src/util/u_queue.h

   1 /*
   2  * Copyright © 2016 Advanced Micro Devices, Inc.
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining
   6  * a copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sub license, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject to
  11  * the following conditions:
  12  *
  13  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  14  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  15  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  16  * NON-INFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT HOLDERS, AUTHORS
  17  * AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  20  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * The above copyright notice and this permission notice (including the
  23  * next paragraph) shall be included in all copies or substantial portions
  24  * of the Software.
  25  */
  26
  27 /* Job queue with execution in a separate thread.
  28  *
  29  * Jobs can be added from any thread. After that, the wait call can be used
  30  * to wait for completion of the job.
  31  */
  32
  33 #ifndef U_QUEUE_H
  34 #define U_QUEUE_H
  35
  36 #include <string.h>
  37
  38 #include "util/futex.h"
  39 #include "util/list.h"
  40 #include "util/macros.h"
  41 #include "util/u_atomic.h"
  42 #include "util/u_thread.h"
  43
  44 #ifdef __cplusplus
  45 extern "C" {
  46 #endif
  47
  48 #define UTIL_QUEUE_INIT_USE_MINIMUM_PRIORITY      (1 << 0)
  49 #define UTIL_QUEUE_INIT_RESIZE_IF_FULL            (1 << 1)
  50
  51 #if defined(__GNUC__) && defined(HAVE_FUTEX)
  52 #define UTIL_QUEUE_FENCE_FUTEX
  53 #else
  54 #define UTIL_QUEUE_FENCE_STANDARD
  55 #endif
  56
  57 #ifdef UTIL_QUEUE_FENCE_FUTEX
  58 /* Job completion fence.
  59  * Put this into your job structure.
  60  */
  61 struct util_queue_fence {
  62    /* The fence can be in one of three states:
  63     *  0 - signaled
  64     *  1 - unsignaled
  65     *  2 - unsignaled, may have waiters
  66     */
  67    uint32_t val;
  68 };
  69
  70 static inline void
  71 util_queue_fence_init(struct util_queue_fence *fence)
  72 {
  73    fence->val = 0;
  74 }
  75
  76 static inline void
  77 util_queue_fence_destroy(struct util_queue_fence *fence)
  78 {
  79    assert(fence->val == 0);
  80    /* no-op */
  81 }
  82
  83 static inline void
  84 util_queue_fence_wait(struct util_queue_fence *fence)
  85 {
  86    uint32_t v = fence->val;
  87
  88    if (likely(v == 0))
  89       return;
  90
  91    do {
  92       if (v != 2) {
  93          v = p_atomic_cmpxchg(&fence->val, 1, 2);
  94          if (v == 0)
  95             return;
  96       }
  97
  98       futex_wait(&fence->val, 2);
  99       v = fence->val;
 100    } while(v != 0);
 101 }
 102
 103 static inline void
 104 util_queue_fence_signal(struct util_queue_fence *fence)
 105 {
 106    uint32_t val = p_atomic_xchg(&fence->val, 0);
 107
 108    assert(val != 0);
 109
 110    if (val == 2)
 111       futex_wake(&fence->val, INT_MAX);
 112 }
 113
 114 /**
 115  * Move \p fence back into unsignalled state.
 116  *
 117  * \warning The caller must ensure that no other thread may currently be
 118  *          waiting (or about to wait) on the fence.
 119  */
 120 static inline void
 121 util_queue_fence_reset(struct util_queue_fence *fence)
 122 {
 123 #ifdef NDEBUG
 124    fence->val = 1;
 125 #else
 126    uint32_t v = p_atomic_xchg(&fence->val, 1);
 127    assert(v == 0);
 128 #endif
 129 }
 130
 131 static inline bool
 132 util_queue_fence_is_signalled(struct util_queue_fence *fence)
 133 {
 134    return fence->val == 0;
 135 }
 136 #endif
 137
 138 #ifdef UTIL_QUEUE_FENCE_STANDARD
 139 /* Job completion fence.
 140  * Put this into your job structure.
 141  */
 142 struct util_queue_fence {
 143    mtx_t mutex;
 144    cnd_t cond;
 145    int signalled;
 146 };
 147
 148 void util_queue_fence_init(struct util_queue_fence *fence);
 149 void util_queue_fence_destroy(struct util_queue_fence *fence);
 150 void util_queue_fence_wait(struct util_queue_fence *fence);
 151 void util_queue_fence_signal(struct util_queue_fence *fence);
 152
 153 /**
 154  * Move \p fence back into unsignalled state.
 155  *
 156  * \warning The caller must ensure that no other thread may currently be
 157  *          waiting (or about to wait) on the fence.
 158  */
 159 static inline void
 160 util_queue_fence_reset(struct util_queue_fence *fence)
 161 {
 162    assert(fence->signalled);
 163    fence->signalled = 0;
 164 }
 165
 166 static inline bool
 167 util_queue_fence_is_signalled(struct util_queue_fence *fence)
 168 {
 169    return fence->signalled != 0;
 170 }
 171 #endif
 172
 173 typedef void (*util_queue_execute_func)(void *job, int thread_index);
 174
 175 struct util_queue_job {
 176    void *job;
 177    struct util_queue_fence *fence;
 178    util_queue_execute_func execute;
 179    util_queue_execute_func cleanup;
 180 };
 181
 182 /* Put this into your context. */
 183 struct util_queue {
 184    const char *name;
 185    mtx_t lock;
 186    cnd_t has_queued_cond;
 187    cnd_t has_space_cond;
 188    thrd_t *threads;
 189    unsigned flags;
 190    int num_queued;
 191    unsigned num_threads;
 192    int kill_threads;
 193    int max_jobs;
 194    int write_idx, read_idx; /* ring buffer pointers */
 195    struct util_queue_job *jobs;
 196
 197    /* for cleanup at exit(), protected by exit_mutex */
 198    struct list_head head;
 199 };
 200
 201 bool util_queue_init(struct util_queue *queue,
 202                      const char *name,
 203                      unsigned max_jobs,
 204                      unsigned num_threads,
 205                      unsigned flags);
 206 void util_queue_destroy(struct util_queue *queue);
 207
 208 /* optional cleanup callback is called after fence is signaled: */
 209 void util_queue_add_job(struct util_queue *queue,
 210                         void *job,
 211                         struct util_queue_fence *fence,
 212                         util_queue_execute_func execute,
 213                         util_queue_execute_func cleanup);
 214 void util_queue_drop_job(struct util_queue *queue,
 215                          struct util_queue_fence *fence);
 216
 217 int64_t util_queue_get_thread_time_nano(struct util_queue *queue,
 218                                         unsigned thread_index);
 219
 220 /* util_queue needs to be cleared to zeroes for this to work */
 221 static inline bool
 222 util_queue_is_initialized(struct util_queue *queue)
 223 {
 224    return queue->threads != NULL;
 225 }
 226
 227 /* Convenient structure for monitoring the queue externally and passing
 228  * the structure between Mesa components. The queue doesn't use it directly.
 229  */
 230 struct util_queue_monitoring
 231 {
 232    /* For querying the thread busyness. */
 233    struct util_queue *queue;
 234
 235    /* Counters updated by the user of the queue. */
 236    unsigned num_offloaded_items;
 237    unsigned num_direct_items;
 238    unsigned num_syncs;
 239 };
 240
 241 #ifdef __cplusplus
 242 }
 243 #endif
 244
 245 #endif