1 files changed, 99 insertions, 0 deletions
diff --git a/media/libcubeb/src/cubeb_array_queue.h b/media/libcubeb/src/cubeb_array_queue.h
new file mode 100644
index 0000000000..d6d9581325
--- /dev/null
+++ b/media/libcubeb/src/cubeb_array_queue.h
@@ -0,0 +1,99 @@
+/*
+ * Copyright © 2016 Mozilla Foundation
+ *
+ * This program is made available under an ISC-style license.  See the
+ * accompanying file LICENSE for details.
+ */
+
+#ifndef CUBEB_ARRAY_QUEUE_H
+#define CUBEB_ARRAY_QUEUE_H
+
+#include <assert.h>
+#include <pthread.h>
+#include <unistd.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+typedef struct {
+  void ** buf;
+  size_t num;
+  size_t writePos;
+  size_t readPos;
+  pthread_mutex_t mutex;
+} array_queue;
+
+array_queue *
+array_queue_create(size_t num)
+{
+  assert(num != 0);
+  array_queue * new_queue = (array_queue *)calloc(1, sizeof(array_queue));
+  new_queue->buf = (void **)calloc(1, sizeof(void *) * num);
+  new_queue->readPos = 0;
+  new_queue->writePos = 0;
+  new_queue->num = num;
+
+  pthread_mutex_init(&new_queue->mutex, NULL);
+
+  return new_queue;
+}
+
+void
+array_queue_destroy(array_queue * aq)
+{
+  assert(aq);
+
+  free(aq->buf);
+  pthread_mutex_destroy(&aq->mutex);
+  free(aq);
+}
+
+int
+array_queue_push(array_queue * aq, void * item)
+{
+  assert(item);
+
+  pthread_mutex_lock(&aq->mutex);
+  int ret = -1;
+  if (aq->buf[aq->writePos % aq->num] == NULL) {
+    aq->buf[aq->writePos % aq->num] = item;
+    aq->writePos = (aq->writePos + 1) % aq->num;
+    ret = 0;
+  }
+  // else queue is full
+  pthread_mutex_unlock(&aq->mutex);
+  return ret;
+}
+
+void *
+array_queue_pop(array_queue * aq)
+{
+  pthread_mutex_lock(&aq->mutex);
+  void * value = aq->buf[aq->readPos % aq->num];
+  if (value) {
+    aq->buf[aq->readPos % aq->num] = NULL;
+    aq->readPos = (aq->readPos + 1) % aq->num;
+  }
+  pthread_mutex_unlock(&aq->mutex);
+  return value;
+}
+
+size_t
+array_queue_get_size(array_queue * aq)
+{
+  pthread_mutex_lock(&aq->mutex);
+  ssize_t r = aq->writePos - aq->readPos;
+  if (r < 0) {
+    r = aq->num + r;
+    assert(r >= 0);
+  }
+  pthread_mutex_unlock(&aq->mutex);
+  return (size_t)r;
+}
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif // CUBE_ARRAY_QUEUE_H