src/gallium/drivers/llvmpipe/lp_fence.c

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   3  * Copyright 2009 VMware, Inc.
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  16  * of the Software.
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  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    struct lp_fence *fence = CALLOC_STRUCT(lp_fence);
  48
  49    pipe_reference_init(&fence->reference, 1);
  50
  51    pipe_mutex_init(fence->mutex);
  52    pipe_condvar_init(fence->signalled);
  53
  54    fence->rank = rank;
  55
  56    return fence;
  57 }
  58
  59
  60 /** Destroy a fence.  Called when refcount hits zero. */
  61 void
  62 lp_fence_destroy(struct lp_fence *fence)
  63 {
  64    pipe_mutex_destroy(fence->mutex);
  65    pipe_condvar_destroy(fence->signalled);
  66    FREE(fence);
  67 }
  68
  69
  70 /**
  71  * For reference counting.
  72  * This is a Gallium API function.
  73  */
  74 static void
  75 llvmpipe_fence_reference(struct pipe_screen *screen,
  76                          struct pipe_fence_handle **ptr,
  77                          struct pipe_fence_handle *fence)
  78 {
  79    struct lp_fence **old = (struct lp_fence **) ptr;
  80    struct lp_fence *f = (struct lp_fence *) fence;
  81
  82    lp_fence_reference(old, f);
  83 }
  84
  85
  86 /**
  87  * Has the fence been executed/finished?
  88  * This is a Gallium API function.
  89  */
  90 static int
  91 llvmpipe_fence_signalled(struct pipe_screen *screen,
  92                          struct pipe_fence_handle *fence,
  93                          unsigned flag)
  94 {
  95    struct lp_fence *f = (struct lp_fence *) fence;
  96
  97    return f->count == f->rank;
  98 }
  99
 100
 101 /**
 102  * Wait for the fence to finish.
 103  * This is a Gallium API function.
 104  */
 105 static int
 106 llvmpipe_fence_finish(struct pipe_screen *screen,
 107                       struct pipe_fence_handle *fence_handle,
 108                       unsigned flag)
 109 {
 110    struct lp_fence *fence = (struct lp_fence *) fence_handle;
 111
 112    pipe_mutex_lock(fence->mutex);
 113    while (fence->count < fence->rank) {
 114       pipe_condvar_wait(fence->signalled, fence->mutex);
 115    }
 116    pipe_mutex_unlock(fence->mutex);
 117
 118    return 0;
 119 }
 120
 121
 122 /**
 123  * Called by the rendering threads to increment the fence counter.
 124  * When the counter == the rank, the fence is finished.
 125  */
 126 void
 127 lp_fence_signal(struct lp_fence *fence)
 128 {
 129    pipe_mutex_lock(fence->mutex);
 130
 131    fence->count++;
 132    assert(fence->count <= fence->rank);
 133
 134    LP_DBG(DEBUG_RAST, "%s count=%u rank=%u\n", __FUNCTION__,
 135           fence->count, fence->rank);
 136
 137    pipe_condvar_signal(fence->signalled);
 138
 139    pipe_mutex_unlock(fence->mutex);
 140 }
 141
 142
 143 void
 144 llvmpipe_init_screen_fence_funcs(struct pipe_screen *screen)
 145 {
 146    screen->fence_reference = llvmpipe_fence_reference;
 147    screen->fence_signalled = llvmpipe_fence_signalled;
 148    screen->fence_finish = llvmpipe_fence_finish;
 149 }