libvpx: Pull from upstream

source/libvpx/vp9/decoder/vp9_dthread.c

 /*
  *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 205 matching lines @@
 // Allocate memory for lf row synchronization
 void vp9_loop_filter_alloc(VP9LfSync *lf_sync, VP9_COMMON *cm, int rows,
                            int width) {
   lf_sync->rows = rows;
 #if CONFIG_MULTITHREAD
   {
     int i;
 
     CHECK_MEM_ERROR(cm, lf_sync->mutex_,
                     vpx_malloc(sizeof(*lf_sync->mutex_) * rows));
-    for (i = 0; i < rows; ++i) {
-      pthread_mutex_init(&lf_sync->mutex_[i], NULL);
+    if (lf_sync->mutex_) {
+      for (i = 0; i < rows; ++i) {
+        pthread_mutex_init(&lf_sync->mutex_[i], NULL);
+      }
     }
 
     CHECK_MEM_ERROR(cm, lf_sync->cond_,
                     vpx_malloc(sizeof(*lf_sync->cond_) * rows));
-    for (i = 0; i < rows; ++i) {
-      pthread_cond_init(&lf_sync->cond_[i], NULL);
+    if (lf_sync->cond_) {
+      for (i = 0; i < rows; ++i) {
+        pthread_cond_init(&lf_sync->cond_[i], NULL);
+      }
     }
   }
 #endif  // CONFIG_MULTITHREAD
 
   CHECK_MEM_ERROR(cm, lf_sync->cur_sb_col,
                   vpx_malloc(sizeof(*lf_sync->cur_sb_col) * rows));
 
   // Set up nsync.
   lf_sync->sync_range = get_sync_range(width);
 }
@@ skipping 16 matching lines @@
       }
       vpx_free(lf_sync->cond_);
     }
 #endif  // CONFIG_MULTITHREAD
     vpx_free(lf_sync->cur_sb_col);
     // clear the structure as the source of this call may be a resize in which
     // case this call will be followed by an _alloc() which may fail.
     vp9_zero(*lf_sync);
   }
 }