mirror of
https://github.com/dart-lang/sdk
synced 2024-09-19 20:51:50 +00:00
874588a859
To avoid deadlock scenarios where an application runs N isolates on a thread pool with T threads (T < N) where all scheduled T isolates will do FFI call and block. That prevents any other isolates from executing. To avoid such a scenario we add support for the isolate-group specific thread pool to dynamically increase the maximum size if a worker is running a isolate mutator thread, which calls to C which exits the isolate. => While such an isolate is descheduled but still occupies a thread pool worker we temporarily incrase the maximum size of the thread pool. Issue https://github.com/dart-lang/sdk/issues/36097 Change-Id: Id61c39b06766da11f76d607ac7cbe8a8e623f250 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/148120 Commit-Queue: Martin Kustermann <kustermann@google.com> Reviewed-by: Ryan Macnak <rmacnak@google.com>
144 lines
4 KiB
C++
144 lines
4 KiB
C++
// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
|
|
// for details. All rights reserved. Use of this source code is governed by a
|
|
// BSD-style license that can be found in the LICENSE file.
|
|
|
|
#ifndef RUNTIME_VM_THREAD_POOL_H_
|
|
#define RUNTIME_VM_THREAD_POOL_H_
|
|
|
|
#include <memory>
|
|
#include <utility>
|
|
|
|
#include "vm/allocation.h"
|
|
#include "vm/globals.h"
|
|
#include "vm/intrusive_dlist.h"
|
|
#include "vm/os_thread.h"
|
|
|
|
namespace dart {
|
|
|
|
class MonitorLocker;
|
|
|
|
class ThreadPool {
|
|
public:
|
|
// Subclasses of Task are able to run on a ThreadPool.
|
|
class Task : public IntrusiveDListEntry<Task> {
|
|
protected:
|
|
Task() {}
|
|
|
|
public:
|
|
virtual ~Task() {}
|
|
|
|
// Override this to provide task-specific behavior.
|
|
virtual void Run() = 0;
|
|
|
|
private:
|
|
DISALLOW_COPY_AND_ASSIGN(Task);
|
|
};
|
|
|
|
explicit ThreadPool(uintptr_t max_pool_size = 0);
|
|
|
|
// Prevent scheduling of new tasks, wait until all pending tasks are done
|
|
// and join worker threads.
|
|
virtual ~ThreadPool();
|
|
|
|
// Runs a task on the thread pool.
|
|
template <typename T, typename... Args>
|
|
bool Run(Args&&... args) {
|
|
return RunImpl(std::unique_ptr<Task>(new T(std::forward<Args>(args)...)));
|
|
}
|
|
|
|
// Returns `true` if the current thread is runing on the [this] thread pool.
|
|
bool CurrentThreadIsWorker();
|
|
|
|
// Mark the current thread as being blocked (e.g. in native code). This might
|
|
// temporarily increase the max thread pool size.
|
|
void MarkCurrentWorkerAsBlocked();
|
|
|
|
// Mark the current thread as being unblocked. Must be called iff
|
|
// [MarkCurrentWorkerAsBlocked] was called before and the thread is now ready
|
|
// to coninue executing.
|
|
void MarkCurrentWorkerAsUnBlocked();
|
|
|
|
// Triggers shutdown, prevents scheduling of new tasks.
|
|
void Shutdown();
|
|
|
|
// Exposed for unit test in thread_pool_test.cc
|
|
uint64_t workers_started() const { return count_idle_ + count_running_; }
|
|
// Exposed for unit test in thread_pool_test.cc
|
|
uint64_t workers_stopped() const { return count_dead_; }
|
|
|
|
private:
|
|
class Worker : public IntrusiveDListEntry<Worker> {
|
|
public:
|
|
explicit Worker(ThreadPool* pool);
|
|
|
|
// Starts the thread for the worker. This should only be called
|
|
// after a task has been set by the initial call to SetTask().
|
|
void StartThread();
|
|
|
|
private:
|
|
friend class ThreadPool;
|
|
|
|
// The main entry point for new worker threads.
|
|
static void Main(uword args);
|
|
|
|
// Fields initialized during construction or in start of main function of
|
|
// thread.
|
|
ThreadPool* pool_;
|
|
ThreadJoinId join_id_;
|
|
OSThread* os_thread_ = nullptr;
|
|
bool is_blocked_ = false;
|
|
|
|
DISALLOW_COPY_AND_ASSIGN(Worker);
|
|
};
|
|
|
|
protected:
|
|
// Called when the thread pool turns idle.
|
|
//
|
|
// Subclasses can override this to perform some action.
|
|
// NOTE: While this function is running the thread pool will be locked.
|
|
virtual void OnEnterIdleLocked(MonitorLocker* ml) {}
|
|
|
|
// Whether a shutdown was requested.
|
|
bool ShuttingDownLocked() { return shutting_down_; }
|
|
|
|
// Whether new tasks are ready to be run.
|
|
bool TasksWaitingToRunLocked() { return !tasks_.IsEmpty(); }
|
|
|
|
private:
|
|
using TaskList = IntrusiveDList<Task>;
|
|
using WorkerList = IntrusiveDList<Worker>;
|
|
|
|
bool RunImpl(std::unique_ptr<Task> task);
|
|
void WorkerLoop(Worker* worker);
|
|
|
|
Worker* ScheduleTaskLocked(MonitorLocker* ml, std::unique_ptr<Task> task);
|
|
|
|
void IdleToRunningLocked(Worker* worker);
|
|
void RunningToIdleLocked(Worker* worker);
|
|
void IdleToDeadLocked(Worker* worker);
|
|
void ObtainDeadWorkersLocked(WorkerList* dead_workers_to_join);
|
|
void JoinDeadWorkersLocked(WorkerList* dead_workers_to_join);
|
|
|
|
Monitor pool_monitor_;
|
|
bool shutting_down_ = false;
|
|
uint64_t count_running_ = 0;
|
|
uint64_t count_idle_ = 0;
|
|
uint64_t count_dead_ = 0;
|
|
WorkerList running_workers_;
|
|
WorkerList idle_workers_;
|
|
WorkerList dead_workers_;
|
|
uint64_t pending_tasks_ = 0;
|
|
TaskList tasks_;
|
|
|
|
Monitor exit_monitor_;
|
|
std::atomic<bool> all_workers_dead_;
|
|
|
|
uintptr_t max_pool_size_ = 0;
|
|
|
|
DISALLOW_COPY_AND_ASSIGN(ThreadPool);
|
|
};
|
|
|
|
} // namespace dart
|
|
|
|
#endif // RUNTIME_VM_THREAD_POOL_H_
|