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| author | marha <marha@users.sourceforge.net> | 2011-04-30 15:25:48 +0000 |
|---|---|---|
| committer | marha <marha@users.sourceforge.net> | 2011-04-30 15:25:48 +0000 |
| commit | 0402d388cb9803652c0f9a52ba7dcb6029fdd0b9 (patch) | |
| tree | afd1b68edb9a74d5c87e63ea72d04b8301705d82 /mesalib/src/gallium/auxiliary/util/u_ringbuffer.c | |
| parent | c4ae0bb951bfb6061e7f0c492ba03de330137515 (diff) | |
| download | vcxsrv-0402d388cb9803652c0f9a52ba7dcb6029fdd0b9.tar.gz vcxsrv-0402d388cb9803652c0f9a52ba7dcb6029fdd0b9.tar.bz2 vcxsrv-0402d388cb9803652c0f9a52ba7dcb6029fdd0b9.zip | |
Added extra needed files
Diffstat (limited to 'mesalib/src/gallium/auxiliary/util/u_ringbuffer.c')
| -rw-r--r-- | mesalib/src/gallium/auxiliary/util/u_ringbuffer.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/mesalib/src/gallium/auxiliary/util/u_ringbuffer.c b/mesalib/src/gallium/auxiliary/util/u_ringbuffer.c new file mode 100644 index 000000000..ad4066aa1 --- /dev/null +++ b/mesalib/src/gallium/auxiliary/util/u_ringbuffer.c @@ -0,0 +1,160 @@ +
+#include "os/os_thread.h"
+#include "pipe/p_defines.h"
+#include "util/u_ringbuffer.h"
+#include "util/u_math.h"
+#include "util/u_memory.h"
+
+/* Generic ringbuffer:
+ */
+struct util_ringbuffer
+{
+ struct util_packet *buf;
+ unsigned mask;
+
+ /* Can this be done with atomic variables??
+ */
+ unsigned head;
+ unsigned tail;
+ pipe_condvar change;
+ pipe_mutex mutex;
+};
+
+
+struct util_ringbuffer *util_ringbuffer_create( unsigned dwords )
+{
+ struct util_ringbuffer *ring = CALLOC_STRUCT(util_ringbuffer);
+ if (ring == NULL)
+ return NULL;
+
+ assert(util_is_power_of_two(dwords));
+
+ ring->buf = MALLOC( dwords * sizeof(unsigned) );
+ if (ring->buf == NULL)
+ goto fail;
+
+ ring->mask = dwords - 1;
+
+ pipe_condvar_init(ring->change);
+ pipe_mutex_init(ring->mutex);
+ return ring;
+
+fail:
+ FREE(ring->buf);
+ FREE(ring);
+ return NULL;
+}
+
+void util_ringbuffer_destroy( struct util_ringbuffer *ring )
+{
+ pipe_condvar_destroy(ring->change);
+ pipe_mutex_destroy(ring->mutex);
+ FREE(ring->buf);
+ 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 )
+{
+ unsigned i;
+
+ /* XXX: over-reliance on mutexes, etc:
+ */
+ 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)
+ pipe_condvar_wait(ring->change, ring->mutex);
+
+ /* Copy data to ring:
+ */
+ for (i = 0; i < packet->dwords; i++) {
+
+ /* Copy all dwords of the packet. Note we're abusing the
+ * typesystem a little - we're being passed a pointer to
+ * something, but probably not an array of packet structs:
+ */
+ ring->buf[ring->head] = packet[i];
+ ring->head++;
+ ring->head &= ring->mask;
+ }
+
+ /* Signal change:
+ */
+ pipe_condvar_signal(ring->change);
+ pipe_mutex_unlock(ring->mutex);
+}
+
+enum pipe_error util_ringbuffer_dequeue( struct util_ringbuffer *ring,
+ struct util_packet *packet,
+ unsigned max_dwords,
+ boolean wait )
+{
+ const struct util_packet *ring_packet;
+ unsigned i;
+ int ret = PIPE_OK;
+
+ /* XXX: over-reliance on mutexes, etc:
+ */
+ pipe_mutex_lock(ring->mutex);
+
+ /* Get next ring entry:
+ */
+ if (wait) {
+ while (util_ringbuffer_empty(ring))
+ pipe_condvar_wait(ring->change, ring->mutex);
+ }
+ else {
+ if (util_ringbuffer_empty(ring)) {
+ ret = PIPE_ERROR_OUT_OF_MEMORY;
+ goto out;
+ }
+ }
+
+ ring_packet = &ring->buf[ring->tail];
+
+ /* Both of these are considered bugs. Raise an assert on debug builds.
+ */
+ if (ring_packet->dwords > ring->mask + 1 - util_ringbuffer_space(ring) ||
+ ring_packet->dwords > max_dwords) {
+ assert(0);
+ ret = PIPE_ERROR_BAD_INPUT;
+ goto out;
+ }
+
+ /* Copy data from ring:
+ */
+ for (i = 0; i < ring_packet->dwords; i++) {
+ packet[i] = ring->buf[ring->tail];
+ ring->tail++;
+ ring->tail &= ring->mask;
+ }
+
+out:
+ /* Signal change:
+ */
+ pipe_condvar_signal(ring->change);
+ pipe_mutex_unlock(ring->mutex);
+ return ret;
+}
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