in reply to Debugging XS with duma/efence?
As to using any debug heap mgrs, you probably already know that XS/Perl obsconds with the std. malloc/free symbols, so you need to create your own version in an externally compiled object. I've been using the following (you'll need to reference your own set of heap mgr libs/methods):
/* * crt_memmgt.c - provides wrappers for malloc, free, and strdup, cuz * Perl core has hijacked the symbols * also provides debug versions of malloc/free */ #include <stdlib.h> #include <stdio.h> #include <string.h> typedef struct inuse_t inuse_t; typedef struct inuse_t { inuse_t *prev; inuse_t *next; int line; } inuse_t; static inuse_t *inuse = NULL; /* * seem to be writing past the end of somethign somewhere...but where +? */ void *crt_malloc(int size) { return malloc(size + sizeof(inuse_t)); } void *crt_free(void *ptr) { if (ptr) free(ptr); return NULL; } void *crt_strdup(char *str) { return strdup(str); } void *crt_realloc(void *ptr, int count, int size, int newcount) { char *tptr = malloc((size * newcount) + sizeof(inuse_t)); if (tptr == NULL) return NULL; if (ptr && count) { memcpy(tptr, ptr, (count * size)); crt_free(ptr); } memset(&tptr[(count * size)], 0, (newcount - count) * size); return tptr; } void *crt_malloc_dbg(int size, int line) { inuse_t *p = (inuse_t *)malloc(size + sizeof(inuse_t)); void *t = (char *)p + sizeof(inuse_t); p->prev = NULL; p->next = inuse; p->line = line; if (inuse) inuse->prev = p; inuse = p; return t; } void *crt_free_dbg(void *ptr, int line) { inuse_t *tp = (inuse_t *)((char *)ptr - sizeof(inuse_t)); inuse_t *s = inuse; while (s && (s != tp)) s = s->next; if (!s) { printf("\n**** BOGUS FREED POINTER %p at %d\n", ptr, line); } else { if (tp->next) tp->next->prev = tp->prev; if (tp->prev) tp->prev->next = tp->next; if (inuse == tp) inuse = tp->next; printf("\n*** FREEING %p ALLOC'd at %d FREED AT %d\n", tp, tp- +>line, line); } free(tp); return NULL; } void *crt_strdup_dbg(char *str, int line) { char *p = crt_malloc_dbg(strlen(str) + 1, line); strcpy(p, str); return p; } void *crt_realloc_dbg(void *ptr, int count, int size, int newcount, in +t line) { char *tptr = crt_malloc_dbg((size * newcount) + sizeof(inuse_t), l +ine); if (tptr == NULL) return NULL; if (ptr && count) { memcpy(tptr, ptr, (count * size)); crt_free_dbg(ptr, line); } memset(&tptr[(count * size)], 0, (newcount - count) * size); return tptr; } void crt_check() { inuse_t *p = inuse; for (; p; p = p->next) printf("\n*** LEFTOVER %p FROM %d\n", p, p->line); }
crt_memmgt.h:
Then, in your Makefile.PL (assuming EU::MM), add the following to your WriteMakefile() arguments:#ifndef CRT_MEMMGT_H /* * Because Perl CORE, in its infinite wisdom, has hijacked * CRT's malloc() and free() symbols, without providing * any replacement symbols for them, we have * to create a separate object to link into our XS code */ #define CRT_Newz(v,n,t) \ if ((v = (t *)crt_malloc((n) * sizeof(t))) == NULL) \ Perl_croak_nocontext("Out of CRT memory!"); \ memzero((char*)(v), (n)*sizeof(t)) #define CRT_Dup(v,n,t,s,l) \ if ((v = (t *)crt_malloc((n) * sizeof(t))) == NULL) \ Perl_croak_nocontext("Out of CRT memory!"); \ memcpy((char*)(v), (char*)(s), (l) * sizeof(t)); \ if ((l) < (n)) \ memzero((char*)(&v[(n)]), ((n) - (l)) * sizeof(t)) #define CRT_Realloc(v,n,t,l) \ if ((v = crt_realloc(v, n, sizeof(t), l)) == NULL) \ Perl_croak_nocontext("Out of CRT memory!"); // #define CRT_DEBUG 1 #ifdef CRT_DEBUG #define crt_malloc(v) crt_malloc_dbg(v, __LINE__) #define crt_free(v) crt_free_dbg(v, __LINE__) #define crt_strdup(v) crt_strdup_dbg(v, __LINE__) #define crt_realloc(v,n,t,l) crt_realloc_dbg(v,n,t,l, __LINE__) void *crt_malloc_dbg(int size, int line); void *crt_free_dbg(void *, int); void *crt_strdup_dbg(void *, int); void *crt_realloc_dbg(void *, int, int, int, int); #else void *crt_malloc(int size); void *crt_free(void *); char *crt_strdup(char *str); void *crt_realloc(void *, int, int, int); #endif void crt_check(); #endif
'OBJECT' => '$(BASEEXT)$(OBJ_EXT) crt_memmgt$(OBJ_EXT)',
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Re^2: Debugging XS with duma/efence?
by suaveant (Parson) on Nov 14, 2007 at 17:36 UTC | |
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Re^2: Debugging XS with duma/efence?
by suaveant (Parson) on Nov 14, 2007 at 19:57 UTC | |
by renodino (Curate) on Nov 14, 2007 at 20:04 UTC |