004
#define POF_NOMEMORY    0x100

static PyTypeObject PyProfiler_Type;

#define PyProfiler_Check(op) PyObject_TypeCheck(op, &PyProfiler_Type)
#define PyProfiler_CheckExact(op) (Py_TYPE(op) == &PyProfiler_Type)

/*** External Timers ***/

static _PyTime_t CallExternalTimer(ProfilerObject *pObj)
{
    PyObject *o = _PyObject_CallNoArg(pObj->externalTimer);
    if (o == NULL) {
        PyErr_WriteUnraisable(pObj->externalTimer);
        return 0;
    }

    _PyTime_t result;
    int err;
    if (pObj->externalTimerUnit > 0.0) {
        /* interpret the result as an integer that will be scaled
           in profiler_getstats() */
        err = _PyTime_FromNanosecondsObject(&result, o);
    }
    else {
        /* interpret the result as a double measured in seconds.
           As the profiler works with _PyTime_t internally
           we convert it to a large integer */
        err = _PyTime_FromSecondsObject(&result, o, _PyTime_ROUND_FLOOR);
    }
    Py_DECREF(o);
    if (err < 0) {
        PyErr_WriteUnraisable(pObj->externalTimer);
        return 0;
    }
    return result;
}

static inline _PyTime_t
call_timer(ProfilerObject *pObj)
{
    if (pObj->externalTimer != NULL) {
        return CallExternalTimer(pObj);
    }
    else {
        return _PyTime_GetPerfCounter();
    }
}


/*** ProfilerObject ***/

static PyObject *
normalizeUserObj(PyObject *obj)
{
    PyCFunctionObject *fn;
    if (!PyCFunction_Check(obj)) {
        Py_INCREF(obj);
        return obj;
    }
    /* Replace built-in function objects with a descriptive string
       because of built-in methods -- keeping a reference to
       __self__ is probably not a good idea. */
    fn = (PyCFunctionObject *)obj;

    if (fn->m_self == NULL) {
        /* built-in function: look up the module name */
        PyObject *mod = fn->m_module;
        PyObject *modname = NULL;
        if (mod != NULL) {
            if (PyUnicode_Check(mod)) {
                modname = mod;
                Py_INCREF(modname);
            }
            else if (PyModule_Check(mod)) {
                modname = PyModule_GetNameObject(mod);
                if (modname == NULL)
                    PyErr_Clear();
            }
        }
        if (modname != NULL) {
            if (!_PyUnicode_EqualToASCIIString(modname, "builtins")) {
                PyObject *result;
                result = PyUnicode_FromFormat("<%U.%s>", modname,
                                              fn->m_ml->ml_name);
                Py_DECREF(modname);
                return result;
            }
            Py_DECREF(modname);
        }
        return PyUnicode_FromFormat("<%s>", fn->m_ml->ml_name);
    }
    else {
        /* built-in method: try to return
            repr(getattr(type(__self__), __name__))
        */
        PyObject *self = fn->m_self;
        PyObject *name = PyUnicode_FromString(fn->m_ml->ml_name);
        PyObject *modname = fn->m_module;

        if (name != NULL) {
            PyObject *mo = _PyType_Lookup(Py_TYPE(self), name);
            Py_XINCREF(mo);
            Py_DECREF(name);
            if (mo != NULL) {
                PyObject *res = PyObject_Repr(mo);
                Py_DECREF(mo);
                if (res != NULL)
                    return res;
            }
        }
        /* Otherwise, use __module__ */
        PyErr_Clear();
        if (modname != NULL && PyUnicode_Check(modname))
            return PyUnicode_FromFormat("<built-in method %S.%s>",
                                        modname,  fn->m_ml->ml_name);
        else
            return PyUnicode_FromFormat("<built-in method %s>",
                                        fn->m_ml->ml_name);
    }
}

static ProfilerEntry*
newProfilerEntry(ProfilerObject *pObj, void *key, PyObject *userObj)
{
    ProfilerEntry *self;
    self = (ProfilerEntry*) PyMem_Malloc(sizeof(ProfilerEntry));
    if (self == NULL) {
        pObj->flags |= POF_NOMEMORY;
        return NULL;
    }
    userObj = normalizeUserObj(userObj);
    if (userObj == NULL) {
        PyErr_Clear();
        PyMem_Free(self);
        pObj->flags |= POF_NOMEMORY;
        return NULL;
    }
    self->header.key = key;
    self->userObj = userObj;
    self->tt = 0;
    self->it = 0;
    self->callcount = 0;
    self->recursivecallcount = 0;
    self->recursionLevel = 0;
    self->calls = EMPTY_ROTATING_TREE;
    RotatingTree_Add(&pObj->profilerEntries, &self->header);
    return self;
}

static ProfilerEntry*
getEntry(ProfilerObject *pObj, void *key)
{
    return (ProfilerEntry*) RotatingTree_Get(&pObj->profilerEntries, key);
}

static ProfilerSubEntry *
getSubEntry(ProfilerObject *pObj, ProfilerEntry *caller, ProfilerEntry* entry)
{
    return (ProfilerSubEntry*) RotatingTree_Get(&caller->calls,
                                                (void *)entry);
}

static ProfilerSubEntry *
newSubEntry(ProfilerObject *pObj,  ProfilerEntry *caller, ProfilerEntry* entry)
{
    ProfilerSubEntry *self;
    self = (ProfilerSubEntry*) PyMem_Malloc(sizeof(ProfilerSubEntry));
    if (self == NULL) {
        pObj->flags |= POF_NOMEMORY;
        return NULL;
    }
    self->header.key = (void *)entry;
    self->tt = 0;
    self->it = 0;
    self->callcount = 0;
    self->recursivecallcount = 0;
    self->recursionLevel = 0;
    RotatingTree_Add(&caller->calls, &self->header);
    return self;
}

static int freeSubEntry(rotating_node_t *header, void *arg)
{
    ProfilerSubEntry *subentry = (ProfilerSubEntry*) header;
    PyMem_Free(subentry);
    return 0;
}

static int freeEntry(rotating_node_t *header, void *arg)
{
    ProfilerEntry *entry = (ProfilerEntry*) header;
    RotatingTree_Enum(entry->calls, freeSubEntry, NULL);
    Py_DECREF(entry->userObj);
    PyMem_Free(entry);
    return 0;
}

static void clearEntries(ProfilerObject *pObj)
{
    RotatingTree_Enum(pObj->profilerEntries, freeEntry, NULL);
    pObj->profilerEntries = EMPTY_ROTATING_TREE;
    /* release the memory hold by the ProfilerContexts */
    if (pObj->currentProfilerContext) {
        PyMem_Free(pObj->currentProfilerContext);
        pObj->currentProfilerContext = NULL;
    }
    while (pObj->freelistProfilerContext) {
        ProfilerContext *c = pObj->freelistProfilerContext;
        pObj->freelistProfilerContext = c->previous;
        PyMem_Free(c);
    }
    pObj->freelistProfilerContext = NULL;
}

static void
initContext(ProfilerObject *pObj, ProfilerContext *self, ProfilerEntry *entry)
{
    self->ctxEntry = entry;
    self->subt = 0;
    self->previous = pObj->currentProfilerContext;
    pObj->currentProfilerContext = self;
    ++entry->recursionLevel;
    if ((pObj->flags & POF_SUBCALLS) && self->previous) {
        /* find or create an entry for me in my caller's entry */
        ProfilerEntry *caller = self->previous->ctxEntry;
        ProfilerSubEntry *subentry = getSubEntry(pObj, caller, entry);
        if (subentry == NULL)
            subentry = newSubEntry(pObj, caller, entry);
        if (subentry)
            ++subentry->recursionLevel;
    }
    self->t0 = call_timer(pObj);
}

static void
Stop(ProfilerObject *pObj, ProfilerContext *self, ProfilerEntry *entry)
{
    _PyTime_t tt = call_timer(pObj) - self->t0;
    _PyTime_t it = tt - self->subt;
    if (self->previous)
        self->previous->subt += tt;
    pObj->currentProfilerContext = self->previous;
    if (--entry->recursionLevel == 0)
        entry->tt += tt;
    else
        ++entry->recursivecallcount;
    entry->it += it;
    entry->callcount++;
    if ((pObj->flags & POF_SUBCALLS) && self->previous) {
        /* find or create an entry for me in my caller's entry */
        ProfilerEntry *caller = self->previous->ctxEntry;
        ProfilerSubEntry *subentry = getSubEntry(pObj, caller, entry);
        if (subentry) {
            if (--subentry->recursionLevel == 0)
                subentry->tt += tt;
            else
                ++subentry->recursivecallcount;
            subentry->it += it;
            ++subentry->callcount;
        }
    }
}

static void
ptrace_enter_call(PyObject *self, void *key, PyObject *userObj)
{
    /* entering a call to the function identified by 'key'
       (which can be a PyCodeObject or a PyMethodDef pointer) */
    ProfilerObject *pObj = (ProfilerObject*)self;
    ProfilerEntry *profEntry;
    ProfilerContext *pContext;

    /* In the case of entering a generator expression frame via a
     * throw (gen_send_ex(.., 1)), we may already have an
     * Exception set here. We must not mess around with this
     * exception, and some of the code under here assumes that
     * PyErr_* is its own to mess around with, so we have to
     * save and restore any current exception. */
    PyObject *last_type, *last_value, *last_tb;
    PyErr_Fetch(&last_type, &last_value, &last_tb);

    profEntry = getEntry(pObj, key);
    if (profEntry == NULL) {
        profEntry = newProfilerEntry(pObj, key, userObj);
        if (profEntry == NULL)
            goto restorePyerr;
    }
    /* grab a ProfilerContext out of the free list */
    pContext = pObj->freelistProfilerContext;
    if (pContext) {
        pObj->freelistProfilerContext = pContext->previous;
    }
    else {
        /* free list exhausted, allocate a new one */
        pContext = (ProfilerContext*)
            PyMem_Malloc(sizeof(ProfilerContext));
        if (pContext == NULL) {
            pObj->flags |= POF_NOMEMORY;
            goto restorePyerr;
        }
    }
    initContext(pObj, pContext, profEntry);

restorePyerr:
    PyErr_Restore(last_type, last_value, last_tb);
}

static void
ptrace_leave_call(PyObject *self, void *key)
{
    /* leaving a call to the function identified by 'key' */
    ProfilerObject *pObj = (ProfilerObject*)self;
    ProfilerEntry *profEntry;
    ProfilerContext *pContext;

    pContext = pObj->currentProfilerContext;
    if (pContext == NULL)
        return;
    profEntry = getEntry(pObj, key);
    if (profEntry) {
        Stop(pObj, pContext, profEntry);
    }
    else {
        pObj->currentProfilerContext = pContext->previous;
    }
    /* put pContext into the free list */
    pContext->previous = pObj->freelistProfilerContext;
    pObj->freelistProfilerContext = pContext;
}

static int
profiler_callback(PyObject *self, PyFrameObject *frame, int what,
                  PyObject *arg)
{
    switch (what) {

    /* the 'frame' of a called function is about to start its execution */
    case PyTrace_CALL:
        ptrace_enter_call(self, (void *)frame->f_code,
                                (PyObject *)frame->f_code);
        break;

    /* the 'frame' of a called function is about to finish
       (either normally or with an exception) */
    case PyTrace_RETURN:
        ptrace_leave_call(self, (void *)frame->f_code);
        break;

    /* case PyTrace_EXCEPTION:
        If the exception results in the function exiting, a
        PyTrace_RETURN event will be generated, so we don't need to
        handle it. */

    /* the Python function 'frame' is issuing a call to the built-in
       function 'arg' */
    case PyTrace_C_CALL:
        if ((((ProfilerObject *)self)->flags & POF_BUILTINS)
            && PyCFunction_Check(arg)) {
            ptrace_enter_call(self,
                              ((PyCFunctionObject *)arg)->m_ml,
                              arg);
        }
        break;

    /* the call to the built-in function 'arg' is returning into its
       caller 'frame' */
    case PyTrace_C_RETURN:              /* ...normally */
    case PyTrace_C_EXCEPTION:           /* ...with an exception set */
        if ((((ProfilerObject *)self)->flags & POF_BUILTINS)
            && PyCFunction_Check(arg)) {
            ptrace_leave_call(self,
                              ((PyCFunctionObject *)arg)->m_ml);
        }
        break;

    default:
        break;
    }
    return 0;
}

static int
pending_exception(ProfilerObject *pObj)
{
    if (pObj->flags & POF_NOMEMORY) {
        pObj->flags -= POF_NOMEMORY;
        PyErr_SetString(PyExc_MemoryError,
                        "memory was exhausted while profiling");
        return -1;
    }
    return 0;
}

/************************************************************/

static PyStructSequence_Field profiler_entry_fields[] = {
    {"code",         "code object or built-in function name"},
    {"callcount",    "how many times this was called"},
    {"reccallcount", "how many times called recursively"},
    {"totaltime",    "total time in this entry"},
    {"inlinetime",   "inline time in this entry (not in subcalls)"},
    {"calls",        "details of the calls"},
    {0}
};

static PyStructSequence_Field profiler_subentry_fields[] = {
    {"code",         "called code object or built-in function name"},
    {"callcount",    "how many times this is called"},
    {"reccallcount", "how many times this is called recursively"},
    {"totaltime",    "total time spent in this call"},
    {"inlinetime",   "inline time (not in further subcalls)"},
    {0}
};

static PyStructSequence_Desc profiler_entry_desc = {
    "_lsprof.profiler_entry", /* name */
    NULL, /* doc */
    profiler_entry_fields,
    6
};

static PyStructSequence_Desc profiler_subentry_desc = {
    "_lsprof.profiler_subentry", /* name */
    NULL, /* doc */
    profiler_subentry_fields,
    5
};

static int initialized;
static PyTypeObject StatsEntryType;
static PyTypeObject StatsSubEntryType;


typedef struct {
    PyObject *list;
    PyObject *sublist;
    double factor;
} statscollector_t;

static int statsForSubEntry(rotating_node_t *node, void *arg)
{
    ProfilerSubEntry *sentry = (ProfilerSubEntry*) node;
    statscollector_t *collect = (statscollector_t*) arg;
    ProfilerEntry *entry = (ProfilerEntry*) sentry->header.key;
    int err;
    PyObject *sinfo;
    sinfo = PyObject_CallFunction((PyObject*) &StatsSubEntryType,
                                  "((Olldd))",
                                  entry->userObj,
                                  sentry->callcount,
                                  sentry->recursivecallcount,
                                  collect->factor * sentry->tt,
                                  collect->factor * sentry->it);
    if (sinfo == NULL)
        return -1;
    err = PyList_Append(collect->sublist, sinfo);
    Py_DECREF(sinfo);
    return err;
}

static int statsForEntry(rotating_node_t *node, void *arg)
{
    ProfilerEntry *entry = (ProfilerEntry*) node;
    statscollector_t *collect = (statscollector_t*) arg;
    PyObject *info;
    int err;
    if (entry->callcount == 0)
        return 0;   /* skip */

    if (entry->calls != EMPTY_ROTATING_TREE) {
        collect->sublist = PyList_New(0);
        if (collect->sublist == NULL)
            return -1;
        if (RotatingTree_Enum(entry->calls,
                              statsForSubEntry, collect) != 0) {
            Py_DECREF(collect->sublist);
            return -1;
        }
    }
    else {
        Py_INCREF(Py_None);
        collect->sublist = Py_None;
    }

    info = PyObject_CallFunction((PyObject*) &StatsEntryType,
                                 "((OllddO))",
                                 entry->userObj,
                                 entry->callcount,
                                 entry->recursivecallcount,
                                 collect->factor * entry->tt,
                                 collect->factor * entry->it,
                                 collect->sublist);
    Py_DECREF(collect->sublist);
    if (info == NULL)
        return -1;
    err = PyList_Append(collect->list, info);
    Py_DECREF(info);
    return err;
}

PyDoc_STRVAR(getstats_doc, "\
getstats() -> list of profiler_entry objects\n\
\n\
Return all information collected by the profiler.\n\
Each profiler_entry is a tuple-like object with the\n\
following attributes:\n\
\n\
    code          code object\n\
    callcount     how many times this was called\n\
    reccallcount  how many times called recursively\n\
    totaltime     total time in this entry\n\
    inlinetime    inline time in this entry (not in subcalls)\n\
    calls         details of the calls\n\
\n\
The calls attribute is either None or a list of\n\
profiler_subentry objects:\n\
\n\
    code          called code object\n\
    callcount     how many times this is called\n\
    reccallcount  how many times this is called recursively\n\
    totaltime     total time spent in this call\n\
    inlinetime    inline time (not in further subcalls)\n\
");

static PyObject*
profiler_getstats(ProfilerObject *pObj, PyObject* noarg)
{
    statscollector_t collect;
    if (pending_exception(pObj))
        return NULL;
    if (!pObj->externalTimer || pObj->externalTimerUnit == 0.0) {
        _PyTime_t onesec = _PyTime_FromSeconds(1);
        collect.factor = (double)1 / onesec;
    }
    else {
        collect.factor = pObj->externalTimerUnit;
    }

    collect.list = PyList_New(0);
    if (collect.list == NULL)
        return NULL;
    if (RotatingTree_Enum(pObj->profilerEntries, statsForEntry, &collect)
        != 0) {
        Py_DECREF(collect.list);
        return NULL;
    }
    return collect.list;
}

static int
setSubcalls(ProfilerObject *pObj, int nvalue)
{
    if (nvalue == 0)
        pObj->flags &= ~POF_SUBCALLS;
    else if (nvalue > 0)
        pObj->flags |=  POF_SUBCALLS;
    return 0;
}

static int
setBuiltins(ProfilerObject *pObj, int nvalue)
{
    if (nvalue == 0)
        pObj->flags &= ~POF_BUILTINS;
    else if (nvalue > 0) {
        pObj->flags |=  POF_BUILTINS;
    }
    return 0;
}

PyDoc_STRVAR(enable_doc, "\
enable(subcalls=True, builtins=True)\n\
\n\
Start collecting profiling information.\n\
If 'subcalls' is True, also records for each function\n\
statistics separated according to its current caller.\n\
If 'builtins' is True, records the time spent in\n\
built-in functions separately from their caller.\n\
");

static PyObject*
profiler_enable(ProfilerObject *self, PyObject *args, PyObject *kwds)
{
    int subcalls = -1;
    int builtins = -1;
    static char *kwlist[] = {"subcalls", "builtins", 0};
    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|ii:enable",
                                     kwlist, &subcalls, &builtins))
        return NULL;
    if (setSubcalls(self, subcalls) < 0 || setBuiltins(self, builtins) < 0)
        return NULL;
    PyEval_SetProfile(profiler_callback, (PyObject*)self);
    self->flags |= POF_ENABLED;
    Py_RETURN_NONE;
}

static void
flush_unmatched(ProfilerObject *pObj)
{
    while (pObj->currentProfilerContext) {
        ProfilerContext *pContext = pObj->currentProfilerContext;
        ProfilerEntry *profEntry= pContext->ctxEntry;
        if (profEntry)
            Stop(pObj, pContext, profEntry);
        else
            pObj->currentProfilerContext = pContext->previous;
        if (pContext)
            PyMem_Free(pContext);
    }

}

PyDoc_STRVAR(disable_doc, "\
disable()\n\
\n\
Stop collecting profiling information.\n\
");

static PyObject*
profiler_disable(ProfilerObject *self, PyObject* noarg)
{
    self->flags &= ~POF_ENABLED;
    PyEval_SetProfile(NULL, NULL);
    flush_unmatched(self);
    if (pending_exception(self))
        return NULL;
    Py_RETURN_NONE;
}

PyDoc_STRVAR(clear_doc, "\
clear()\n\
\n\
Clear all profiling information collected so far.\n\
");

static PyObject*
profiler_clear(ProfilerObject *pObj, PyObject* noarg)
{
    clearEntries(pObj);
    Py_RETURN_NONE;
}

static void
profiler_dealloc(ProfilerObject *op)
{
    if (op->flags & POF_ENABLED)
        PyEval_SetProfile(NULL, NULL);
    flush_unmatched(op);
    clearEntries(op);
    Py_XDECREF(op->externalTimer);
    Py_TYPE(op)->tp_free(op);
}

static int
profiler_init(ProfilerObject *pObj, PyObject *args, PyObject *kw)
{
    PyObject *timer = NULL;
    double timeunit = 0.0;
    int subcalls = 1;
    int builtins = 1;
    static char *kwlist[] = {"timer", "timeunit",
                                   "subcalls", "builtins", 0};

    if (!PyArg_ParseTupleAndKeywords(args, kw, "|Odii:Profiler", kwlist,
                                     &timer, &timeunit,
                                     &subcalls, &builtins))
        return -1;

    if (setSubcalls(pObj, subcalls) < 0 || setBuiltins(pObj, builtins) < 0)
        return -1;
    pObj->externalTimerUnit = timeunit;
    Py_XINCREF(timer);
    Py_XSETREF(pObj->externalTimer, timer);
    return 0;
}

static PyMethodDef profiler_methods[] = {
    {"getstats",    (PyCFunction)profiler_getstats,
                    METH_NOARGS,                        getstats_doc},
    {"enable",          (PyCFunction)(void(*)(void))profiler_enable,
                    METH_VARARGS | METH_KEYWORDS,       enable_doc},
    {"disable",         (PyCFunction)profiler_disable,
                    METH_NOARGS,                        disable_doc},
    {"clear",           (PyCFunction)profiler_clear,
                    METH_NOARGS,                        clear_doc},
    {NULL, NULL}
};

PyDoc_STRVAR(profiler_doc, "\
Profiler(timer=None, timeunit=None, subcalls=True, builtins=True)\n\
\n\
    Builds a profiler object using the specified timer function.\n\
    The default timer is a fast built-in one based on real time.\n\
    For custom timer functions returning integers, timeunit can\n\
    be a float specifying a scale (i.e. how long each integer unit\n\
    is, in seconds).\n\
");

static PyTypeObject PyProfiler_Type = {
    PyVarObject_HEAD_INIT(NULL, 0)
    "_lsprof.Profiler",                     /* tp_name */
    sizeof(ProfilerObject),                 /* tp_basicsize */
    0,                                      /* tp_itemsize */
    (destructor)profiler_dealloc,           /* tp_dealloc */
    0,                                      /* tp_vectorcall_offset */
    0,                                      /* tp_getattr */
    0,                                      /* tp_setattr */
    0,                                      /* tp_as_async */
    0,                                      /* tp_repr */
    0,                                      /* tp_as_number */
    0,                                      /* tp_as_sequence */
    0,                                      /* tp_as_mapping */
    0,                                      /* tp_hash */
    0,                                      /* tp_call */
    0,                                      /* tp_str */
    0,                                      /* tp_getattro */
    0,                                      /* tp_setattro */
    0,                                      /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
    profiler_doc,                           /* tp_doc */
    0,                                      /* tp_traverse */
    0,                                      /* tp_clear */
    0,                                      /* tp_richcompare */
    0,                                      /* tp_weaklistoffset */
    0,                                      /* tp_iter */
    0,                                      /* tp_iternext */
    profiler_methods,                       /* tp_methods */
    0,                                      /* tp_members */
    0,                                      /* tp_getset */
    0,                                      /* tp_base */
    0,                                      /* tp_dict */
    0,                                      /* tp_descr_get */
    0,                                      /* tp_descr_set */
    0,                                      /* tp_dictoffset */
    (initproc)profiler_init,                /* tp_init */
    PyType_GenericAlloc,                    /* tp_alloc */
    PyType_GenericNew,                      /* tp_new */
    PyObject_Del,                           /* tp_free */
};

static PyMethodDef moduleMethods[] = {
    {NULL, NULL}
};


static struct PyModuleDef _lsprofmodule = {
    PyModuleDef_HEAD_INIT,
    "_lsprof",
    "Fast profiler",
    -1,
    moduleMethods,
    NULL,
    NULL,
    NULL,
    NULL
};

PyMODINIT_FUNC
PyInit__lsprof(void)
{
    PyObject *module, *d;
    module = PyModule_Create(&_lsprofmodule);
    if (module == NULL)
        return NULL;
    d = PyModule_GetDict(module);
    if (PyType_Ready(&PyProfiler_Type) < 0)
        return NULL;
    PyDict_SetItemString(d, "Profiler", (PyObject *)&PyProfiler_Type);

    if (!initialized) {
        if (PyStructSequence_InitType2(&StatsEntryType,
                                       &profiler_entry_desc) < 0)
            return NULL;
        if (PyStructSequence_InitType2(&StatsSubEntryType,
                                       &profiler_subentry_desc) < 0)
            return NULL;
    }
    Py_INCREF((PyObject*) &StatsEntryType);
    Py_INCREF((PyObject*) &StatsSubEntryType);
    PyModule_AddObject(module, "profiler_entry",
                       (PyObject*) &StatsEntryType);
    PyModule_AddObject(module, "profiler_subentry",
                       (PyObject*) &StatsSubEntryType);
    initialized = 1;
    return module;
}