* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/* MT safe */
+
+#include "config.h"
+#include "glibconfig.h"
+
+#if defined HAVE_POSIX_MEMALIGN && defined POSIX_MEMALIGN_WITH_COMPLIANT_ALLOCS
+# define HAVE_COMPLIANT_POSIX_MEMALIGN 1
+#endif
+
+#if defined(HAVE_COMPLIANT_POSIX_MEMALIGN) && !defined(_XOPEN_SOURCE)
#define _XOPEN_SOURCE 600 /* posix_memalign() */
+#endif
#include <stdlib.h> /* posix_memalign() */
-#include <unistd.h> /* sysconf() */
-#include <assert.h> /* assert() for nomessage phase */
#include <string.h>
#include <errno.h>
-#include "config.h"
+
+#ifdef G_OS_UNIX
+#include <unistd.h> /* sysconf() */
+#endif
+#ifdef G_OS_WIN32
+#include <windows.h>
+#include <process.h>
+#endif
+
+#include <stdio.h> /* fputs/fprintf */
+
+#include "gslice.h"
+
+#include "gmain.h"
#include "gmem.h" /* gslice.h */
-#include "gthreadinit.h"
-#include "galias.h"
-#include "glib.h"
+#include "gstrfuncs.h"
+#include "gutils.h"
+#include "gtrashstack.h"
+#include "gtestutils.h"
+#include "gthread.h"
+#include "glib_trace.h"
+
+#include "valgrind.h"
+
+/**
+ * SECTION:memory_slices
+ * @title: Memory Slices
+ * @short_description: efficient way to allocate groups of equal-sized
+ * chunks of memory
+ *
+ * Memory slices provide a space-efficient and multi-processing scalable
+ * way to allocate equal-sized pieces of memory, just like the original
+ * #GMemChunks (from GLib 2.8), while avoiding their excessive
+ * memory-waste, scalability and performance problems.
+ *
+ * To achieve these goals, the slice allocator uses a sophisticated,
+ * layered design that has been inspired by Bonwick's slab allocator
+ * ([Bonwick94](http://citeseer.ist.psu.edu/bonwick94slab.html)
+ * Jeff Bonwick, The slab allocator: An object-caching kernel
+ * memory allocator. USENIX 1994, and
+ * [Bonwick01](http://citeseer.ist.psu.edu/bonwick01magazines.html)
+ * Bonwick and Jonathan Adams, Magazines and vmem: Extending the
+ * slab allocator to many cpu's and arbitrary resources. USENIX 2001)
+ *
+ * It uses posix_memalign() to optimize allocations of many equally-sized
+ * chunks, and has per-thread free lists (the so-called magazine layer)
+ * to quickly satisfy allocation requests of already known structure sizes.
+ * This is accompanied by extra caching logic to keep freed memory around
+ * for some time before returning it to the system. Memory that is unused
+ * due to alignment constraints is used for cache colorization (random
+ * distribution of chunk addresses) to improve CPU cache utilization. The
+ * caching layer of the slice allocator adapts itself to high lock contention
+ * to improve scalability.
+ *
+ * The slice allocator can allocate blocks as small as two pointers, and
+ * unlike malloc(), it does not reserve extra space per block. For large block
+ * sizes, g_slice_new() and g_slice_alloc() will automatically delegate to the
+ * system malloc() implementation. For newly written code it is recommended
+ * to use the new `g_slice` API instead of g_malloc() and
+ * friends, as long as objects are not resized during their lifetime and the
+ * object size used at allocation time is still available when freeing.
+ *
+ * Here is an example for using the slice allocator:
+ * |[<!-- language="C" -->
+ * gchar *mem[10000];
+ * gint i;
+ *
+ * // Allocate 10000 blocks.
+ * for (i = 0; i < 10000; i++)
+ * {
+ * mem[i] = g_slice_alloc (50);
+ *
+ * // Fill in the memory with some junk.
+ * for (j = 0; j < 50; j++)
+ * mem[i][j] = i * j;
+ * }
+ *
+ * // Now free all of the blocks.
+ * for (i = 0; i < 10000; i++)
+ * g_slice_free1 (50, mem[i]);
+ * ]|
+ *
+ * And here is an example for using the using the slice allocator
+ * with data structures:
+ * |[<!-- language="C" -->
+ * GRealArray *array;
+ *
+ * // Allocate one block, using the g_slice_new() macro.
+ * array = g_slice_new (GRealArray);
+
+ * // We can now use array just like a normal pointer to a structure.
+ * array->data = NULL;
+ * array->len = 0;
+ * array->alloc = 0;
+ * array->zero_terminated = (zero_terminated ? 1 : 0);
+ * array->clear = (clear ? 1 : 0);
+ * array->elt_size = elt_size;
+ *
+ * // We can free the block, so it can be reused.
+ * g_slice_free (GRealArray, array);
+ * ]|
+ */
/* the GSlice allocator is split up into 4 layers, roughly modelled after the slab
* allocator and magazine extensions as outlined in:
* a chunk size specific maximum to limit magazine storage sizes to roughly
* 16KB.
* [4] allocating ca. 8 chunks per block/page keeps a good balance between
- * external and internal fragmentation (<= 12.5%) [Bonwick94]
+ * external and internal fragmentation (<= 12.5%). [Bonwick94]
*/
/* --- macros and constants --- */
#define SLAB_INFO_SIZE P2ALIGN (sizeof (SlabInfo) + NATIVE_MALLOC_PADDING)
#define MAX_MAGAZINE_SIZE (256) /* see [3] and allocator_get_magazine_threshold() for this */
#define MIN_MAGAZINE_SIZE (4)
-#define MAX_STAMP_COUNTER (13) /* distributes the load of gettimeofday() */
+#define MAX_STAMP_COUNTER (7) /* distributes the load of gettimeofday() */
#define MAX_SLAB_CHUNK_SIZE(al) (((al)->max_page_size - SLAB_INFO_SIZE) / 8) /* we want at last 8 chunks per page, see [4] */
#define MAX_SLAB_INDEX(al) (SLAB_INDEX (al, MAX_SLAB_CHUNK_SIZE (al)) + 1)
#define SLAB_INDEX(al, asize) ((asize) / P2ALIGNMENT - 1) /* asize must be P2ALIGNMENT aligned */
#define SLAB_CHUNK_SIZE(al, ix) (((ix) + 1) * P2ALIGNMENT)
-#define SLAB_PAGE_SIZE(al,csz) (ALIGN (8 * (csz) + SLAB_INFO_SIZE, (al)->min_page_size))
+#define SLAB_BPAGE_SIZE(al,csz) (8 * (csz) + SLAB_INFO_SIZE)
/* optimized version of ALIGN (size, P2ALIGNMENT) */
#if GLIB_SIZEOF_SIZE_T * 2 == 8 /* P2ALIGNMENT */
#define P2ALIGN(size) ALIGN (size, P2ALIGNMENT)
#endif
+/* special helpers to avoid gmessage.c dependency */
+static void mem_error (const char *format, ...) G_GNUC_PRINTF (1,2);
+#define mem_assert(cond) do { if (G_LIKELY (cond)) ; else mem_error ("assertion failed: %s", #cond); } while (0)
+
/* --- structures --- */
typedef struct _ChunkLink ChunkLink;
typedef struct _SlabInfo SlabInfo;
typedef struct {
gboolean always_malloc;
gboolean bypass_magazines;
- gboolean always_free;
+ gboolean debug_blocks;
gsize working_set_msecs;
+ guint color_increment;
} SliceConfig;
typedef struct {
/* const after initialization */
gsize min_page_size, max_page_size;
SliceConfig config;
- guint max_slab_chunk_size_for_magazine_cache;
+ gsize max_slab_chunk_size_for_magazine_cache;
/* magazine cache */
- GMutex *magazine_mutex;
+ GMutex magazine_mutex;
ChunkLink **magazines; /* array of MAX_SLAB_INDEX (allocator) */
guint *contention_counters; /* array of MAX_SLAB_INDEX (allocator) */
gint mutex_counter;
guint stamp_counter;
guint last_stamp;
/* slab allocator */
- GMutex *slab_mutex;
+ GMutex slab_mutex;
SlabInfo **slab_stack; /* array of MAX_SLAB_INDEX (allocator) */
guint color_accu;
} Allocator;
-/* --- prototypes --- */
-static gpointer slab_allocator_alloc_chunk (guint chunk_size);
-static void slab_allocator_free_chunk (guint chunk_size,
+/* --- g-slice prototypes --- */
+static gpointer slab_allocator_alloc_chunk (gsize chunk_size);
+static void slab_allocator_free_chunk (gsize chunk_size,
gpointer mem);
static void private_thread_memory_cleanup (gpointer data);
static gpointer allocator_memalign (gsize alignment,
static void allocator_memfree (gsize memsize,
gpointer mem);
static inline void magazine_cache_update_stamp (void);
-static inline guint allocator_get_magazine_threshold (Allocator *allocator,
+static inline gsize allocator_get_magazine_threshold (Allocator *allocator,
guint ix);
+/* --- g-slice memory checker --- */
+static void smc_notify_alloc (void *pointer,
+ size_t size);
+static int smc_notify_free (void *pointer,
+ size_t size);
+
/* --- variables --- */
-static GPrivate *private_thread_memory = NULL;
-static gsize sys_page_size = 0;
-static Allocator allocator[1] = { { 0, }, };
-static SliceConfig slice_config = {
+static GPrivate private_thread_memory = G_PRIVATE_INIT (private_thread_memory_cleanup);
+static gsize sys_page_size = 0;
+static Allocator allocator[1] = { { 0, }, };
+static SliceConfig slice_config = {
FALSE, /* always_malloc */
FALSE, /* bypass_magazines */
- FALSE, /* always_free */
+ FALSE, /* debug_blocks */
15 * 1000, /* working_set_msecs */
+ 1, /* color increment, alt: 0x7fffffff */
};
+static GMutex smc_tree_mutex; /* mutex for G_SLICE=debug-blocks */
-/* --- auxillary funcitons --- */
+/* --- auxiliary funcitons --- */
void
g_slice_set_config (GSliceConfig ckey,
gint64 value)
case G_SLICE_CONFIG_BYPASS_MAGAZINES:
slice_config.bypass_magazines = value != 0;
break;
- case G_SLICE_CONFIG_ALWAYS_FREE:
- slice_config.always_free = value != 0;
- break;
case G_SLICE_CONFIG_WORKING_SET_MSECS:
slice_config.working_set_msecs = value;
break;
+ case G_SLICE_CONFIG_COLOR_INCREMENT:
+ slice_config.color_increment = value;
default: ;
}
}
return slice_config.always_malloc;
case G_SLICE_CONFIG_BYPASS_MAGAZINES:
return slice_config.bypass_magazines;
- case G_SLICE_CONFIG_ALWAYS_FREE:
- return slice_config.always_free;
case G_SLICE_CONFIG_WORKING_SET_MSECS:
return slice_config.working_set_msecs;
case G_SLICE_CONFIG_CHUNK_SIZES:
return MAX_SLAB_INDEX (allocator);
+ case G_SLICE_CONFIG_COLOR_INCREMENT:
+ return slice_config.color_increment;
default:
return 0;
}
}
static void
+slice_config_init (SliceConfig *config)
+{
+ const gchar *val;
+
+ *config = slice_config;
+
+ val = getenv ("G_SLICE");
+ if (val != NULL)
+ {
+ gint flags;
+ const GDebugKey keys[] = {
+ { "always-malloc", 1 << 0 },
+ { "debug-blocks", 1 << 1 },
+ };
+
+ flags = g_parse_debug_string (val, keys, G_N_ELEMENTS (keys));
+ if (flags & (1 << 0))
+ config->always_malloc = TRUE;
+ if (flags & (1 << 1))
+ config->debug_blocks = TRUE;
+ }
+ else
+ {
+ /* G_SLICE was not specified, so check if valgrind is running and
+ * disable ourselves if it is.
+ *
+ * This way it's possible to force gslice to be enabled under
+ * valgrind just by setting G_SLICE to the empty string.
+ */
+ if (RUNNING_ON_VALGRIND)
+ config->always_malloc = TRUE;
+ }
+}
+
+static void
g_slice_init_nomessage (void)
{
/* we may not use g_error() or friends here */
- assert (sys_page_size == 0);
+ mem_assert (sys_page_size == 0);
+ mem_assert (MIN_MAGAZINE_SIZE >= 4);
+#ifdef G_OS_WIN32
+ {
+ SYSTEM_INFO system_info;
+ GetSystemInfo (&system_info);
+ sys_page_size = system_info.dwPageSize;
+ }
+#else
sys_page_size = sysconf (_SC_PAGESIZE); /* = sysconf (_SC_PAGE_SIZE); = getpagesize(); */
- assert (sys_page_size >= 2 * LARGEALIGNMENT);
- allocator->config = slice_config;
+#endif
+ mem_assert (sys_page_size >= 2 * LARGEALIGNMENT);
+ mem_assert ((sys_page_size & (sys_page_size - 1)) == 0);
+ slice_config_init (&allocator->config);
allocator->min_page_size = sys_page_size;
-#if HAVE_POSIX_MEMALIGN || HAVE_MEMALIGN
+#if HAVE_COMPLIANT_POSIX_MEMALIGN || HAVE_MEMALIGN
/* allow allocation of pages up to 8KB (with 8KB alignment).
* this is useful because many medium to large sized structures
* fit less than 8 times (see [4]) into 4KB pages.
+ * we allow very small page sizes here, to reduce wastage in
+ * threads if only small allocations are required (this does
+ * bear the risk of increasing allocation times and fragmentation
+ * though).
*/
allocator->min_page_size = MAX (allocator->min_page_size, 4096);
allocator->max_page_size = MAX (allocator->min_page_size, 8192);
+ allocator->min_page_size = MIN (allocator->min_page_size, 128);
#else
/* we can only align to system page size */
allocator->max_page_size = sys_page_size;
#endif
- allocator->magazine_mutex = NULL; /* _g_slice_thread_init_nomessage() */
- allocator->magazines = g_new0 (ChunkLink*, MAX_SLAB_INDEX (allocator));
- allocator->contention_counters = g_new0 (guint, MAX_SLAB_INDEX (allocator));
+ if (allocator->config.always_malloc)
+ {
+ allocator->contention_counters = NULL;
+ allocator->magazines = NULL;
+ allocator->slab_stack = NULL;
+ }
+ else
+ {
+ allocator->contention_counters = g_new0 (guint, MAX_SLAB_INDEX (allocator));
+ allocator->magazines = g_new0 (ChunkLink*, MAX_SLAB_INDEX (allocator));
+ allocator->slab_stack = g_new0 (SlabInfo*, MAX_SLAB_INDEX (allocator));
+ }
+
allocator->mutex_counter = 0;
allocator->stamp_counter = MAX_STAMP_COUNTER; /* force initial update */
allocator->last_stamp = 0;
- allocator->slab_mutex = NULL; /* _g_slice_thread_init_nomessage() */
- allocator->slab_stack = g_new0 (SlabInfo*, MAX_SLAB_INDEX (allocator));
allocator->color_accu = 0;
magazine_cache_update_stamp();
/* values cached for performance reasons */
}
static inline guint
-allocator_categorize (guint aligned_chunk_size)
+allocator_categorize (gsize aligned_chunk_size)
{
/* speed up the likely path */
if (G_LIKELY (aligned_chunk_size && aligned_chunk_size <= allocator->max_slab_chunk_size_for_magazine_cache))
return 1; /* use magazine cache */
- /* the above will fail (max_slab_chunk_size_for_magazine_cache == 0) if the
- * allocator is still uninitialized, or if we are not configured to use the
- * magazine cache.
- */
- if (!sys_page_size)
- g_slice_init_nomessage ();
if (!allocator->config.always_malloc &&
aligned_chunk_size &&
aligned_chunk_size <= MAX_SLAB_CHUNK_SIZE (allocator))
return 0; /* use malloc() */
}
-void
-_g_slice_thread_init_nomessage (void)
-{
- /* we may not use g_error() or friends here */
- if (!sys_page_size)
- g_slice_init_nomessage();
- private_thread_memory = g_private_new (private_thread_memory_cleanup);
- allocator->magazine_mutex = g_mutex_new();
- allocator->slab_mutex = g_mutex_new();
-}
-
static inline void
g_mutex_lock_a (GMutex *mutex,
- guint *threshold)
+ guint *contention_counter)
{
gboolean contention = FALSE;
if (!g_mutex_trylock (mutex))
if (allocator->mutex_counter >= 1) /* quickly adapt to contention */
{
allocator->mutex_counter = 0;
- *threshold = MIN (*threshold + 1, MAX_MAGAZINE_SIZE);
+ *contention_counter = MIN (*contention_counter + 1, MAX_MAGAZINE_SIZE);
}
}
else /* !contention */
if (allocator->mutex_counter < -11) /* moderately recover magazine sizes */
{
allocator->mutex_counter = 0;
- *threshold = MAX (*threshold, 1) - 1;
+ *contention_counter = MAX (*contention_counter, 1) - 1;
}
}
}
static inline ThreadMemory*
thread_memory_from_self (void)
{
- ThreadMemory *tmem = g_private_get (private_thread_memory);
+ ThreadMemory *tmem = g_private_get (&private_thread_memory);
if (G_UNLIKELY (!tmem))
{
- const guint n_magazines = MAX_SLAB_INDEX (allocator);
+ static GMutex init_mutex;
+ guint n_magazines;
+
+ g_mutex_lock (&init_mutex);
+ if G_UNLIKELY (sys_page_size == 0)
+ g_slice_init_nomessage ();
+ g_mutex_unlock (&init_mutex);
+
+ n_magazines = MAX_SLAB_INDEX (allocator);
tmem = g_malloc0 (sizeof (ThreadMemory) + sizeof (Magazine) * 2 * n_magazines);
tmem->magazine1 = (Magazine*) (tmem + 1);
tmem->magazine2 = &tmem->magazine1[n_magazines];
- g_private_set (private_thread_memory, tmem);
+ g_private_set (&private_thread_memory, tmem);
}
return tmem;
}
return chunk;
}
+#if 0 /* useful for debugging */
static guint
magazine_count (ChunkLink *head)
{
}
return count;
}
+#endif
-static inline guint
+static inline gsize
allocator_get_magazine_threshold (Allocator *allocator,
guint ix)
{
/* the magazine size calculated here has a lower bound of MIN_MAGAZINE_SIZE,
* which is required by the implementation. also, for moderately sized chunks
* (say >= 64 bytes), magazine sizes shouldn't be much smaller then the number
- * of chunks available per page to avoid excessive traffic in the magazine
+ * of chunks available per page/2 to avoid excessive traffic in the magazine
* cache for small to medium sized structures.
* the upper bound of the magazine size is effectively provided by
* MAX_MAGAZINE_SIZE. for larger chunks, this number is scaled down so that
* the content of a single magazine doesn't exceed ca. 16KB.
*/
- guint chunk_size = SLAB_CHUNK_SIZE (allocator, ix);
- guint threshold = MAX (MIN_MAGAZINE_SIZE, sys_page_size / MAX (chunk_size, 64));
+ gsize chunk_size = SLAB_CHUNK_SIZE (allocator, ix);
+ guint threshold = MAX (MIN_MAGAZINE_SIZE, allocator->max_page_size / MAX (5 * chunk_size, 5 * 32));
guint contention_counter = allocator->contention_counters[ix];
if (G_UNLIKELY (contention_counter)) /* single CPU bias */
{
static inline ChunkLink*
magazine_chain_prepare_fields (ChunkLink *magazine_chunks)
{
- g_assert (MIN_MAGAZINE_SIZE >= 4);
+ ChunkLink *chunk1;
+ ChunkLink *chunk2;
+ ChunkLink *chunk3;
+ ChunkLink *chunk4;
+ /* checked upon initialization: mem_assert (MIN_MAGAZINE_SIZE >= 4); */
/* ensure a magazine with at least 4 unused data pointers */
- ChunkLink *chunk1 = magazine_chain_pop_head (&magazine_chunks);
- ChunkLink *chunk2 = magazine_chain_pop_head (&magazine_chunks);
- ChunkLink *chunk3 = magazine_chain_pop_head (&magazine_chunks);
- ChunkLink *chunk4 = magazine_chain_pop_head (&magazine_chunks);
+ chunk1 = magazine_chain_pop_head (&magazine_chunks);
+ chunk2 = magazine_chain_pop_head (&magazine_chunks);
+ chunk3 = magazine_chain_pop_head (&magazine_chunks);
+ chunk4 = magazine_chain_pop_head (&magazine_chunks);
chunk4->next = magazine_chunks;
chunk3->next = chunk4;
chunk2->next = chunk3;
/* access the first 3 fields of a specially prepared magazine chain */
#define magazine_chain_prev(mc) ((mc)->data)
#define magazine_chain_stamp(mc) ((mc)->next->data)
+#define magazine_chain_uint_stamp(mc) GPOINTER_TO_UINT ((mc)->next->data)
#define magazine_chain_next(mc) ((mc)->next->next->data)
#define magazine_chain_count(mc) ((mc)->next->next->next->data)
/* trim magazine cache from tail */
ChunkLink *current = magazine_chain_prev (allocator->magazines[ix]);
ChunkLink *trash = NULL;
- while (allocator->config.always_free ||
- ABS (stamp - (guint) magazine_chain_stamp (current)) > allocator->config.working_set_msecs)
+ while (ABS (stamp - magazine_chain_uint_stamp (current)) >= allocator->config.working_set_msecs)
{
/* unlink */
ChunkLink *prev = magazine_chain_prev (current);
}
current = prev;
}
- g_mutex_unlock (allocator->magazine_mutex);
+ g_mutex_unlock (&allocator->magazine_mutex);
/* free trash */
if (trash)
{
- const guint chunk_size = SLAB_CHUNK_SIZE (allocator, ix);
- g_mutex_lock (allocator->slab_mutex);
+ const gsize chunk_size = SLAB_CHUNK_SIZE (allocator, ix);
+ g_mutex_lock (&allocator->slab_mutex);
while (trash)
{
current = trash;
slab_allocator_free_chunk (chunk_size, chunk);
}
}
- g_mutex_unlock (allocator->slab_mutex);
+ g_mutex_unlock (&allocator->slab_mutex);
}
}
{
ChunkLink *current = magazine_chain_prepare_fields (magazine_chunks);
ChunkLink *next, *prev;
- g_mutex_lock (allocator->magazine_mutex);
+ g_mutex_lock (&allocator->magazine_mutex);
/* add magazine at head */
next = allocator->magazines[ix];
if (next)
magazine_chain_count (current) = (gpointer) count;
/* stamp magazine */
magazine_cache_update_stamp();
- magazine_chain_stamp (current) = (gpointer) allocator->last_stamp;
+ magazine_chain_stamp (current) = GUINT_TO_POINTER (allocator->last_stamp);
allocator->magazines[ix] = current;
/* free old magazines beyond a certain threshold */
magazine_cache_trim (allocator, ix, allocator->last_stamp);
magazine_cache_pop_magazine (guint ix,
gsize *countp)
{
- g_mutex_lock_a (allocator->magazine_mutex, &allocator->contention_counters[ix]);
+ g_mutex_lock_a (&allocator->magazine_mutex, &allocator->contention_counters[ix]);
if (!allocator->magazines[ix])
{
guint magazine_threshold = allocator_get_magazine_threshold (allocator, ix);
gsize i, chunk_size = SLAB_CHUNK_SIZE (allocator, ix);
- ChunkLink *current = NULL;
- g_mutex_unlock (allocator->magazine_mutex);
- g_mutex_lock (allocator->slab_mutex);
- for (i = 0; i < magazine_threshold; i++)
+ ChunkLink *chunk, *head;
+ g_mutex_unlock (&allocator->magazine_mutex);
+ g_mutex_lock (&allocator->slab_mutex);
+ head = slab_allocator_alloc_chunk (chunk_size);
+ head->data = NULL;
+ chunk = head;
+ for (i = 1; i < magazine_threshold; i++)
{
- ChunkLink *chunk = slab_allocator_alloc_chunk (chunk_size);
+ chunk->next = slab_allocator_alloc_chunk (chunk_size);
+ chunk = chunk->next;
chunk->data = NULL;
- chunk->next = current;
- current = chunk;
}
- g_mutex_unlock (allocator->slab_mutex);
+ chunk->next = NULL;
+ g_mutex_unlock (&allocator->slab_mutex);
*countp = i;
- return current;
+ return head;
}
else
{
magazine_chain_next (prev) = next;
magazine_chain_prev (next) = prev;
allocator->magazines[ix] = next == current ? NULL : next;
- g_mutex_unlock (allocator->magazine_mutex);
+ g_mutex_unlock (&allocator->magazine_mutex);
/* clear special fields and hand out */
*countp = (gsize) magazine_chain_count (current);
magazine_chain_prev (current) = NULL;
magazine_cache_push_magazine (ix, mag->chunks, mag->count);
else
{
- const guint chunk_size = SLAB_CHUNK_SIZE (allocator, ix);
- g_mutex_lock (allocator->slab_mutex);
+ const gsize chunk_size = SLAB_CHUNK_SIZE (allocator, ix);
+ g_mutex_lock (&allocator->slab_mutex);
while (mag->chunks)
{
ChunkLink *chunk = magazine_chain_pop_head (&mag->chunks);
slab_allocator_free_chunk (chunk_size, chunk);
}
- g_mutex_unlock (allocator->slab_mutex);
+ g_mutex_unlock (&allocator->slab_mutex);
}
}
}
guint ix)
{
Magazine *mag = &tmem->magazine1[ix];
- g_assert (mag->chunks == NULL); /* ensure that we may reset mag->count */
+ mem_assert (mag->chunks == NULL); /* ensure that we may reset mag->count */
mag->count = 0;
mag->chunks = magazine_cache_pop_magazine (ix, &mag->count);
}
}
/* --- API functions --- */
+
+/**
+ * g_slice_new:
+ * @type: the type to allocate, typically a structure name
+ *
+ * A convenience macro to allocate a block of memory from the
+ * slice allocator.
+ *
+ * It calls g_slice_alloc() with `sizeof (@type)` and casts the
+ * returned pointer to a pointer of the given type, avoiding a type
+ * cast in the source code. Note that the underlying slice allocation
+ * mechanism can be changed with the [`G_SLICE=always-malloc`][G_SLICE]
+ * environment variable.
+ *
+ * Returns: a pointer to the allocated block, cast to a pointer to @type
+ *
+ * Since: 2.10
+ */
+
+/**
+ * g_slice_new0:
+ * @type: the type to allocate, typically a structure name
+ *
+ * A convenience macro to allocate a block of memory from the
+ * slice allocator and set the memory to 0.
+ *
+ * It calls g_slice_alloc0() with `sizeof (@type)`
+ * and casts the returned pointer to a pointer of the given type,
+ * avoiding a type cast in the source code.
+ * Note that the underlying slice allocation mechanism can
+ * be changed with the [`G_SLICE=always-malloc`][G_SLICE]
+ * environment variable.
+ *
+ * Since: 2.10
+ */
+
+/**
+ * g_slice_dup:
+ * @type: the type to duplicate, typically a structure name
+ * @mem: the memory to copy into the allocated block
+ *
+ * A convenience macro to duplicate a block of memory using
+ * the slice allocator.
+ *
+ * It calls g_slice_copy() with `sizeof (@type)`
+ * and casts the returned pointer to a pointer of the given type,
+ * avoiding a type cast in the source code.
+ * Note that the underlying slice allocation mechanism can
+ * be changed with the [`G_SLICE=always-malloc`][G_SLICE]
+ * environment variable.
+ *
+ * Returns: a pointer to the allocated block, cast to a pointer to @type
+ *
+ * Since: 2.14
+ */
+
+/**
+ * g_slice_free:
+ * @type: the type of the block to free, typically a structure name
+ * @mem: a pointer to the block to free
+ *
+ * A convenience macro to free a block of memory that has
+ * been allocated from the slice allocator.
+ *
+ * It calls g_slice_free1() using `sizeof (type)`
+ * as the block size.
+ * Note that the exact release behaviour can be changed with the
+ * [`G_DEBUG=gc-friendly`][G_DEBUG] environment variable, also see
+ * [`G_SLICE`][G_SLICE] for related debugging options.
+ *
+ * Since: 2.10
+ */
+
+/**
+ * g_slice_free_chain:
+ * @type: the type of the @mem_chain blocks
+ * @mem_chain: a pointer to the first block of the chain
+ * @next: the field name of the next pointer in @type
+ *
+ * Frees a linked list of memory blocks of structure type @type.
+ * The memory blocks must be equal-sized, allocated via
+ * g_slice_alloc() or g_slice_alloc0() and linked together by
+ * a @next pointer (similar to #GSList). The name of the
+ * @next field in @type is passed as third argument.
+ * Note that the exact release behaviour can be changed with the
+ * [`G_DEBUG=gc-friendly`][G_DEBUG] environment variable, also see
+ * [`G_SLICE`][G_SLICE] for related debugging options.
+ *
+ * Since: 2.10
+ */
+
+/**
+ * g_slice_alloc:
+ * @block_size: the number of bytes to allocate
+ *
+ * Allocates a block of memory from the slice allocator.
+ * The block adress handed out can be expected to be aligned
+ * to at least 1 * sizeof (void*),
+ * though in general slices are 2 * sizeof (void*) bytes aligned,
+ * if a malloc() fallback implementation is used instead,
+ * the alignment may be reduced in a libc dependent fashion.
+ * Note that the underlying slice allocation mechanism can
+ * be changed with the [`G_SLICE=always-malloc`][G_SLICE]
+ * environment variable.
+ *
+ * Returns: a pointer to the allocated memory block
+ *
+ * Since: 2.10
+ */
gpointer
g_slice_alloc (gsize mem_size)
{
+ ThreadMemory *tmem;
gsize chunk_size;
gpointer mem;
guint acat;
+
+ /* This gets the private structure for this thread. If the private
+ * structure does not yet exist, it is created.
+ *
+ * This has a side effect of causing GSlice to be initialised, so it
+ * must come first.
+ */
+ tmem = thread_memory_from_self ();
+
chunk_size = P2ALIGN (mem_size);
acat = allocator_categorize (chunk_size);
if (G_LIKELY (acat == 1)) /* allocate through magazine layer */
{
- ThreadMemory *tmem = thread_memory_from_self();
guint ix = SLAB_INDEX (allocator, chunk_size);
if (G_UNLIKELY (thread_memory_magazine1_is_empty (tmem, ix)))
{
}
else if (acat == 2) /* allocate through slab allocator */
{
- g_mutex_lock (allocator->slab_mutex);
+ g_mutex_lock (&allocator->slab_mutex);
mem = slab_allocator_alloc_chunk (chunk_size);
- g_mutex_unlock (allocator->slab_mutex);
+ g_mutex_unlock (&allocator->slab_mutex);
}
else /* delegate to system malloc */
mem = g_malloc (mem_size);
+ if (G_UNLIKELY (allocator->config.debug_blocks))
+ smc_notify_alloc (mem, mem_size);
+
+ TRACE (GLIB_SLICE_ALLOC((void*)mem, mem_size));
+
return mem;
}
+/**
+ * g_slice_alloc0:
+ * @block_size: the number of bytes to allocate
+ *
+ * Allocates a block of memory via g_slice_alloc() and initializes
+ * the returned memory to 0. Note that the underlying slice allocation
+ * mechanism can be changed with the [`G_SLICE=always-malloc`][G_SLICE]
+ * environment variable.
+ *
+ * Returns: a pointer to the allocated block
+ *
+ * Since: 2.10
+ */
gpointer
-g_slice_alloc0 (guint mem_size)
+g_slice_alloc0 (gsize mem_size)
{
gpointer mem = g_slice_alloc (mem_size);
if (mem)
return mem;
}
+/**
+ * g_slice_copy:
+ * @block_size: the number of bytes to allocate
+ * @mem_block: the memory to copy
+ *
+ * Allocates a block of memory from the slice allocator
+ * and copies @block_size bytes into it from @mem_block.
+ *
+ * Returns: a pointer to the allocated memory block
+ *
+ * Since: 2.14
+ */
+gpointer
+g_slice_copy (gsize mem_size,
+ gconstpointer mem_block)
+{
+ gpointer mem = g_slice_alloc (mem_size);
+ if (mem)
+ memcpy (mem, mem_block, mem_size);
+ return mem;
+}
+
+/**
+ * g_slice_free1:
+ * @block_size: the size of the block
+ * @mem_block: a pointer to the block to free
+ *
+ * Frees a block of memory.
+ *
+ * The memory must have been allocated via g_slice_alloc() or
+ * g_slice_alloc0() and the @block_size has to match the size
+ * specified upon allocation. Note that the exact release behaviour
+ * can be changed with the [`G_DEBUG=gc-friendly`][G_DEBUG] environment
+ * variable, also see [`G_SLICE`][G_SLICE] for related debugging options.
+ *
+ * Since: 2.10
+ */
void
-g_slice_free1 (guint mem_size,
+g_slice_free1 (gsize mem_size,
gpointer mem_block)
{
- guint chunk_size = P2ALIGN (mem_size);
+ gsize chunk_size = P2ALIGN (mem_size);
guint acat = allocator_categorize (chunk_size);
if (G_UNLIKELY (!mem_block))
- /* pass */;
- else if (G_LIKELY (acat == 1)) /* allocate through magazine layer */
+ return;
+ if (G_UNLIKELY (allocator->config.debug_blocks) &&
+ !smc_notify_free (mem_block, mem_size))
+ abort();
+ if (G_LIKELY (acat == 1)) /* allocate through magazine layer */
{
ThreadMemory *tmem = thread_memory_from_self();
guint ix = SLAB_INDEX (allocator, chunk_size);
if (G_UNLIKELY (thread_memory_magazine2_is_full (tmem, ix)))
thread_memory_magazine2_unload (tmem, ix);
}
+ if (G_UNLIKELY (g_mem_gc_friendly))
+ memset (mem_block, 0, chunk_size);
thread_memory_magazine2_free (tmem, ix, mem_block);
}
else if (acat == 2) /* allocate through slab allocator */
{
- g_mutex_lock (allocator->slab_mutex);
+ if (G_UNLIKELY (g_mem_gc_friendly))
+ memset (mem_block, 0, chunk_size);
+ g_mutex_lock (&allocator->slab_mutex);
slab_allocator_free_chunk (chunk_size, mem_block);
- g_mutex_unlock (allocator->slab_mutex);
+ g_mutex_unlock (&allocator->slab_mutex);
}
- else /* delegate to system malloc */
- g_free (mem_block);
+ else /* delegate to system malloc */
+ {
+ if (G_UNLIKELY (g_mem_gc_friendly))
+ memset (mem_block, 0, mem_size);
+ g_free (mem_block);
+ }
+ TRACE (GLIB_SLICE_FREE((void*)mem_block, mem_size));
}
+/**
+ * g_slice_free_chain_with_offset:
+ * @block_size: the size of the blocks
+ * @mem_chain: a pointer to the first block of the chain
+ * @next_offset: the offset of the @next field in the blocks
+ *
+ * Frees a linked list of memory blocks of structure type @type.
+ *
+ * The memory blocks must be equal-sized, allocated via
+ * g_slice_alloc() or g_slice_alloc0() and linked together by a
+ * @next pointer (similar to #GSList). The offset of the @next
+ * field in each block is passed as third argument.
+ * Note that the exact release behaviour can be changed with the
+ * [`G_DEBUG=gc-friendly`][G_DEBUG] environment variable, also see
+ * [`G_SLICE`][G_SLICE] for related debugging options.
+ *
+ * Since: 2.10
+ */
void
-g_slice_free_chain (guint mem_size,
- gpointer mem_chain,
- guint next_offset)
+g_slice_free_chain_with_offset (gsize mem_size,
+ gpointer mem_chain,
+ gsize next_offset)
{
- GSList *slice = mem_chain;
- g_return_if_fail (next_offset == G_STRUCT_OFFSET (GSList, next));
- g_return_if_fail (mem_size >= sizeof (GSList));
- while (slice)
- {
- GSList *current = slice;
- slice = slice->next;
- g_slice_free1 (mem_size, current);
- }
+ gpointer slice = mem_chain;
/* while the thread magazines and the magazine cache are implemented so that
* they can easily be extended to allow for free lists containing more free
* lists for the first level nodes, which would allow O(1) freeing in this
* - memory usage histograms on larger applications seem to indicate that
* the amount of released multi node lists is negligible in comparison
* to single node releases.
+ * - the major performance bottle neck, namely g_private_get() or
+ * g_mutex_lock()/g_mutex_unlock() has already been moved out of the
+ * inner loop for freeing chained slices.
*/
+ gsize chunk_size = P2ALIGN (mem_size);
+ guint acat = allocator_categorize (chunk_size);
+ if (G_LIKELY (acat == 1)) /* allocate through magazine layer */
+ {
+ ThreadMemory *tmem = thread_memory_from_self();
+ guint ix = SLAB_INDEX (allocator, chunk_size);
+ while (slice)
+ {
+ guint8 *current = slice;
+ slice = *(gpointer*) (current + next_offset);
+ if (G_UNLIKELY (allocator->config.debug_blocks) &&
+ !smc_notify_free (current, mem_size))
+ abort();
+ if (G_UNLIKELY (thread_memory_magazine2_is_full (tmem, ix)))
+ {
+ thread_memory_swap_magazines (tmem, ix);
+ if (G_UNLIKELY (thread_memory_magazine2_is_full (tmem, ix)))
+ thread_memory_magazine2_unload (tmem, ix);
+ }
+ if (G_UNLIKELY (g_mem_gc_friendly))
+ memset (current, 0, chunk_size);
+ thread_memory_magazine2_free (tmem, ix, current);
+ }
+ }
+ else if (acat == 2) /* allocate through slab allocator */
+ {
+ g_mutex_lock (&allocator->slab_mutex);
+ while (slice)
+ {
+ guint8 *current = slice;
+ slice = *(gpointer*) (current + next_offset);
+ if (G_UNLIKELY (allocator->config.debug_blocks) &&
+ !smc_notify_free (current, mem_size))
+ abort();
+ if (G_UNLIKELY (g_mem_gc_friendly))
+ memset (current, 0, chunk_size);
+ slab_allocator_free_chunk (chunk_size, current);
+ }
+ g_mutex_unlock (&allocator->slab_mutex);
+ }
+ else /* delegate to system malloc */
+ while (slice)
+ {
+ guint8 *current = slice;
+ slice = *(gpointer*) (current + next_offset);
+ if (G_UNLIKELY (allocator->config.debug_blocks) &&
+ !smc_notify_free (current, mem_size))
+ abort();
+ if (G_UNLIKELY (g_mem_gc_friendly))
+ memset (current, 0, mem_size);
+ g_free (current);
+ }
}
/* --- single page allocator --- */
allocator->slab_stack[ix] = sinfo;
}
+static gsize
+allocator_aligned_page_size (Allocator *allocator,
+ gsize n_bytes)
+{
+ gsize val = 1 << g_bit_storage (n_bytes - 1);
+ val = MAX (val, allocator->min_page_size);
+ return val;
+}
+
static void
allocator_add_slab (Allocator *allocator,
guint ix,
- guint chunk_size)
+ gsize chunk_size)
{
+ ChunkLink *chunk;
SlabInfo *sinfo;
- gsize padding, n_chunks, color = 0;
- gsize page_size = SLAB_PAGE_SIZE (allocator, chunk_size);
+ gsize addr, padding, n_chunks, color = 0;
+ gsize page_size = allocator_aligned_page_size (allocator, SLAB_BPAGE_SIZE (allocator, chunk_size));
/* allocate 1 page for the chunks and the slab */
gpointer aligned_memory = allocator_memalign (page_size, page_size - NATIVE_MALLOC_PADDING);
guint8 *mem = aligned_memory;
+ guint i;
if (!mem)
- g_error ("%s: failed to allocate %lu bytes: %s", "GSlicedMemory", (gulong) (page_size - NATIVE_MALLOC_PADDING), g_strerror (errno));
- /* mask page adress */
- gsize addr = ((gsize) mem / page_size) * page_size;
+ {
+ const gchar *syserr = strerror (errno);
+ mem_error ("failed to allocate %u bytes (alignment: %u): %s\n",
+ (guint) (page_size - NATIVE_MALLOC_PADDING), (guint) page_size, syserr);
+ }
+ /* mask page address */
+ addr = ((gsize) mem / page_size) * page_size;
/* assert alignment */
- g_assert (aligned_memory == (gpointer) addr);
+ mem_assert (aligned_memory == (gpointer) addr);
/* basic slab info setup */
sinfo = (SlabInfo*) (mem + page_size - SLAB_INFO_SIZE);
sinfo->n_allocated = 0;
if (padding)
{
color = (allocator->color_accu * P2ALIGNMENT) % padding;
- allocator->color_accu += 1; /* alternatively: + 0x7fffffff */
+ allocator->color_accu += allocator->config.color_increment;
}
/* add chunks to free list */
- ChunkLink *chunk = (ChunkLink*) (mem + color);
- guint i;
+ chunk = (ChunkLink*) (mem + color);
sinfo->chunks = chunk;
for (i = 0; i < n_chunks - 1; i++)
{
}
static gpointer
-slab_allocator_alloc_chunk (guint chunk_size)
+slab_allocator_alloc_chunk (gsize chunk_size)
{
+ ChunkLink *chunk;
guint ix = SLAB_INDEX (allocator, chunk_size);
/* ensure non-empty slab */
if (!allocator->slab_stack[ix] || !allocator->slab_stack[ix]->chunks)
allocator_add_slab (allocator, ix, chunk_size);
/* allocate chunk */
- ChunkLink *chunk = allocator->slab_stack[ix]->chunks;
+ chunk = allocator->slab_stack[ix]->chunks;
allocator->slab_stack[ix]->chunks = chunk->next;
allocator->slab_stack[ix]->n_allocated++;
/* rotate empty slabs */
}
static void
-slab_allocator_free_chunk (guint chunk_size,
+slab_allocator_free_chunk (gsize chunk_size,
gpointer mem)
{
+ ChunkLink *chunk;
+ gboolean was_empty;
guint ix = SLAB_INDEX (allocator, chunk_size);
- gsize page_size = SLAB_PAGE_SIZE (allocator, chunk_size);
+ gsize page_size = allocator_aligned_page_size (allocator, SLAB_BPAGE_SIZE (allocator, chunk_size));
gsize addr = ((gsize) mem / page_size) * page_size;
- /* mask page adress */
+ /* mask page address */
guint8 *page = (guint8*) addr;
SlabInfo *sinfo = (SlabInfo*) (page + page_size - SLAB_INFO_SIZE);
/* assert valid chunk count */
- g_assert (sinfo->n_allocated > 0);
+ mem_assert (sinfo->n_allocated > 0);
/* add chunk to free list */
- gboolean was_empty = sinfo->chunks == NULL;
- ChunkLink *chunk = (ChunkLink*) mem;
+ was_empty = sinfo->chunks == NULL;
+ chunk = (ChunkLink*) mem;
chunk->next = sinfo->chunks;
sinfo->chunks = chunk;
sinfo->n_allocated--;
}
/* --- memalign implementation --- */
+#ifdef HAVE_MALLOC_H
#include <malloc.h> /* memalign() */
+#endif
/* from config.h:
- * define HAVE_POSIX_MEMALIGN 1 // if free(posix_memalign(3)) works, <stdlib.h>
- * define HAVE_MEMALIGN 1 // if free(memalign(3)) works, <malloc.h>
- * define HAVE_VALLOC 1 // if free(valloc(3)) works, <stdlib.h> or <malloc.h>
+ * define HAVE_POSIX_MEMALIGN 1 // if free(posix_memalign(3)) works, <stdlib.h>
+ * define HAVE_COMPLIANT_POSIX_MEMALIGN 1 // if free(posix_memalign(3)) works for sizes != 2^n, <stdlib.h>
+ * define HAVE_MEMALIGN 1 // if free(memalign(3)) works, <malloc.h>
+ * define HAVE_VALLOC 1 // if free(valloc(3)) works, <stdlib.h> or <malloc.h>
* if none is provided, we implement malloc(3)-based alloc-only page alignment
*/
-#if !(HAVE_POSIX_MEMALIGN || HAVE_MEMALIGN || HAVE_VALLOC)
+#if !(HAVE_COMPLIANT_POSIX_MEMALIGN || HAVE_MEMALIGN || HAVE_VALLOC)
static GTrashStack *compat_valloc_trash = NULL;
#endif
{
gpointer aligned_memory = NULL;
gint err = ENOMEM;
-#if HAVE_POSIX_MEMALIGN
+#if HAVE_COMPLIANT_POSIX_MEMALIGN
err = posix_memalign (&aligned_memory, alignment, memsize);
#elif HAVE_MEMALIGN
errno = 0;
err = errno;
#else
/* simplistic non-freeing page allocator */
- g_assert (alignment == sys_page_size);
- g_assert (memsize <= sys_page_size);
+ mem_assert (alignment == sys_page_size);
+ mem_assert (memsize <= sys_page_size);
if (!compat_valloc_trash)
{
const guint n_pages = 16;
allocator_memfree (gsize memsize,
gpointer mem)
{
-#if HAVE_POSIX_MEMALIGN || HAVE_MEMALIGN || HAVE_VALLOC
+#if HAVE_COMPLIANT_POSIX_MEMALIGN || HAVE_MEMALIGN || HAVE_VALLOC
free (mem);
#else
- g_assert (memsize <= sys_page_size);
+ mem_assert (memsize <= sys_page_size);
g_trash_stack_push (&compat_valloc_trash, mem);
#endif
}
-#define __G_SLICE_C__
-#include "galiasdef.c"
+static void
+mem_error (const char *format,
+ ...)
+{
+ const char *pname;
+ va_list args;
+ /* at least, put out "MEMORY-ERROR", in case we segfault during the rest of the function */
+ fputs ("\n***MEMORY-ERROR***: ", stderr);
+ pname = g_get_prgname();
+ fprintf (stderr, "%s[%ld]: GSlice: ", pname ? pname : "", (long)getpid());
+ va_start (args, format);
+ vfprintf (stderr, format, args);
+ va_end (args);
+ fputs ("\n", stderr);
+ abort();
+ _exit (1);
+}
+
+/* --- g-slice memory checker tree --- */
+typedef size_t SmcKType; /* key type */
+typedef size_t SmcVType; /* value type */
+typedef struct {
+ SmcKType key;
+ SmcVType value;
+} SmcEntry;
+static void smc_tree_insert (SmcKType key,
+ SmcVType value);
+static gboolean smc_tree_lookup (SmcKType key,
+ SmcVType *value_p);
+static gboolean smc_tree_remove (SmcKType key);
+
+
+/* --- g-slice memory checker implementation --- */
+static void
+smc_notify_alloc (void *pointer,
+ size_t size)
+{
+ size_t adress = (size_t) pointer;
+ if (pointer)
+ smc_tree_insert (adress, size);
+}
+
+#if 0
+static void
+smc_notify_ignore (void *pointer)
+{
+ size_t adress = (size_t) pointer;
+ if (pointer)
+ smc_tree_remove (adress);
+}
+#endif
+
+static int
+smc_notify_free (void *pointer,
+ size_t size)
+{
+ size_t adress = (size_t) pointer;
+ SmcVType real_size;
+ gboolean found_one;
+
+ if (!pointer)
+ return 1; /* ignore */
+ found_one = smc_tree_lookup (adress, &real_size);
+ if (!found_one)
+ {
+ fprintf (stderr, "GSlice: MemChecker: attempt to release non-allocated block: %p size=%" G_GSIZE_FORMAT "\n", pointer, size);
+ return 0;
+ }
+ if (real_size != size && (real_size || size))
+ {
+ fprintf (stderr, "GSlice: MemChecker: attempt to release block with invalid size: %p size=%" G_GSIZE_FORMAT " invalid-size=%" G_GSIZE_FORMAT "\n", pointer, real_size, size);
+ return 0;
+ }
+ if (!smc_tree_remove (adress))
+ {
+ fprintf (stderr, "GSlice: MemChecker: attempt to release non-allocated block: %p size=%" G_GSIZE_FORMAT "\n", pointer, size);
+ return 0;
+ }
+ return 1; /* all fine */
+}
+
+/* --- g-slice memory checker tree implementation --- */
+#define SMC_TRUNK_COUNT (4093 /* 16381 */) /* prime, to distribute trunk collisions (big, allocated just once) */
+#define SMC_BRANCH_COUNT (511) /* prime, to distribute branch collisions */
+#define SMC_TRUNK_EXTENT (SMC_BRANCH_COUNT * 2039) /* key address space per trunk, should distribute uniformly across BRANCH_COUNT */
+#define SMC_TRUNK_HASH(k) ((k / SMC_TRUNK_EXTENT) % SMC_TRUNK_COUNT) /* generate new trunk hash per megabyte (roughly) */
+#define SMC_BRANCH_HASH(k) (k % SMC_BRANCH_COUNT)
+
+typedef struct {
+ SmcEntry *entries;
+ unsigned int n_entries;
+} SmcBranch;
+
+static SmcBranch **smc_tree_root = NULL;
+
+static void
+smc_tree_abort (int errval)
+{
+ const char *syserr = strerror (errval);
+ mem_error ("MemChecker: failure in debugging tree: %s", syserr);
+}
+
+static inline SmcEntry*
+smc_tree_branch_grow_L (SmcBranch *branch,
+ unsigned int index)
+{
+ unsigned int old_size = branch->n_entries * sizeof (branch->entries[0]);
+ unsigned int new_size = old_size + sizeof (branch->entries[0]);
+ SmcEntry *entry;
+ mem_assert (index <= branch->n_entries);
+ branch->entries = (SmcEntry*) realloc (branch->entries, new_size);
+ if (!branch->entries)
+ smc_tree_abort (errno);
+ entry = branch->entries + index;
+ memmove (entry + 1, entry, (branch->n_entries - index) * sizeof (entry[0]));
+ branch->n_entries += 1;
+ return entry;
+}
+
+static inline SmcEntry*
+smc_tree_branch_lookup_nearest_L (SmcBranch *branch,
+ SmcKType key)
+{
+ unsigned int n_nodes = branch->n_entries, offs = 0;
+ SmcEntry *check = branch->entries;
+ int cmp = 0;
+ while (offs < n_nodes)
+ {
+ unsigned int i = (offs + n_nodes) >> 1;
+ check = branch->entries + i;
+ cmp = key < check->key ? -1 : key != check->key;
+ if (cmp == 0)
+ return check; /* return exact match */
+ else if (cmp < 0)
+ n_nodes = i;
+ else /* (cmp > 0) */
+ offs = i + 1;
+ }
+ /* check points at last mismatch, cmp > 0 indicates greater key */
+ return cmp > 0 ? check + 1 : check; /* return insertion position for inexact match */
+}
+
+static void
+smc_tree_insert (SmcKType key,
+ SmcVType value)
+{
+ unsigned int ix0, ix1;
+ SmcEntry *entry;
+
+ g_mutex_lock (&smc_tree_mutex);
+ ix0 = SMC_TRUNK_HASH (key);
+ ix1 = SMC_BRANCH_HASH (key);
+ if (!smc_tree_root)
+ {
+ smc_tree_root = calloc (SMC_TRUNK_COUNT, sizeof (smc_tree_root[0]));
+ if (!smc_tree_root)
+ smc_tree_abort (errno);
+ }
+ if (!smc_tree_root[ix0])
+ {
+ smc_tree_root[ix0] = calloc (SMC_BRANCH_COUNT, sizeof (smc_tree_root[0][0]));
+ if (!smc_tree_root[ix0])
+ smc_tree_abort (errno);
+ }
+ entry = smc_tree_branch_lookup_nearest_L (&smc_tree_root[ix0][ix1], key);
+ if (!entry || /* need create */
+ entry >= smc_tree_root[ix0][ix1].entries + smc_tree_root[ix0][ix1].n_entries || /* need append */
+ entry->key != key) /* need insert */
+ entry = smc_tree_branch_grow_L (&smc_tree_root[ix0][ix1], entry - smc_tree_root[ix0][ix1].entries);
+ entry->key = key;
+ entry->value = value;
+ g_mutex_unlock (&smc_tree_mutex);
+}
+
+static gboolean
+smc_tree_lookup (SmcKType key,
+ SmcVType *value_p)
+{
+ SmcEntry *entry = NULL;
+ unsigned int ix0 = SMC_TRUNK_HASH (key), ix1 = SMC_BRANCH_HASH (key);
+ gboolean found_one = FALSE;
+ *value_p = 0;
+ g_mutex_lock (&smc_tree_mutex);
+ if (smc_tree_root && smc_tree_root[ix0])
+ {
+ entry = smc_tree_branch_lookup_nearest_L (&smc_tree_root[ix0][ix1], key);
+ if (entry &&
+ entry < smc_tree_root[ix0][ix1].entries + smc_tree_root[ix0][ix1].n_entries &&
+ entry->key == key)
+ {
+ found_one = TRUE;
+ *value_p = entry->value;
+ }
+ }
+ g_mutex_unlock (&smc_tree_mutex);
+ return found_one;
+}
+
+static gboolean
+smc_tree_remove (SmcKType key)
+{
+ unsigned int ix0 = SMC_TRUNK_HASH (key), ix1 = SMC_BRANCH_HASH (key);
+ gboolean found_one = FALSE;
+ g_mutex_lock (&smc_tree_mutex);
+ if (smc_tree_root && smc_tree_root[ix0])
+ {
+ SmcEntry *entry = smc_tree_branch_lookup_nearest_L (&smc_tree_root[ix0][ix1], key);
+ if (entry &&
+ entry < smc_tree_root[ix0][ix1].entries + smc_tree_root[ix0][ix1].n_entries &&
+ entry->key == key)
+ {
+ unsigned int i = entry - smc_tree_root[ix0][ix1].entries;
+ smc_tree_root[ix0][ix1].n_entries -= 1;
+ memmove (entry, entry + 1, (smc_tree_root[ix0][ix1].n_entries - i) * sizeof (entry[0]));
+ if (!smc_tree_root[ix0][ix1].n_entries)
+ {
+ /* avoid useless pressure on the memory system */
+ free (smc_tree_root[ix0][ix1].entries);
+ smc_tree_root[ix0][ix1].entries = NULL;
+ }
+ found_one = TRUE;
+ }
+ }
+ g_mutex_unlock (&smc_tree_mutex);
+ return found_one;
+}
+
+#ifdef G_ENABLE_DEBUG
+void
+g_slice_debug_tree_statistics (void)
+{
+ g_mutex_lock (&smc_tree_mutex);
+ if (smc_tree_root)
+ {
+ unsigned int i, j, t = 0, o = 0, b = 0, su = 0, ex = 0, en = 4294967295u;
+ double tf, bf;
+ for (i = 0; i < SMC_TRUNK_COUNT; i++)
+ if (smc_tree_root[i])
+ {
+ t++;
+ for (j = 0; j < SMC_BRANCH_COUNT; j++)
+ if (smc_tree_root[i][j].n_entries)
+ {
+ b++;
+ su += smc_tree_root[i][j].n_entries;
+ en = MIN (en, smc_tree_root[i][j].n_entries);
+ ex = MAX (ex, smc_tree_root[i][j].n_entries);
+ }
+ else if (smc_tree_root[i][j].entries)
+ o++; /* formerly used, now empty */
+ }
+ en = b ? en : 0;
+ tf = MAX (t, 1.0); /* max(1) to be a valid divisor */
+ bf = MAX (b, 1.0); /* max(1) to be a valid divisor */
+ fprintf (stderr, "GSlice: MemChecker: %u trunks, %u branches, %u old branches\n", t, b, o);
+ fprintf (stderr, "GSlice: MemChecker: %f branches per trunk, %.2f%% utilization\n",
+ b / tf,
+ 100.0 - (SMC_BRANCH_COUNT - b / tf) / (0.01 * SMC_BRANCH_COUNT));
+ fprintf (stderr, "GSlice: MemChecker: %f entries per branch, %u minimum, %u maximum\n",
+ su / bf, en, ex);
+ }
+ else
+ fprintf (stderr, "GSlice: MemChecker: root=NULL\n");
+ g_mutex_unlock (&smc_tree_mutex);
+
+ /* sample statistics (beast + GSLice + 24h scripted core & GUI activity):
+ * PID %CPU %MEM VSZ RSS COMMAND
+ * 8887 30.3 45.8 456068 414856 beast-0.7.1 empty.bse
+ * $ cat /proc/8887/statm # total-program-size resident-set-size shared-pages text/code data/stack library dirty-pages
+ * 114017 103714 2354 344 0 108676 0
+ * $ cat /proc/8887/status
+ * Name: beast-0.7.1
+ * VmSize: 456068 kB
+ * VmLck: 0 kB
+ * VmRSS: 414856 kB
+ * VmData: 434620 kB
+ * VmStk: 84 kB
+ * VmExe: 1376 kB
+ * VmLib: 13036 kB
+ * VmPTE: 456 kB
+ * Threads: 3
+ * (gdb) print g_slice_debug_tree_statistics ()
+ * GSlice: MemChecker: 422 trunks, 213068 branches, 0 old branches
+ * GSlice: MemChecker: 504.900474 branches per trunk, 98.81% utilization
+ * GSlice: MemChecker: 4.965039 entries per branch, 1 minimum, 37 maximum
+ */
+}
+#endif /* G_ENABLE_DEBUG */
projects / platform / upstream / glib.git / blobdiff