diff options
Diffstat (limited to 'rtkaio/sysdeps/unix/sysv/linux/kaio_suspend.c')
| -rw-r--r-- | rtkaio/sysdeps/unix/sysv/linux/kaio_suspend.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/rtkaio/sysdeps/unix/sysv/linux/kaio_suspend.c b/rtkaio/sysdeps/unix/sysv/linux/kaio_suspend.c new file mode 100644 index 0000000000..2400c5223c --- /dev/null +++ b/rtkaio/sysdeps/unix/sysv/linux/kaio_suspend.c @@ -0,0 +1,327 @@ +/* Suspend until termination of a requests. + Copyright (C) 1997, 1998, 1999, 2000, 2002, 2003, 2006 + Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + + +/* We use an UGLY hack to prevent gcc from finding us cheating. The + implementations of aio_suspend and aio_suspend64 are identical and so + we want to avoid code duplication by using aliases. But gcc sees + the different parameter lists and prints a warning. We define here + a function so that aio_suspend64 has no prototype. */ +#define aio_suspend64 XXX +#include <aio.h> +/* And undo the hack. */ +#undef aio_suspend64 + +#include <kaio_misc.h> + +#ifndef USE_KAIO +#include <aio_suspend.c> +#else + +#include <assert.h> +#include <errno.h> +#include <stdbool.h> +#include <stdlib.h> +#include <sys/time.h> + +#include <bits/libc-lock.h> +#include <sysdep-cancel.h> + + +struct clparam +{ + const struct aiocb *const *list; + struct waitlist *waitlist; + struct requestlist **requestlist; +#ifndef DONT_NEED_AIO_MISC_COND + pthread_cond_t *cond; +#endif + int nent; +}; + + +static void +cleanup (void *arg) +{ +#ifdef DONT_NEED_AIO_MISC_COND + /* Acquire the mutex. If pthread_cond_*wait is used this would + happen implicitly. */ + pthread_mutex_lock (&__aio_requests_mutex); +#endif + + const struct clparam *param = (const struct clparam *) arg; + + /* Now remove the entry in the waiting list for all requests + which didn't terminate. */ + int cnt = param->nent; + while (cnt-- > 0) + if (param->list[cnt] != NULL + && param->list[cnt]->__error_code == EINPROGRESS) + { + struct waitlist **listp; + + assert (param->requestlist[cnt] != NULL); + + /* There is the chance that we cannot find our entry anymore. This + could happen if the request terminated and restarted again. */ + listp = ¶m->requestlist[cnt]->waiting; + while (*listp != NULL && *listp != ¶m->waitlist[cnt]) + listp = &(*listp)->next; + + if (*listp != NULL) + *listp = (*listp)->next; + } + +#ifndef DONT_NEED_AIO_MISC_COND + /* Release the conditional variable. */ + (void) pthread_cond_destroy (param->cond); +#endif + + /* Release the mutex. */ + pthread_mutex_unlock (&__aio_requests_mutex); +} + + +int +aio_suspend (list, nent, timeout) + const struct aiocb *const list[]; + int nent; + const struct timespec *timeout; +{ + if (__builtin_expect (nent < 0, 0)) + { + __set_errno (EINVAL); + return -1; + } + + struct waitlist waitlist[nent]; + struct requestlist *requestlist[nent]; +#ifndef DONT_NEED_AIO_MISC_COND + pthread_cond_t cond = PTHREAD_COND_INITIALIZER; +#endif + int cnt; + int result = 0; + int cntr = 1; + int total = 0, ktotal = 0; + + /* Request the mutex. */ + pthread_mutex_lock (&__aio_requests_mutex); + + /* There is not yet a finished request. Signal the request that + we are working for it. */ + for (cnt = 0; cnt < nent; ++cnt) + if (list[cnt] != NULL) + { + if (list[cnt]->__error_code == EINPROGRESS) + { + requestlist[cnt] = __aio_find_req ((aiocb_union *) list[cnt]); + + if (requestlist[cnt] != NULL) + { +#ifndef DONT_NEED_AIO_MISC_COND + waitlist[cnt].cond = &cond; +#endif + waitlist[cnt].result = NULL; + waitlist[cnt].next = requestlist[cnt]->waiting; + waitlist[cnt].counterp = &cntr; + waitlist[cnt].sigevp = NULL; +#ifdef BROKEN_THREAD_SIGNALS + waitlist[cnt].caller_pid = 0; /* Not needed. */ +#endif + requestlist[cnt]->waiting = &waitlist[cnt]; + total++; + if (requestlist[cnt]->kioctx != KCTX_NONE) + ktotal++; + } + else + /* We will never suspend. */ + break; + } + else + /* We will never suspend. */ + break; + } + + + /* Only if none of the entries is NULL or finished to be wait. */ + if (cnt == nent && total) + { + struct clparam clparam = + { + .list = list, + .waitlist = waitlist, + .requestlist = requestlist, +#ifndef DONT_NEED_AIO_MISC_COND + .cond = &cond, +#endif + .nent = nent + }; + + pthread_cleanup_push (cleanup, &clparam); + + if (!__kernel_thread_started && ktotal) + { + /* If the kernel aio thread was not started yet all requests + are served by the kernel and there are no other threads running, + read events with mutex hold, so that nobody else can get them + instead of us here. */ + if (SINGLE_THREAD_P && total == ktotal) + { + if (timeout == NULL) + { + while (cntr == 1) + __aio_wait_for_events (__aio_kioctx, NULL); + } + else + { + struct timeval now; + struct timespec abstime, ts; + + __gettimeofday (&now, NULL); + abstime.tv_nsec = timeout->tv_nsec + now.tv_usec * 1000; + abstime.tv_sec = timeout->tv_sec + now.tv_sec; + if (abstime.tv_nsec >= 1000000000) + { + abstime.tv_nsec -= 1000000000; + abstime.tv_sec += 1; + } + + for (;;) + { + result = __aio_wait_for_events (__aio_kioctx, timeout); + if (cntr < 1) + break; + if (result == ETIMEDOUT) + break; + + __gettimeofday (&now, NULL); + if (now.tv_sec > abstime.tv_sec + || (now.tv_sec == abstime.tv_sec + && now.tv_usec * 1000 >= abstime.tv_nsec)) + break; + + ts.tv_nsec = abstime.tv_nsec - now.tv_usec * 1000; + ts.tv_sec = abstime.tv_sec - now.tv_sec; + if (abstime.tv_nsec < now.tv_usec * 1000) + { + ts.tv_nsec += 1000000000; + ts.tv_sec -= 1; + } + timeout = &ts; + } + + if (cntr < 1) + result = 0; + else + result = ETIMEDOUT; + } + total = 0; + } + else if (__aio_create_kernel_thread () < 0) + { + total = 0; + __set_errno (ENOMEM); + result = -1; + } + } + + if (total == 0) + /* Suspending was handled above. */ + ; +#ifdef DONT_NEED_AIO_MISC_COND + else + AIO_MISC_WAIT (result, cntr, timeout, 1); +#else + else if (timeout == NULL) + result = pthread_cond_wait (&cond, &__aio_requests_mutex); + else + { + /* We have to convert the relative timeout value into an + absolute time value with pthread_cond_timedwait expects. */ + struct timeval now; + struct timespec abstime; + + __gettimeofday (&now, NULL); + abstime.tv_nsec = timeout->tv_nsec + now.tv_usec * 1000; + abstime.tv_sec = timeout->tv_sec + now.tv_sec; + if (abstime.tv_nsec >= 1000000000) + { + abstime.tv_nsec -= 1000000000; + abstime.tv_sec += 1; + } + + result = pthread_cond_timedwait (&cond, &__aio_requests_mutex, + &abstime); + } +#endif + + pthread_cleanup_pop (0); + } + + /* Now remove the entry in the waiting list for all requests + which didn't terminate. */ + while (cnt-- > 0) + if (list[cnt] != NULL && list[cnt]->__error_code == EINPROGRESS) + { + struct waitlist **listp; + + assert (requestlist[cnt] != NULL); + + /* There is the chance that we cannot find our entry anymore. This + could happen if the request terminated and restarted again. */ + listp = &requestlist[cnt]->waiting; + while (*listp != NULL && *listp != &waitlist[cnt]) + listp = &(*listp)->next; + + if (*listp != NULL) + *listp = (*listp)->next; + } + +#ifndef DONT_NEED_AIO_MISC_COND + /* Release the conditional variable. */ + if (__builtin_expect (pthread_cond_destroy (&cond) != 0, 0)) + /* This must never happen. */ + abort (); +#endif + + if (result != 0) + { +#ifndef DONT_NEED_AIO_MISC_COND + /* An error occurred. Possibly it's ETIMEDOUT. We have to translate + the timeout error report of `pthread_cond_timedwait' to the + form expected from `aio_suspend'. */ + if (result == ETIMEDOUT) + __set_errno (EAGAIN); + else +#endif + __set_errno (result); + + result = -1; + } + + /* Release the mutex. */ + pthread_mutex_unlock (&__aio_requests_mutex); + + return result; +} + +weak_alias (aio_suspend, aio_suspend64) +#endif |