From: mquinson Date: Sat, 27 Oct 2007 14:35:18 +0000 (+0000) Subject: Cleanups around the inter-unixes portability code for sem_init, sem_timedwait and... X-Git-Tag: v3.3~886 X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/fa0ec6d96aad54b7bc6cca1934d59ca74b16bd58 Cleanups around the inter-unixes portability code for sem_init, sem_timedwait and mutex_timedlock git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/simgrid/simgrid/trunk@4916 48e7efb5-ca39-0410-a469-dd3cf9ba447f --- diff --git a/src/xbt/xbt_os_thread.c b/src/xbt/xbt_os_thread.c index efc534d071..63f7bb020a 100644 --- a/src/xbt/xbt_os_thread.c +++ b/src/xbt/xbt_os_thread.c @@ -10,6 +10,11 @@ /* This program is free software; you can redistribute it and/or modify it * under the terms of the license (GNU LGPL) which comes with this package. */ +#ifdef HAVE_PTHREAD_H +/* XOPEN_SOURCE is needed to get sem_timedwait (on amd64 at least). Declare it before everything else to play safe. */ +#define _XOPEN_SOURCE 600 +#endif + #include "xbt/sysdep.h" #include "xbt/ex.h" #include "xbt/ex_interface.h" /* We play crude games with exceptions */ @@ -22,14 +27,21 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_sync_os,xbt,"Synchronization mechanism (OS-l /* ********************************* PTHREAD IMPLEMENTATION ************************************ */ #ifdef HAVE_PTHREAD_H + +/* XOPEN_SOURCE is needed to get sem_timedwait (on amd64 at least) according to the man page, + but the headers seem to follow __USE_XOPEN2K. + So let's get safe and declare both before loading headers. */ +#define _XOPEN_SOURCE 600 +#include + #include #include -/* use named sempahore instead */ -#ifndef HAVE_SEM_WAIT -# define MAX_SEM_NAME ((size_t)13) - static int __next_sem_ID = 0; - static pthread_mutex_t __next_sem_ID_lock; + +/* use named sempahore when sem_init() does not work */ +#ifndef HAVE_SEM_INIT + static int next_sem_ID = 0; + static xbt_os_mutex_t next_sem_ID_lock; #endif typedef struct xbt_os_thread_ { @@ -82,17 +94,12 @@ void xbt_os_thread_mod_init(void) { __xbt_ex_ctx = _os_thread_ex_ctx; __xbt_ex_terminate = _os_thread_ex_terminate; + thread_mod_inited = 1; + #ifndef HAVE_SEM_WAIT - - /* initialize the mutex use to protect the incrementation of the variable __next_sem_ID - * used to build the name of the named sempahore - */ - if ((errcode = pthread_mutex_init(&__next_sem_ID_lock,NULL))) - THROW1(system_error,errcode,"pthread_mutex_init() failed: %s",strerror(errcode)); - + next_sem_ID_lock = xbt_os_mutex_init(); #endif - thread_mod_inited = 1; } void xbt_os_thread_mod_exit(void) { /* FIXME: don't try to free our key on shutdown. @@ -212,71 +219,61 @@ void xbt_os_mutex_acquire(xbt_os_mutex_t mutex) { } - -#ifndef HAVE_PTHREAD_MUTEX_TIMEDLOCK -/* if the function is not availabled or if is MAC OS X use pthread_mutex_trylock() to define - * it. - */ -#include /* declaration of the timespec structure and of the nanosleep() function */ -int pthread_mutex_timedlock(pthread_mutex_t * mutex, const struct timespec * abs_timeout) -{ - int rv; - long ellapsed_time = 0; - struct timespec ts; - - do - { - /* the mutex could not be acquired because it was already locked by an other thread */ - rv = pthread_mutex_trylock(mutex); - - ts.tv_sec = 0; - ts.tv_nsec = 2.5e7 /* (25 ms (2 context switch + 5 ms)) */; - - do - { - nanosleep(&ts, &ts); - }while(EINTR == errno); - - ellapsed_time += ts.tv_nsec; - - } - while (/* locked */ (EBUSY == rv) && /* !timeout */ (ellapsed_time < ((long)(abs_timeout->tv_sec * 1e9) + abs_timeout->tv_nsec))); - - return (EBUSY == rv) ? ETIMEDOUT : rv; -} - -#endif - void xbt_os_mutex_timedacquire(xbt_os_mutex_t mutex, double delay) { int errcode; - struct timespec ts_end; - double end = delay + xbt_os_time(); if (delay < 0) { xbt_os_mutex_acquire(mutex); - } - else if(!delay /* equals 0 */) - { - if ((errcode=pthread_mutex_trylock(&(mutex->m)))) - THROW2(system_error,errcode,"pthread_mutex_trylock(%p) failed: %s",mutex, strerror(errcode)); + + } else if (delay == 0) { + errcode=pthread_mutex_trylock(&(mutex->m)); + + switch (errcode) { + case 0: + return; + case ETIMEDOUT: + THROW1(timeout_error,0,"mutex %p not ready",mutex); + default: + THROW2(system_error,errcode,"xbt_mutex_tryacquire(%p) failed: %s",mutex, strerror(errcode)); + } + } else { + +#ifdef HAVE_MUTEX_TIMEDLOCK + struct timespec ts_end; + double end = delay + xbt_os_time(); + ts_end.tv_sec = (time_t) floor(end); ts_end.tv_nsec = (long) ( ( end - ts_end.tv_sec) * 1000000000); DEBUG2("pthread_mutex_timedlock(%p,%p)",&(mutex->m), &ts_end); - switch ((errcode=pthread_mutex_timedlock(&(mutex->m),&ts_end))) - { - case 0: - return; - - case ETIMEDOUT: - THROW2(timeout_error,errcode,"mutex %p wasn't signaled before timeout (%f)",mutex,delay); - - default: - THROW3(system_error,errcode,"pthread_mutex_timedlock(%p,%f) failed: %s",mutex,delay, strerror(errcode)); - } - } + errcode=pthread_mutex_timedlock(&(mutex->m),&ts_end); + +#else /* Well, let's reimplement it since those lazy libc dudes didn't */ + double start = xbt_os_time(); + do { + errcode = pthread_mutex_trylock(&(mutex->m)); + if (errcode == EBUSY) + xbt_os_thread_yield(); + } while (errcode == EBUSY && xbt_os_time()-start name = (char*) calloc(MAX_SEM_NAME + 1,sizeof(char)); - - if((errcode = pthread_mutex_lock(&__next_sem_ID_lock))) - THROW1(system_error,errcode,"pthread_mutex_lock() failed: %s", strerror(errcode)); - - __next_sem_ID++; - - if((errcode = pthread_mutex_unlock(&__next_sem_ID_lock))) - THROW1(system_error,errcode,"pthread_mutex_unlock() failed: %s", strerror(errcode)); - - sprintf(res->name,"/%d.%d",(*xbt_getpid)(),__next_sem_ID); +#ifndef SEM_FAILED +#define SEM_FAILED (-1) +#endif - if((res->s = sem_open(res->name, O_CREAT, 0644, value)) == (sem_t*)SEM_FAILED) - THROW1(system_error,errno,"sem_open() failed: %s",strerror(errno)); - - if(sem_unlink(res->name) < 0) - THROW1(system_error,errno,"sem_unlink() failed: %s", strerror(errno)); +xbt_os_sem_t +xbt_os_sem_init(unsigned int value) { + xbt_os_sem_t res = xbt_new(s_xbt_os_sem_t,1); + /* On some systems (MAC OS X), only the stub of sem_init is to be found. + * Any attempt to use it leads to ENOSYS (function not implemented). + * If such a prehistoric system is detected, do the job with sem_open instead + */ +#ifdef HAVE_SEM_INIT + if(sem_init(&(res->s),0,value) != 0) + THROW1(system_error,errno,"sem_init() failed: %s", strerror(errno)); + res->ps = &(res->s); + +#else /* damn, no sem_init(). Reimplement it */ + + xbt_os_mutex_acquire(next_sem_ID_lock); + res->name = bprintf("/%d.%d",(*xbt_getpid)(),++next_sem_ID); + xbt_os_mutex_release(next_sem_ID_lock); + + res->ps = sem_open(res->name, O_CREAT, 0644, value); + if ((res->ps == (sem_t *)SEM_FAILED) && (errno == ENAMETOOLONG)) { + /* Old darwins only allow 13 chars. Did you create *that* amount of semaphores? */ + res->name[13] = '\0'; + res->ps = sem_open(res->name, O_CREAT, 0644, 1); + } + if ((res->ps == (sem_t *)SEM_FAILED)) + THROW1(system_error,errno,"sem_open() failed: %s",strerror(errno)); + + /* Remove the name from the semaphore namespace: we never join on it */ + if(sem_unlink(res->name) < 0) + THROW1(system_error,errno,"sem_unlink() failed: %s", strerror(errno)); - #else - /* sem_init() is implemented, use it */ - if(sem_init(&(res->s),0,value) < 0) - THROW1(system_error,errno,"sem_init() failed: %s", - strerror(errno)); - #endif +#endif return res; } void -xbt_os_sem_acquire(xbt_os_sem_t sem) -{ - if(!sem) - THROW0(arg_error,EINVAL,"Cannot acquire of the NULL semaphore"); - #ifndef HAVE_SEM_WAIT - if(sem_wait((sem->s)) < 0) - THROW1(system_error,errno,"sem_wait() failed: %s", - strerror(errno)); - #else - if(sem_wait(&(sem->s)) < 0) - THROW1(system_error,errno,"sem_wait() failed: %s", - strerror(errno)); - #endif +xbt_os_sem_acquire(xbt_os_sem_t sem) { + if(!sem) + THROW0(arg_error,EINVAL,"Cannot acquire of the NULL semaphore"); + if(sem_wait(sem->ps) < 0) + THROW1(system_error,errno,"sem_wait() failed: %s", strerror(errno)); } -#ifndef HAVE_SEM_TIMEDWAIT -/* if the function is not availabled or if is MAC OS X use sem_trywait() to define - * it. - */ -#include /* declaration of the timespec structure and of the nanosleep() function */ -int sem_timedwait(sem_t* sem, const struct timespec * abs_timeout) -{ - int rv; - long ellapsed_time = 0; - struct timespec ts; - - do - { - rv = sem_trywait(sem); - ts.tv_sec = 0; - ts.tv_nsec = 2.5e7 /* (25 ms (2 * context switch + 5 ms)) */; - - do - { - nanosleep(&ts, &ts); - }while(EINTR == errno); - - ellapsed_time += ts.tv_nsec; +void xbt_os_sem_timedacquire(xbt_os_sem_t sem, double delay) { + int errcode; - } - while(/* locked */ (EAGAIN == rv) && /* !timeout */ ellapsed_time < ((long)(abs_timeout->tv_sec * 1e9) + abs_timeout->tv_nsec)); + if(!sem) + THROW0(arg_error,EINVAL,"Cannot acquire of the NULL semaphore"); - return (EAGAIN == rv) ? ETIMEDOUT : rv; -} + if (delay < 0) { + xbt_os_sem_acquire(sem); + } else if (delay==0) { + errcode = sem_trywait(sem->ps); + switch (errcode) { + case 0: + return; + case ETIMEDOUT: + THROW1(timeout_error,0,"semaphore %p not ready",sem); + default: + THROW2(system_error,errcode,"xbt_sem_tryacquire(%p) failed: %s",sem, strerror(errcode)); + } + + } else { +#ifdef HAVE_SEM_WAIT + struct timespec ts_end; + double end = delay + xbt_os_time(); + + ts_end.tv_sec = (time_t) floor(end); + ts_end.tv_nsec = (long) ( ( end - ts_end.tv_sec) * 1000000000); + DEBUG2("sem_timedwait(%p,%p)",sem->ps,&ts_end); + errcode = sem_timedwait(sem->s,&ts_end); + +#else /* Okay, reimplement this function then */ + double start = xbt_os_time(); + do { + errcode = sem_trywait(sem->ps); + if (errcode == EBUSY) + xbt_os_thread_yield(); + } while (errcode == EBUSY && xbt_os_time()-start s) < 0) - THROW2(system_error,errno,"sem_trywait(%p) failed: %s",sem,strerror(errno)); - #else - if(sem_trywait(sem->s) < 0) - THROW2(system_error,errno,"sem_trywait(%p) failed: %s",sem,strerror(errno)); - #endif - } - else - { - ts_end.tv_sec = (time_t) floor(end); - ts_end.tv_nsec = (long) ( ( end - ts_end.tv_sec) * 1000000000); - DEBUG2("sem_timedwait(%p,%p)",&(sem->s),&ts_end); - - #ifndef HAVE_SEM_WAIT - switch ((errcode = sem_timedwait(sem->s,&ts_end))) - #else - switch ((errcode = sem_timedwait(&(sem->s),&ts_end))) - #endif - { - case 0: - return; - - case ETIMEDOUT: - THROW2(timeout_error,errcode,"semaphore %p wasn't signaled before timeout (%f)",sem,timeout); - - default: - THROW3(system_error,errcode,"sem_timedwait(%p,%f) failed: %s",sem,timeout, strerror(errcode)); - } - } + case ETIMEDOUT: + THROW2(timeout_error,delay,"semaphore %p wasn't signaled before timeout (%f)",sem,delay); + default: + THROW3(system_error,errcode,"sem_timedwait(%p,%f) failed: %s",sem,delay, strerror(errcode)); + } + } } void @@ -526,40 +490,29 @@ xbt_os_sem_release(xbt_os_sem_t sem) if(!sem) THROW0(arg_error,EINVAL,"Cannot release of the NULL semaphore"); - #ifndef HAVE_SEM_WAIT - if(sem_post((sem->s)) < 0) - THROW1(system_error,errno,"sem_post() failed: %s", - strerror(errno)); - #else - if(sem_post(&(sem->s)) < 0) + if(sem_post(sem->ps) < 0) THROW1(system_error,errno,"sem_post() failed: %s", strerror(errno)); - #endif } void xbt_os_sem_destroy(xbt_os_sem_t sem) { - if(!sem) - THROW0(arg_error,EINVAL,"Cannot destroy the NULL sempahore"); - - #ifndef HAVE_SEM_WAIT - /* MAC OS X does not implement the sem_init() function so, - * we use the named semaphore (sem_open) - */ - if(sem_close((sem->s)) < 0) - THROW1(system_error,errno,"sem_close() failed: %s", - strerror(errno)); + if(!sem) + THROW0(arg_error,EINVAL,"Cannot destroy the NULL sempahore"); - xbt_free(sem->name); - - #else - if(sem_destroy(&(sem->s)) < 0) - THROW1(system_error,errno,"sem_destroy() failed: %s", +#ifdef HAVE_SEM_INIT + if(sem_destroy(sem->ps)) < 0) + THROW1(system_error,errno,"sem_destroy() failed: %s", + strerror(errno)); +#else + if(sem_close(sem->ps) < 0) + THROW1(system_error,errno,"sem_close() failed: %s", strerror(errno)); - #endif + xbt_free(sem->name); - xbt_free(sem); +#endif + xbt_free(sem); } void @@ -568,15 +521,9 @@ xbt_os_sem_get_value(xbt_os_sem_t sem, int* svalue) if(!sem) THROW0(arg_error,EINVAL,"Cannot get the value of the NULL semaphore"); - #ifndef HAVE_SEM_WAIT - if(sem_getvalue((sem->s),svalue) < 0) - THROW1(system_error,errno,"sem_getvalue() failed: %s", - strerror(errno)); - #else if(sem_getvalue(&(sem->s),svalue) < 0) THROW1(system_error,errno,"sem_getvalue() failed: %s", strerror(errno)); - #endif } /* ********************************* WINDOWS IMPLEMENTATION ************************************ */