dspark::SpinLock Class Reference

A minimal, real-time safe spin lock with a TTAS wait loop. More...

#include <SpinLock.h>

Classes
class	ScopedLock
	RAII wrapper that acquires the lock on construction and releases on destruction. More...
class	ScopedTryLock
	RAII wrapper that tries to acquire the lock without blocking. More...

Public Member Functions
	SpinLock () noexcept=default
	Constructs an unlocked SpinLock.
	SpinLock (const SpinLock &)=delete
SpinLock &	operator= (const SpinLock &)=delete
void	lock () noexcept
	Acquires the lock, spinning until successful.
bool	tryLock () noexcept
	Attempts to acquire the lock without waiting.
bool	try_lock () noexcept
	Standard-library spelling of tryLock().
void	unlock () noexcept
	Releases the lock, restoring it to the clear state.

Detailed Description

A minimal, real-time safe spin lock with a TTAS wait loop.

Fulfills the standard Lockable requirements (lock / try_lock / unlock), so it composes with std::lock_guard, std::unique_lock and std::scoped_lock.

• lock() busy-waits using a Test-and-Test-and-Set (TTAS) pattern to avoid cache thrashing.
• tryLock() attempts a single acquire without waiting: the right call on the audio thread.
• unlock() releases the lock safely.

Definition at line 69 of file SpinLock.h.

Constructor & Destructor Documentation

SpinLock() [1/2]

dspark::SpinLock::SpinLock ( )

defaultnoexcept

Constructs an unlocked SpinLock.

SpinLock() [2/2]

dspark::SpinLock::SpinLock ( const SpinLock &  )

delete

Member Function Documentation

lock()

void dspark::SpinLock::lock ( )

inlinenoexcept

Acquires the lock, spinning until successful.

Employs a TTAS (Test-and-Test-and-Set) loop: after a failed acquire it re-reads the flag with memory_order_relaxed (C++20 atomic_flag::test), keeping the cache line in a shared state and avoiding bus traffic until the lock appears free.

Note

Call only when the lock holder is guaranteed to release quickly.

Definition at line 88 of file SpinLock.h.

operator=()

SpinLock & dspark::SpinLock::operator= ( const SpinLock &  )

delete

try_lock()

bool dspark::SpinLock::try_lock ( )

inlinenoexcept

Standard-library spelling of tryLock().

Completes the C++ Lockable requirements so the lock works with std::unique_lock(std::try_to_lock) and multi-lock std::scoped_lock.

Definition at line 119 of file SpinLock.h.

tryLock()

bool dspark::SpinLock::tryLock ( )

inlinenoexcept

Attempts to acquire the lock without waiting.

Returns

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

Definition at line 108 of file SpinLock.h.

unlock()

void dspark::SpinLock::unlock ( )

inlinenoexcept

Releases the lock, restoring it to the clear state.

Definition at line 124 of file SpinLock.h.

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

• Core/SpinLock.h