vlink::SpinLock Class Reference

Adaptive spin lock satisfying the C++ Lockable named requirement. More...

#include <spin_lock.h>

Collaboration diagram for vlink::SpinLock:

Public Member Functions
	SpinLock () noexcept=default
	Constructs an unlocked spin lock. More...
	~SpinLock () noexcept=default
	Destructor. Assumes the lock has already been released. More...
void	lock () noexcept
	Acquires the lock, spinning with adaptive back-off until it becomes free. More...
bool	try_lock () noexcept
	Attempts a single non-blocking acquire of the lock. More...
void	unlock () noexcept
	Releases the lock with memory_order_release. More...

Detailed Description

Adaptive spin lock satisfying the C++ Lockable named requirement.

Cache-line aligned through alignas(64) to prevent false sharing. Composes with std::lock_guard, std::unique_lock and the supplied SpinLockGuard.

Constructor & Destructor Documentation

SpinLock()

vlink::SpinLock::SpinLock ( )

defaultnoexcept

Constructs an unlocked spin lock.

~SpinLock()

vlink::SpinLock::~SpinLock ( )

defaultnoexcept

Destructor. Assumes the lock has already been released.

Member Function Documentation

lock()

void vlink::SpinLock::lock ( )

inlinenoexcept

Acquires the lock, spinning with adaptive back-off until it becomes free.

Details.

The inner loop alternates exchange attempts with relaxed-load spins. Each back-off rung doubles the spin budget from 8 up to 1024 then yields the CPU. After 50000 spins the back-off action switches to a 10 us sleep and a one-time warning is emitted.

Warning

Recursive acquisition by the same thread deadlocks the lock.

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try_lock()

bool vlink::SpinLock::try_lock ( )

inlinenoexcept

Attempts a single non-blocking acquire of the lock.

Returns

true when the lock was successfully acquired.

unlock()

void vlink::SpinLock::unlock ( )

inlinenoexcept

Releases the lock with memory_order_release.

May only be called by the thread that currently owns the lock.

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

• include/vlink/base/spin_lock.h