summaryrefslogtreecommitdiff
path: root/boehm-gc/mark.c
diff options
context:
space:
mode:
authorjsturm <jsturm@138bc75d-0d04-0410-961f-82ee72b054a4>2003-07-28 04:18:23 +0000
committerjsturm <jsturm@138bc75d-0d04-0410-961f-82ee72b054a4>2003-07-28 04:18:23 +0000
commit341281013a7334da0896c950d9c254e42692c479 (patch)
tree827bf34dcb0c2786d314e5fa136528e5a4feb6f7 /boehm-gc/mark.c
parent975f1a7b2a8b2194905616d3fb05653329a2afce (diff)
downloadgcc-341281013a7334da0896c950d9c254e42692c479.tar.gz
Import GC 6.3alpha1.
* BCC_MAKEFILE: Merge with GC 6.3alpha1 release. * ChangeLog: Likewise. * Makefile.am: Likewise. * Makefile.direct: Likewise. * Makefile.dj: Likewise. * allchblk.c: Likewise. * alloc.c: Likewise. * backgraph.c: Likewise. * configure.host: Likewise. * configure.in: Likewise. * dbg_mlc.c: Likewise. * dyn_load.c: Likewise. * finalize.c: Likewise. * gc_cpp.cc: Likewise. * gc_dlopen.c: Likewise. * gcj_mlc.c: Likewise. * if_mach.c: Likewise. * mach_dep.c: Likewise. * malloc.c: Likewise. * mallocx.c: Likewise. * mark.c: Likewise. * mark_rts.c: Likewise. * misc.c: Likewise. * os_dep.c: Likewise. * ptr_chck.c: Likewise. * reclaim.c: Likewise. * solaris_pthreads.c: Likewise. * solaris_threads.c: Likewise. * sparc_mach_dep.S: Likewise. * threadlibs.c: Likewise. * typd_mlc.c: Likewise. * version.h: Likewise. * win32_threads.c: Likewise. * Mac_files/MacOS_Test_config.h: Likewise. * Mac_files/MacOS_config.h: Likewise. * cord/cordbscs.c: Likewise. * cord/cordprnt.c: Likewise. * cord/de_win.c: Likewise. * doc/README: Likewise. * doc/README.MacOSX: Likewise. * doc/README.changes: Likewise. * doc/README.environment: Likewise. * doc/README.ews4800: Likewise. * doc/README.linux: Likewise. * doc/README.macros: Likewise. * doc/README.win32: Likewise. * doc/debugging.html: Likewise. * doc/gcdescr.html: Likewise. * doc/tree.html: Likewise. * include/Makefile.in: Likewise. * include/gc.h: Likewise. * include/gc_cpp.h: Likewise. * include/gc_local_alloc.h: Likewise. * include/gc_mark.h: Likewise. * include/gc_pthread_redirects.h: Likewise. * include/gc_typed.h: Likewise. * include/new_gc_alloc.h: Likewise. * include/private/dbg_mlc.h: Likewise. * include/private/gc_hdrs.h: Likewise. * include/private/gc_locks.h: Likewise. * include/private/gc_pmark.h: Likewise. * include/private/gc_priv.h: Likewise. * include/private/gcconfig.h: Likewise. * include/private/solaris_threads.h: Likewise. * include/private/specific.h: Likewise. * tests/test.c: Likewise. * tests/test_cpp.cc: Likewise. * configure: Rebuild. * Makefile.in: Rebuild. * mips_sgi_mach_dep.s: Add. * alpha_mach_dep.s: Remove. * irix_threads.c: Remove. * linux_threads.c: Remove. * mips_sgi_mach_dep.S: Remove. * missing: Remove. * powerpc_macosx_mach_dep.s: Remove. * doc/Makefile.am: Remove. * doc/Makefile.in: Remove. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@69880 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'boehm-gc/mark.c')
-rw-r--r--boehm-gc/mark.c216
1 files changed, 168 insertions, 48 deletions
diff --git a/boehm-gc/mark.c b/boehm-gc/mark.c
index eb5b9eeb34d..ca947290291 100644
--- a/boehm-gc/mark.c
+++ b/boehm-gc/mark.c
@@ -19,6 +19,10 @@
# include <stdio.h>
# include "private/gc_pmark.h"
+#if defined(MSWIN32) && defined(__GNUC__)
+# include <excpt.h>
+#endif
+
/* We put this here to minimize the risk of inlining. */
/*VARARGS*/
#ifdef __WATCOMC__
@@ -261,20 +265,20 @@ static void alloc_mark_stack();
/* remains valid until all marking is complete. */
/* A zero value indicates that it's OK to miss some */
/* register values. */
-GC_bool GC_mark_some(cold_gc_frame)
-ptr_t cold_gc_frame;
+/* We hold the allocation lock. In the case of */
+/* incremental collection, the world may not be stopped.*/
+#ifdef MSWIN32
+ /* For win32, this is called after we establish a structured */
+ /* exception handler, in case Windows unmaps one of our root */
+ /* segments. See below. In either case, we acquire the */
+ /* allocator lock long before we get here. */
+ GC_bool GC_mark_some_inner(cold_gc_frame)
+ ptr_t cold_gc_frame;
+#else
+ GC_bool GC_mark_some(cold_gc_frame)
+ ptr_t cold_gc_frame;
+#endif
{
-#if defined(MSWIN32) && !defined(__GNUC__)
- /* Windows 98 appears to asynchronously create and remove writable */
- /* memory mappings, for reasons we haven't yet understood. Since */
- /* we look for writable regions to determine the root set, we may */
- /* try to mark from an address range that disappeared since we */
- /* started the collection. Thus we have to recover from faults here. */
- /* This code does not appear to be necessary for Windows 95/NT/2000. */
- /* Note that this code should never generate an incremental GC write */
- /* fault. */
- __try {
-#endif /* defined(MSWIN32) && !defined(__GNUC__) */
switch(GC_mark_state) {
case MS_NONE:
return(FALSE);
@@ -395,23 +399,130 @@ ptr_t cold_gc_frame;
ABORT("GC_mark_some: bad state");
return(FALSE);
}
-#if defined(MSWIN32) && !defined(__GNUC__)
- } __except (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION ?
- EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH) {
-# ifdef CONDPRINT
- if (GC_print_stats) {
- GC_printf0("Caught ACCESS_VIOLATION in marker. "
- "Memory mapping disappeared.\n");
+}
+
+
+#ifdef MSWIN32
+
+# ifdef __GNUC__
+
+ typedef struct {
+ EXCEPTION_REGISTRATION ex_reg;
+ void *alt_path;
+ } ext_ex_regn;
+
+
+ static EXCEPTION_DISPOSITION mark_ex_handler(
+ struct _EXCEPTION_RECORD *ex_rec,
+ void *est_frame,
+ struct _CONTEXT *context,
+ void *disp_ctxt)
+ {
+ if (ex_rec->ExceptionCode == STATUS_ACCESS_VIOLATION) {
+ ext_ex_regn *xer = (ext_ex_regn *)est_frame;
+
+ /* Unwind from the inner function assuming the standard */
+ /* function prologue. */
+ /* Assumes code has not been compiled with */
+ /* -fomit-frame-pointer. */
+ context->Esp = context->Ebp;
+ context->Ebp = *((DWORD *)context->Esp);
+ context->Esp = context->Esp - 8;
+
+ /* Resume execution at the "real" handler within the */
+ /* wrapper function. */
+ context->Eip = (DWORD )(xer->alt_path);
+
+ return ExceptionContinueExecution;
+
+ } else {
+ return ExceptionContinueSearch;
+ }
+ }
+# endif /* __GNUC__ */
+
+
+ GC_bool GC_mark_some(cold_gc_frame)
+ ptr_t cold_gc_frame;
+ {
+ GC_bool ret_val;
+
+# ifndef __GNUC__
+ /* Windows 98 appears to asynchronously create and remove */
+ /* writable memory mappings, for reasons we haven't yet */
+ /* understood. Since we look for writable regions to */
+ /* determine the root set, we may try to mark from an */
+ /* address range that disappeared since we started the */
+ /* collection. Thus we have to recover from faults here. */
+ /* This code does not appear to be necessary for Windows */
+ /* 95/NT/2000. Note that this code should never generate */
+ /* an incremental GC write fault. */
+
+ __try {
+
+# else /* __GNUC__ */
+
+ /* Manually install an exception handler since GCC does */
+ /* not yet support Structured Exception Handling (SEH) on */
+ /* Win32. */
+
+ ext_ex_regn er;
+
+ er.alt_path = &&handle_ex;
+ er.ex_reg.handler = mark_ex_handler;
+ asm volatile ("movl %%fs:0, %0" : "=r" (er.ex_reg.prev));
+ asm volatile ("movl %0, %%fs:0" : : "r" (&er));
+
+# endif /* __GNUC__ */
+
+ ret_val = GC_mark_some_inner(cold_gc_frame);
+
+# ifndef __GNUC__
+
+ } __except (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION ?
+ EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH) {
+
+# else /* __GNUC__ */
+
+ /* Prevent GCC from considering the following code unreachable */
+ /* and thus eliminating it. */
+ if (er.alt_path != 0)
+ goto rm_handler;
+
+handle_ex:
+ /* Execution resumes from here on an access violation. */
+
+# endif /* __GNUC__ */
+
+# ifdef CONDPRINT
+ if (GC_print_stats) {
+ GC_printf0("Caught ACCESS_VIOLATION in marker. "
+ "Memory mapping disappeared.\n");
+ }
+# endif /* CONDPRINT */
+
+ /* We have bad roots on the stack. Discard mark stack. */
+ /* Rescan from marked objects. Redetermine roots. */
+ GC_invalidate_mark_state();
+ scan_ptr = 0;
+
+ ret_val = FALSE;
+
+# ifndef __GNUC__
+
}
-# endif /* CONDPRINT */
- /* We have bad roots on the stack. Discard mark stack. */
- /* Rescan from marked objects. Redetermine roots. */
- GC_invalidate_mark_state();
- scan_ptr = 0;
- return FALSE;
+
+# else /* __GNUC__ */
+
+rm_handler:
+ /* Uninstall the exception handler */
+ asm volatile ("mov %0, %%fs:0" : : "r" (er.ex_reg.prev));
+
+# endif /* __GNUC__ */
+
+ return ret_val;
}
-#endif /* defined(MSWIN32) && !defined(__GNUC__) */
-}
+#endif /* MSWIN32 */
GC_bool GC_mark_stack_empty()
@@ -434,13 +545,7 @@ GC_bool GC_mark_stack_empty()
/* for the large object. */
/* - just return current if it does not point to a large object. */
/*ARGSUSED*/
-# ifdef PRINT_BLACK_LIST
- ptr_t GC_find_start(current, hhdr, new_hdr_p, source)
- ptr_t source;
-# else
- ptr_t GC_find_start(current, hhdr, new_hdr_p)
-# define source 0
-# endif
+ptr_t GC_find_start(current, hhdr, new_hdr_p)
register ptr_t current;
register hdr *hhdr, **new_hdr_p;
{
@@ -468,7 +573,6 @@ register hdr *hhdr, **new_hdr_p;
} else {
return(current);
}
-# undef source
}
void GC_invalidate_mark_state()
@@ -546,8 +650,8 @@ mse * mark_stack_limit;
/* Large length. */
/* Process part of the range to avoid pushing too much on the */
/* stack. */
- GC_ASSERT(descr < GC_greatest_plausible_heap_addr
- - GC_least_plausible_heap_addr);
+ GC_ASSERT(descr < (word)GC_greatest_plausible_heap_addr
+ - (word)GC_least_plausible_heap_addr);
# ifdef PARALLEL_MARK
# define SHARE_BYTES 2048
if (descr > SHARE_BYTES && GC_parallel
@@ -578,6 +682,7 @@ mse * mark_stack_limit;
while (descr != 0) {
if ((signed_word)descr < 0) {
current = *current_p;
+ FIXUP_POINTER(current);
if ((ptr_t)current >= least_ha && (ptr_t)current < greatest_ha) {
PREFETCH(current);
HC_PUSH_CONTENTS((ptr_t)current, mark_stack_top,
@@ -652,6 +757,7 @@ mse * mark_stack_limit;
PREFETCH((ptr_t)limit - PREF_DIST*CACHE_LINE_SIZE);
GC_ASSERT(limit >= current_p);
deferred = *limit;
+ FIXUP_POINTER(deferred);
limit = (word *)((char *)limit - ALIGNMENT);
if ((ptr_t)deferred >= least_ha && (ptr_t)deferred < greatest_ha) {
PREFETCH(deferred);
@@ -661,6 +767,7 @@ mse * mark_stack_limit;
/* Unroll once, so we don't do too many of the prefetches */
/* based on limit. */
deferred = *limit;
+ FIXUP_POINTER(deferred);
limit = (word *)((char *)limit - ALIGNMENT);
if ((ptr_t)deferred >= least_ha && (ptr_t)deferred < greatest_ha) {
PREFETCH(deferred);
@@ -675,6 +782,7 @@ mse * mark_stack_limit;
/* Since HC_PUSH_CONTENTS expands to a lot of code, */
/* we don't. */
current = *current_p;
+ FIXUP_POINTER(current);
PREFETCH((ptr_t)current_p + PREF_DIST*CACHE_LINE_SIZE);
if ((ptr_t)current >= least_ha && (ptr_t)current < greatest_ha) {
/* Prefetch the contents of the object we just pushed. It's */
@@ -726,22 +834,33 @@ mse * GC_steal_mark_stack(mse * low, mse * high, mse * local,
mse *top = local - 1;
unsigned i = 0;
+ /* Make sure that prior writes to the mark stack are visible. */
+ /* On some architectures, the fact that the reads are */
+ /* volatile should suffice. */
+# if !defined(IA64) && !defined(HP_PA) && !defined(I386)
+ GC_memory_barrier();
+# endif
GC_ASSERT(high >= low-1 && high - low + 1 <= GC_mark_stack_size);
for (p = low; p <= high && i <= max; ++p) {
word descr = *(volatile word *) &(p -> mse_descr);
+ /* In the IA64 memory model, the following volatile store is */
+ /* ordered after this read of descr. Thus a thread must read */
+ /* the original nonzero value. HP_PA appears to be similar, */
+ /* and if I'm reading the P4 spec correctly, X86 is probably */
+ /* also OK. In some other cases we need a barrier. */
+# if !defined(IA64) && !defined(HP_PA) && !defined(I386)
+ GC_memory_barrier();
+# endif
if (descr != 0) {
*(volatile word *) &(p -> mse_descr) = 0;
+ /* More than one thread may get this entry, but that's only */
+ /* a minor performance problem. */
++top;
top -> mse_descr = descr;
top -> mse_start = p -> mse_start;
GC_ASSERT( top -> mse_descr & GC_DS_TAGS != GC_DS_LENGTH ||
top -> mse_descr < GC_greatest_plausible_heap_addr
- GC_least_plausible_heap_addr);
- /* There is no synchronization here. We assume that at */
- /* least one thread will see the original descriptor. */
- /* Otherwise we need a barrier. */
- /* More than one thread may get this entry, but that's only */
- /* a minor performance problem. */
/* If this is a big object, count it as */
/* size/256 + 1 objects. */
++i;
@@ -778,7 +897,7 @@ void GC_return_mark_stack(mse * low, mse * high)
BCOPY(low, my_start, stack_size * sizeof(mse));
GC_ASSERT(GC_mark_stack_top = my_top);
# if !defined(IA64) && !defined(HP_PA)
- GC_memory_write_barrier();
+ GC_memory_barrier();
# endif
/* On IA64, the volatile write acts as a release barrier. */
GC_mark_stack_top = my_top + stack_size;
@@ -1342,8 +1461,8 @@ ptr_t top;
# define GC_least_plausible_heap_addr least_ha
if (top == 0) return;
- /* check all pointers in range and put in push if they appear */
- /* to be valid. */
+ /* check all pointers in range and push if they appear */
+ /* to be valid. */
lim = t - 1 /* longword */;
for (p = b; p <= lim; p = (word *)(((char *)p) + ALIGNMENT)) {
q = *p;
@@ -1366,7 +1485,7 @@ ptr_t bottom;
ptr_t top;
ptr_t cold_gc_frame;
{
- if (GC_all_interior_pointers) {
+ if (!NEED_FIXUP_POINTER && GC_all_interior_pointers) {
# define EAGER_BYTES 1024
/* Push the hot end of the stack eagerly, so that register values */
/* saved inside GC frames are marked before they disappear. */
@@ -1375,6 +1494,7 @@ ptr_t cold_gc_frame;
GC_push_all_stack(bottom, top);
return;
}
+ GC_ASSERT(bottom <= cold_gc_frame && cold_gc_frame <= top);
# ifdef STACK_GROWS_DOWN
GC_push_all(cold_gc_frame - sizeof(ptr_t), top);
GC_push_all_eager(bottom, cold_gc_frame);
@@ -1395,7 +1515,7 @@ void GC_push_all_stack(bottom, top)
ptr_t bottom;
ptr_t top;
{
- if (GC_all_interior_pointers) {
+ if (!NEED_FIXUP_POINTER && GC_all_interior_pointers) {
GC_push_all(bottom, top);
} else {
GC_push_all_eager(bottom, top);