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pthread_cond_init()

Initialize a condition variable

Synopsis:

#include <pthread.h>

pthread_cond_t cond = PTHREAD_COND_INITIALIZER;

int pthread_cond_init( pthread_cond_t* cond,
                       pthread_condattr_t* attr );

Arguments:

cond

A pointer to the pthread_cond_t object that you want to initialize.

attr

NULL, or a pointer to a pthread_condattr_t object that specifies the attributes that you want to use for the condvar. For more information, see pthread_condattr_init().

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The pthread_cond_init() function initializes the condition variable cond with the attributes in the condition variable attribute object attr. If attr is NULL, cond is initialized with the default values for the attributes.

If the condition variable is statically allocated, you can initialize it with the default attribute values by assigning to it the macro PTHREAD_COND_INITIALIZER.

Condition variables have at least the following attributes defined:

PTHREAD_PROCESS_PRIVATE

The condition variable can only be accessed by threads created within the same process as the thread that initialized the condition variable.

PTHREAD_PROCESS_SHARED

Any thread that has access to the memory where the condition variable is allocated can access the condition variable.

For more information about these attributes, see pthread_condattr_getpshared() and pthread_condattr_setpshared().

Returns:

EOK

Success.

EAGAIN

All kernel synchronization objects are in use.

EBUSY

Previously initialized condition variable, cond, hasn't been destroyed.

EFAULT

A fault occurred when the kernel tried to access cond or attr.

EINVAL

The value specified by cond is invalid.

Classification:

POSIX 1003.1 THR

See also:

pthread_condattr_init(), pthread_cond_destroy()