libpad: add pad flags and flag for zeroing memory

1 files changed, 22 insertions, 3 deletions

diff --git a/src/pad.c b/src/pad.c
index e0bc56d..bac5291 100644
--- a/src/pad.c
+++ b/src/pad.c
@@ -71,6 +71,7 @@ typedef struct alloc_t {
 struct pad_t {
 	chunk_t		*chunk;		/* current chunk allocations come from */
 	unsigned	chunk_size;	/* size chunks are allocated in */
+	unsigned	flags;		/* flags of this pad */
 	list_head_t	free_chunks;	/* list of completely free chunks */
 	list_head_t	pinned_chunks;	/* list of chunks pinned because they have an outstanding allocation */
 };
@@ -96,7 +97,12 @@ static inline void chunk_unref(chunk_t *chunk)
 	assert(chunk->n_refs > 0);
 
 	if (chunk->n_refs == 1) {
-		list_move(&chunk->chunks, &chunk->pad->free_chunks);
+		pad_t	*pad = chunk->pad;
+
+		list_move(&chunk->chunks, &pad->free_chunks);
+
+		if ((pad->flags & PAD_FLAGS_ZERO))
+			memset(chunk->mem, 0, pad->chunk_size);
 		
 		return;
 	}
@@ -126,7 +132,11 @@ static chunk_t * chunk_get(pad_t *pad)
 		list_del(&chunk->chunks);
 	} else {
 		/* No free chunks, must ask libc for memory */
-		chunk = malloc(chunk_alloc_size(pad));
+		if ((pad->flags & PAD_FLAGS_ZERO))
+			chunk = calloc(1, chunk_alloc_size(pad));
+		else
+			chunk = malloc(chunk_alloc_size(pad));
+
 		if (!chunk)
 			return NULL;
 	}
@@ -145,7 +155,7 @@ static chunk_t * chunk_get(pad_t *pad)
 
 
 /* Create a new pad. */
-pad_t * pad_new(unsigned chunk_size)
+pad_t * pad_new(unsigned chunk_size, unsigned flags)
 {
 	pad_t	*pad;
 
@@ -158,6 +168,7 @@ pad_t * pad_new(unsigned chunk_size)
 
 	/* XXX: pad->chunk_size does not include the size of the chunk_t container */
 	pad->chunk_size = ALIGN(chunk_size, CHUNK_ALIGNMENT);
+	pad->flags = flags;
 
 	return pad;
 }
@@ -172,6 +183,14 @@ void pad_reset(pad_t *pad)
 	assert(pad);
 
 	pad->chunk = NULL;
+
+	if ((pad->flags & PAD_FLAGS_ZERO)) {
+		chunk_t	*c;
+
+		list_for_each_entry(c, &pad->pinned_chunks, chunks)
+			memset(c->mem, 0, pad->chunk_size);
+	}
+
 	list_splice_init(&pad->pinned_chunks, &pad->free_chunks);
 }