From 89bb07730b1c0f292d1d70a99466e8a885fb87bf Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Mon, 18 Jan 2010 14:35:43 -0700 Subject: util: fix broken util_ringbuffer_dequeue() The tests for an empty ring buffer were incorrect. Fixes glxinfo segfaults. Plus, add a new assertion. --- src/gallium/auxiliary/util/u_ringbuffer.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) (limited to 'src/gallium/auxiliary/util/u_ringbuffer.c') diff --git a/src/gallium/auxiliary/util/u_ringbuffer.c b/src/gallium/auxiliary/util/u_ringbuffer.c index 3f43a19e018..e73ba0b3481 100644 --- a/src/gallium/auxiliary/util/u_ringbuffer.c +++ b/src/gallium/auxiliary/util/u_ringbuffer.c @@ -53,11 +53,22 @@ void util_ringbuffer_destroy( struct util_ringbuffer *ring ) FREE(ring); } +/** + * Return number of free entries in the ring + */ static INLINE unsigned util_ringbuffer_space( const struct util_ringbuffer *ring ) { return (ring->tail - (ring->head + 1)) & ring->mask; } +/** + * Is the ring buffer empty? + */ +static INLINE boolean util_ringbuffer_empty( const struct util_ringbuffer *ring ) +{ + return util_ringbuffer_space(ring) == ring->mask; +} + void util_ringbuffer_enqueue( struct util_ringbuffer *ring, const struct util_packet *packet ) { @@ -67,6 +78,10 @@ void util_ringbuffer_enqueue( struct util_ringbuffer *ring, */ pipe_mutex_lock(ring->mutex); + /* make sure we don't request an impossible amount of space + */ + assert(packet->dwords <= ring->mask); + /* Wait for free space: */ while (util_ringbuffer_space(ring) < packet->dwords) @@ -104,14 +119,14 @@ enum pipe_error util_ringbuffer_dequeue( struct util_ringbuffer *ring, */ pipe_mutex_lock(ring->mutex); - /* Wait for free space: + /* Get next ring entry: */ if (wait) { - while (util_ringbuffer_space(ring) == 0) + while (util_ringbuffer_empty(ring)) pipe_condvar_wait(ring->change, ring->mutex); } else { - if (util_ringbuffer_space(ring) == 0) { + if (util_ringbuffer_empty(ring)) { ret = PIPE_ERROR_OUT_OF_MEMORY; goto out; } -- cgit v1.2.3