Condition Struct Reference

#include <Condition.h>

Overview

POSIX Threads conditional variables.

Conditions combine a Lock with a signaling mechanism, so that Threads may inform one another when a condition is met.

Definition at line 44 of file Condition.h.

Inheritance diagram for Condition:

Properties
Lock	lock
	The superclass. More...
Properties inherited from Lock
Object	object
	The superclass. More...
Properties inherited from Object
Class *	clazz
	Every instance of Object begins with a pointer to its Class. More...

Methods
Class *	_Condition (void)
	The Condition archetype. More...
void	broadcast (Condition *self)
	Signals all Threads waiting on this Condition. More...
Condition *	init (Condition *self)
	Initializes this Condition. More...
void	signal (Condition *self)
	Signals a single Thread waiting on this Condition. More...
void	wait (Condition *self)
	Waits indefinitely for this Condition to be signaled. More...
_Bool	waitUntilDate (Condition *self, const Date *date)
	Waits until the specified Date for this Condition to be signaled. More...
Methods inherited from Lock
Class *	_Lock (void)
	The Lock archetype. More...
Lock *	init (Lock *self)
	Initializes this Lock. More...
void	lock (Lock *self)
	Acquire this lock, waiting indefinitely. More...
_Bool	tryLock (Lock *self)
	Attempt to acquire this lock immediately. More...
void	unlock (Lock *self)
	Release this Lock. More...
Methods inherited from Object
Class *	_Object (void)
	The Object archetype. More...
Object *	copy (const Object *self)
	Creates a shallow copy of this Object. More...
void	dealloc (Object *self)
	Frees all resources held by this Object. More...
String *	description (const Object *self)
int	hash (const Object *self)
Object *	init (Object *self)
	Initializes this Object. More...
_Bool	isEqual (const Object *self, const Object *other)
	Tests equality of the other Object. More...
_Bool	isKindOfClass (const Object *self, const Class *clazz)
	Tests for Class hierarchy membership. More...

Protected Attributes
ConditionInterface *	interface
	The interface. More...
Protected Attributes inherited from Lock
LockInterface *	interface
	The interface. More...
Protected Attributes inherited from Object
ObjectInterface *	interface
	The interface. More...

Property Details

interface

ConditionInterface* Condition::interface

protected

The interface.

Definition at line 55 of file Condition.h.

lock

Lock Condition::lock

The superclass.

Definition at line 49 of file Condition.h.

Method Details

_Condition()

Class * _Condition

(

void

)

The Condition archetype.

Returns

The Condition Class.

Definition at line 141 of file Condition.c.

                        {
    static Class *clazz;
    static Once once;
 
    do_once(&once, {
        clazz = _initialize(&(const ClassDef) {
            .name = "Condition",
            .superclass = _Lock(),
            .instanceSize = sizeof(Condition),
            .interfaceOffset = offsetof(Condition, interface),
            .interfaceSize = sizeof(ConditionInterface),
            .initialize = initialize,
        });
    });
 
    return clazz;
}

broadcast()

void broadcast

(

Condition *

self

)

Signals all Threads waiting on this Condition.

Parameters

self	The Condition.

Remarks

This method should only be called when the Condition is locked.

Definition at line 57 of file Condition.c.

                                       {
 
    int err = pthread_cond_broadcast(self->condition);
    assert(err == 0);
}

init()

Condition * init

(

Condition *

self

)

Initializes this Condition.

Parameters

self	The Condition.

Returns

The initialized Condition, or NULL on error.

Definition at line 67 of file Condition.c.

                                        {
 
    self = (Condition *) super(Lock, self, init);
    if (self) {
 
        self->condition = calloc(1, sizeof(pthread_cond_t));
        assert(self->condition);
 
        const int err = pthread_cond_init(self->condition, NULL);
        assert(err == 0);
    }
 
    return self;
}

signal()

void signal

(

Condition *

self

)

Signals a single Thread waiting on this Condition.

Parameters

self	The Condition.

Remarks

This method should only be called when the Condition is locked.

wait()

void wait

(

Condition *

self

)

Waits indefinitely for this Condition to be signaled.

Parameters

self	The Condition.

Remarks

This method should only be called when the Condition is locked.

waitUntilDate()

_Bool waitUntilDate	(	Condition *	self,
		const Date *	date
	)

Waits until the specified Date for this Condition to be signaled.

Parameters

self	The Condition.
date	The Date until which to wait.

Returns

true if this Condition was signaled before date, false otherwise.

Remarks

This method should only be called when the Condition is locked.

Definition at line 106 of file Condition.c.

                                                              {
 
    Lock *lock = (Lock *) self;
 
    const struct timespec time = {
        .tv_sec = date->time.tv_sec,
        .tv_nsec = date->time.tv_usec * 1000
    };
 
    int err = pthread_cond_timedwait(self->condition, lock->lock, &time);
    assert(err == 0 || err == ETIMEDOUT);
 
    return err == 0;
}

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

• Sources/Objectively/Condition.h
• Sources/Objectively/Condition.c