src/gallium/drivers/llvmpipe/lp_fence.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2009 VMware, Inc.
   4  * All Rights Reserved.
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   7  * copy of this software and associated documentation files (the
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  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
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  26  **************************************************************************/
  27
  28
  29 #include "pipe/p_screen.h"
  30 #include "util/u_memory.h"
  31 #include "util/u_inlines.h"
  32 #include "lp_debug.h"
  33 #include "lp_fence.h"
  34
  35
  36 /**
  37  * Create a new fence object.
  38  *
  39  * The rank will be the number of bins in the scene.  Whenever a rendering
  40  * thread hits a fence command, it'll increment the fence counter.  When
  41  * the counter == the rank, the fence is finished.
  42  *
  43  * \param rank  the expected finished value of the fence counter.
  44  */
  45 struct lp_fence *
  46 lp_fence_create(unsigned rank)
  47 {
  48    struct lp_fence *fence = CALLOC_STRUCT(lp_fence);
  49
  50    pipe_reference_init(&fence->reference, 1);
  51
  52    pipe_mutex_init(fence->mutex);
  53    pipe_condvar_init(fence->signalled);
  54
  55    fence->rank = rank;
  56
  57    return fence;
  58 }
  59
  60
  61 /** Destroy a fence.  Called when refcount hits zero. */
  62 static void
  63 lp_fence_destroy(struct lp_fence *fence)
  64 {
  65    pipe_mutex_destroy(fence->mutex);
  66    pipe_condvar_destroy(fence->signalled);
  67    FREE(fence);
  68 }
  69
  70
  71 /**
  72  * For reference counting.
  73  * This is a Gallium API function.
  74  */
  75 static void
  76 llvmpipe_fence_reference(struct pipe_screen *screen,
  77                          struct pipe_fence_handle **ptr,
  78                          struct pipe_fence_handle *fence)
  79 {
  80    struct lp_fence *old = (struct lp_fence *) *ptr;
  81    struct lp_fence *f = (struct lp_fence *) fence;
  82
  83    if (pipe_reference(&old->reference, &f->reference)) {
  84       lp_fence_destroy(old);
  85    }
  86 }
  87
  88
  89 /**
  90  * Has the fence been executed/finished?
  91  * This is a Gallium API function.
  92  */
  93 static int
  94 llvmpipe_fence_signalled(struct pipe_screen *screen,
  95                          struct pipe_fence_handle *fence,
  96                          unsigned flag)
  97 {
  98    struct lp_fence *f = (struct lp_fence *) fence;
  99
 100    return f->count == f->rank;
 101 }
 102
 103
 104 /**
 105  * Wait for the fence to finish.
 106  * This is a Gallium API function.
 107  */
 108 static int
 109 llvmpipe_fence_finish(struct pipe_screen *screen,
 110                       struct pipe_fence_handle *fence_handle,
 111                       unsigned flag)
 112 {
 113    struct lp_fence *fence = (struct lp_fence *) fence_handle;
 114
 115    pipe_mutex_lock(fence->mutex);
 116    while (fence->count < fence->rank) {
 117       pipe_condvar_wait(fence->signalled, fence->mutex);
 118    }
 119    pipe_mutex_unlock(fence->mutex);
 120
 121    return 0;
 122 }
 123
 124
 125 /**
 126  * Called by the rendering threads to increment the fence counter.
 127  * When the counter == the rank, the fence is finished.
 128  */
 129 void
 130 lp_fence_signal(struct lp_fence *fence)
 131 {
 132    pipe_mutex_lock(fence->mutex);
 133
 134    fence->count++;
 135    assert(fence->count <= fence->rank);
 136
 137    LP_DBG(DEBUG_RAST, "%s count=%u rank=%u\n", __FUNCTION__,
 138           fence->count, fence->rank);
 139
 140    pipe_condvar_signal(fence->signalled);
 141
 142    pipe_mutex_unlock(fence->mutex);
 143 }
 144
 145
 146 void
 147 llvmpipe_init_screen_fence_funcs(struct pipe_screen *screen)
 148 {
 149    screen->fence_reference = llvmpipe_fence_reference;
 150    screen->fence_signalled = llvmpipe_fence_signalled;
 151    screen->fence_finish = llvmpipe_fence_finish;
 152 }