Source code

Revision control

Other Tools

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef AUDIOTHREADREGISTRY_H
#define AUDIOTHREADREGISTRY_H
#include <cstdint>
#include <mozilla/DataMutex.h>
#include <nsTArray.h>
#include <thread>
#include <GeckoProfiler.h>
namespace mozilla {
// This class is a singleton that tracks all audio callback threads and makes
// sure they are registered or unregistered to the profiler safely and
// consistently.
//
// Register and Unregister are fairly expensive and shouldn't be used in a hot
// path.
class AudioThreadRegistry final {
public:
AudioThreadRegistry() : mThreadIds("AudioThreadId") {}
~AudioThreadRegistry() {
// It would be nice to be able to assert that all threads have be
// unregistered, but we can't: it's legal to suspend an audio stream, so
// that the callback isn't called, and then immediately destroy it.
}
// This is intended to be called when an object starts an audio callback
// thread.
void Register(ProfilerThreadId aThreadId) {
if (!aThreadId.IsSpecified()) {
// profiler_current_thread_id is unspecified on unsupported platforms.
return;
}
auto threadIds = mThreadIds.Lock();
for (uint32_t i = 0; i < threadIds->Length(); i++) {
if ((*threadIds)[i].mId == aThreadId) {
(*threadIds)[i].mUserCount++;
return;
}
}
ThreadUserCount tuc;
tuc.mId = aThreadId;
tuc.mUserCount = 1;
threadIds->AppendElement(tuc);
PROFILER_REGISTER_THREAD("NativeAudioCallback");
}
// This is intended to be called when an object stops an audio callback thread
void Unregister(ProfilerThreadId aThreadId) {
if (!aThreadId.IsSpecified()) {
// profiler_current_thread_id is unspedified on unsupported platforms.
return;
}
auto threadIds = mThreadIds.Lock();
for (uint32_t i = 0; i < threadIds->Length(); i++) {
if ((*threadIds)[i].mId == aThreadId) {
MOZ_ASSERT((*threadIds)[i].mUserCount > 0);
(*threadIds)[i].mUserCount--;
if ((*threadIds)[i].mUserCount == 0) {
PROFILER_UNREGISTER_THREAD();
threadIds->RemoveElementAt(i);
}
return;
}
}
MOZ_ASSERT(false);
}
private:
AudioThreadRegistry(const AudioThreadRegistry&) = delete;
AudioThreadRegistry& operator=(const AudioThreadRegistry&) = delete;
AudioThreadRegistry(AudioThreadRegistry&&) = delete;
AudioThreadRegistry& operator=(AudioThreadRegistry&&) = delete;
struct ThreadUserCount {
ProfilerThreadId mId; // from profiler_current_thread_id
int mUserCount;
};
DataMutex<nsTArray<ThreadUserCount>> mThreadIds;
};
} // namespace mozilla
#endif // AUDIOTHREADREGISTRY_H