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author | Andrew Tridgell <tridge@samba.org> | 2003-08-13 01:53:07 +0000 |
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committer | Andrew Tridgell <tridge@samba.org> | 2003-08-13 01:53:07 +0000 |
commit | cc3a6ea9920f30925a678c566b4af417da6d455b (patch) | |
tree | 60015a1a5f4b47ac3d133bdbbe32b75815595d4d /source4/lib/talloc.c | |
parent | 4d1f9d1def5bf5fea64722626028d94da49c654c (diff) | |
parent | ef2e26c91b80556af033d3335e55f5dfa6fff31d (diff) | |
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This commit was generated by cvs2svn to compensate for changes in r30,
which included commits to RCS files with non-trunk default branches.
(This used to be commit 3a69cffb062d4f1238b8cae10481c1f2ea4d3d8b)
Diffstat (limited to 'source4/lib/talloc.c')
-rw-r--r-- | source4/lib/talloc.c | 515 |
1 files changed, 515 insertions, 0 deletions
diff --git a/source4/lib/talloc.c b/source4/lib/talloc.c new file mode 100644 index 0000000000..83a99d8071 --- /dev/null +++ b/source4/lib/talloc.c @@ -0,0 +1,515 @@ +/* + Samba Unix SMB/CIFS implementation. + Samba temporary memory allocation functions + Copyright (C) Andrew Tridgell 2000 + Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +/** + @defgroup talloc Simple memory allocator + @{ + + This is a very simple temporary memory allocator. To use it do the following: + + 1) when you first want to allocate a pool of meomry use + talloc_init() and save the resulting context pointer somewhere + + 2) to allocate memory use talloc() + + 3) when _all_ of the memory allocated using this context is no longer needed + use talloc_destroy() + + talloc does not zero the memory. It guarantees memory of a + TALLOC_ALIGN alignment + + @sa talloc.h +*/ + +/** + * @todo We could allocate both the talloc_chunk structure, and the + * memory it contains all in one allocation, which might be a bit + * faster and perhaps use less memory overhead. + * + * That smells like a premature optimization, though. -- mbp + **/ + +/** + * If you want testing for memory corruption, link with dmalloc or use + * Insure++. It doesn't seem useful to duplicate them here. + **/ + +#include "includes.h" + +struct talloc_chunk { + struct talloc_chunk *next; + size_t size; + void *ptr; +}; + + +struct talloc_ctx { + struct talloc_chunk *list; + off_t total_alloc_size; + + /** The name recorded for this pool, if any. Should describe + * the purpose for which it was allocated. The string is + * allocated within the pool. **/ + char *name; + + /** Pointer to the next allocate talloc pool, so that we can + * summarize all talloc memory usage. **/ + struct talloc_ctx *next, *prev; +}; + + +/** + * Start of linked list of all talloc pools. + * + * @todo We should turn the global list off when using Insure++, + * otherwise all the memory will be seen as still reachable. + **/ +static TALLOC_CTX *list_head; + +/** + * Add to the global list + **/ +static void talloc_enroll(TALLOC_CTX *t) +{ +#if 0 + /* disabled enrole/disenrole until we have __thread support */ + MUTEX_LOCK_BY_ID(MUTEX_TALLOC); + DLIST_ADD(list_head, t); + MUTEX_UNLOCK_BY_ID(MUTEX_TALLOC); +#endif +} + + +static void talloc_disenroll(TALLOC_CTX *t) +{ +#if 0 + /* disabled enrole/disenrole until we have __thread support */ + MUTEX_LOCK_BY_ID(MUTEX_TALLOC); + DLIST_REMOVE(list_head, t); + MUTEX_UNLOCK_BY_ID(MUTEX_TALLOC); +#endif +} + + +/** Create a new talloc context. **/ +static TALLOC_CTX *talloc_init_internal(void) +{ + TALLOC_CTX *t; + + t = (TALLOC_CTX *)malloc(sizeof(TALLOC_CTX)); + if (t) { + t->list = NULL; + t->total_alloc_size = 0; + t->name = NULL; + talloc_enroll(t); + } + + return t; +} + + + +/** + * Create a new talloc context, with a name specifying its purpose. + **/ + + TALLOC_CTX *talloc_init(char const *fmt, ...) +{ + TALLOC_CTX *t; + va_list ap; + + t = talloc_init_internal(); + if (t && fmt) { + /* + * t->name must not be talloced. + * as destroying the pool would destroy it. JRA. + */ + t->name = NULL; + va_start(ap, fmt); + vasprintf(&t->name, fmt, ap); + va_end(ap); + if (!t->name) { + talloc_destroy(t); + t = NULL; + } + } + + return t; +} + + +/** Allocate a bit of memory from the specified pool **/ +void *talloc(TALLOC_CTX *t, size_t size) +{ + void *p; + struct talloc_chunk *tc; + + if (!t || size == 0) return NULL; + + p = malloc(size); + if (p) { + tc = malloc(sizeof(*tc)); + if (tc) { + tc->ptr = p; + tc->size = size; + tc->next = t->list; + t->list = tc; + t->total_alloc_size += size; + } + else { + SAFE_FREE(p); + } + } + return p; +} + +/** A talloc version of realloc */ +void *talloc_realloc(TALLOC_CTX *t, void *ptr, size_t size) +{ + struct talloc_chunk *tc; + void *new_ptr; + + /* size zero is equivalent to free() */ + if (!t || size == 0) + return NULL; + + /* realloc(NULL) is equavalent to malloc() */ + if (ptr == NULL) + return talloc(t, size); + + for (tc=t->list; tc; tc=tc->next) { + if (tc->ptr == ptr) { + new_ptr = Realloc(ptr, size); + if (new_ptr) { + t->total_alloc_size += (size - tc->size); + tc->size = size; + tc->ptr = new_ptr; + } + return new_ptr; + } + } + return NULL; +} + +/** Destroy all the memory allocated inside @p t, but not @p t + * itself. */ +void talloc_destroy_pool(TALLOC_CTX *t) +{ + struct talloc_chunk *c; + + if (!t) + return; + + while (t->list) { + c = t->list->next; + SAFE_FREE(t->list->ptr); + SAFE_FREE(t->list); + t->list = c; + } + + t->total_alloc_size = 0; +} + +/** Destroy a whole pool including the context */ +void talloc_destroy(TALLOC_CTX *t) +{ + if (!t) + return; + + talloc_destroy_pool(t); + talloc_disenroll(t); + SAFE_FREE(t->name); + SAFE_FREE(t); +} + +/** Return the current total size of the pool. */ +size_t talloc_pool_size(TALLOC_CTX *t) +{ + return t->total_alloc_size; +} + +const char *talloc_pool_name(TALLOC_CTX const *t) +{ + if (t) return t->name; + + return NULL; +} + + +/** talloc and zero memory. */ +void *talloc_zero(TALLOC_CTX *t, size_t size) +{ + void *p = talloc(t, size); + + if (p) { + memset(p, '\0', size); + } + + return p; +} + + +/** memdup with a talloc. */ +void *talloc_memdup(TALLOC_CTX *t, const void *p, size_t size) +{ + void *newp = talloc(t,size); + + if (newp) { + memcpy(newp, p, size); + } + + return newp; +} + +/** strdup with a talloc */ +char *talloc_strdup(TALLOC_CTX *t, const char *p) +{ + return talloc_memdup(t, p, strlen(p) + 1); +} + +/** strndup with a talloc */ +char *talloc_strndup(TALLOC_CTX *t, const char *p, size_t n) +{ + size_t len = strnlen(p, n); + char *ret; + + ret = talloc(t, len + 1); + if (!ret) { return NULL; } + memcpy(ret, p, len); + ret[len] = 0; + return ret; +} + +/** strdup_w with a talloc */ +smb_ucs2_t *talloc_strdup_w(TALLOC_CTX *t, const smb_ucs2_t *p) +{ + if (p) + return talloc_memdup(t, p, (strlen_w(p) + 1) * sizeof(smb_ucs2_t)); + return NULL; +} + +/** + * Perform string formatting, and return a pointer to newly allocated + * memory holding the result, inside a memory pool. + **/ + char *talloc_asprintf(TALLOC_CTX *t, const char *fmt, ...) +{ + va_list ap; + char *ret; + + va_start(ap, fmt); + ret = talloc_vasprintf(t, fmt, ap); + va_end(ap); + return ret; +} + + + char *talloc_vasprintf(TALLOC_CTX *t, const char *fmt, va_list ap) +{ + int len; + char *ret; + va_list ap2; + + VA_COPY(ap2, ap); + + len = vsnprintf(NULL, 0, fmt, ap2); + + ret = talloc(t, len+1); + if (ret) { + VA_COPY(ap2, ap); + vsnprintf(ret, len+1, fmt, ap2); + } + + return ret; +} + + +/** + * Realloc @p s to append the formatted result of @p fmt and return @p + * s, which may have moved. Good for gradually accumulating output + * into a string buffer. + **/ + char *talloc_asprintf_append(TALLOC_CTX *t, char *s, + const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + s = talloc_vasprintf_append(t, s, fmt, ap); + va_end(ap); + return s; +} + + + +/** + * Realloc @p s to append the formatted result of @p fmt and @p ap, + * and return @p s, which may have moved. Good for gradually + * accumulating output into a string buffer. + **/ + char *talloc_vasprintf_append(TALLOC_CTX *t, char *s, + const char *fmt, va_list ap) +{ + int len, s_len; + va_list ap2; + + VA_COPY(ap2, ap); + + s_len = strlen(s); + len = vsnprintf(NULL, 0, fmt, ap2); + + s = talloc_realloc(t, s, s_len + len+1); + if (!s) return NULL; + + VA_COPY(ap2, ap); + + vsnprintf(s+s_len, len+1, fmt, ap2); + + return s; +} + + +/** + * Return a human-readable description of all talloc memory usage. + * The result is allocated from @p t. + **/ +char *talloc_describe_all(TALLOC_CTX *rt) +{ + int n_pools = 0, total_chunks = 0; + size_t total_bytes = 0; + TALLOC_CTX *it; + char *s; + + if (!rt) return NULL; + + s = talloc_asprintf(rt, "global talloc allocations in pid: %u\n", + (unsigned) getpid()); + s = talloc_asprintf_append(rt, s, "%-40s %8s %8s\n", + "name", "chunks", "bytes"); + s = talloc_asprintf_append(rt, s, "%-40s %8s %8s\n", + "----------------------------------------", + "--------", + "--------"); + MUTEX_LOCK_BY_ID(MUTEX_TALLOC); + + for (it = list_head; it; it = it->next) { + size_t bytes; + int n_chunks; + fstring what; + + n_pools++; + + talloc_get_allocation(it, &bytes, &n_chunks); + + if (it->name) + fstrcpy(what, it->name); + else + slprintf(what, sizeof(what), "@%p", it); + + s = talloc_asprintf_append(rt, s, "%-40s %8u %8u\n", + what, + (unsigned) n_chunks, + (unsigned) bytes); + total_bytes += bytes; + total_chunks += n_chunks; + } + + MUTEX_UNLOCK_BY_ID(MUTEX_TALLOC); + + s = talloc_asprintf_append(rt, s, "%-40s %8s %8s\n", + "----------------------------------------", + "--------", + "--------"); + + s = talloc_asprintf_append(rt, s, "%-40s %8u %8u\n", + "TOTAL", + (unsigned) total_chunks, (unsigned) total_bytes); + + return s; +} + + + +/** + * Return an estimated memory usage for the specified pool. This does + * not include memory used by the underlying malloc implementation. + **/ +void talloc_get_allocation(TALLOC_CTX *t, + size_t *total_bytes, + int *n_chunks) +{ + struct talloc_chunk *chunk; + + if (t) { + *total_bytes = 0; + *n_chunks = 0; + + for (chunk = t->list; chunk; chunk = chunk->next) { + n_chunks[0]++; + *total_bytes += chunk->size; + } + } +} + + +/* + move a lump of memory from one talloc context to another + return the ptr on success, or NULL if it could not be found + in the old context or could not be transferred +*/ +const void *talloc_steal(TALLOC_CTX *old_ctx, TALLOC_CTX *new_ctx, const void *ptr) +{ + struct talloc_chunk *tc, *tc2; + + if (!ptr || !old_ctx->list) return NULL; + + /* as a special case, see if its the first element in the + list */ + if (old_ctx->list->ptr == ptr) { + tc = old_ctx->list; + old_ctx->list = old_ctx->list->next; + tc->next = new_ctx->list; + new_ctx->list = tc; + old_ctx->total_alloc_size -= tc->size; + new_ctx->total_alloc_size += tc->size; + return ptr; + } + + /* find it in the old context */ + for (tc=old_ctx->list; tc->next; tc=tc->next) { + if (tc->next->ptr == ptr) break; + } + + if (!tc->next) return NULL; + + /* move it to the new context */ + tc2 = tc->next; + tc->next = tc->next->next; + tc2->next = new_ctx->list; + new_ctx->list = tc2; + old_ctx->total_alloc_size -= tc2->size; + new_ctx->total_alloc_size += tc2->size; + + return ptr; +} + + +/** @} */ |