Coverage Report

Created: 2025-06-13 07:07

/src/aom/aom_util/aom_thread.c
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Source (jump to first uncovered line)
1
/*
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 * Copyright (c) 2016, Alliance for Open Media. All rights reserved.
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 *
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 * This source code is subject to the terms of the BSD 2 Clause License and
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 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
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 * was not distributed with this source code in the LICENSE file, you can
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 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
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 * Media Patent License 1.0 was not distributed with this source code in the
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 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
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 */
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//
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// Multi-threaded worker
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//
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// Original source:
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//  https://chromium.googlesource.com/webm/libwebp
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// Enable GNU extensions in glibc so that we can call pthread_setname_np().
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// This must be before any #include statements.
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#ifndef _GNU_SOURCE
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#define _GNU_SOURCE
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#endif
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#include <assert.h>
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#include <string.h>  // for memset()
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#include "config/aom_config.h"
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#include "aom_mem/aom_mem.h"
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#include "aom_ports/sanitizer.h"
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#include "aom_util/aom_pthread.h"
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#include "aom_util/aom_thread.h"
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#if CONFIG_MULTITHREAD
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struct AVxWorkerImpl {
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  pthread_mutex_t mutex_;
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  pthread_cond_t condition_;
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  pthread_t thread_;
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};
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//------------------------------------------------------------------------------
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static void execute(AVxWorker *const worker);  // Forward declaration.
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45
125k
static THREADFN thread_loop(void *ptr) {
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125k
  AVxWorker *const worker = (AVxWorker *)ptr;
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#ifdef __APPLE__
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  if (worker->thread_name != NULL) {
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    // Apple's version of pthread_setname_np takes one argument and operates on
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    // the current thread only. The maximum size of the thread_name buffer was
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    // noted in the Chromium source code and was confirmed by experiments. If
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    // thread_name is too long, pthread_setname_np returns -1 with errno
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    // ENAMETOOLONG (63).
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    char thread_name[64];
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    strncpy(thread_name, worker->thread_name, sizeof(thread_name) - 1);
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    thread_name[sizeof(thread_name) - 1] = '\0';
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    pthread_setname_np(thread_name);
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  }
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#elif (defined(__GLIBC__) && !defined(__GNU__)) || defined(__BIONIC__)
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125k
  if (worker->thread_name != NULL) {
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    // Linux and Android require names (with nul) fit in 16 chars, otherwise
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    // pthread_setname_np() returns ERANGE (34).
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125k
    char thread_name[16];
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125k
    strncpy(thread_name, worker->thread_name, sizeof(thread_name) - 1);
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125k
    thread_name[sizeof(thread_name) - 1] = '\0';
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125k
    pthread_setname_np(pthread_self(), thread_name);
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125k
  }
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125k
#endif
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125k
  pthread_mutex_lock(&worker->impl_->mutex_);
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2.44M
  for (;;) {
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4.89M
    while (worker->status_ == AVX_WORKER_STATUS_OK) {  // wait in idling mode
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2.44M
      pthread_cond_wait(&worker->impl_->condition_, &worker->impl_->mutex_);
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2.44M
    }
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2.44M
    if (worker->status_ == AVX_WORKER_STATUS_WORKING) {
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      // When worker->status_ is AVX_WORKER_STATUS_WORKING, the main thread
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      // doesn't change worker->status_ and will wait until the worker changes
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      // worker->status_ to AVX_WORKER_STATUS_OK. See change_state(). So the
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      // worker can safely call execute() without holding worker->impl_->mutex_.
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      // When the worker reacquires worker->impl_->mutex_, worker->status_ must
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      // still be AVX_WORKER_STATUS_WORKING.
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2.32M
      pthread_mutex_unlock(&worker->impl_->mutex_);
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2.32M
      execute(worker);
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2.32M
      pthread_mutex_lock(&worker->impl_->mutex_);
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2.32M
      assert(worker->status_ == AVX_WORKER_STATUS_WORKING);
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2.32M
      worker->status_ = AVX_WORKER_STATUS_OK;
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      // signal to the main thread that we're done (for sync())
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2.32M
      pthread_cond_signal(&worker->impl_->condition_);
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2.32M
    } else {
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125k
      assert(worker->status_ == AVX_WORKER_STATUS_NOT_OK);  // finish the worker
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125k
      break;
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125k
    }
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2.44M
  }
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127k
  pthread_mutex_unlock(&worker->impl_->mutex_);
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127k
  return THREAD_EXIT_SUCCESS;  // Thread is finished
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125k
}
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// main thread state control
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7.15M
static void change_state(AVxWorker *const worker, AVxWorkerStatus new_status) {
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  // No-op when attempting to change state on a thread that didn't come up.
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  // Checking status_ without acquiring the lock first would result in a data
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  // race.
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7.15M
  if (worker->impl_ == NULL) return;
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104
6.47M
  pthread_mutex_lock(&worker->impl_->mutex_);
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6.47M
  if (worker->status_ >= AVX_WORKER_STATUS_OK) {
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    // wait for the worker to finish
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6.57M
    while (worker->status_ != AVX_WORKER_STATUS_OK) {
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98.7k
      pthread_cond_wait(&worker->impl_->condition_, &worker->impl_->mutex_);
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98.7k
    }
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    // assign new status and release the working thread if needed
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6.47M
    if (new_status != AVX_WORKER_STATUS_OK) {
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2.44M
      worker->status_ = new_status;
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2.44M
      pthread_cond_signal(&worker->impl_->condition_);
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2.44M
    }
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6.47M
  }
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6.47M
  pthread_mutex_unlock(&worker->impl_->mutex_);
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6.47M
}
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#endif  // CONFIG_MULTITHREAD
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//------------------------------------------------------------------------------
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161k
static void init(AVxWorker *const worker) {
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161k
  memset(worker, 0, sizeof(*worker));
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161k
  worker->status_ = AVX_WORKER_STATUS_NOT_OK;
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161k
}
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128
4.71M
static int sync(AVxWorker *const worker) {
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4.71M
#if CONFIG_MULTITHREAD
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4.71M
  change_state(worker, AVX_WORKER_STATUS_OK);
131
4.71M
#endif
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4.71M
  assert(worker->status_ <= AVX_WORKER_STATUS_OK);
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4.71M
  return !worker->had_error;
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4.71M
}
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136
125k
static int reset(AVxWorker *const worker) {
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125k
  int ok = 1;
138
125k
  worker->had_error = 0;
139
125k
  if (worker->status_ < AVX_WORKER_STATUS_OK) {
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125k
#if CONFIG_MULTITHREAD
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125k
    worker->impl_ = (AVxWorkerImpl *)aom_calloc(1, sizeof(*worker->impl_));
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125k
    if (worker->impl_ == NULL) {
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0
      return 0;
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0
    }
145
125k
    if (pthread_mutex_init(&worker->impl_->mutex_, NULL)) {
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0
      goto Error;
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0
    }
148
125k
    if (pthread_cond_init(&worker->impl_->condition_, NULL)) {
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0
      pthread_mutex_destroy(&worker->impl_->mutex_);
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0
      goto Error;
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0
    }
152
125k
    pthread_attr_t attr;
153
125k
    if (pthread_attr_init(&attr)) goto Error2;
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      // Debug ASan builds require at least ~1MiB of stack; prevents
155
      // failures on macOS arm64 where the default is 512KiB.
156
      // See: https://crbug.com/aomedia/3379
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#if defined(AOM_ADDRESS_SANITIZER) && defined(__APPLE__) && AOM_ARCH_ARM && \
158
    !defined(NDEBUG)
159
    const size_t kMinStackSize = 1024 * 1024;
160
#else
161
125k
    const size_t kMinStackSize = 256 * 1024;
162
125k
#endif
163
125k
    size_t stacksize;
164
125k
    if (!pthread_attr_getstacksize(&attr, &stacksize)) {
165
125k
      if (stacksize < kMinStackSize &&
166
125k
          pthread_attr_setstacksize(&attr, kMinStackSize)) {
167
0
        pthread_attr_destroy(&attr);
168
0
        goto Error2;
169
0
      }
170
125k
    }
171
125k
    pthread_mutex_lock(&worker->impl_->mutex_);
172
125k
    ok = !pthread_create(&worker->impl_->thread_, &attr, thread_loop, worker);
173
125k
    if (ok) worker->status_ = AVX_WORKER_STATUS_OK;
174
125k
    pthread_mutex_unlock(&worker->impl_->mutex_);
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125k
    pthread_attr_destroy(&attr);
176
125k
    if (!ok) {
177
0
    Error2:
178
0
      pthread_mutex_destroy(&worker->impl_->mutex_);
179
0
      pthread_cond_destroy(&worker->impl_->condition_);
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0
    Error:
181
0
      aom_free(worker->impl_);
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0
      worker->impl_ = NULL;
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0
      return 0;
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0
    }
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#else
186
    worker->status_ = AVX_WORKER_STATUS_OK;
187
#endif
188
125k
  } else if (worker->status_ > AVX_WORKER_STATUS_OK) {
189
0
    ok = sync(worker);
190
0
  }
191
125k
  assert(!ok || (worker->status_ == AVX_WORKER_STATUS_OK));
192
125k
  return ok;
193
125k
}
194
195
2.75M
static void execute(AVxWorker *const worker) {
196
2.75M
  if (worker->hook != NULL) {
197
2.75M
    worker->had_error |= !worker->hook(worker->data1, worker->data2);
198
2.75M
  }
199
2.75M
}
200
201
2.32M
static void launch(AVxWorker *const worker) {
202
2.32M
#if CONFIG_MULTITHREAD
203
2.32M
  change_state(worker, AVX_WORKER_STATUS_WORKING);
204
#else
205
  execute(worker);
206
#endif
207
2.32M
}
208
209
161k
static void end(AVxWorker *const worker) {
210
161k
#if CONFIG_MULTITHREAD
211
161k
  if (worker->impl_ != NULL) {
212
125k
    change_state(worker, AVX_WORKER_STATUS_NOT_OK);
213
125k
    pthread_join(worker->impl_->thread_, NULL);
214
125k
    pthread_mutex_destroy(&worker->impl_->mutex_);
215
125k
    pthread_cond_destroy(&worker->impl_->condition_);
216
125k
    aom_free(worker->impl_);
217
125k
    worker->impl_ = NULL;
218
125k
  }
219
#else
220
  worker->status_ = AVX_WORKER_STATUS_NOT_OK;
221
  assert(worker->impl_ == NULL);
222
#endif
223
161k
  assert(worker->status_ == AVX_WORKER_STATUS_NOT_OK);
224
161k
}
225
226
//------------------------------------------------------------------------------
227
228
static AVxWorkerInterface g_worker_interface = { init,   reset,   sync,
229
                                                 launch, execute, end };
230
231
0
int aom_set_worker_interface(const AVxWorkerInterface *const winterface) {
232
0
  if (winterface == NULL || winterface->init == NULL ||
233
0
      winterface->reset == NULL || winterface->sync == NULL ||
234
0
      winterface->launch == NULL || winterface->execute == NULL ||
235
0
      winterface->end == NULL) {
236
0
    return 0;
237
0
  }
238
0
  g_worker_interface = *winterface;
239
0
  return 1;
240
0
}
241
242
1.40M
const AVxWorkerInterface *aom_get_worker_interface(void) {
243
1.40M
  return &g_worker_interface;
244
1.40M
}
245
246
//------------------------------------------------------------------------------