src/gallium/drivers/llvmpipe/lp_fence.c

   1 /**************************************************************************
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   3  * Copyright 2009 VMware, Inc.
   4  * All Rights Reserved.
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  11  * permit persons to whom the Software is furnished to do so, subject to
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  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
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  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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  26  **************************************************************************/
  27
  28
  29 #include "pipe/p_screen.h"
  30 #include "util/u_memory.h"
  31 #include "lp_debug.h"
  32 #include "lp_fence.h"
  33
  34
  35 /**
  36  * Create a new fence object.
  37  *
  38  * The rank will be the number of bins in the scene.  Whenever a rendering
  39  * thread hits a fence command, it'll increment the fence counter.  When
  40  * the counter == the rank, the fence is finished.
  41  *
  42  * \param rank  the expected finished value of the fence counter.
  43  */
  44 struct lp_fence *
  45 lp_fence_create(unsigned rank)
  46 {
  47    static int fence_id;
  48    struct lp_fence *fence = CALLOC_STRUCT(lp_fence);
  49
  50    if (!fence)
  51       return NULL;
  52
  53    pipe_reference_init(&fence->reference, 1);
  54
  55    pipe_mutex_init(fence->mutex);
  56    cnd_init(&fence->signalled);
  57
  58    fence->id = fence_id++;
  59    fence->rank = rank;
  60
  61    if (LP_DEBUG & DEBUG_FENCE)
  62       debug_printf("%s %d\n", __FUNCTION__, fence->id);
  63
  64    return fence;
  65 }
  66
  67
  68 /** Destroy a fence.  Called when refcount hits zero. */
  69 void
  70 lp_fence_destroy(struct lp_fence *fence)
  71 {
  72    if (LP_DEBUG & DEBUG_FENCE)
  73       debug_printf("%s %d\n", __FUNCTION__, fence->id);
  74
  75    pipe_mutex_destroy(fence->mutex);
  76    cnd_destroy(&fence->signalled);
  77    FREE(fence);
  78 }
  79
  80
  81 /**
  82  * Called by the rendering threads to increment the fence counter.
  83  * When the counter == the rank, the fence is finished.
  84  */
  85 void
  86 lp_fence_signal(struct lp_fence *fence)
  87 {
  88    if (LP_DEBUG & DEBUG_FENCE)
  89       debug_printf("%s %d\n", __FUNCTION__, fence->id);
  90
  91    pipe_mutex_lock(fence->mutex);
  92
  93    fence->count++;
  94    assert(fence->count <= fence->rank);
  95
  96    if (LP_DEBUG & DEBUG_FENCE)
  97       debug_printf("%s count=%u rank=%u\n", __FUNCTION__,
  98                    fence->count, fence->rank);
  99
 100    /* Wakeup all threads waiting on the mutex:
 101     */
 102    cnd_broadcast(&fence->signalled);
 103
 104    pipe_mutex_unlock(fence->mutex);
 105 }
 106
 107 boolean
 108 lp_fence_signalled(struct lp_fence *f)
 109 {
 110    return f->count == f->rank;
 111 }
 112
 113 void
 114 lp_fence_wait(struct lp_fence *f)
 115 {
 116    if (LP_DEBUG & DEBUG_FENCE)
 117       debug_printf("%s %d\n", __FUNCTION__, f->id);
 118
 119    pipe_mutex_lock(f->mutex);
 120    assert(f->issued);
 121    while (f->count < f->rank) {
 122       cnd_wait(&f->signalled, &f->mutex);
 123    }
 124    pipe_mutex_unlock(f->mutex);
 125 }
 126
 127