[NaCl SDK} Add EventListener and EventEmitter to support epoll.

native_client_sdk/src/libraries/nacl_io/event_emitter.cc

+/* Copyright (c) 2013 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */

[Sam Clegg, 2013/07/17 17:34:56]

C++ comments.

[noelallen1, 2013/07/17 21:00:18]

We use C comments here throughout nacl_io

+#include <assert.h>
+
+#include "nacl_io/event_emitter.h"

[Sam Clegg, 2013/07/17 17:34:56]

I think event_emitter.h is supposed to be the very first #include.

[noelallen1, 2013/07/17 21:00:18]

Consistent with nacl_io, we could create a separate CL to change this.

+#include "nacl_io/event_listener.h"
+
+#include "sdk_util/auto_lock.h"
+
+
+void EventEmitter::Destroy() {
+  // We can not grab the EmitterLock prior to grabbing the EventListener lock,
+  // however the ref count proves this is the only thread which has a
+  // reference to the emitter at this point so accessing events_ is safe.
+  EventInfoSet_t::iterator it;
+  for (it = events_.begin(); it != events_.end(); it++) {
+    ScopedEventInfo info = *it;
+    info->listener->AbandonedEventInfo(info);
+  }
+}
+
+void EventEmitter::RegisterEventInfo(const ScopedEventInfo& info) {
+  AutoLock lock(emitter_lock_);
+
+  events_.insert(info);
+  ChainRegister(info);
+}
+
+void EventEmitter::UnregisterEventInfo(const ScopedEventInfo& info) {
+  AutoLock lock(emitter_lock_);
+
+  ChainUnregister(info);
+  events_.erase(info);
+}
+
+void EventEmitter::RaiseEvent(uint32_t event_bits) {
+  AutoLock lock(emitter_lock_);
+
+  EventInfoSet_t::iterator it;
+  for (it = events_.begin(); it != events_.end(); it++) {
+    // If this event is allowed by the filter, signal it
+    ScopedEventInfo info = *it;
+    if (info->filter & event_bits) {
+      info->events |= event_bits;
+      info->listener->Signal(info);
+    }
+  }
+}
+
+// Provided to allow one EventEmitter to register the same EventInfo with

[binji, 2013/07/17 22:23:20]

might be more valuable to move this comment to the header.

[noelallen1, 2013/07/18 22:18:16]

Done.

+// a child EventEmitter so that they can both signal the EventListener.
+void EventEmitter::ChainRegister(const ScopedEventInfo& info) {}
+void EventEmitter::ChainUnregister(const ScopedEventInfo& info) {}