SCOND_T(STHREAD )

Shore Programmer's Manual - 2 August 96

NAME

scond_t \- Shore Condition Variable Class

SYNOPSIS

#include <sthread.h>

/*
 *  Condition Variable
 */
class scond_t : public sthread_named_base_t  {
public:
    NORET			scond_t(const char* name = 0);
    NORET			~scond_t();

    w_rc_t			wait(
	smutex_t& 		    m, 
	int4_t			    timeout = WAIT_FOREVER);
    void 			signal();
    void 			broadcast();
    bool			is_hot() const;

};

DESCRIPTION

Threads usually wait on a conditional variable because they can only continue after a certain condition is met (for example, a consumer thread might wait for the condition that the input queue is not empty). Every condition variable should be protected by a smutex_t.

scond_t(name)

: The constructor creates a condition variable. The name parameter is stored in the condition variable for debugging purposes.

~scond_t()

wait(mutex, timeout)

: The wait method suspends the current thread, which must hold mutex, on the condition variable and releases mutex. Later, when the condition variable is signaled, the thread is awakened and it will reacquire mutex before returning from wait.

signal()

: The signal method wakes up at least one thread waiting on the condition variable.

broadcast()

: The broadcast method wakes up all threads waiting on the condition variable.

is_hot()

: The is_hot method returns true if at least one thread is waiting on the condition.

ERRORS

TODO.

EXAMPLES

TODO.

VERSION

This manual page applies to Version 1.0 of theShore software.

SPONSORSHIP

The Shore project is sponsored by the Advanced Research Project Agency, ARPA order number 018 (formerly 8230), monitored by the U.S. Army Research Laboratory under contract DAAB07-92-C-Q508.