-/* -*- mode: C; c-file-style: "gnu" -*- */
-/* dbus-memory.c D-BUS memory handling
+/* -*- 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 1.2
+ * 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
*
* 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
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
+#include <config.h>
#include "dbus-memory.h"
#include "dbus-internals.h"
+#include "dbus-sysdeps.h"
+#include "dbus-list.h"
+#include "dbus-threads.h"
#include <stdlib.h>
-
/**
* @defgroup DBusMemory Memory Allocation
* @ingroup DBus
* 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
+ *
* @{
*/
* @param memory the memory to free
*/
-#ifdef DBUS_BUILD_TESTS
-static dbus_bool_t inited = FALSE;
-static int fail_counts = -1;
+/** @} */ /* end of public API docs */
+
+/**
+ * @addtogroup DBusMemoryInternals
+ *
+ * @{
+ */
+
+#ifdef DBUS_ENABLE_EMBEDDED_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 dbus_bool_t malloc_cannot_fail = 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_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)
-#endif
-#ifdef DBUS_BUILD_TESTS
static void
-initialize_malloc_debug (void)
+_dbus_initialize_malloc_debug (void)
{
- if (!inited)
+ if (!debug_initialized)
{
+ debug_initialized = TRUE;
+
if (_dbus_getenv ("DBUS_MALLOC_FAIL_NTH") != NULL)
{
- fail_counts = atoi (_dbus_getenv ("DBUS_MALLOC_FAIL_NTH"));
- _dbus_set_fail_alloc_counter (fail_counts);
+ fail_nth = atoi (_dbus_getenv ("DBUS_MALLOC_FAIL_NTH"));
+ fail_alloc_counter = fail_nth;
+ _dbus_verbose ("Will fail dbus_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"));
+ {
+ 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;
+ {
+ guards = TRUE;
+ _dbus_verbose ("Will use dbus_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 dbus_malloc\n");
+ }
+
+ if (_dbus_getenv ("DBUS_MALLOC_CANNOT_FAIL") != NULL)
+ {
+ malloc_cannot_fail = TRUE;
+ _dbus_verbose ("Will abort if system malloc() and friends fail\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_ENABLE_EMBEDDED_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 ();
+#ifdef DBUS_WIN_FIXME
+ {
+ static dbus_bool_t called = 0;
+
+ if (!called)
+ {
+ _dbus_verbose("TODO: memory allocation testing errors disabled for now\n");
+ called = 1;
+ }
+ return FALSE;
+ }
+#endif
+
+ if (fail_alloc_counter <= 0)
+ {
+ if (backtrace_on_fail_alloc)
+ _dbus_print_backtrace ();
+
+ _dbus_verbose ("failure %d\n", n_failures_this_failure);
- inited = TRUE;
+ 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_ENABLE_EMBEDDED_TESTS */
+
+/**
+ * Get the number of outstanding malloc()'d blocks.
+ *
+ * @returns number of blocks
+ */
+int
+_dbus_get_malloc_blocks_outstanding (void)
+{
+ return _dbus_atomic_get (&n_blocks_outstanding);
+}
/**
* Where the block came from.
}
static void
-check_guards (void *free_block)
+check_guards (void *free_block,
+ dbus_bool_t overwrite)
{
if (free_block != NULL)
{
dbus_uint32_t value = *(dbus_uint32_t*) &block[i];
if (value != GUARD_VALUE)
{
- _dbus_warn ("Block of %u bytes from %s had start guard value 0x%x at %d expected 0x%x\n",
- requested_bytes, source_string (source),
+ _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;
}
dbus_uint32_t value = *(dbus_uint32_t*) &block[i];
if (value != GUARD_VALUE)
{
- _dbus_warn ("Block of %u bytes from %s had end guard value 0x%x at %d expected 0x%x\n",
- requested_bytes, source_string (source),
+ _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");
}
i += 4;
}
- check_guards (block + GUARD_START_OFFSET);
+ 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
- initialize_malloc_debug ();
+#ifdef DBUS_ENABLE_EMBEDDED_TESTS
+ _dbus_initialize_malloc_debug ();
if (_dbus_decrement_fail_alloc_counter ())
{
- if (fail_counts != -1)
- _dbus_set_fail_alloc_counter (fail_counts);
-
+ _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;
-#if DBUS_BUILD_TESTS
+#ifdef DBUS_ENABLE_EMBEDDED_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);
+ }
+ else if (malloc_cannot_fail)
+ {
+ _dbus_warn ("out of memory: malloc (%ld + %ld)\n",
+ (long) bytes, (long) GUARD_EXTRA_SIZE);
+ _dbus_abort ();
+ }
+
return set_guards (block, bytes, SOURCE_MALLOC);
}
#endif
else
- return malloc (bytes);
+ {
+ void *mem;
+ mem = malloc (bytes);
+
+#ifdef DBUS_ENABLE_EMBEDDED_TESTS
+ if (mem)
+ {
+ _dbus_atomic_inc (&n_blocks_outstanding);
+ }
+ else if (malloc_cannot_fail)
+ {
+ _dbus_warn ("out of memory: malloc (%ld)\n", (long) bytes);
+ _dbus_abort ();
+ }
+#endif
+
+ return mem;
+ }
}
/**
* 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
- initialize_malloc_debug ();
+#ifdef DBUS_ENABLE_EMBEDDED_TESTS
+ _dbus_initialize_malloc_debug ();
if (_dbus_decrement_fail_alloc_counter ())
{
- if (fail_counts != -1)
- _dbus_set_fail_alloc_counter (fail_counts);
+ _dbus_verbose (" FAILING malloc0 of %ld bytes\n", (long) bytes);
return NULL;
}
#endif
-
+
if (bytes == 0)
return NULL;
-#if DBUS_BUILD_TESTS
+#ifdef DBUS_ENABLE_EMBEDDED_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);
+ }
+ else if (malloc_cannot_fail)
+ {
+ _dbus_warn ("out of memory: calloc (%ld + %ld, 1)\n",
+ (long) bytes, (long) GUARD_EXTRA_SIZE);
+ _dbus_abort ();
+ }
+
return set_guards (block, bytes, SOURCE_MALLOC_ZERO);
}
#endif
else
- return calloc (bytes, 1);
+ {
+ void *mem;
+ mem = calloc (bytes, 1);
+
+#ifdef DBUS_ENABLE_EMBEDDED_TESTS
+ if (mem)
+ {
+ _dbus_atomic_inc (&n_blocks_outstanding);
+ }
+ else if (malloc_cannot_fail)
+ {
+ _dbus_warn ("out of memory: calloc (%ld)\n", (long) bytes);
+ _dbus_abort ();
+ }
+#endif
+
+ return mem;
+ }
}
/**
dbus_realloc (void *memory,
size_t bytes)
{
-#ifdef DBUS_BUILD_TESTS
- initialize_malloc_debug ();
+#ifdef DBUS_ENABLE_EMBEDDED_TESTS
+ _dbus_initialize_malloc_debug ();
if (_dbus_decrement_fail_alloc_counter ())
{
- if (fail_counts != -1)
- _dbus_set_fail_alloc_counter (fail_counts);
+ _dbus_verbose (" FAILING realloc of %ld bytes\n", (long) bytes);
return NULL;
}
dbus_free (memory);
return NULL;
}
-#if DBUS_BUILD_TESTS
+#ifdef DBUS_ENABLE_EMBEDDED_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);
+ check_guards (memory, FALSE);
block = realloc (((unsigned char*)memory) - GUARD_START_OFFSET,
bytes + GUARD_EXTRA_SIZE);
-
- /* old guards shouldn't have moved */
- check_guards (((unsigned char*)block) + GUARD_START_OFFSET);
+
+ if (block == NULL)
+ {
+ if (malloc_cannot_fail)
+ {
+ _dbus_warn ("out of memory: realloc (%p, %ld + %ld)\n",
+ memory, (long) bytes, (long) GUARD_EXTRA_SIZE);
+ _dbus_abort ();
+ }
+
+ return NULL;
+ }
+
+ old_bytes = *(dbus_uint32_t*)block;
+ if (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);
}
void *block;
block = malloc (bytes + GUARD_EXTRA_SIZE);
+
+ if (block)
+ {
+ _dbus_atomic_inc (&n_blocks_outstanding);
+ }
+ else if (malloc_cannot_fail)
+ {
+ _dbus_warn ("out of memory: malloc (%ld + %ld)\n",
+ (long) bytes, (long) GUARD_EXTRA_SIZE);
+ _dbus_abort ();
+ }
+
return set_guards (block, bytes, SOURCE_REALLOC_NULL);
}
}
#endif
else
{
- return realloc (memory, bytes);
+ void *mem;
+ mem = realloc (memory, bytes);
+
+#ifdef DBUS_ENABLE_EMBEDDED_TESTS
+ if (mem == NULL && malloc_cannot_fail)
+ {
+ _dbus_warn ("out of memory: malloc (%ld)\n", (long) bytes);
+ _dbus_abort ();
+ }
+
+ if (memory == NULL && mem != NULL)
+ _dbus_atomic_inc (&n_blocks_outstanding);
+#endif
+ return mem;
}
}
void
dbus_free (void *memory)
{
-#ifdef DBUS_BUILD_TESTS
+#ifdef DBUS_ENABLE_EMBEDDED_TESTS
if (guards)
{
- check_guards (memory);
+ check_guards (memory, TRUE);
if (memory)
- free (((unsigned char*)memory) - GUARD_START_OFFSET);
+ {
+#ifdef DBUS_DISABLE_ASSERT
+ _dbus_atomic_dec (&n_blocks_outstanding);
+#else
+ dbus_int32_t old_value;
+
+ old_value = _dbus_atomic_dec (&n_blocks_outstanding);
+ _dbus_assert (old_value >= 1);
+#endif
+
+ free (((unsigned char*)memory) - GUARD_START_OFFSET);
+ }
+
return;
}
#endif
if (memory) /* we guarantee it's safe to free (NULL) */
- free (memory);
+ {
+#ifdef DBUS_ENABLE_EMBEDDED_TESTS
+#ifdef DBUS_DISABLE_ASSERT
+ _dbus_atomic_dec (&n_blocks_outstanding);
+#else
+ dbus_int32_t old_value;
+
+ old_value = _dbus_atomic_dec (&n_blocks_outstanding);
+ _dbus_assert (old_value >= 1);
+#endif
+#endif
+
+ free (memory);
+ }
}
/**
}
}
-/** @} */
+/** @} */ /* 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 */
+};
+
+/* Protected by _DBUS_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)
+{
+ dbus_bool_t ok;
+
+ if (!_DBUS_LOCK (shutdown_funcs))
+ return FALSE;
+
+ ok = _dbus_register_shutdown_func_unlocked (func, data);
+ _DBUS_UNLOCK (shutdown_funcs);
+ return ok;
+}
+
+dbus_bool_t
+_dbus_register_shutdown_func_unlocked (DBusShutdownFunction func,
+ void *data)
+{
+ ShutdownClosure *c;
+
+ c = dbus_new (ShutdownClosure, 1);
+
+ if (c == NULL)
+ return FALSE;
+
+ c->func = func;
+ c->data = data;
+
+ c->next = registered_globals;
+ registered_globals = c;
+
+ 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);
+ }
+
+ /* We wrap this in the thread-initialization lock because
+ * dbus_threads_init() uses the current generation to tell whether
+ * we're initialized, so we need to make sure that un-initializing
+ * propagates into all threads. */
+ _dbus_threads_lock_platform_specific ();
+ _dbus_current_generation += 1;
+ _dbus_threads_unlock_platform_specific ();
+}
+
+/** @} */ /** End of public API docs block */
+
+#ifdef DBUS_ENABLE_EMBEDDED_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
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