ecl/src/c/threads/condition_variable.d

104 lines
3.2 KiB
C

/* -*- mode: c; c-basic-offset: 8 -*- */
/*
condition_variable.d -- Native threads.
*/
/*
Copyright (c) 2003, Juan Jose Garcia Ripoll.
ECL is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
See file '../Copyright' for full details.
*/
#include <ecl/ecl.h>
#include <ecl/internal.h>
/*----------------------------------------------------------------------
* CONDITION VARIABLES
*/
cl_object
mp_make_condition_variable(void)
{
cl_object output = ecl_alloc_object(t_condition_variable);
output->condition_variable.queue_list = ECL_NIL;
output->condition_variable.queue_spinlock = ECL_NIL;
output->condition_variable.lock = ECL_NIL;
@(return output)
}
static cl_object
condition_variable_wait(cl_env_ptr env, cl_object cv)
{
cl_object lock = cv->condition_variable.lock;
cl_object own_process = env->own_process;
/* We have entered the queue and still own the mutex? */
if (lock->lock.owner == own_process) {
mp_giveup_lock(lock);
}
/* We always return when we have been explicitly awaken */
return (own_process->process.waiting_for != cv)? ECL_T : ECL_NIL;
}
cl_object
mp_condition_variable_wait(cl_object cv, cl_object lock)
{
cl_env_ptr env = ecl_process_env();
cl_object own_process = env->own_process;
unlikely_if (ecl_t_of(cv) != t_condition_variable) {
FEwrong_type_nth_arg(@[mp::condition-variable-wait], 1, cv,
@[mp::condition-variable]);
}
unlikely_if (ecl_t_of(lock) != t_lock) {
FEwrong_type_nth_arg(@[mp::condition-variable-wait], 2, lock,
@[mp::lock]);
}
unlikely_if (cv->condition_variable.lock != ECL_NIL &&
cv->condition_variable.lock != lock)
{
FEerror("Attempt to associate lock ~A~%with condition variable ~A,"
"~%which is already associated to lock ~A", 2, lock,
cv, cv->condition_variable.lock);
}
unlikely_if (lock->lock.owner != own_process) {
FEerror("Attempt to wait on a condition variable using lock~%~S"
"~%which is not owned by process~%~S", 2, lock, own_process);
}
unlikely_if (lock->lock.counter > 1) {
FEerror("mp:condition-variable-wait can not be used with recursive"
" locks:~%~S", 1, lock);
}
print_lock("waiting cv %p", cv, env);
cv->condition_variable.lock = lock;
env->own_process->process.waiting_for = cv;
ecl_wait_on(env, condition_variable_wait, cv);
mp_get_lock_wait(lock);
@(return ECL_T)
}
cl_object
mp_condition_variable_timedwait(cl_object cv, cl_object lock, cl_object seconds)
{
FEerror("Timed condition variables are not supported.", 0);
}
cl_object
mp_condition_variable_signal(cl_object cv)
{
cl_object lock = cv->condition_variable.lock;
ecl_wakeup_waiters(ecl_process_env(), cv,
ECL_WAKEUP_RESET_FLAG | ECL_WAKEUP_ONE);
@(return ECL_T)
}
cl_object
mp_condition_variable_broadcast(cl_object cv)
{
print_lock("waking up cv", cv);
ecl_wakeup_waiters(ecl_process_env(), cv,
ECL_WAKEUP_RESET_FLAG | ECL_WAKEUP_ALL);
@(return ECL_T)
}