# New Ticket Created by Andy Dougherty
# Please include the string: [perl #38576]
# in the subject line of all future correspondence about this issue.
# <URL: https://rt.perl.org/rt3/Ticket/Display.html?id=38576 >
While trying to debug an "Out of mem" PANIC, I decided to try using
DETAIL_MEMORY_DEBUG in src/memory.c. Alas, it didn't help for two
reasons:
1. It prints to standard output, so that when you try to rebuild
parrot, you get things like
$ make parrot
Invoking Parrot to generate runtime/parrot/include/config.fpmc --cross your
fingers
./miniparrot config_lib.pasm > runtime/parrot/include/config.fpmc
perl5.6 tools/build/parrot_config_c.pl > src/parrot_config.c
[ . . . ]
cc -o parrot [. . . ] src/parrot_config.o [ . . . ]
which ends up putting all that debug information into
src/parrot_config.o, and, eventually, into parrot. The resulting
parrot dumps core immediately. Not very helpful.
2. Some (but not all) of the debugging statements were *after* the
call to PANIC. That means that you never get to see the call to the
function that triggered the panic.
The following patch to src/memory.c re-orders statements, and prints to
stderr instead of stdout. I know stderr might not be available in
all situations, but this at least can work sometimes.
Finally, I put in a guard against calling free(0). It might not be
necessary, but we do end up trying to call it, and old habits die
hard.:-).
--- parrot-current/src/memory.c Sat Feb 11 12:23:31 2006
+++ parrot-andy/src/memory.c Wed Feb 15 12:36:51 2006
@@ -41,11 +41,11 @@
mem_sys_allocate(size_t size)
{
void *ptr = malloc((size_t)size);
- if (!ptr)
- PANIC("Out of mem");
#ifdef DETAIL_MEMORY_DEBUG
- printf("Allocated %i at %p\n", size, ptr);
+ fprintf(stderr, "Allocated %i at %p\n", size, ptr);
#endif
+ if (!ptr)
+ PANIC("Out of mem");
return ptr;
}
@@ -54,7 +54,7 @@
{
void *ptr = malloc((size_t)size);
#ifdef DETAIL_MEMORY_DEBUG
- printf("Internal malloc %i at %p (%s/%d)\n", size, ptr, file, line);
+ fprintf(stderr, "Internal malloc %i at %p (%s/%d)\n", size, ptr, file,
line);
#endif
if (!ptr)
PANIC("Out of mem");
@@ -76,11 +76,11 @@
mem_sys_allocate_zeroed(size_t size)
{
void *ptr = calloc(1, (size_t)size);
- if (!ptr)
- PANIC("Out of mem");
#ifdef DETAIL_MEMORY_DEBUG
- printf("Allocated %i at %p\n", size, ptr);
+ fprintf(stderr, "Allocated %i at %p\n", size, ptr);
#endif
+ if (!ptr)
+ PANIC("Out of mem");
return ptr;
}
@@ -88,11 +88,11 @@
mem__internal_allocate_zeroed(size_t size, const char *file, int line)
{
void *ptr = calloc(1, (size_t)size);
- if (!ptr)
- PANIC("Out of mem");
#ifdef DETAIL_MEMORY_DEBUG
- printf("Internal malloc %i at %p (%s/%d)\n", size, ptr, file, line);
+ fprintf(stderr, "Internal malloc %i at %p (%s/%d)\n", size, ptr, file,
line);
#endif
+ if (!ptr)
+ PANIC("Out of mem");
return ptr;
}
@@ -112,14 +112,14 @@
{
void *ptr;
#ifdef DETAIL_MEMORY_DEBUG
- printf("Freed %p (realloc -- %i bytes)\n", from, size);
+ fprintf(stderr, "Freed %p (realloc -- %i bytes)\n", from, size);
#endif
ptr = realloc(from, size);
- if (!ptr)
- PANIC("Out of mem");
#ifdef DETAIL_MEMORY_DEBUG
- printf("Allocated %i at %p\n", size, ptr);
+ fprintf(stderr, "Allocated %i at %p\n", size, ptr);
#endif
+ if (!ptr)
+ PANIC("Out of mem");
return ptr;
}
@@ -127,12 +127,12 @@
mem__internal_realloc(void *from, size_t size, const char *file, int line)
{
void *ptr = realloc(from, size);
- if (!ptr)
- PANIC("Out of mem");
#ifdef DETAIL_MEMORY_DEBUG
- printf("internal free of %p (realloc -- %i bytes) (%s/%d)\n", from, size,
file, line);
- printf("Internal malloc %i at %p (%s/%d)\n", size, ptr, file, line);
+ fprintf(stderr, "internal free of %p (realloc -- %i bytes) (%s/%d)\n",
from, size, file, line);
+ fprintf(stderr, "Internal malloc %i at %p (%s/%d)\n", size, ptr, file,
line);
#endif
+ if (!ptr)
+ PANIC("Out of mem");
return ptr;
}
#undef interpreter
@@ -152,16 +152,17 @@
mem_sys_free(void *from)
{
#ifdef DETAIL_MEMORY_DEBUG
- printf("Freed %p\n", from);
+ fprintf(stderr, "Freed %p\n", from);
#endif
- free(from);
+ if (from)
+ free(from);
}
void
mem__internal_free(void *from, const char *file, int line)
{
#ifdef DETAIL_MEMORY_DEBUG
- printf("Internal free of %p (%s/%d)\n", from, file, line);
+ fprintf(stderr, "Internal free of %p (%s/%d)\n", from, file, line);
#endif
free(from);
}
--
Andy Dougherty [EMAIL PROTECTED]
