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Diffstat (limited to 'mit-pthreads/pthreads/wait.c')
| -rw-r--r-- | mit-pthreads/pthreads/wait.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/mit-pthreads/pthreads/wait.c b/mit-pthreads/pthreads/wait.c new file mode 100644 index 00000000000..9f0418ca8a1 --- /dev/null +++ b/mit-pthreads/pthreads/wait.c @@ -0,0 +1,159 @@ +/* ==== wait.c ============================================================ + * Copyright (c) 1994 by Chris Provenzano, proven@mit.edu + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Chris Provenzano. + * 4. The name of Chris Provenzano may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL CHRIS PROVENZANO BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * Description : All the appropriate wait routines. + * + * 1.38 94/06/13 proven + * -Started coding this file. + * + */ + +#ifndef lint +static const char rcsid[] = "$Id$"; +#endif + +#include <pthread.h> +#include <signal.h> +#include <sys/types.h> +#include <sys/time.h> +#include <pthread/posix.h> +#include <sys/compat.h> +#include <sys/wait.h> + +/* This is an UGLY hack to get wait to compile, something better is needed. */ +/* #define _POSIX_SOURCE +#undef _POSIX_SOURCE +*/ + +struct pthread_queue wait_queue = { NULL, NULL, NULL }; +extern void sig_handler_real(); + +/* ========================================================================== + * wait_wakeup() + * + * This routine is called by the interrupt handler which has locked + * the current kthread semaphore. Since only threads owned by the + * current kthread can be queue here, no additional locks are necessary. + */ +int wait_wakeup() +{ + struct pthread *pthread; + int ret = 0; + + if (pthread = pthread_queue_deq(& wait_queue)) { + /* Wakeup all threads, and enqueue them on the run queue */ + do { + pthread->state = PS_RUNNING; + if (pthread->pthread_priority > ret) { + ret = pthread->pthread_priority; + } + pthread_prio_queue_enq(pthread_current_prio_queue, pthread); + } while (pthread = pthread_queue_deq(&wait_queue)); + return(ret); + } + return(NOTOK); +} + +/* ========================================================================== + * For the wait calls, it is important that the current kthread is locked + * before the apropriate wait syscall is preformed. This way we ensure + * that there is never a case where a thread is waiting for a child but + * missed the interrupt for that child. + * Patched by William S. Lear 1997-02-02 + */ + +/* ========================================================================== + * waitpid() + */ +pid_t waitpid(pid_t pid, int *status, int options) +{ + pid_t ret; + + pthread_sched_prevent(); + ret = machdep_sys_waitpid(pid, status, options | WNOHANG); + /* If we are not doing nohang, try again, else return immediately */ + if (!(options & WNOHANG)) { + while (ret == OK) { + /* Enqueue thread on wait queue */ + pthread_queue_enq(&wait_queue, pthread_run); + + /* reschedule unlocks scheduler */ + SET_PF_AT_CANCEL_POINT(pthread_run); /* This is a cancel point */ + pthread_resched_resume(PS_WAIT_WAIT); + CLEAR_PF_AT_CANCEL_POINT(pthread_run); /* No longer at cancel point */ + + pthread_sched_prevent(); + + ret = machdep_sys_waitpid(pid, status, options | WNOHANG); + } + } + pthread_sched_resume(); + return(ret); +} + +/* ========================================================================== + * wait3() + * Patched by Monty 1997-02-02 + */ +pid_t wait3(__WAIT_STATUS status, int options, void * rusage) +{ + semaphore * lock; + pid_t ret; + + pthread_sched_prevent(); + ret = machdep_sys_wait3(status, options | WNOHANG, rusage); + /* If we are not doing nohang, try again, else return immediately */ + if (!(options & WNOHANG)) { + while (ret == OK) { + /* Enqueue thread on wait queue */ + pthread_queue_enq(&wait_queue, pthread_run); + + /* reschedule unlocks scheduler */ + SET_PF_AT_CANCEL_POINT(pthread_run); /* This is a cancel point */ + pthread_resched_resume(PS_WAIT_WAIT); + CLEAR_PF_AT_CANCEL_POINT(pthread_run); /* No longer at cancel point */ + + pthread_sched_prevent(); + + machdep_sys_wait3(status, options | WNOHANG, rusage); + } + } + pthread_sched_resume(); + return(ret); +} + +/* ========================================================================== + * wait() + */ +pid_t wait(__WAIT_STATUS status) +{ + return(waitpid((pid_t)-1, (int *)status, 0)); +} |