folly::python::GILAwareManualExecutor Class Reference

#include <GILAwareManualExecutor.h>

Inheritance diagram for folly::python::GILAwareManualExecutor:

Public Member Functions
void	add (Func) override
void	drive () override
Public Member Functions inherited from folly::DrivableExecutor
	~DrivableExecutor () override=default
Public Member Functions inherited from folly::Executor
virtual	~Executor ()
virtual void	addWithPriority (Func, int8_t priority)
virtual uint8_t	getNumPriorities () const

Private Member Functions
void	waitBeforeDrive ()
void	driveImpl ()

Private Attributes
std::mutex	lock_
std::queue< Func >	funcs_
std::condition_variable	cv_

Additional Inherited Members
Static Public Member Functions inherited from folly::Executor
template<typename ExecutorT >
static KeepAlive< ExecutorT >	getKeepAliveToken (ExecutorT *executor)
template<typename ExecutorT >
static KeepAlive< ExecutorT >	getKeepAliveToken (ExecutorT &executor)
Static Public Attributes inherited from folly::Executor
static const int8_t	LO_PRI = SCHAR_MIN
static const int8_t	MID_PRI = 0
static const int8_t	HI_PRI = SCHAR_MAX
Protected Member Functions inherited from folly::Executor
virtual bool	keepAliveAcquire ()
virtual void	keepAliveRelease ()
Static Protected Member Functions inherited from folly::Executor
template<typename ExecutorT >
static bool	isKeepAliveDummy (const KeepAlive< ExecutorT > &keepAlive)
template<typename ExecutorT >
static KeepAlive< ExecutorT >	makeKeepAlive (ExecutorT *executor)

Detailed Description

A simple ManualExecutor intended to be run directly on a Python thread. It releases Python GIL while waiting for tasks to execute.

Definition at line 34 of file GILAwareManualExecutor.h.

Member Function Documentation

void folly::python::GILAwareManualExecutor::add ( Func  )

overridevirtual

Enqueue a function to executed by this executor. This and all variants must be threadsafe.

Implements folly::Executor.

Definition at line 26 of file GILAwareManualExecutor.cpp.

References cv_, funcs_, folly::lock(), lock_, and folly::gen::move.

                                              {
  {
    std::lock_guard<std::mutex> lock(lock_);
    funcs_.emplace(std::move(callback));
  }
  cv_.notify_one();
}

void folly::python::GILAwareManualExecutor::drive ( )

inlineoverridevirtual

Implements folly::DrivableExecutor.

Definition at line 39 of file GILAwareManualExecutor.h.

References driveImpl(), and waitBeforeDrive().

                        {
    waitBeforeDrive();
    driveImpl();
  }

void folly::python::GILAwareManualExecutor::driveImpl ( )

private

Definition at line 51 of file GILAwareManualExecutor.cpp.

References funcs_, folly::lock(), lock_, and folly::gen::move.

Referenced by drive().

                                       {
  Func func;
  while (true) {
    {
      std::lock_guard<std::mutex> lock(lock_);
      if (funcs_.empty()) {
        break;
      }

      func = std::move(funcs_.front());
      funcs_.pop();
    }
    func();
  }
}

void folly::python::GILAwareManualExecutor::waitBeforeDrive ( )

private

Definition at line 34 of file GILAwareManualExecutor.cpp.

References cv_, funcs_, folly::lock(), lock_, and SCOPE_EXIT.

Referenced by drive().

                                             {
  std::unique_lock<std::mutex> lock(lock_);
  if (!funcs_.empty()) {
    return;
  }

  // Release GIL before waiting on lock
  auto* pyThreadState = PyEval_SaveThread();
  SCOPE_EXIT {
    // Release lock before re-acquiring GIL,
    // to avoid deadlock if another GIL-owning thread is calling add
    lock.unlock();
    PyEval_RestoreThread(pyThreadState);
  };
  cv_.wait(lock, [&] { return !funcs_.empty(); });
}

Member Data Documentation

std::condition_variable folly::python::GILAwareManualExecutor::cv_

private

Definition at line 50 of file GILAwareManualExecutor.h.

Referenced by add(), and waitBeforeDrive().

std::queue<Func> folly::python::GILAwareManualExecutor::funcs_

private

Definition at line 49 of file GILAwareManualExecutor.h.

Referenced by add(), driveImpl(), and waitBeforeDrive().

std::mutex folly::python::GILAwareManualExecutor::lock_

private

Definition at line 48 of file GILAwareManualExecutor.h.

Referenced by add(), driveImpl(), and waitBeforeDrive().

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The documentation for this class was generated from the following files:

• proxygen/folly/folly/python/GILAwareManualExecutor.h
• proxygen/folly/folly/python/GILAwareManualExecutor.cpp