X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/4d4df3cd2b640e7d3f60d5c3438afea8a8cf5de5..a02348b5df636914e356b539d91ed21f7b3a1ab5:/lib/pool_alloc.c

diff --git a/lib/pool_alloc.c b/lib/pool_alloc.c
index c5648b6b..0fb31225 100644
--- a/lib/pool_alloc.c
+++ b/lib/pool_alloc.c
@@ -6,21 +6,18 @@ 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	*/
+	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
@@ -33,27 +30,29 @@ struct pool_extent
 };
 
 struct align_test {
-    void *foo;
-    uint64 bar;
+	void *foo;
+	int64 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))))
+	if (!(pool = new(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)
-	{
+	if (flags & POOL_INTERN) {
 		pool->size -= sizeof (struct pool_extent);
 		flags |= POOL_APPEND;
 	}
@@ -73,15 +72,7 @@ pool_destroy(alloc_pool_t p)
 	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))
@@ -91,7 +82,7 @@ pool_destroy(alloc_pool_t p)
 }
 
 void *
-pool_alloc(alloc_pool_t p, size_t len, char *bomb)
+pool_alloc(alloc_pool_t p, size_t len, const char *bomb_msg)
 {
 	struct alloc_pool *pool = (struct alloc_pool *) p;
 	if (!pool)
@@ -103,21 +94,15 @@ pool_alloc(alloc_pool_t p, size_t len, char *bomb)
 		len += pool->quantum - len % pool->quantum;
 
 	if (len > pool->size)
-		goto bomb;
+		goto bomb_out;
 
-	if (!pool->live || len > pool->live->free)
-	{
+	if (!pool->extents || len > pool->extents->free) {
 		void	*start;
 		size_t	free;
 		size_t	bound;
-		size_t	sqew;
+		size_t	skew;
 		size_t	asize;
-
-		if (pool->live)
-		{
-			pool->live->next = pool->free;
-			pool->free = pool->live;
-		}
+		struct pool_extent *ext;
 
 		free = pool->size;
 		bound = 0;
@@ -126,30 +111,26 @@ pool_alloc(alloc_pool_t p, size_t len, char *bomb)
 		if (pool->flags & POOL_APPEND)
 			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);
+			memset(start, 0, free);
 
 		if (pool->flags & POOL_APPEND)
-		{
-			pool->live = start + free;
-		}
-		else if (!(pool->live = (struct pool_extent *) malloc(sizeof (struct pool_extent))))
-		{
-			goto bomb;
-		}
+			ext = PTR_ADD(start, free);
+		else if (!(ext = new(struct pool_extent)))
+			goto bomb_out;
 		if (pool->flags & POOL_QALIGN && pool->quantum > 1
-		    && (sqew = (size_t)(start + free) % pool->quantum))
-		{
-			bound  += sqew;
-			free -= sqew;
+		    && (skew = (size_t)PTR_ADD(start, free) % pool->quantum)) {
+			bound  += skew;
+			free -= skew;
 		}
-		pool->live->start = start;
-		pool->live->free = free;
-		pool->live->bound = bound;
-		pool->live->next = NULL;
+		ext->start = start;
+		ext->free = free;
+		ext->bound = bound;
+		ext->next = pool->extents;
+		pool->extents = ext;
 
 		pool->e_created++;
 	}
@@ -157,22 +138,24 @@ pool_alloc(alloc_pool_t p, size_t len, char *bomb)
 	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;
@@ -182,79 +165,141 @@ pool_free(alloc_pool_t p, size_t len, void *addr)
 	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;
-	}
 	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) {
+			size_t skew;
 
+			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;
+			    && (skew = (size_t)PTR_ADD(cur->start, cur->free) % pool->quantum)) {
+				cur->bound += skew;
+				cur->free -= skew;
 			}
+		} 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;
+			free(cur->start);
+			if (!(pool->flags & POOL_APPEND))
+				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;
-	}
-	cur->bound += len;
+	if (addr == PTR_ADD(cur->start, cur->free)) {
+		if (prev) {
+			prev->next = NULL;
+			next = cur;
+		} else {
+			size_t skew;
 
-	if (cur->free + cur->bound >= pool->size)
-	{
-		pool->free = cur->next;
+			/* 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;
+			if (pool->flags & POOL_QALIGN && pool->quantum > 1
+			    && (skew = (size_t)PTR_ADD(cur->start, cur->free) % pool->quantum)) {
+				cur->bound += skew;
+				cur->free -= skew;
+			}
+			next = cur->next;
+			cur->next = NULL;
+		}
+	} else {
+		next = cur->next;
+		cur->next = NULL;
+	}
 
+	while ((cur = next) != NULL) {
+		next = cur->next;
 		free(cur->start);
 		if (!(pool->flags & POOL_APPEND))
 			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));
+	snprintf(buf, sizeof buf, label, value), \
+	write(fd, buf, strlen(buf))
 
 #define FDEXTSTAT(ext) \
-	snprintf(buf, BUFSIZ, "  %12ld  %5ld\n", \
+	snprintf(buf, sizeof buf, "  %12ld  %5ld\n", \
 		(long) ext->free, \
 		(long) ext->bound), \
 	write(fd, buf, strlen(buf))
@@ -275,26 +320,17 @@ pool_stats(alloc_pool_t p, int fd, int summarize)
 	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)
+	if (!pool->extents)
 		return;
 
 	write(fd, "\n", 1);
 
-	if (pool->live)
-	{
-		FDEXTSTAT(pool->live);
-	}
-	strcpy(buf, "   FREE    BOUND\n");
-	write(fd, buf, strlen(buf));
-
-	for (cur = pool->free; cur; cur = cur->next)
-	{
+	for (cur = pool->extents; cur; cur = cur->next)
 		FDEXTSTAT(cur);
-	}
 }