+++ /dev/null
-
-#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;
- cnd_t change;
- mtx_t mutex;
-};
-
-
-struct util_ringbuffer *util_ringbuffer_create( unsigned dwords )
-{
- struct util_ringbuffer *ring = CALLOC_STRUCT(util_ringbuffer);
- if (!ring)
- return NULL;
-
- assert(util_is_power_of_two_or_zero(dwords));
-
- ring->buf = MALLOC( dwords * sizeof(unsigned) );
- if (ring->buf == NULL)
- goto fail;
-
- ring->mask = dwords - 1;
-
- cnd_init(&ring->change);
- (void) mtx_init(&ring->mutex, mtx_plain);
- return ring;
-
-fail:
- FREE(ring->buf);
- FREE(ring);
- return NULL;
-}
-
-void util_ringbuffer_destroy( struct util_ringbuffer *ring )
-{
- cnd_destroy(&ring->change);
- mtx_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:
- */
- mtx_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)
- cnd_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:
- */
- cnd_signal(&ring->change);
- mtx_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:
- */
- mtx_lock(&ring->mutex);
-
- /* Get next ring entry:
- */
- if (wait) {
- while (util_ringbuffer_empty(ring))
- cnd_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:
- */
- cnd_signal(&ring->change);
- mtx_unlock(&ring->mutex);
- return ret;
-}
projects / mesa.git / commitdiff