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#include "node_platform.h"
#include "util.h"
namespace node {
using v8::Isolate;
using v8::Platform;
using v8::Task;
using v8::TracingController;
static void FlushTasks(uv_async_t* handle) {
NodePlatform* platform = static_cast<NodePlatform*>(handle->data);
platform->FlushForegroundTasksInternal();
}
static void BackgroundRunner(void* data) {
TaskQueue<Task>* background_tasks = static_cast<TaskQueue<Task>*>(data);
while (Task* task = background_tasks->BlockingPop()) {
task->Run();
delete task;
background_tasks->NotifyOfCompletion();
}
}
NodePlatform::NodePlatform(int thread_pool_size, uv_loop_t* loop,
TracingController* tracing_controller)
: loop_(loop) {
CHECK_EQ(0, uv_async_init(loop, &flush_tasks_, FlushTasks));
flush_tasks_.data = static_cast<void*>(this);
uv_unref(reinterpret_cast<uv_handle_t*>(&flush_tasks_));
if (tracing_controller) {
tracing_controller_.reset(tracing_controller);
} else {
TracingController* controller = new TracingController();
tracing_controller_.reset(controller);
}
for (int i = 0; i < thread_pool_size; i++) {
uv_thread_t* t = new uv_thread_t();
if (uv_thread_create(t, BackgroundRunner, &background_tasks_) != 0) {
delete t;
break;
}
threads_.push_back(std::unique_ptr<uv_thread_t>(t));
}
}
void NodePlatform::Shutdown() {
background_tasks_.Stop();
for (size_t i = 0; i < threads_.size(); i++) {
CHECK_EQ(0, uv_thread_join(threads_[i].get()));
}
// uv_run cannot be called from the time before the beforeExit callback
// runs until the program exits unless the event loop has any referenced
// handles after beforeExit terminates. This prevents unrefed timers
// that happen to terminate during shutdown from being run unsafely.
// Since uv_run cannot be called, this handle will never be fully cleaned
// up.
uv_close(reinterpret_cast<uv_handle_t*>(&flush_tasks_), nullptr);
}
size_t NodePlatform::NumberOfAvailableBackgroundThreads() {
return threads_.size();
}
static void RunForegroundTask(uv_timer_t* handle) {
Task* task = static_cast<Task*>(handle->data);
task->Run();
delete task;
uv_close(reinterpret_cast<uv_handle_t*>(handle), [](uv_handle_t* handle) {
delete reinterpret_cast<uv_timer_t*>(handle);
});
}
void NodePlatform::DrainBackgroundTasks() {
FlushForegroundTasksInternal();
background_tasks_.BlockingDrain();
}
void NodePlatform::FlushForegroundTasksInternal() {
while (auto delayed = foreground_delayed_tasks_.Pop()) {
uint64_t delay_millis =
static_cast<uint64_t>(delayed->second + 0.5) * 1000;
uv_timer_t* handle = new uv_timer_t();
handle->data = static_cast<void*>(delayed->first);
uv_timer_init(loop_, handle);
// Timers may not guarantee queue ordering of events with the same delay if
// the delay is non-zero. This should not be a problem in practice.
uv_timer_start(handle, RunForegroundTask, delay_millis, 0);
uv_unref(reinterpret_cast<uv_handle_t*>(handle));
delete delayed;
}
while (Task* task = foreground_tasks_.Pop()) {
task->Run();
delete task;
}
}
void NodePlatform::CallOnBackgroundThread(Task* task,
ExpectedRuntime expected_runtime) {
background_tasks_.Push(task);
}
void NodePlatform::CallOnForegroundThread(Isolate* isolate, Task* task) {
foreground_tasks_.Push(task);
uv_async_send(&flush_tasks_);
}
void NodePlatform::CallDelayedOnForegroundThread(Isolate* isolate,
Task* task,
double delay_in_seconds) {
auto pair = new std::pair<Task*, double>(task, delay_in_seconds);
foreground_delayed_tasks_.Push(pair);
uv_async_send(&flush_tasks_);
}
bool NodePlatform::IdleTasksEnabled(Isolate* isolate) { return false; }
double NodePlatform::MonotonicallyIncreasingTime() {
// Convert nanos to seconds.
return uv_hrtime() / 1e9;
}
TracingController* NodePlatform::GetTracingController() {
return tracing_controller_.get();
}
template <class T>
TaskQueue<T>::TaskQueue()
: lock_(), tasks_available_(), tasks_drained_(),
outstanding_tasks_(0), stopped_(false), task_queue_() { }
template <class T>
void TaskQueue<T>::Push(T* task) {
Mutex::ScopedLock scoped_lock(lock_);
outstanding_tasks_++;
task_queue_.push(task);
tasks_available_.Signal(scoped_lock);
}
template <class T>
T* TaskQueue<T>::Pop() {
Mutex::ScopedLock scoped_lock(lock_);
T* result = nullptr;
if (!task_queue_.empty()) {
result = task_queue_.front();
task_queue_.pop();
}
return result;
}
template <class T>
T* TaskQueue<T>::BlockingPop() {
Mutex::ScopedLock scoped_lock(lock_);
while (task_queue_.empty() && !stopped_) {
tasks_available_.Wait(scoped_lock);
}
if (stopped_) {
return nullptr;
}
T* result = task_queue_.front();
task_queue_.pop();
return result;
}
template <class T>
void TaskQueue<T>::NotifyOfCompletion() {
Mutex::ScopedLock scoped_lock(lock_);
if (--outstanding_tasks_ == 0) {
tasks_drained_.Broadcast(scoped_lock);
}
}
template <class T>
void TaskQueue<T>::BlockingDrain() {
Mutex::ScopedLock scoped_lock(lock_);
while (outstanding_tasks_ > 0) {
tasks_drained_.Wait(scoped_lock);
}
}
template <class T>
void TaskQueue<T>::Stop() {
Mutex::ScopedLock scoped_lock(lock_);
stopped_ = true;
tasks_available_.Broadcast(scoped_lock);
}
} // namespace node
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