vlink::SpinLock Class Reference

Adaptive, cache-line-aligned spin lock. More...

#include <spin_lock.h>

Collaboration diagram for vlink::SpinLock:

Public Member Functions
	SpinLock () noexcept=default
	Default constructor. Initialises the flag to false (unlocked).
	~SpinLock () noexcept=default
	Destructor.
void	lock () noexcept
	Acquires the lock, spinning until successful.
bool	try_lock () noexcept
	Attempts to acquire the lock without blocking.
void	unlock () noexcept
	Releases the lock.

Detailed Description

Adaptive, cache-line-aligned spin lock.

Implements the Lockable named requirement: lock(), try_lock(), and unlock(). Can be used directly with std::lock_guard.

Constructor & Destructor Documentation

SpinLock()

vlink::SpinLock::SpinLock ( )

defaultnoexcept

Default constructor. Initialises the flag to false (unlocked).

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~SpinLock()

vlink::SpinLock::~SpinLock ( )

defaultnoexcept

Destructor.

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Member Function Documentation

lock()

void vlink::SpinLock::lock ( )

inlinenoexcept

Acquires the lock, spinning until successful.

Details.

Uses an exponential back-off strategy to reduce bus contention:

• Spins with load(relaxed) for up to backoff iterations.
• Calls Utils::yield_cpu() (PAUSE/WFE/yield) when backoff is reached.
• Back-off doubles each round up to 1024.
• After 50000 total spins, logs an error and sleeps 10 us.

Warning

This function must not be called recursively from the same thread; doing so will cause an infinite deadlock.

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try_lock()

bool vlink::SpinLock::try_lock ( )

inlinenoexcept

Attempts to acquire the lock without blocking.

Performs a single exchange(true, acquire). Returns immediately regardless of whether the lock was acquired.

Returns

true if the lock was successfully acquired, false if it was already held by another thread.

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unlock()

void vlink::SpinLock::unlock ( )

inlinenoexcept

Releases the lock.

Stores false with release memory order. Must only be called by the thread that successfully called lock() or try_lock().

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

• include/vlink/base/spin_lock.h