#define POOL_DEF_EXTENT (32 * 1024)
+#define POOL_QALIGN_P2 (1<<16) /* power-of-2 qalign */
+
struct alloc_pool
{
size_t size; /* extent size */
size_t quantum; /* allocation quantum */
- struct pool_extent *live; /* current extent for
- * allocations */
- struct pool_extent *free; /* unfreed extent list */
- void (*bomb)();
- /* function to call if
+ struct pool_extent *extents; /* top extent is "live" */
+ void (*bomb)(); /* function to call if
* malloc fails */
int flags;
/* statistical data */
unsigned long e_created; /* extents created */
- unsigned long e_freed; /* extents detroyed */
- uint64 n_allocated; /* calls to alloc */
- uint64 n_freed; /* calls to free */
- uint64 b_allocated; /* cum. bytes allocated */
- uint64 b_freed; /* cum. bytes freed */
+ unsigned long e_freed; /* extents destroyed */
+ int64 n_allocated; /* calls to alloc */
+ int64 n_freed; /* calls to free */
+ int64 b_allocated; /* cum. bytes allocated */
+ int64 b_freed; /* cum. bytes freed */
};
struct pool_extent
{
+ struct pool_extent *next;
void *start; /* starting address */
size_t free; /* free bytecount */
- size_t bound; /* bytes bound by padding,
- * overhead and freed */
- struct pool_extent *next;
+ size_t bound; /* trapped free bytes */
};
-#define MINALIGN (sizeof (void *))
+struct align_test {
+ uchar foo;
+ union {
+ int64 i;
+ void *p;
+ } bar;
+};
+
+#define MINALIGN offsetof(struct align_test, bar)
+
+/* Temporarily cast a void* var into a char* var when adding an offset (to
+ * keep some compilers from complaining about the pointer arithmetic). */
+#define PTR_ADD(b,o) ( (void*) ((char*)(b) + (o)) )
alloc_pool_t
-pool_create(size_t size, size_t quantum,
- void (*bomb)(char *), int flags)
+pool_create(size_t size, size_t quantum, void (*bomb)(const char *), int flags)
{
- struct alloc_pool *pool;
-
- if (!(pool = (struct alloc_pool*) malloc(sizeof (struct alloc_pool))))
- return pool;
- memset(pool, 0, sizeof (struct alloc_pool));
-
- pool->size = size /* round extent size to min alignment reqs */
- ? (size + MINALIGN - 1) & ~(MINALIGN - 1)
- : POOL_DEF_EXTENT;
- if (pool->flags & POOL_INTERN)
- {
- pool->size -= sizeof (struct pool_extent);
- flags |= POOL_APPEND;
+ struct alloc_pool *pool;
+
+ if (!(pool = new0(struct alloc_pool)))
+ return NULL;
+
+ if ((MINALIGN & (MINALIGN - 1)) != 0) {
+ if (bomb)
+ (*bomb)("Compiler error: MINALIGN is not a power of 2\n");
+ return NULL;
}
- pool->quantum = quantum ? quantum : MINALIGN;
+
+ if (!size)
+ size = POOL_DEF_EXTENT;
+ if (!quantum)
+ quantum = MINALIGN;
+
+ if (flags & POOL_INTERN) {
+ if (size <= sizeof (struct pool_extent))
+ size = quantum;
+ else
+ size -= sizeof (struct pool_extent);
+ flags |= POOL_PREPEND;
+ }
+
+ if (quantum <= 1)
+ flags = (flags | POOL_NO_QALIGN) & ~POOL_QALIGN_P2;
+ else if (!(flags & POOL_NO_QALIGN)) {
+ if (size % quantum)
+ size += quantum - size % quantum;
+ /* If quantum is a power of 2, we'll avoid using modulus. */
+ if (!(quantum & (quantum - 1)))
+ flags |= POOL_QALIGN_P2;
+ }
+
+ pool->size = size;
+ pool->quantum = quantum;
pool->bomb = bomb;
pool->flags = flags;
pool_destroy(alloc_pool_t p)
{
struct alloc_pool *pool = (struct alloc_pool *) p;
- struct pool_extent *cur, *next;
+ struct pool_extent *cur, *next;
if (!pool)
return;
- if (pool->live)
- {
- cur = pool->live;
- free(cur->start);
- if (!(pool->flags & POOL_APPEND))
- free(cur);
- }
- for (cur = pool->free; cur; cur = next)
- {
+ for (cur = pool->extents; cur; cur = next) {
next = cur->next;
- free(cur->start);
- if (!(pool->flags & POOL_APPEND))
+ if (pool->flags & POOL_PREPEND)
+ free(PTR_ADD(cur->start, -sizeof (struct pool_extent)));
+ else {
+ free(cur->start);
free(cur);
+ }
}
+
free(pool);
}
-void *pool_alloc(alloc_pool_t p, size_t len, char *bomb)
+void *
+pool_alloc(alloc_pool_t p, size_t len, const char *bomb_msg)
{
struct alloc_pool *pool = (struct alloc_pool *) p;
if (!pool)
if (!len)
len = pool->quantum;
- else if (pool->quantum > 1 && len % pool->quantum)
- len += pool->quantum - len % pool->quantum;
+ else if (pool->flags & POOL_QALIGN_P2) {
+ if (len & (pool->quantum - 1))
+ len += pool->quantum - (len & (pool->quantum - 1));
+ } else if (!(pool->flags & POOL_NO_QALIGN)) {
+ if (len % pool->quantum)
+ len += pool->quantum - len % pool->quantum;
+ }
if (len > pool->size)
- goto bomb;
-
- if (!pool->live || len > pool->live->free)
- {
- void *start;
- size_t free;
- size_t bound;
- size_t sqew;
- size_t asize;
-
- if (pool->live)
- {
- pool->live->next = pool->free;
- pool->free = pool->live;
- }
+ goto bomb_out;
- free = pool->size;
- bound = 0;
+ if (!pool->extents || len > pool->extents->free) {
+ void *start;
+ size_t asize;
+ struct pool_extent *ext;
asize = pool->size;
- if (pool->flags & POOL_APPEND)
+ if (pool->flags & POOL_PREPEND)
asize += sizeof (struct pool_extent);
- if (!(start = (void *) malloc(asize)))
- goto bomb;
+ if (!(start = new_array(char, asize)))
+ goto bomb_out;
if (pool->flags & POOL_CLEAR)
- memset(start, 0, pool->size);
-
- if (pool->flags & POOL_APPEND)
- {
- pool->live = start + free;
- }
- else if (!(pool->live = (struct pool_extent *) malloc(sizeof (struct pool_extent))))
- {
- goto bomb;
- }
- if (pool->flags & POOL_QALIGN && pool->quantum > 1
- && (sqew = (size_t)(start + free) % pool->quantum))
- {
- bound += sqew;
- free -= sqew;
- }
- pool->live->start = start;
- pool->live->free = free;
- pool->live->bound = bound;
- pool->live->next = NULL;
+ memset(start, 0, asize);
+
+ if (pool->flags & POOL_PREPEND) {
+ ext = start;
+ start = PTR_ADD(start, sizeof (struct pool_extent));
+ } else if (!(ext = new(struct pool_extent)))
+ goto bomb_out;
+ ext->start = start;
+ ext->free = pool->size;
+ ext->bound = 0;
+ ext->next = pool->extents;
+ pool->extents = ext;
pool->e_created++;
}
pool->n_allocated++;
pool->b_allocated += len;
- pool->live->free -= len;
+ pool->extents->free -= len;
- return pool->live->start + pool->live->free;
+ return PTR_ADD(pool->extents->start, pool->extents->free);
-bomb:
+ bomb_out:
if (pool->bomb)
- (*pool->bomb)(bomb);
+ (*pool->bomb)(bomb_msg);
return NULL;
}
+/* This function allows you to declare memory in the pool that you are done
+ * using. If you free all the memory in a pool's extent, that extent will
+ * be freed. */
void
pool_free(alloc_pool_t p, size_t len, void *addr)
{
- struct alloc_pool *pool = (struct alloc_pool *) p;
- struct pool_extent *cur;
- struct pool_extent *prev;
+ struct alloc_pool *pool = (struct alloc_pool *)p;
+ struct pool_extent *cur, *prev;
if (!pool)
return;
+ if (!addr) {
+ /* A NULL addr starts a fresh extent for new allocations. */
+ if ((cur = pool->extents) != NULL && cur->free != pool->size) {
+ cur->bound += cur->free;
+ cur->free = 0;
+ }
+ return;
+ }
+
if (!len)
len = pool->quantum;
- else if (pool->quantum > 1 && len % pool->quantum)
- len += pool->quantum - len % pool->quantum;
-
- if (!addr && pool->live)
- {
- pool->live->next = pool->free;
- pool->free = pool->live;
- pool->live = NULL;
- return;
+ else if (pool->flags & POOL_QALIGN_P2) {
+ if (len & (pool->quantum - 1))
+ len += pool->quantum - (len & (pool->quantum - 1));
+ } else if (!(pool->flags & POOL_NO_QALIGN)) {
+ if (len % pool->quantum)
+ len += pool->quantum - len % pool->quantum;
}
+
pool->n_freed++;
pool->b_freed += len;
- cur = pool->live;
- if (cur
- && addr >= cur->start
- && addr < cur->start + pool->size)
- {
- if (addr == cur->start + cur->free)
- {
- if (pool->flags & POOL_CLEAR)
- memset(addr, 0, len);
- pool->b_freed += len;
- } else {
- cur->bound += len;
- }
- if (cur->free + cur->bound >= pool->size)
- {
- size_t sqew;
+ for (prev = NULL, cur = pool->extents; cur; prev = cur, cur = cur->next) {
+ if (addr >= cur->start
+ && addr < PTR_ADD(cur->start, pool->size))
+ break;
+ }
+ if (!cur)
+ return;
+ if (!prev) {
+ /* The "live" extent is kept ready for more allocations. */
+ if (cur->free + cur->bound + len >= pool->size) {
+ if (pool->flags & POOL_CLEAR) {
+ memset(PTR_ADD(cur->start, cur->free), 0,
+ pool->size - cur->free);
+ }
cur->free = pool->size;
cur->bound = 0;
- if (pool->flags & POOL_QALIGN && pool->quantum > 1
- && (sqew = (size_t)(cur->start + cur->free) % pool->quantum))
- {
- cur->bound += sqew;
- cur->free -= sqew;
+ } else if (addr == PTR_ADD(cur->start, cur->free)) {
+ if (pool->flags & POOL_CLEAR)
+ memset(addr, 0, len);
+ cur->free += len;
+ } else
+ cur->bound += len;
+ } else {
+ cur->bound += len;
+
+ if (cur->free + cur->bound >= pool->size) {
+ prev->next = cur->next;
+ if (pool->flags & POOL_PREPEND)
+ free(PTR_ADD(cur->start, -sizeof (struct pool_extent)));
+ else {
+ free(cur->start);
+ free(cur);
}
+ pool->e_freed++;
+ } else if (prev != pool->extents) {
+ /* Move the extent to be the first non-live extent. */
+ prev->next = cur->next;
+ cur->next = pool->extents->next;
+ pool->extents->next = cur;
}
- return;
}
- for (prev = NULL, cur = pool->free; cur; prev = cur, cur = cur->next)
- {
+}
+
+/* This allows you to declare that the given address marks the edge of some
+ * pool memory that is no longer needed. Any extents that hold only data
+ * older than the boundary address are freed. NOTE: You MUST NOT USE BOTH
+ * pool_free() and pool_free_old() on the same pool!! */
+void
+pool_free_old(alloc_pool_t p, void *addr)
+{
+ struct alloc_pool *pool = (struct alloc_pool *)p;
+ struct pool_extent *cur, *prev, *next;
+
+ if (!pool || !addr)
+ return;
+
+ for (prev = NULL, cur = pool->extents; cur; prev = cur, cur = cur->next) {
if (addr >= cur->start
- && addr < cur->start + pool->size)
+ && addr < PTR_ADD(cur->start, pool->size))
break;
}
if (!cur)
return;
- if (prev)
- {
- prev->next = cur->next;
- cur->next = pool->free;
- pool->free = cur;
+ if (addr == PTR_ADD(cur->start, cur->free)) {
+ if (prev) {
+ prev->next = NULL;
+ next = cur;
+ } else {
+ /* The most recent live extent can just be reset. */
+ if (pool->flags & POOL_CLEAR)
+ memset(addr, 0, pool->size - cur->free);
+ cur->free = pool->size;
+ cur->bound = 0;
+ next = cur->next;
+ cur->next = NULL;
+ }
+ } else {
+ next = cur->next;
+ cur->next = NULL;
}
- cur->bound += len;
- if (cur->free + cur->bound >= pool->size)
- {
- pool->free = cur->next;
-
- free(cur->start);
- if (!(pool->flags & POOL_APPEND))
+ while ((cur = next) != NULL) {
+ next = cur->next;
+ if (pool->flags & POOL_PREPEND)
+ free(PTR_ADD(cur->start, -sizeof (struct pool_extent)));
+ else {
+ free(cur->start);
free(cur);
+ }
pool->e_freed++;
}
- return;
+}
+
+/* If the current extent doesn't have "len" free space in it, mark it as full
+ * so that the next alloc will start a new extent. If len is (size_t)-1, this
+ * bump will always occur. The function returns a boundary address that can
+ * be used with pool_free_old(), or a NULL if no memory is allocated. */
+void *
+pool_boundary(alloc_pool_t p, size_t len)
+{
+ struct alloc_pool *pool = (struct alloc_pool *)p;
+ struct pool_extent *cur;
+
+ if (!pool || !pool->extents)
+ return NULL;
+
+ cur = pool->extents;
+
+ if (cur->free < len) {
+ cur->bound += cur->free;
+ cur->free = 0;
+ }
+
+ return PTR_ADD(cur->start, cur->free);
}
#define FDPRINT(label, value) \
- snprintf(buf, BUFSIZ, label, value), \
- write(fd, buf, strlen(buf));
+ do { \
+ int len = snprintf(buf, sizeof buf, label, value); \
+ if (write(fd, buf, len) != len) \
+ ret = -1; \
+ } while (0)
#define FDEXTSTAT(ext) \
- snprintf(buf, BUFSIZ, " %12ld %5ld\n", \
- (long) ext->free, \
- (long) ext->bound), \
- write(fd, buf, strlen(buf))
-
-void
+ do { \
+ int len = snprintf(buf, sizeof buf, " %12ld %5ld\n", \
+ (long)ext->free, (long)ext->bound); \
+ if (write(fd, buf, len) != len) \
+ ret = -1; \
+ } while (0)
+
+int
pool_stats(alloc_pool_t p, int fd, int summarize)
{
struct alloc_pool *pool = (struct alloc_pool *) p;
- struct pool_extent *cur;
+ struct pool_extent *cur;
char buf[BUFSIZ];
+ int ret = 0;
if (!pool)
- return;
+ return ret;
FDPRINT(" Extent size: %12ld\n", (long) pool->size);
FDPRINT(" Alloc quantum: %12ld\n", (long) pool->quantum);
FDPRINT(" Extents freed: %12ld\n", pool->e_freed);
FDPRINT(" Alloc count: %12.0f\n", (double) pool->n_allocated);
FDPRINT(" Free Count: %12.0f\n", (double) pool->n_freed);
- FDPRINT(" Alloc bytes: %12.0f\n", (double) pool->b_allocated);
- FDPRINT(" Free bytes: %12.0f\n", (double) pool->b_freed);
+ FDPRINT(" Bytes allocated: %12.0f\n", (double) pool->b_allocated);
+ FDPRINT(" Bytes freed: %12.0f\n", (double) pool->b_freed);
if (summarize)
- return;
-
- if (!pool->live && !pool->free)
- return;
+ return ret;
- write(fd, "\n", 1);
+ if (!pool->extents)
+ return ret;
- if (pool->live)
- {
- FDEXTSTAT(pool->live);
- }
- strcpy(buf, " FREE BOUND\n");
- write(fd, buf, strlen(buf));
+ if (write(fd, "\n", 1) != 1)
+ ret = -1;
- cur = pool->free;
- while (cur)
- {
+ for (cur = pool->extents; cur; cur = cur->next)
FDEXTSTAT(cur);
- cur = cur->next;
- }
-}
+ return ret;
+}