+++ /dev/null
-/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
-/* dbus-memory.c D-Bus memory handling
- *
- * Copyright (C) 2002, 2003 Red Hat Inc.
- *
- * Licensed under the Academic Free License version 2.1
- *
- * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- */
-
-#include "dbus-memory.h"
-#include "dbus-internals.h"
-#include "dbus-sysdeps.h"
-#include "dbus-list.h"
-#include <stdlib.h>
-
-/**
- * @defgroup DBusMemory Memory Allocation
- * @ingroup DBus
- * @brief dbus_malloc(), dbus_free(), etc.
- *
- * Functions and macros related to allocating and releasing
- * blocks of memory.
- *
- */
-
-/**
- * @defgroup DBusMemoryInternals Memory allocation implementation details
- * @ingroup DBusInternals
- * @brief internals of dbus_malloc() etc.
- *
- * Implementation details related to allocating and releasing blocks
- * of memory.
- */
-
-/**
- * @addtogroup DBusMemory
- *
- * @{
- */
-
-/**
- * @def dbus_new
- *
- * Safe macro for using dbus_malloc(). Accepts the type
- * to allocate and the number of type instances to
- * allocate as arguments, and returns a memory block
- * cast to the desired type, instead of as a void*.
- *
- * @param type type name to allocate
- * @param count number of instances in the allocated array
- * @returns the new memory block or #NULL on failure
- */
-
-/**
- * @def dbus_new0
- *
- * Safe macro for using dbus_malloc0(). Accepts the type
- * to allocate and the number of type instances to
- * allocate as arguments, and returns a memory block
- * cast to the desired type, instead of as a void*.
- * The allocated array is initialized to all-bits-zero.
- *
- * @param type type name to allocate
- * @param count number of instances in the allocated array
- * @returns the new memory block or #NULL on failure
- */
-
-/**
- * @typedef DBusFreeFunction
- *
- * The type of a function which frees a block of memory.
- *
- * @param memory the memory to free
- */
-
-/** @} */ /* end of public API docs */
-
-/**
- * @addtogroup DBusMemoryInternals
- *
- * @{
- */
-
-#ifdef DBUS_BUILD_TESTS
-static dbus_bool_t debug_initialized = FALSE;
-static int fail_nth = -1;
-static size_t fail_size = 0;
-static int fail_alloc_counter = _DBUS_INT_MAX;
-static int n_failures_per_failure = 1;
-static int n_failures_this_failure = 0;
-static dbus_bool_t guards = FALSE;
-static dbus_bool_t disable_mem_pools = FALSE;
-static dbus_bool_t backtrace_on_fail_alloc = FALSE;
-static DBusAtomic n_blocks_outstanding = {0};
-
-/** value stored in guard padding for debugging buffer overrun */
-#define GUARD_VALUE 0xdeadbeef
-/** size of the information about the block stored in guard mode */
-#define GUARD_INFO_SIZE 8
-/** size of the GUARD_VALUE-filled padding after the header info */
-#define GUARD_START_PAD 16
-/** size of the GUARD_VALUE-filled padding at the end of the block */
-#define GUARD_END_PAD 16
-/** size of stuff at start of block */
-#define GUARD_START_OFFSET (GUARD_START_PAD + GUARD_INFO_SIZE)
-/** total extra size over the requested allocation for guard stuff */
-#define GUARD_EXTRA_SIZE (GUARD_START_OFFSET + GUARD_END_PAD)
-
-static void
-_dbus_initialize_malloc_debug (void)
-{
- if (!debug_initialized)
- {
- debug_initialized = TRUE;
-
- if (_dbus_getenv ("DBUS_MALLOC_FAIL_NTH") != NULL)
- {
- fail_nth = atoi (_dbus_getenv ("DBUS_MALLOC_FAIL_NTH"));
- fail_alloc_counter = fail_nth;
- _dbus_verbose ("Will fail malloc every %d times\n", fail_nth);
- }
-
- if (_dbus_getenv ("DBUS_MALLOC_FAIL_GREATER_THAN") != NULL)
- {
- fail_size = atoi (_dbus_getenv ("DBUS_MALLOC_FAIL_GREATER_THAN"));
- _dbus_verbose ("Will fail mallocs over %ld bytes\n",
- (long) fail_size);
- }
-
- if (_dbus_getenv ("DBUS_MALLOC_GUARDS") != NULL)
- {
- guards = TRUE;
- _dbus_verbose ("Will use malloc guards\n");
- }
-
- if (_dbus_getenv ("DBUS_DISABLE_MEM_POOLS") != NULL)
- {
- disable_mem_pools = TRUE;
- _dbus_verbose ("Will disable memory pools\n");
- }
-
- if (_dbus_getenv ("DBUS_MALLOC_BACKTRACES") != NULL)
- {
- backtrace_on_fail_alloc = TRUE;
- _dbus_verbose ("Will backtrace on failing a malloc\n");
- }
- }
-}
-
-/**
- * Whether to turn off mem pools, useful for leak checking.
- *
- * @returns #TRUE if mempools should not be used.
- */
-dbus_bool_t
-_dbus_disable_mem_pools (void)
-{
- _dbus_initialize_malloc_debug ();
- return disable_mem_pools;
-}
-
-/**
- * Sets the number of allocations until we simulate a failed
- * allocation. If set to 0, the next allocation to run
- * fails; if set to 1, one succeeds then the next fails; etc.
- * Set to _DBUS_INT_MAX to not fail anything.
- *
- * @param until_next_fail number of successful allocs before one fails
- */
-void
-_dbus_set_fail_alloc_counter (int until_next_fail)
-{
- _dbus_initialize_malloc_debug ();
-
- fail_alloc_counter = until_next_fail;
-
-#if 0
- _dbus_verbose ("Set fail alloc counter = %d\n", fail_alloc_counter);
-#endif
-}
-
-/**
- * Gets the number of successful allocs until we'll simulate
- * a failed alloc.
- *
- * @returns current counter value
- */
-int
-_dbus_get_fail_alloc_counter (void)
-{
- _dbus_initialize_malloc_debug ();
-
- return fail_alloc_counter;
-}
-
-/**
- * Sets how many mallocs to fail when the fail alloc counter reaches
- * 0.
- *
- * @param failures_per_failure number to fail
- */
-void
-_dbus_set_fail_alloc_failures (int failures_per_failure)
-{
- n_failures_per_failure = failures_per_failure;
-}
-
-/**
- * Gets the number of failures we'll have when the fail malloc
- * counter reaches 0.
- *
- * @returns number of failures planned
- */
-int
-_dbus_get_fail_alloc_failures (void)
-{
- return n_failures_per_failure;
-}
-
-#ifdef DBUS_BUILD_TESTS
-/**
- * Called when about to alloc some memory; if
- * it returns #TRUE, then the allocation should
- * fail. If it returns #FALSE, then the allocation
- * should not fail.
- *
- * @returns #TRUE if this alloc should fail
- */
-dbus_bool_t
-_dbus_decrement_fail_alloc_counter (void)
-{
- _dbus_initialize_malloc_debug ();
-
- if (fail_alloc_counter <= 0)
- {
- if (backtrace_on_fail_alloc)
- _dbus_print_backtrace ();
-
- _dbus_verbose ("failure %d\n", n_failures_this_failure);
-
- n_failures_this_failure += 1;
- if (n_failures_this_failure >= n_failures_per_failure)
- {
- if (fail_nth >= 0)
- fail_alloc_counter = fail_nth;
- else
- fail_alloc_counter = _DBUS_INT_MAX;
-
- n_failures_this_failure = 0;
-
- _dbus_verbose ("reset fail alloc counter to %d\n", fail_alloc_counter);
- }
-
- return TRUE;
- }
- else
- {
- fail_alloc_counter -= 1;
- return FALSE;
- }
-}
-#endif /* DBUS_BUILD_TESTS */
-
-/**
- * Get the number of outstanding malloc()'d blocks.
- *
- * @returns number of blocks
- */
-int
-_dbus_get_malloc_blocks_outstanding (void)
-{
- return n_blocks_outstanding.value;
-}
-
-/**
- * Where the block came from.
- */
-typedef enum
-{
- SOURCE_UNKNOWN,
- SOURCE_MALLOC,
- SOURCE_REALLOC,
- SOURCE_MALLOC_ZERO,
- SOURCE_REALLOC_NULL
-} BlockSource;
-
-static const char*
-source_string (BlockSource source)
-{
- switch (source)
- {
- case SOURCE_UNKNOWN:
- return "unknown";
- case SOURCE_MALLOC:
- return "malloc";
- case SOURCE_REALLOC:
- return "realloc";
- case SOURCE_MALLOC_ZERO:
- return "malloc0";
- case SOURCE_REALLOC_NULL:
- return "realloc(NULL)";
- }
- _dbus_assert_not_reached ("Invalid malloc block source ID");
- return "invalid!";
-}
-
-static void
-check_guards (void *free_block,
- dbus_bool_t overwrite)
-{
- if (free_block != NULL)
- {
- unsigned char *block = ((unsigned char*)free_block) - GUARD_START_OFFSET;
- size_t requested_bytes = *(dbus_uint32_t*)block;
- BlockSource source = *(dbus_uint32_t*)(block + 4);
- unsigned int i;
- dbus_bool_t failed;
-
- failed = FALSE;
-
-#if 0
- _dbus_verbose ("Checking %d bytes request from source %s\n",
- requested_bytes, source_string (source));
-#endif
-
- i = GUARD_INFO_SIZE;
- while (i < GUARD_START_OFFSET)
- {
- dbus_uint32_t value = *(dbus_uint32_t*) &block[i];
- if (value != GUARD_VALUE)
- {
- _dbus_warn ("Block of %lu bytes from %s had start guard value 0x%ux at %d expected 0x%x\n",
- (long) requested_bytes, source_string (source),
- value, i, GUARD_VALUE);
- failed = TRUE;
- }
-
- i += 4;
- }
-
- i = GUARD_START_OFFSET + requested_bytes;
- while (i < (GUARD_START_OFFSET + requested_bytes + GUARD_END_PAD))
- {
- dbus_uint32_t value = *(dbus_uint32_t*) &block[i];
- if (value != GUARD_VALUE)
- {
- _dbus_warn ("Block of %lu bytes from %s had end guard value 0x%ux at %d expected 0x%x\n",
- (long) requested_bytes, source_string (source),
- value, i, GUARD_VALUE);
- failed = TRUE;
- }
-
- i += 4;
- }
-
- /* set memory to anything but nul bytes */
- if (overwrite)
- memset (free_block, 'g', requested_bytes);
-
- if (failed)
- _dbus_assert_not_reached ("guard value corruption");
- }
-}
-
-static void*
-set_guards (void *real_block,
- size_t requested_bytes,
- BlockSource source)
-{
- unsigned char *block = real_block;
- unsigned int i;
-
- if (block == NULL)
- return NULL;
-
- _dbus_assert (GUARD_START_OFFSET + GUARD_END_PAD == GUARD_EXTRA_SIZE);
-
- *((dbus_uint32_t*)block) = requested_bytes;
- *((dbus_uint32_t*)(block + 4)) = source;
-
- i = GUARD_INFO_SIZE;
- while (i < GUARD_START_OFFSET)
- {
- (*(dbus_uint32_t*) &block[i]) = GUARD_VALUE;
-
- i += 4;
- }
-
- i = GUARD_START_OFFSET + requested_bytes;
- while (i < (GUARD_START_OFFSET + requested_bytes + GUARD_END_PAD))
- {
- (*(dbus_uint32_t*) &block[i]) = GUARD_VALUE;
-
- i += 4;
- }
-
- check_guards (block + GUARD_START_OFFSET, FALSE);
-
- return block + GUARD_START_OFFSET;
-}
-
-#endif
-
-/** @} */ /* End of internals docs */
-
-
-/**
- * @addtogroup DBusMemory
- *
- * @{
- */
-
-/**
- * Allocates the given number of bytes, as with standard
- * malloc(). Guaranteed to return #NULL if bytes is zero
- * on all platforms. Returns #NULL if the allocation fails.
- * The memory must be released with dbus_free().
- *
- * dbus_malloc() memory is NOT safe to free with regular free() from
- * the C library. Free it with dbus_free() only.
- *
- * @param bytes number of bytes to allocate
- * @return allocated memory, or #NULL if the allocation fails.
- */
-void*
-dbus_malloc (size_t bytes)
-{
-#ifdef DBUS_BUILD_TESTS
- _dbus_initialize_malloc_debug ();
-
- if (_dbus_decrement_fail_alloc_counter ())
- {
- _dbus_verbose (" FAILING malloc of %ld bytes\n", (long) bytes);
- return NULL;
- }
-#endif
-
- if (bytes == 0) /* some system mallocs handle this, some don't */
- return NULL;
-#ifdef DBUS_BUILD_TESTS
- else if (fail_size != 0 && bytes > fail_size)
- return NULL;
- else if (guards)
- {
- void *block;
-
- block = malloc (bytes + GUARD_EXTRA_SIZE);
- if (block)
- _dbus_atomic_inc (&n_blocks_outstanding);
-
- return set_guards (block, bytes, SOURCE_MALLOC);
- }
-#endif
- else
- {
- void *mem;
- mem = malloc (bytes);
-#ifdef DBUS_BUILD_TESTS
- if (mem)
- _dbus_atomic_inc (&n_blocks_outstanding);
-#endif
- return mem;
- }
-}
-
-/**
- * Allocates the given number of bytes, as with standard malloc(), but
- * all bytes are initialized to zero as with calloc(). Guaranteed to
- * return #NULL if bytes is zero on all platforms. Returns #NULL if the
- * allocation fails. The memory must be released with dbus_free().
- *
- * dbus_malloc0() memory is NOT safe to free with regular free() from
- * the C library. Free it with dbus_free() only.
- *
- * @param bytes number of bytes to allocate
- * @return allocated memory, or #NULL if the allocation fails.
- */
-void*
-dbus_malloc0 (size_t bytes)
-{
-#ifdef DBUS_BUILD_TESTS
- _dbus_initialize_malloc_debug ();
-
- if (_dbus_decrement_fail_alloc_counter ())
- {
- _dbus_verbose (" FAILING malloc0 of %ld bytes\n", (long) bytes);
-
- return NULL;
- }
-#endif
-
- if (bytes == 0)
- return NULL;
-#ifdef DBUS_BUILD_TESTS
- else if (fail_size != 0 && bytes > fail_size)
- return NULL;
- else if (guards)
- {
- void *block;
-
- block = calloc (bytes + GUARD_EXTRA_SIZE, 1);
- if (block)
- _dbus_atomic_inc (&n_blocks_outstanding);
- return set_guards (block, bytes, SOURCE_MALLOC_ZERO);
- }
-#endif
- else
- {
- void *mem;
- mem = calloc (bytes, 1);
-#ifdef DBUS_BUILD_TESTS
- if (mem)
- _dbus_atomic_inc (&n_blocks_outstanding);
-#endif
- return mem;
- }
-}
-
-/**
- * Resizes a block of memory previously allocated by dbus_malloc() or
- * dbus_malloc0(). Guaranteed to free the memory and return #NULL if bytes
- * is zero on all platforms. Returns #NULL if the resize fails.
- * If the resize fails, the memory is not freed.
- *
- * @param memory block to be resized
- * @param bytes new size of the memory block
- * @return allocated memory, or #NULL if the resize fails.
- */
-void*
-dbus_realloc (void *memory,
- size_t bytes)
-{
-#ifdef DBUS_BUILD_TESTS
- _dbus_initialize_malloc_debug ();
-
- if (_dbus_decrement_fail_alloc_counter ())
- {
- _dbus_verbose (" FAILING realloc of %ld bytes\n", (long) bytes);
-
- return NULL;
- }
-#endif
-
- if (bytes == 0) /* guarantee this is safe */
- {
- dbus_free (memory);
- return NULL;
- }
-#ifdef DBUS_BUILD_TESTS
- else if (fail_size != 0 && bytes > fail_size)
- return NULL;
- else if (guards)
- {
- if (memory)
- {
- size_t old_bytes;
- void *block;
-
- check_guards (memory, FALSE);
-
- block = realloc (((unsigned char*)memory) - GUARD_START_OFFSET,
- bytes + GUARD_EXTRA_SIZE);
-
- old_bytes = *(dbus_uint32_t*)block;
- if (block && bytes >= old_bytes)
- /* old guards shouldn't have moved */
- check_guards (((unsigned char*)block) + GUARD_START_OFFSET, FALSE);
-
- return set_guards (block, bytes, SOURCE_REALLOC);
- }
- else
- {
- void *block;
-
- block = malloc (bytes + GUARD_EXTRA_SIZE);
-
- if (block)
- _dbus_atomic_inc (&n_blocks_outstanding);
-
- return set_guards (block, bytes, SOURCE_REALLOC_NULL);
- }
- }
-#endif
- else
- {
- void *mem;
- mem = realloc (memory, bytes);
-#ifdef DBUS_BUILD_TESTS
- if (memory == NULL && mem != NULL)
- _dbus_atomic_inc (&n_blocks_outstanding);
-#endif
- return mem;
- }
-}
-
-/**
- * Frees a block of memory previously allocated by dbus_malloc() or
- * dbus_malloc0(). If passed #NULL, does nothing.
- *
- * @param memory block to be freed
- */
-void
-dbus_free (void *memory)
-{
-#ifdef DBUS_BUILD_TESTS
- if (guards)
- {
- check_guards (memory, TRUE);
- if (memory)
- {
- _dbus_atomic_dec (&n_blocks_outstanding);
-
- _dbus_assert (n_blocks_outstanding.value >= 0);
-
- free (((unsigned char*)memory) - GUARD_START_OFFSET);
- }
-
- return;
- }
-#endif
-
- if (memory) /* we guarantee it's safe to free (NULL) */
- {
-#ifdef DBUS_BUILD_TESTS
- _dbus_atomic_dec (&n_blocks_outstanding);
-
- _dbus_assert (n_blocks_outstanding.value >= 0);
-#endif
-
- free (memory);
- }
-}
-
-/**
- * Frees a #NULL-terminated array of strings.
- * If passed #NULL, does nothing.
- *
- * @param str_array the array to be freed
- */
-void
-dbus_free_string_array (char **str_array)
-{
- if (str_array)
- {
- int i;
-
- i = 0;
- while (str_array[i])
- {
- dbus_free (str_array[i]);
- i++;
- }
-
- dbus_free (str_array);
- }
-}
-
-/** @} */ /* End of public API docs block */
-
-
-/**
- * @addtogroup DBusMemoryInternals
- *
- * @{
- */
-
-/**
- * _dbus_current_generation is used to track each
- * time that dbus_shutdown() is called, so we can
- * reinit things after it's been called. It is simply
- * incremented each time we shut down.
- */
-int _dbus_current_generation = 1;
-
-/**
- * Represents a function to be called on shutdown.
- */
-typedef struct ShutdownClosure ShutdownClosure;
-
-/**
- * This struct represents a function to be called on shutdown.
- */
-struct ShutdownClosure
-{
- ShutdownClosure *next; /**< Next ShutdownClosure */
- DBusShutdownFunction func; /**< Function to call */
- void *data; /**< Data for function */
-};
-
-_DBUS_DEFINE_GLOBAL_LOCK (shutdown_funcs);
-static ShutdownClosure *registered_globals = NULL;
-
-/**
- * Register a cleanup function to be called exactly once
- * the next time dbus_shutdown() is called.
- *
- * @param func the function
- * @param data data to pass to the function
- * @returns #FALSE on not enough memory
- */
-dbus_bool_t
-_dbus_register_shutdown_func (DBusShutdownFunction func,
- void *data)
-{
- ShutdownClosure *c;
-
- c = dbus_new (ShutdownClosure, 1);
-
- if (c == NULL)
- return FALSE;
-
- c->func = func;
- c->data = data;
-
- _DBUS_LOCK (shutdown_funcs);
-
- c->next = registered_globals;
- registered_globals = c;
-
- _DBUS_UNLOCK (shutdown_funcs);
-
- return TRUE;
-}
-
-/** @} */ /* End of private API docs block */
-
-
-/**
- * @addtogroup DBusMemory
- *
- * @{
- */
-
-/**
- * Frees all memory allocated internally by libdbus and
- * reverses the effects of dbus_threads_init(). libdbus keeps internal
- * global variables, for example caches and thread locks, and it
- * can be useful to free these internal data structures.
- *
- * dbus_shutdown() does NOT free memory that was returned
- * to the application. It only returns libdbus-internal
- * data structures.
- *
- * You MUST free all memory and release all reference counts
- * returned to you by libdbus prior to calling dbus_shutdown().
- *
- * You can't continue to use any D-Bus objects, such as connections,
- * that were allocated prior to dbus_shutdown(). You can, however,
- * start over; call dbus_threads_init() again, create new connections,
- * and so forth.
- *
- * WARNING: dbus_shutdown() is NOT thread safe, it must be called
- * while NO other threads are using D-Bus. (Remember, you have to free
- * all D-Bus objects and memory before you call dbus_shutdown(), so no
- * thread can be using libdbus.)
- *
- * The purpose of dbus_shutdown() is to allow applications to get
- * clean output from memory leak checkers. dbus_shutdown() may also be
- * useful if you want to dlopen() libdbus instead of linking to it,
- * and want to be able to unload the library again.
- *
- * There is absolutely no requirement to call dbus_shutdown() - in fact,
- * most applications won't bother and should not feel guilty.
- *
- * You have to know that nobody is using libdbus in your application's
- * process before you can call dbus_shutdown(). One implication of this
- * is that calling dbus_shutdown() from a library is almost certainly
- * wrong, since you don't know what the rest of the app is up to.
- *
- */
-void
-dbus_shutdown (void)
-{
- while (registered_globals != NULL)
- {
- ShutdownClosure *c;
-
- c = registered_globals;
- registered_globals = c->next;
-
- (* c->func) (c->data);
-
- dbus_free (c);
- }
-
- _dbus_current_generation += 1;
-}
-
-/** @} */ /** End of public API docs block */
-
-#ifdef DBUS_BUILD_TESTS
-#include "dbus-test.h"
-
-/**
- * @ingroup DBusMemoryInternals
- * Unit test for DBusMemory
- * @returns #TRUE on success.
- */
-dbus_bool_t
-_dbus_memory_test (void)
-{
- dbus_bool_t old_guards;
- void *p;
- size_t size;
-
- old_guards = guards;
- guards = TRUE;
- p = dbus_malloc (4);
- if (p == NULL)
- _dbus_assert_not_reached ("no memory");
- for (size = 4; size < 256; size += 4)
- {
- p = dbus_realloc (p, size);
- if (p == NULL)
- _dbus_assert_not_reached ("no memory");
- }
- for (size = 256; size != 0; size -= 4)
- {
- p = dbus_realloc (p, size);
- if (p == NULL)
- _dbus_assert_not_reached ("no memory");
- }
- dbus_free (p);
- guards = old_guards;
- return TRUE;
-}
-
-#endif
projects / monky / blobdiff