WaitQueue Class Reference

#include <WaitQueue.h>

Collaboration diagram for WaitQueue:

Classes
struct	Channel
class	Guard
struct	Waiter

Public Types
enum class	WakeReason {   Waiting , Signalled , Event , Unwinding ,   Terminating , Spurious }
using	StackDiscardCleanup = void(*)(void *)
using	AbandonCallback = StackDiscardCleanup

Public Member Functions
MUST_USE_RESULT Guard	acquire ()
bool	wakeOne (WakeReason reason=WakeReason::Signalled, const Channel &channel=Channel())
size_t	wakeAll (WakeReason reason=WakeReason::Signalled, const Channel &channel=Channel())
size_t	wakeAllIfWaiting (WakeReason reason=WakeReason::Signalled, const Channel &channel=Channel())
size_t	waiterCount ()

Private Member Functions
WakeReason	wait (Guard &guard, Mutex *mutex, const Channel &channel, size_t debugState, uintptr_t debugAddress, bool deferTerminal, bool dispatchEvents)
bool	wakeOneLocked (Guard &guard, WakeReason reason, const Channel &channel)
size_t	wakeAllLocked (Guard &guard, WakeReason reason, const Channel &channel)
size_t	wakeAndRequeueLocked (Guard &guard, const Channel &source, size_t wakeCount, const Channel &destination, size_t requeueCount)
bool	completeWaiter (Guard &guard, Waiter *waiter, WakeReason reason)
void	removeWaiterLocked (Waiter *waiter)
void	clearWaitIntentIfEmpty ()
void	cancel (Waiter *waiter, WakeReason reason)

Static Private Member Functions
static void	publishReady (Waiter *waiter)

Private Attributes
Spinlock	m_Lock
Waiter *	m_pFirstWaiter
Waiter *	m_pLastWaiter
size_t	m_WaiterCount
bool	m_WaitIntent

Friends
class	Thread

Detailed Description

Owns the complete transition between testing a wait predicate and blocking.

A Guard serialises the predicate with wakeOne/wakeAll. wait() consumes the Guard and installs a persistent wait record before releasing the queue lock. Consequently, a wake arriving before the scheduler commits Sleeping is retained and causes the scheduler to abort the sleep.

Definition at line 28 of file WaitQueue.h.

Member Typedef Documentation

AbandonCallback

using WaitQueue::AbandonCallback = StackDiscardCleanup

Definition at line 34 of file WaitQueue.h.

StackDiscardCleanup

using WaitQueue::StackDiscardCleanup = void (*)(void*)

Definition at line 33 of file WaitQueue.h.

Member Enumeration Documentation

WakeReason

enum class WaitQueue::WakeReason

strong

Definition at line 36 of file WaitQueue.h.

Constructor & Destructor Documentation

WaitQueue()

WaitQueue::WaitQueue

(

)

Definition at line 193 of file WaitQueue.cc.

~WaitQueue()

WaitQueue::~WaitQueue

(

)

Definition at line 200 of file WaitQueue.cc.

Member Function Documentation

acquire()

MUST_USE_RESULT Guard WaitQueue::acquire ( )

inline

Definition at line 139 of file WaitQueue.h.

cancel()

void WaitQueue::cancel ( Waiter *  waiter, WakeReason  reason  )

private

Definition at line 508 of file WaitQueue.cc.

clearWaitIntentIfEmpty()

void WaitQueue::clearWaitIntentIfEmpty ( )

private

Definition at line 355 of file WaitQueue.cc.

completeWaiter()

bool WaitQueue::completeWaiter ( Guard &  guard, Waiter *  waiter, WakeReason  reason  )

private

Definition at line 434 of file WaitQueue.cc.

publishReady()

void WaitQueue::publishReady ( Waiter *  waiter )

staticprivate

Definition at line 461 of file WaitQueue.cc.

removeWaiterLocked()

void WaitQueue::removeWaiterLocked ( Waiter *  waiter )

private

Definition at line 480 of file WaitQueue.cc.

wait()

WaitQueue::WakeReason WaitQueue::wait ( Guard &  guard, Mutex *  mutex, const Channel &  channel, size_t  debugState, uintptr_t  debugAddress, bool  deferTerminal, bool  dispatchEvents  )

private

Definition at line 206 of file WaitQueue.cc.

waiterCount()

size_t WaitQueue::waiterCount

(

)

Definition at line 556 of file WaitQueue.cc.

wakeAll()

size_t WaitQueue::wakeAll	(	WakeReason	reason = WakeReason::Signalled,
		const Channel &	channel = Channel()
	)

Definition at line 340 of file WaitQueue.cc.

wakeAllIfWaiting()

size_t WaitQueue::wakeAllIfWaiting	(	WakeReason	reason = WakeReason::Signalled,
		const Channel &	channel = Channel()
	)

Skips an empty queue. Every matching waiter must use prepareToWait(), and the caller must publish its predicate with sequential consistency before calling this method. Ordinary wakeAll has no such requirement.

Definition at line 345 of file WaitQueue.cc.

References ProcessorBase::guardDeviceHardIrqOperation().

Referenced by Cache::read(), and Semaphore::release().

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wakeAllLocked()

size_t WaitQueue::wakeAllLocked ( Guard &  guard, WakeReason  reason, const Channel &  channel  )

private

Definition at line 379 of file WaitQueue.cc.

wakeAndRequeueLocked()

size_t WaitQueue::wakeAndRequeueLocked ( Guard &  guard, const Channel &  source, size_t  wakeCount, const Channel &  destination, size_t  requeueCount  )

private

Definition at line 396 of file WaitQueue.cc.

wakeOne()

bool WaitQueue::wakeOne	(	WakeReason	reason = WakeReason::Signalled,
		const Channel &	channel = Channel()
	)

Definition at line 335 of file WaitQueue.cc.

wakeOneLocked()

bool WaitQueue::wakeOneLocked ( Guard &  guard, WakeReason  reason, const Channel &  channel  )

private

Definition at line 363 of file WaitQueue.cc.

Friends And Related Symbol Documentation

Thread

friend class Thread

friend

Definition at line 169 of file WaitQueue.h.

Member Data Documentation

m_Lock

Spinlock WaitQueue::m_Lock

private

Definition at line 243 of file WaitQueue.h.

m_pFirstWaiter

Waiter* WaitQueue::m_pFirstWaiter

private

Definition at line 244 of file WaitQueue.h.

m_pLastWaiter

Waiter* WaitQueue::m_pLastWaiter

private

Definition at line 245 of file WaitQueue.h.

m_WaiterCount

size_t WaitQueue::m_WaiterCount

private

Definition at line 246 of file WaitQueue.h.

m_WaitIntent

bool WaitQueue::m_WaitIntent

private

Definition at line 247 of file WaitQueue.h.

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

• WaitQueue.h
• WaitQueue.cc