folly::MicroSpinLock Struct Reference

#include <MicroSpinLock.h>

Inheritance diagram for folly::MicroSpinLock:

Public Types
enum	{ FREE = 0, LOCKED = 1 }

Public Member Functions
void	init () noexcept
bool	try_lock () noexcept
void	lock () noexcept
void	unlock () noexcept

Public Attributes
uint8_t	lock_

Private Member Functions
std::atomic< uint8_t > *	payload () noexcept
bool	cas (uint8_t compare, uint8_t newVal) noexcept

Detailed Description

Definition at line 65 of file MicroSpinLock.h.

Member Enumeration Documentation

anonymous enum

Enumerator
FREE
LOCKED

Definition at line 66 of file MicroSpinLock.h.

{ FREE = 0, LOCKED = 1 };

Member Function Documentation

bool folly::MicroSpinLock::cas ( uint8_t  compare, uint8_t  newVal  )

inlineprivatenoexcept

Definition at line 100 of file MicroSpinLock.h.

References payload(), and value.

Referenced by try_lock().

                                                     {
    return std::atomic_compare_exchange_strong_explicit(
        payload(),
        &compare,
        newVal,
        std::memory_order_acquire,
        std::memory_order_relaxed);
  }

void folly::MicroSpinLock::init ( )

inlinenoexcept

Definition at line 72 of file MicroSpinLock.h.

References FREE, and payload().

Referenced by folly::detail::SkipListNode< T >::SkipListNode(), and folly::SpinLock::SpinLock().

                       {
    payload()->store(FREE);
  }

void folly::MicroSpinLock::lock ( )

inlinenoexcept

Definition at line 80 of file MicroSpinLock.h.

References deadlock::load(), LOCKED, payload(), try_lock(), and folly::detail::Sleeper::wait().

Referenced by folly::SpinLock::lock(), folly::futures::detail::SpinLock::SpinLock(), and folly::SpinLockGuardImpl< LOCK >::SpinLockGuardImpl().

                       {
    detail::Sleeper sleeper;
    while (!try_lock()) {
      do {
        sleeper.wait();
      } while (payload()->load(std::memory_order_relaxed) == LOCKED);
    }
    assert(payload()->load() == LOCKED);
  }

std::atomic<uint8_t>* folly::MicroSpinLock::payload ( )

inlineprivatenoexcept

Definition at line 96 of file MicroSpinLock.h.

References lock_.

Referenced by cas(), init(), lock(), and unlock().

                                         {
    return reinterpret_cast<std::atomic<uint8_t>*>(&this->lock_);
  }

bool folly::MicroSpinLock::try_lock ( )

inlinenoexcept

Definition at line 76 of file MicroSpinLock.h.

References cas(), FREE, and LOCKED.

Referenced by lock(), and folly::SpinLock::try_lock().

                           {
    return cas(FREE, LOCKED);
  }

void folly::MicroSpinLock::unlock ( )

inlinenoexcept

Definition at line 90 of file MicroSpinLock.h.

References FREE, deadlock::load(), LOCKED, and payload().

Referenced by folly::futures::detail::SpinLock::SpinLock(), folly::SpinLock::unlock(), and folly::SpinLockGuardImpl< LOCK >::~SpinLockGuardImpl().

                         {
    assert(payload()->load() == LOCKED);
    payload()->store(FREE, std::memory_order_release);
  }

Member Data Documentation

uint8_t folly::MicroSpinLock::lock_

Definition at line 68 of file MicroSpinLock.h.

Referenced by payload().

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

• proxygen/folly/folly/synchronization/MicroSpinLock.h