#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
* 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
*/
+/** @} */ /* end of public API docs */
+
+/**
+ * @addtogroup DBusMemoryInternals
+ *
+ * @{
+ */
+
#ifdef DBUS_BUILD_TESTS
-static dbus_bool_t inited = FALSE;
-static int fail_counts = -1;
+static dbus_bool_t debug_initialized = FALSE;
+static int fail_nth = -1;
static size_t fail_size = 0;
-#endif
+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 int 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)
-#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 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 %d bytes\n",
+ 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;
+}
+
+/**
+ * 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);
+ }
- inited = TRUE;
+ return TRUE;
+ }
+ else
+ {
+ fail_alloc_counter -= 1;
+ return FALSE;
}
}
+
+/**
+ * Get the number of outstanding malloc()'d blocks.
+ *
+ * @returns number of blocks
+ */
+int
+_dbus_get_malloc_blocks_outstanding (void)
+{
+ return n_blocks_outstanding;
+}
+
+/**
+ * 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)
+{
+ 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 %u bytes from %s had start guard value 0x%x at %d expected 0x%x\n",
+ 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 %u bytes from %s had end guard value 0x%x at %d expected 0x%x\n",
+ requested_bytes, source_string (source),
+ value, i, GUARD_VALUE);
+ failed = TRUE;
+ }
+
+ i += 4;
+ }
+
+ 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);
+
+ return block + GUARD_START_OFFSET;
+}
+
+#endif
+
+/** @} */ /* End of internals docs */
+
+
+/**
+ * @addtogroup DBusMemory
+ *
+ * @{
+ */
/**
* Allocates the given number of bytes, as with standard
dbus_malloc (size_t bytes)
{
#ifdef DBUS_BUILD_TESTS
- initialize_malloc_debug ();
+ _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 %d bytes\n", bytes);
return NULL;
}
if (bytes == 0) /* some system mallocs handle this, some don't */
return NULL;
-#if DBUS_BUILD_TESTS
+#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)
+ n_blocks_outstanding += 1;
+
+ return set_guards (block, bytes, SOURCE_MALLOC);
+ }
#endif
else
- return malloc (bytes);
+ {
+ void *mem;
+ mem = malloc (bytes);
+#ifdef DBUS_BUILD_TESTS
+ if (mem)
+ n_blocks_outstanding += 1;
+#endif
+ return mem;
+ }
}
/**
dbus_malloc0 (size_t bytes)
{
#ifdef DBUS_BUILD_TESTS
- initialize_malloc_debug ();
+ _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 %d bytes\n", bytes);
return NULL;
}
if (bytes == 0)
return NULL;
-#if DBUS_BUILD_TESTS
+#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)
+ n_blocks_outstanding += 1;
+ return set_guards (block, bytes, SOURCE_MALLOC_ZERO);
+ }
#endif
else
- return calloc (bytes, 1);
+ {
+ void *mem;
+ mem = calloc (bytes, 1);
+#ifdef DBUS_BUILD_TESTS
+ if (mem)
+ n_blocks_outstanding += 1;
+#endif
+ return mem;
+ }
}
/**
size_t bytes)
{
#ifdef DBUS_BUILD_TESTS
- initialize_malloc_debug ();
+ _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 %d bytes\n", bytes);
return NULL;
}
dbus_free (memory);
return NULL;
}
-#if DBUS_BUILD_TESTS
+#ifdef DBUS_BUILD_TESTS
else if (fail_size != 0 && bytes > fail_size)
return NULL;
+ else if (guards)
+ {
+ if (memory)
+ {
+ void *block;
+
+ check_guards (memory);
+
+ block = realloc (((unsigned char*)memory) - GUARD_START_OFFSET,
+ bytes + GUARD_EXTRA_SIZE);
+
+ if (block)
+ /* old guards shouldn't have moved */
+ check_guards (((unsigned char*)block) + GUARD_START_OFFSET);
+
+ return set_guards (block, bytes, SOURCE_REALLOC);
+ }
+ else
+ {
+ void *block;
+
+ block = malloc (bytes + GUARD_EXTRA_SIZE);
+
+ if (block)
+ n_blocks_outstanding += 1;
+
+ return set_guards (block, bytes, SOURCE_REALLOC_NULL);
+ }
+ }
#endif
else
{
- return realloc (memory, bytes);
+ void *mem;
+ mem = realloc (memory, bytes);
+#ifdef DBUS_BUILD_TESTS
+ if (memory == NULL && mem != NULL)
+ n_blocks_outstanding += 1;
+#endif
+ return mem;
}
}
void
dbus_free (void *memory)
{
+#ifdef DBUS_BUILD_TESTS
+ if (guards)
+ {
+ check_guards (memory);
+ if (memory)
+ {
+ n_blocks_outstanding -= 1;
+
+ _dbus_assert (n_blocks_outstanding >= 0);
+
+ free (((unsigned char*)memory) - GUARD_START_OFFSET);
+ }
+
+ return;
+ }
+#endif
+
if (memory) /* we guarantee it's safe to free (NULL) */
- free (memory);
+ {
+#ifdef DBUS_BUILD_TESTS
+ n_blocks_outstanding -= 1;
+
+ _dbus_assert (n_blocks_outstanding >= 0);
+#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 */
+};
+
+_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
+ *
+ * @{
+ */
+
+/**
+ * The D-BUS library keeps some internal global variables, for example
+ * to cache the username of the current process. This function is
+ * used to free these global variables. It is really useful only for
+ * leak-checking cleanliness and the like. WARNING: this function is
+ * NOT thread safe, it must be called while NO other threads are using
+ * D-BUS. You cannot continue using D-BUS after calling this function,
+ * as it does things like free global mutexes created by
+ * dbus_threads_init(). To use a D-BUS function after calling
+ * dbus_shutdown(), you have to start over from scratch, e.g. calling
+ * dbus_threads_init() again.
+ */
+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 */
projects / platform / upstream / dbus.git / blobdiff