diff options
| -rw-r--r-- | source4/lib/talloc/talloc.c | 510 |
1 files changed, 299 insertions, 211 deletions
diff --git a/source4/lib/talloc/talloc.c b/source4/lib/talloc/talloc.c index 87b4d51ba4..bae1942f43 100644 --- a/source4/lib/talloc/talloc.c +++ b/source4/lib/talloc/talloc.c @@ -77,6 +77,17 @@ #endif #endif +/* these macros gain us a few percent of speed on gcc */ +#if (__GNUC__ >= 3) +/* the strange !! is to ensure that __builtin_expect() takes either 0 or 1 + as its first argument */ +#define likely(x) __builtin_expect(!!(x), 1) +#define unlikely(x) __builtin_expect(!!(x), 0) +#else +#define likely(x) x +#define unlikely(x) x +#endif + /* this null_context is only used if talloc_enable_leak_report() or talloc_enable_leak_report_full() is called, otherwise it remains NULL @@ -106,15 +117,16 @@ struct talloc_chunk { #define TC_PTR_FROM_CHUNK(tc) ((void *)(TC_HDR_SIZE + (char*)tc)) /* panic if we get a bad magic value */ -static struct talloc_chunk *talloc_chunk_from_ptr(const void *ptr) +static inline struct talloc_chunk *talloc_chunk_from_ptr(const void *ptr) { const char *pp = (const char *)ptr; struct talloc_chunk *tc = discard_const_p(struct talloc_chunk, pp - TC_HDR_SIZE); - if ((tc->flags & ~0xF) != TALLOC_MAGIC) { - TALLOC_ABORT("Bad talloc magic value - unknown value"); - } - if (tc->flags & TALLOC_FLAG_FREE) { - TALLOC_ABORT("Bad talloc magic value - double free"); + if (unlikely((tc->flags & (TALLOC_FLAG_FREE | ~0xF)) != TALLOC_MAGIC)) { + if (tc->flags & TALLOC_FLAG_FREE) { + TALLOC_ABORT("Bad talloc magic value - double free"); + } else { + TALLOC_ABORT("Bad talloc magic value - unknown value"); + } } return tc; } @@ -163,23 +175,43 @@ void *talloc_parent(const void *ptr) return tc? TC_PTR_FROM_CHUNK(tc) : NULL; } +/* + find parents name +*/ +const char *talloc_parent_name(const void *context) +{ + struct talloc_chunk *tc; + + if (unlikely(context == NULL)) { + return NULL; + } + + tc = talloc_chunk_from_ptr(context); + while (tc && tc->prev) tc = tc->prev; + if (tc) { + tc = tc->parent; + } + return tc->name; +} + + /* Allocate a bit of memory as a child of an existing pointer */ -void *_talloc(const void *context, size_t size) +static inline void *__talloc(const void *context, size_t size) { struct talloc_chunk *tc; - if (context == NULL) { + if (unlikely(context == NULL)) { context = null_context; } - if (size >= MAX_TALLOC_SIZE) { + if (unlikely(size >= MAX_TALLOC_SIZE)) { return NULL; } tc = (struct talloc_chunk *)malloc(TC_HDR_SIZE+size); - if (tc == NULL) return NULL; + if (unlikely(tc == NULL)) return NULL; tc->size = size; tc->flags = TALLOC_MAGIC; @@ -188,16 +220,19 @@ void *_talloc(const void *context, size_t size) tc->name = NULL; tc->refs = NULL; - if (context) { + if (likely(context)) { struct talloc_chunk *parent = talloc_chunk_from_ptr(context); - tc->parent = parent; - if (parent->child) { parent->child->parent = NULL; + tc->next = parent->child; + tc->next->prev = tc; + } else { + tc->next = NULL; } - - _TLIST_ADD(parent->child, tc); + tc->parent = parent; + tc->prev = NULL; + parent->child = tc; } else { tc->next = tc->prev = tc->parent = NULL; } @@ -205,7 +240,6 @@ void *_talloc(const void *context, size_t size) return TC_PTR_FROM_CHUNK(tc); } - /* setup a destructor to be called on free of a pointer the destructor should return 0 on success, or -1 on failure. @@ -223,7 +257,7 @@ void _talloc_set_destructor(const void *ptr, int (*destructor)(void *)) */ int talloc_increase_ref_count(const void *ptr) { - if (!talloc_reference(null_context, ptr)) { + if (unlikely(!talloc_reference(null_context, ptr))) { return -1; } return 0; @@ -240,6 +274,33 @@ static int talloc_reference_destructor(struct talloc_reference_handle *handle) } /* + more efficient way to add a name to a pointer - the name must point to a + true string constant +*/ +static inline void _talloc_set_name_const(const void *ptr, const char *name) +{ + struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); + tc->name = name; +} + +/* + internal talloc_named_const() +*/ +static inline void *_talloc_named_const(const void *context, size_t size, const char *name) +{ + void *ptr; + + ptr = __talloc(context, size); + if (unlikely(ptr == NULL)) { + return NULL; + } + + _talloc_set_name_const(ptr, name); + + return ptr; +} + +/* make a secondary reference to a pointer, hanging off the given context. the pointer remains valid until both the original caller and this given context are freed. @@ -252,13 +313,13 @@ void *_talloc_reference(const void *context, const void *ptr) { struct talloc_chunk *tc; struct talloc_reference_handle *handle; - if (ptr == NULL) return NULL; + if (unlikely(ptr == NULL)) return NULL; tc = talloc_chunk_from_ptr(ptr); - handle = (struct talloc_reference_handle *)talloc_named_const(context, + handle = (struct talloc_reference_handle *)_talloc_named_const(context, sizeof(struct talloc_reference_handle), TALLOC_MAGIC_REFERENCE); - if (handle == NULL) return NULL; + if (unlikely(handle == NULL)) return NULL; /* note that we hang the destructor off the handle, not the main context as that allows the caller to still setup their @@ -269,6 +330,152 @@ void *_talloc_reference(const void *context, const void *ptr) return handle->ptr; } + +/* + internal talloc_free call +*/ +static inline int _talloc_free(void *ptr) +{ + struct talloc_chunk *tc; + + if (unlikely(ptr == NULL)) { + return -1; + } + + tc = talloc_chunk_from_ptr(ptr); + + if (unlikely(tc->refs)) { + int is_child; + /* check this is a reference from a child or grantchild + * back to it's parent or grantparent + * + * in that case we need to remove the reference and + * call another instance of talloc_free() on the current + * pointer. + */ + is_child = talloc_is_parent(tc->refs, ptr); + _talloc_free(tc->refs); + if (is_child) { + return _talloc_free(ptr); + } + return -1; + } + + if (unlikely(tc->flags & TALLOC_FLAG_LOOP)) { + /* we have a free loop - stop looping */ + return 0; + } + + if (unlikely(tc->destructor)) { + talloc_destructor_t d = tc->destructor; + if (d == (talloc_destructor_t)-1) { + return -1; + } + tc->destructor = (talloc_destructor_t)-1; + if (d(ptr) == -1) { + tc->destructor = d; + return -1; + } + tc->destructor = NULL; + } + + if (tc->parent) { + _TLIST_REMOVE(tc->parent->child, tc); + if (tc->parent->child) { + tc->parent->child->parent = tc->parent; + } + } else { + if (tc->prev) tc->prev->next = tc->next; + if (tc->next) tc->next->prev = tc->prev; + } + + tc->flags |= TALLOC_FLAG_LOOP; + + while (tc->child) { + /* we need to work out who will own an abandoned child + if it cannot be freed. In priority order, the first + choice is owner of any remaining reference to this + pointer, the second choice is our parent, and the + final choice is the null context. */ + void *child = TC_PTR_FROM_CHUNK(tc->child); + const void *new_parent = null_context; + if (unlikely(tc->child->refs)) { + struct talloc_chunk *p = talloc_parent_chunk(tc->child->refs); + if (p) new_parent = TC_PTR_FROM_CHUNK(p); + } + if (unlikely(_talloc_free(child) == -1)) { + if (new_parent == null_context) { + struct talloc_chunk *p = talloc_parent_chunk(ptr); + if (p) new_parent = TC_PTR_FROM_CHUNK(p); + } + talloc_steal(new_parent, child); + } + } + + tc->flags |= TALLOC_FLAG_FREE; + free(tc); + return 0; +} + +/* + move a lump of memory from one talloc context to another return the + ptr on success, or NULL if it could not be transferred. + passing NULL as ptr will always return NULL with no side effects. +*/ +void *_talloc_steal(const void *new_ctx, const void *ptr) +{ + struct talloc_chunk *tc, *new_tc; + + if (unlikely(!ptr)) { + return NULL; + } + + if (unlikely(new_ctx == NULL)) { + new_ctx = null_context; + } + + tc = talloc_chunk_from_ptr(ptr); + + if (unlikely(new_ctx == NULL)) { + if (tc->parent) { + _TLIST_REMOVE(tc->parent->child, tc); + if (tc->parent->child) { + tc->parent->child->parent = tc->parent; + } + } else { + if (tc->prev) tc->prev->next = tc->next; + if (tc->next) tc->next->prev = tc->prev; + } + + tc->parent = tc->next = tc->prev = NULL; + return discard_const_p(void, ptr); + } + + new_tc = talloc_chunk_from_ptr(new_ctx); + + if (unlikely(tc == new_tc || tc->parent == new_tc)) { + return discard_const_p(void, ptr); + } + + if (tc->parent) { + _TLIST_REMOVE(tc->parent->child, tc); + if (tc->parent->child) { + tc->parent->child->parent = tc->parent; + } + } else { + if (tc->prev) tc->prev->next = tc->next; + if (tc->next) tc->next->prev = tc->prev; + } + + tc->parent = new_tc; + if (new_tc->child) new_tc->child->parent = NULL; + _TLIST_ADD(new_tc->child, tc); + + return discard_const_p(void, ptr); +} + + + /* remove a secondary reference to a pointer. This undo's what talloc_reference() has done. The context and pointer arguments @@ -279,7 +486,7 @@ static int talloc_unreference(const void *context, const void *ptr) struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); struct talloc_reference_handle *h; - if (context == NULL) { + if (unlikely(context == NULL)) { context = null_context; } @@ -295,7 +502,7 @@ static int talloc_unreference(const void *context, const void *ptr) return -1; } - return talloc_free(h); + return _talloc_free(h); } /* @@ -332,7 +539,7 @@ int talloc_unlink(const void *context, void *ptr) tc_p = talloc_chunk_from_ptr(ptr); if (tc_p->refs == NULL) { - return talloc_free(ptr); + return _talloc_free(ptr); } new_p = talloc_parent_chunk(tc_p->refs); @@ -360,8 +567,8 @@ static const char *talloc_set_name_v(const void *ptr, const char *fmt, va_list a { struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); tc->name = talloc_vasprintf(ptr, fmt, ap); - if (tc->name) { - talloc_set_name_const(tc->name, ".name"); + if (likely(tc->name)) { + _talloc_set_name_const(tc->name, ".name"); } return tc->name; } @@ -379,15 +586,6 @@ const char *talloc_set_name(const void *ptr, const char *fmt, ...) return name; } -/* - more efficient way to add a name to a pointer - the name must point to a - true string constant -*/ -void talloc_set_name_const(const void *ptr, const char *name) -{ - struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); - tc->name = name; -} /* create a named talloc pointer. Any talloc pointer can be named, and @@ -400,15 +598,15 @@ void *talloc_named(const void *context, size_t size, const char *fmt, ...) void *ptr; const char *name; - ptr = _talloc(context, size); - if (ptr == NULL) return NULL; + ptr = __talloc(context, size); + if (unlikely(ptr == NULL)) return NULL; va_start(ap, fmt); name = talloc_set_name_v(ptr, fmt, ap); va_end(ap); - if (name == NULL) { - talloc_free(ptr); + if (unlikely(name == NULL)) { + _talloc_free(ptr); return NULL; } @@ -416,34 +614,15 @@ void *talloc_named(const void *context, size_t size, const char *fmt, ...) } /* - create a named talloc pointer. Any talloc pointer can be named, and - talloc_named() operates just like talloc() except that it allows you - to name the pointer. -*/ -void *talloc_named_const(const void *context, size_t size, const char *name) -{ - void *ptr; - - ptr = _talloc(context, size); - if (ptr == NULL) { - return NULL; - } - - talloc_set_name_const(ptr, name); - - return ptr; -} - -/* return the name of a talloc ptr, or "UNNAMED" */ const char *talloc_get_name(const void *ptr) { struct talloc_chunk *tc = talloc_chunk_from_ptr(ptr); - if (tc->name == TALLOC_MAGIC_REFERENCE) { + if (unlikely(tc->name == TALLOC_MAGIC_REFERENCE)) { return ".reference"; } - if (tc->name) { + if (likely(tc->name)) { return tc->name; } return "UNNAMED"; @@ -457,9 +636,9 @@ const char *talloc_get_name(const void *ptr) void *talloc_check_name(const void *ptr, const char *name) { const char *pname; - if (ptr == NULL) return NULL; + if (unlikely(ptr == NULL)) return NULL; pname = talloc_get_name(ptr); - if (pname == name || strcmp(pname, name) == 0) { + if (likely(pname == name || strcmp(pname, name) == 0)) { return discard_const_p(void, ptr); } return NULL; @@ -482,15 +661,15 @@ void *talloc_init(const char *fmt, ...) */ talloc_enable_null_tracking(); - ptr = _talloc(NULL, 0); - if (ptr == NULL) return NULL; + ptr = __talloc(NULL, 0); + if (unlikely(ptr == NULL)) return NULL; va_start(ap, fmt); name = talloc_set_name_v(ptr, fmt, ap); va_end(ap); - if (name == NULL) { - talloc_free(ptr); + if (unlikely(name == NULL)) { + _talloc_free(ptr); return NULL; } @@ -506,7 +685,7 @@ void talloc_free_children(void *ptr) { struct talloc_chunk *tc; - if (ptr == NULL) { + if (unlikely(ptr == NULL)) { return; } @@ -520,11 +699,11 @@ void talloc_free_children(void *ptr) final choice is the null context. */ void *child = TC_PTR_FROM_CHUNK(tc->child); const void *new_parent = null_context; - if (tc->child->refs) { + if (unlikely(tc->child->refs)) { struct talloc_chunk *p = talloc_parent_chunk(tc->child->refs); if (p) new_parent = TC_PTR_FROM_CHUNK(p); } - if (talloc_free(child) == -1) { + if (unlikely(_talloc_free(child) == -1)) { if (new_parent == null_context) { struct talloc_chunk *p = talloc_parent_chunk(ptr); if (p) new_parent = TC_PTR_FROM_CHUNK(p); @@ -535,6 +714,32 @@ void talloc_free_children(void *ptr) } /* + Allocate a bit of memory as a child of an existing pointer +*/ +void *_talloc(const void *context, size_t size) +{ + return __talloc(context, size); +} + +/* + externally callable talloc_set_name_const() +*/ +void talloc_set_name_const(const void *ptr, const char *name) +{ + _talloc_set_name_const(ptr, name); +} + +/* + create a named talloc pointer. Any talloc pointer can be named, and + talloc_named() operates just like talloc() except that it allows you + to name the pointer. +*/ +void *talloc_named_const(const void *context, size_t size, const char *name) +{ + return _talloc_named_const(context, size, name); +} + +/* free a talloc pointer. This also frees all child pointers of this pointer recursively @@ -544,68 +749,7 @@ void talloc_free_children(void *ptr) */ int talloc_free(void *ptr) { - struct talloc_chunk *tc; - int old_errno; - - if (ptr == NULL) { - return -1; - } - - tc = talloc_chunk_from_ptr(ptr); - - if (tc->refs) { - int is_child; - /* check this is a reference from a child or grantchild - * back to it's parent or grantparent - * - * in that case we need to remove the reference and - * call another instance of talloc_free() on the current - * pointer. - */ - is_child = talloc_is_parent(tc->refs, ptr); - talloc_free(tc->refs); - if (is_child) { - return talloc_free(ptr); - } - return -1; - } - - if (tc->flags & TALLOC_FLAG_LOOP) { - /* we have a free loop - stop looping */ - return 0; - } - - if (tc->destructor) { - talloc_destructor_t d = tc->destructor; - if (d == (talloc_destructor_t)-1) { - return -1; - } - tc->destructor = (talloc_destructor_t)-1; - if (d(ptr) == -1) { - tc->destructor = d; - return -1; - } - tc->destructor = NULL; - } - - if (tc->parent) { - _TLIST_REMOVE(tc->parent->child, tc); - if (tc->parent->child) { - tc->parent->child->parent = tc->parent; - } - } else { - if (tc->prev) tc->prev->next = tc->next; - if (tc->next) tc->next->prev = tc->prev; - } - - tc->flags |= TALLOC_FLAG_LOOP; - talloc_free_children(ptr); - - tc->flags |= TALLOC_FLAG_FREE; - old_errno = errno; - free(tc); - errno = old_errno; - return 0; + return _talloc_free(ptr); } @@ -620,24 +764,24 @@ void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *n void *new_ptr; /* size zero is equivalent to free() */ - if (size == 0) { - talloc_free(ptr); + if (unlikely(size == 0)) { + _talloc_free(ptr); return NULL; } - if (size >= MAX_TALLOC_SIZE) { + if (unlikely(size >= MAX_TALLOC_SIZE)) { return NULL; } /* realloc(NULL) is equavalent to malloc() */ if (ptr == NULL) { - return talloc_named_const(context, size, name); + return _talloc_named_const(context, size, name); } tc = talloc_chunk_from_ptr(ptr); /* don't allow realloc on referenced pointers */ - if (tc->refs) { + if (unlikely(tc->refs)) { return NULL; } @@ -653,7 +797,7 @@ void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *n #else new_ptr = realloc(tc, size + TC_HDR_SIZE); #endif - if (!new_ptr) { + if (unlikely(!new_ptr)) { tc->flags &= ~TALLOC_FLAG_FREE; return NULL; } @@ -675,68 +819,11 @@ void *_talloc_realloc(const void *context, void *ptr, size_t size, const char *n } tc->size = size; - talloc_set_name_const(TC_PTR_FROM_CHUNK(tc), name); + _talloc_set_name_const(TC_PTR_FROM_CHUNK(tc), name); return TC_PTR_FROM_CHUNK(tc); } -/* - move a lump of memory from one talloc context to another return the - ptr on success, or NULL if it could not be transferred. - passing NULL as ptr will always return NULL with no side effects. -*/ -void *_talloc_steal(const void *new_ctx, const void *ptr) -{ - struct talloc_chunk *tc, *new_tc; - - if (!ptr) { - return NULL; - } - - if (new_ctx == NULL) { - new_ctx = null_context; - } - - tc = talloc_chunk_from_ptr(ptr); - - if (new_ctx == NULL) { - if (tc->parent) { - _TLIST_REMOVE(tc->parent->child, tc); - if (tc->parent->child) { - tc->parent->child->parent = tc->parent; - } - } else { - if (tc->prev) tc->prev->next = tc->next; - if (tc->next) tc->next->prev = tc->prev; - } - - tc->parent = tc->next = tc->prev = NULL; - return discard_const_p(void, ptr); - } - - new_tc = talloc_chunk_from_ptr(new_ctx); - - if (tc == new_tc || tc->parent == new_tc) { - return discard_const_p(void, ptr); - } - - if (tc->parent) { - _TLIST_REMOVE(tc->parent->child, tc); - if (tc->parent->child) { - tc->parent->child->parent = tc->parent; - } - } else { - if (tc->prev) tc->prev->next = tc->next; - if (tc->next) tc->next->prev = tc->prev; - } - - tc->parent = new_tc; - if (new_tc->child) new_tc->child->parent = NULL; - _TLIST_ADD(new_tc->child, tc); - - return discard_const_p(void, ptr); -} - /* a wrapper around talloc_steal() for situations where you are moving a pointer between two structures, and want the old pointer to be set to NULL @@ -880,12 +967,12 @@ static void talloc_report_depth_FILE_helper(const void *ptr, int depth, int max_ return; } - fprintf(f, "%*s%-30s contains %6lu bytes in %3lu blocks (ref %d)\n", + fprintf(f, "%*s%-30s contains %6lu bytes in %3lu blocks (ref %d) %p\n", depth*4, "", name, (unsigned long)talloc_total_size(ptr), (unsigned long)talloc_total_blocks(ptr), - (int)talloc_reference_count(ptr)); + (int)talloc_reference_count(ptr), ptr); #if 0 fprintf(f, "content: "); @@ -956,7 +1043,7 @@ static void talloc_report_null_full(void) void talloc_enable_null_tracking(void) { if (null_context == NULL) { - null_context = talloc_named_const(NULL, 0, "null_context"); + null_context = _talloc_named_const(NULL, 0, "null_context"); } } @@ -965,7 +1052,7 @@ void talloc_enable_null_tracking(void) */ void talloc_disable_null_tracking(void) { - talloc_free(null_context); + _talloc_free(null_context); null_context = NULL; } @@ -992,7 +1079,7 @@ void talloc_enable_leak_report_full(void) */ void *_talloc_zero(const void *ctx, size_t size, const char *name) { - void *p = talloc_named_const(ctx, size, name); + void *p = _talloc_named_const(ctx, size, name); if (p) { memset(p, '\0', size); @@ -1007,9 +1094,9 @@ void *_talloc_zero(const void *ctx, size_t size, const char *name) */ void *_talloc_memdup(const void *t, const void *p, size_t size, const char *name) { - void *newp = talloc_named_const(t, size, name); + void *newp = _talloc_named_const(t, size, name); - if (newp) { + if (likely(newp)) { memcpy(newp, p, size); } @@ -1026,8 +1113,8 @@ char *talloc_strdup(const void *t, const char *p) return NULL; } ret = (char *)talloc_memdup(t, p, strlen(p) + 1); - if (ret) { - talloc_set_name_const(ret, ret); + if (likely(ret)) { + _talloc_set_name_const(ret, ret); } return ret; } @@ -1066,11 +1153,11 @@ char *talloc_strndup(const void *t, const char *p, size_t n) for (len=0; len<n && p[len]; len++) ; - ret = (char *)_talloc(t, len + 1); + ret = (char *)__talloc(t, len + 1); if (!ret) { return NULL; } memcpy(ret, p, len); ret[len] = 0; - talloc_set_name_const(ret, ret); + _talloc_set_name_const(ret, ret); return ret; } @@ -1096,11 +1183,11 @@ char *talloc_vasprintf(const void *t, const char *fmt, va_list ap) return NULL; } - ret = (char *)_talloc(t, len+1); + ret = (char *)__talloc(t, len+1); if (ret) { va_copy(ap2, ap); vsnprintf(ret, len+1, fmt, ap2); - talloc_set_name_const(ret, ret); + _talloc_set_name_const(ret, ret); } return ret; @@ -1160,7 +1247,7 @@ char *talloc_vasprintf_append(char *s, const char *fmt, va_list ap) va_copy(ap2, ap); vsnprintf(s+s_len, len+1, fmt, ap2); - talloc_set_name_const(s, s); + _talloc_set_name_const(s, s); return s; } @@ -1188,7 +1275,7 @@ void *_talloc_array(const void *ctx, size_t el_size, unsigned count, const char if (count >= MAX_TALLOC_SIZE/el_size) { return NULL; } - return talloc_named_const(ctx, el_size * count, name); + return _talloc_named_const(ctx, el_size * count, name); } /* @@ -1233,7 +1320,7 @@ static int talloc_autofree_destructor(void *ptr) static void talloc_autofree(void) { - talloc_free(autofree_context); + _talloc_free(autofree_context); } /* @@ -1243,7 +1330,7 @@ static void talloc_autofree(void) void *talloc_autofree_context(void) { if (autofree_context == NULL) { - autofree_context = talloc_named_const(NULL, 0, "autofree_context"); + autofree_context = _talloc_named_const(NULL, 0, "autofree_context"); talloc_set_destructor(autofree_context, talloc_autofree_destructor); atexit(talloc_autofree); } @@ -1307,6 +1394,7 @@ void talloc_show_parents(const void *context, FILE *file) tc = tc->parent; } } + fflush(file); } /* |