distortos::ConditionVariable Class Reference

ConditionVariable is an advanced synchronization primitive. More...

#include "distortos/ConditionVariable.hpp"

Collaboration diagram for distortos::ConditionVariable:

Public Member Functions
constexpr	ConditionVariable ()
	ConditionVariable's constructor. More...
	~ConditionVariable ()=default
	ConditionVariable's destructor. More...
void	notifyAll ()
	Notifies all waiting threads. More...
void	notifyOne ()
	Notifies one waiting thread. More...
int	wait (Mutex &mutex)
	Waits for notification. More...
template<typename Predicate >
int	wait (Mutex &mutex, Predicate predicate)
	Waits for predicate to become true. More...
int	waitFor (Mutex &mutex, TickClock::duration duration)
	Waits for notification for given duration of time. More...
template<typename Rep , typename Period >
int	waitFor (Mutex &mutex, const std::chrono::duration< Rep, Period > duration)
	Waits for notification for given duration of time. More...
template<typename Rep , typename Period , typename Predicate >
int	waitFor (Mutex &mutex, const std::chrono::duration< Rep, Period > duration, Predicate predicate)
	Waits for predicate to become true for given duration of time. More...
int	waitUntil (Mutex &mutex, TickClock::time_point timePoint)
	Waits for notification until given time point. More...
template<typename Duration >
int	waitUntil (Mutex &mutex, const std::chrono::time_point< TickClock, Duration > timePoint)
	Waits for notification until given time point. More...
template<typename Duration , typename Predicate >
int	waitUntil (Mutex &mutex, std::chrono::time_point< TickClock, Duration > timePoint, Predicate predicate)
	Waits for predicate to become true until given time point. More...

Private Attributes
internal::ThreadList	blockedList_
	ThreadControlBlock objects blocked on this condition variable. More...

Detailed Description

ConditionVariable is an advanced synchronization primitive.

Similar to std::condition_variable - http://en.cppreference.com/w/cpp/thread/condition_variable Similar to POSIX pthread_cond_t

Constructor & Destructor Documentation

ConditionVariable()

constexpr distortos::ConditionVariable::ConditionVariable ( )

inline

ConditionVariable's constructor.

Similar to std::condition_variable::condition_variable() - http://en.cppreference.com/w/cpp/thread/condition_variable/condition_variable Similar to pthread_cond_init() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_init.html

~ConditionVariable()

distortos::ConditionVariable::~ConditionVariable ( )

default

ConditionVariable's destructor.

Similar to std::condition_variable::~condition_variable() - http://en.cppreference.com/w/cpp/thread/condition_variable/~condition_variable Similar to pthread_cond_destroy() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_destroy.html

It shall be safe to destroy an initialized condition variable upon which no threads are currently blocked. Attempting to destroy a condition variable upon which other threads are currently blocked results in undefined behavior.

Member Function Documentation

notifyAll()

void distortos::ConditionVariable::notifyAll

(

)

Notifies all waiting threads.

Similar to std::condition_variable::notify_all() - http://en.cppreference.com/w/cpp/thread/condition_variable/notify_all Similar to pthread_cond_broadcast() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_signal.html

Unblocks all threads waiting on this condition variable. The notifying thread does not need to hold the same mutex as the one held by the waiting thread(s).

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notifyOne()

void distortos::ConditionVariable::notifyOne

(

)

Notifies one waiting thread.

Similar to std::condition_variable::notify_one() - http://en.cppreference.com/w/cpp/thread/condition_variable/notify_one Similar to pthread_cond_signal() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_signal.html

Unblocks one thread waiting on this condition variable. The notifying thread does not need to hold the same mutex as the one held by the waiting thread(s).

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wait() [1/2]

int distortos::ConditionVariable::wait

(

Mutex &

mutex

)

Waits for notification.

Similar to std::condition_variable::wait() - http://en.cppreference.com/w/cpp/thread/condition_variable/wait Similar to pthread_cond_wait() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_wait.html

Atomically releases supplied mutex and blocks current thread until the condition variable is notified. The thread will be unblocked when notifyAll() or notifyOne() is executed. It may also be unblocked spuriously. When unblocked, regardless of the reason, lock is reacquired and wait exits.

Warning

This function must not be called from interrupt context!

Parameters

[in]

mutex

is a reference to mutex which must be owned by calling thread

Returns

0 if the wait was completed successfully, error code otherwise:

• EPERM - the mutex type is errorChecking or recursive, and the current thread does not own the mutex;

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wait() [2/2]

template<typename Predicate >

int distortos::ConditionVariable::wait	(	Mutex &	mutex,
		Predicate	predicate
	)

Waits for predicate to become true.

Similar to std::condition_variable::wait() - http://en.cppreference.com/w/cpp/thread/condition_variable/wait Similar to pthread_cond_wait() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_wait.html

Overload for wait() which also checks the predicate. This function will return only if the predicate is true.

Warning

This function must not be called from interrupt context!

Template Parameters

Predicate

is a type of functor to check the predicate

Parameters

[in]	mutex	is a reference to mutex which must be owned by calling thread
[in]	predicate	is the predicate that will be checked

Returns

0 if the wait was completed successfully, error code otherwise:

• EPERM - the mutex type is errorChecking or recursive, and the current thread does not own the mutex;

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waitFor() [1/3]

int distortos::ConditionVariable::waitFor	(	Mutex &	mutex,
		TickClock::duration	duration
	)

Waits for notification for given duration of time.

Similar to std::condition_variable::wait_for() - http://en.cppreference.com/w/cpp/thread/condition_variable/wait_for Similar to pthread_cond_timedwait() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html#

Atomically releases supplied mutex and blocks current thread until the condition variable is notified. The thread will be unblocked when notifyAll() or notifyOne() is executed or when given duration of time expires. It may also be unblocked spuriously. When unblocked, regardless of the reason, lock is reacquired and wait exits.

Warning

This function must not be called from interrupt context!

Parameters

[in]	mutex	is a reference to mutex which must be owned by calling thread
[in]	duration	is the duration after which the wait for notification will be terminated

Returns

0 if the wait was completed successfully, error code otherwise:

• EPERM - the mutex type is errorChecking or recursive, and the current thread does not own the mutex;
• ETIMEDOUT - no notification was received before the specified timeout expired;

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waitFor() [2/3]

template<typename Rep , typename Period >

int distortos::ConditionVariable::waitFor ( Mutex &  mutex, const std::chrono::duration< Rep, Period >  duration  )

inline

Waits for notification for given duration of time.

Similar to std::condition_variable::wait_for() - http://en.cppreference.com/w/cpp/thread/condition_variable/wait_for Similar to pthread_cond_timedwait() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html#

Template variant of waitFor(Mutex& mutex, TickClock::duration duration).

Warning

This function must not be called from interrupt context!

Template Parameters

Rep	is type of tick counter
Period	is std::ratio type representing the tick period of the clock, seconds

Parameters

[in]	mutex	is a reference to mutex which must be owned by calling thread
[in]	duration	is the duration after which the wait for notification will be terminated

Returns

0 if the wait was completed successfully, error code otherwise:

• EPERM - the mutex type is errorChecking or recursive, and the current thread does not own the mutex;
• ETIMEDOUT - no notification was received before the specified timeout expired;

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waitFor() [3/3]

template<typename Rep , typename Period , typename Predicate >

int distortos::ConditionVariable::waitFor ( Mutex &  mutex, const std::chrono::duration< Rep, Period >  duration, Predicate  predicate  )

inline

Waits for predicate to become true for given duration of time.

Similar to std::condition_variable::wait_for() - http://en.cppreference.com/w/cpp/thread/condition_variable/wait_for Similar to pthread_cond_timedwait() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html#

Overload for waitFor() which also checks the predicate. This function will return only if the predicate is true or when given duration of time expires.

Warning

This function must not be called from interrupt context!

Template Parameters

Rep	is type of tick counter
Period	is std::ratio type representing the tick period of the clock, seconds
Predicate	is a type of functor to check the predicate

Parameters

[in]	mutex	is a reference to mutex which must be owned by calling thread
[in]	duration	is the duration after which the wait for notification will be terminated
[in]	predicate	is the predicate that will be checked

Returns

0 if the wait was completed successfully, error code otherwise:

• EPERM - the mutex type is errorChecking or recursive, and the current thread does not own the mutex;
• ETIMEDOUT - no notification was received before the specified timeout expired;

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waitUntil() [1/3]

int distortos::ConditionVariable::waitUntil	(	Mutex &	mutex,
		TickClock::time_point	timePoint
	)

Waits for notification until given time point.

Similar to std::condition_variable::wait_until() - http://en.cppreference.com/w/cpp/thread/condition_variable/wait_until Similar to pthread_cond_timedwait() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html#

Atomically releases supplied mutex and blocks current thread until the condition variable is notified. The thread will be unblocked when notifyAll() or notifyOne() is executed or when given time point is reached. It may also be unblocked spuriously. When unblocked, regardless of the reason, lock is reacquired and wait exits.

Warning

This function must not be called from interrupt context!

Parameters

[in]	mutex	is a reference to mutex which must be owned by calling thread
[in]	timePoint	is the time point at which the wait for notification will be terminated

Returns

0 if the wait was completed successfully, error code otherwise:

• EPERM - the mutex type is errorChecking or recursive, and the current thread does not own the mutex;
• ETIMEDOUT - no notification was received before the specified timeout expired;

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waitUntil() [2/3]

template<typename Duration >

int distortos::ConditionVariable::waitUntil ( Mutex &  mutex, const std::chrono::time_point< TickClock, Duration >  timePoint  )

inline

Waits for notification until given time point.

Similar to std::condition_variable::wait_until() - http://en.cppreference.com/w/cpp/thread/condition_variable/wait_until Similar to pthread_cond_timedwait() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html#

Template variant of waitUntil(Mutex& mutex, TickClock::time_point timePoint).

Warning

This function must not be called from interrupt context!

Template Parameters

Duration

is a std::chrono::duration type used to measure duration

Parameters

[in]	mutex	is a reference to mutex which must be owned by calling thread
[in]	timePoint	is the time point at which the wait for notification will be terminated

Returns

0 if the wait was completed successfully, error code otherwise:

• EPERM - the mutex type is errorChecking or recursive, and the current thread does not own the mutex;
• ETIMEDOUT - no notification was received before the specified timeout expired;

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waitUntil() [3/3]

template<typename Duration , typename Predicate >

int distortos::ConditionVariable::waitUntil	(	Mutex &	mutex,
		std::chrono::time_point< TickClock, Duration >	timePoint,
		Predicate	predicate
	)

Waits for predicate to become true until given time point.

Similar to std::condition_variable::wait_until() - http://en.cppreference.com/w/cpp/thread/condition_variable/wait_until Similar to pthread_cond_timedwait() - http://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html#

Overload for waitUntil() which also checks the predicate. This function will return only if the predicate is true or when given time point is reached.

Warning

This function must not be called from interrupt context!

Template Parameters

Duration	is a std::chrono::duration type used to measure duration
Predicate	is a type of functor to check the predicate

Parameters

[in]	mutex	is a reference to mutex which must be owned by calling thread
[in]	timePoint	is the time point at which the wait for notification will be terminated
[in]	predicate	is the predicate that will be checked

Returns

0 if the wait was completed successfully, error code otherwise:

• EPERM - the mutex type is errorChecking or recursive, and the current thread does not own the mutex;
• ETIMEDOUT - no notification was received before the specified timeout expired;

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Member Data Documentation

blockedList_

internal::ThreadList distortos::ConditionVariable::blockedList_

private

ThreadControlBlock objects blocked on this condition variable.

---

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

• include/distortos/ConditionVariable.hpp
• source/synchronization/ConditionVariable.cpp