folly::PriorityThreadFactory Class Reference

#include <PriorityThreadFactory.h>

Inheritance diagram for folly::PriorityThreadFactory:

Public Member Functions
	PriorityThreadFactory (std::shared_ptr< ThreadFactory > factory, int priority)
std::thread	newThread (Func &&func) override
Public Member Functions inherited from folly::ThreadFactory
virtual	~ThreadFactory ()=default

Private Attributes
std::shared_ptr< ThreadFactory >	factory_
int	priority_

Detailed Description

A ThreadFactory that sets nice values for each thread. The main use case for this class is if there are multiple CPUThreadPoolExecutors in a single process, or between multiple processes, where some should have a higher priority than the others.

Note that per-thread nice values are not POSIX standard, but both pthreads and linux support per-thread nice. The default linux scheduler uses these values to do smart thread prioritization. sched_priority function calls only affect real-time schedulers.

Definition at line 38 of file PriorityThreadFactory.h.

Constructor & Destructor Documentation

folly::PriorityThreadFactory::PriorityThreadFactory ( std::shared_ptr< ThreadFactory >  factory, int  priority  )

inlineexplicit

Definition at line 40 of file PriorityThreadFactory.h.

      : factory_(std::move(factory)), priority_(priority) {}

Member Function Documentation

std::thread folly::PriorityThreadFactory::newThread ( Func &&  func )

inlineoverridevirtual

Implements folly::ThreadFactory.

Definition at line 45 of file PriorityThreadFactory.h.

References folly::errnoStr(), factory_, folly::gen::move, and priority_.

Referenced by TEST().

                                            {
    int priority = priority_;
    return factory_->newThread([priority, func = std::move(func)]() mutable {
      if (setpriority(PRIO_PROCESS, 0, priority) != 0) {
        LOG(ERROR) << "setpriority failed (are you root?) with error " << errno,
            errnoStr(errno);
      }
      func();
    });
  }

Member Data Documentation

std::shared_ptr<ThreadFactory> folly::PriorityThreadFactory::factory_

private

Definition at line 57 of file PriorityThreadFactory.h.

Referenced by newThread().

int folly::PriorityThreadFactory::priority_

private

Definition at line 58 of file PriorityThreadFactory.h.

Referenced by newThread().

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

• proxygen/folly/folly/executors/thread_factory/PriorityThreadFactory.h