diff options
Diffstat (limited to 'rt/lio_listio.c')
| -rw-r--r-- | rt/lio_listio.c | 236 |
1 files changed, 222 insertions, 14 deletions
diff --git a/rt/lio_listio.c b/rt/lio_listio.c index db4ce68..2cab3c2 100644 --- a/rt/lio_listio.c +++ b/rt/lio_listio.c @@ -1,6 +1,7 @@ -/* Enqueue a list of read or write requests. Stub version. - Copyright (C) 2001-2021 Free Software Foundation, Inc. +/* Enqueue and list of read or write requests. + Copyright (C) 1997-2021 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 @@ -16,25 +17,232 @@ License along with the GNU C Library; if not, see <https://www.gnu.org/licenses/>. */ +#ifndef lio_listio #include <aio.h> +#include <assert.h> #include <errno.h> +#include <stdlib.h> +#include <unistd.h> -#ifdef BE_AIO64 -#define lio_listio lio_listio64 -#define aiocb aiocb64 -#define aio_read aio_read64 -#define aio_write aio_write64 -#define aio_suspend aio_suspend64 +#include <aio_misc.h> + +#define LIO_OPCODE_BASE 0 +#endif + +#include <shlib-compat.h> + + +/* We need this special structure to handle asynchronous I/O. */ +struct async_waitlist + { + unsigned int counter; + struct sigevent sigev; + struct waitlist list[0]; + }; + + +/* The code in glibc 2.1 to glibc 2.4 issued only one event when all + requests submitted with lio_listio finished. The existing practice + is to issue events for the individual requests as well. This is + what the new code does. */ +#if SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_4) +# define LIO_MODE(mode) ((mode) & 127) +# define NO_INDIVIDUAL_EVENT_P(mode) ((mode) & 128) +#else +# define LIO_MODE(mode) mode +# define NO_INDIVIDUAL_EVENT_P(mode) 0 +#endif + + +static int +lio_listio_internal (int mode, struct aiocb *const list[], int nent, + struct sigevent *sig) +{ + struct sigevent defsigev; + struct requestlist *requests[nent]; + int cnt; + volatile unsigned int total = 0; + int result = 0; + + if (sig == NULL) + { + defsigev.sigev_notify = SIGEV_NONE; + sig = &defsigev; + } + + /* Request the mutex. */ + pthread_mutex_lock (&__aio_requests_mutex); + + /* Now we can enqueue all requests. Since we already acquired the + mutex the enqueue function need not do this. */ + for (cnt = 0; cnt < nent; ++cnt) + if (list[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP) + { + if (NO_INDIVIDUAL_EVENT_P (mode)) + list[cnt]->aio_sigevent.sigev_notify = SIGEV_NONE; + + requests[cnt] = __aio_enqueue_request ((aiocb_union *) list[cnt], + (list[cnt]->aio_lio_opcode + | LIO_OPCODE_BASE)); + + if (requests[cnt] != NULL) + /* Successfully enqueued. */ + ++total; + else + /* Signal that we've seen an error. `errno' and the error code + of the aiocb will tell more. */ + result = -1; + } + else + requests[cnt] = NULL; + + if (total == 0) + { + /* We don't have anything to do except signalling if we work + asynchronously. */ + + /* Release the mutex. We do this before raising a signal since the + signal handler might do a `siglongjmp' and then the mutex is + locked forever. */ + pthread_mutex_unlock (&__aio_requests_mutex); + + if (LIO_MODE (mode) == LIO_NOWAIT) + __aio_notify_only (sig); + + return result; + } + else if (LIO_MODE (mode) == LIO_WAIT) + { +#ifndef DONT_NEED_AIO_MISC_COND + pthread_cond_t cond = PTHREAD_COND_INITIALIZER; + int oldstate; +#endif + struct waitlist waitlist[nent]; + + total = 0; + for (cnt = 0; cnt < nent; ++cnt) + { + assert (requests[cnt] == NULL || list[cnt] != NULL); + + if (requests[cnt] != NULL && list[cnt]->aio_lio_opcode != LIO_NOP) + { +#ifndef DONT_NEED_AIO_MISC_COND + waitlist[cnt].cond = &cond; #endif + waitlist[cnt].result = &result; + waitlist[cnt].next = requests[cnt]->waiting; + waitlist[cnt].counterp = &total; + waitlist[cnt].sigevp = NULL; + requests[cnt]->waiting = &waitlist[cnt]; + ++total; + } + } +#ifdef DONT_NEED_AIO_MISC_COND + AIO_MISC_WAIT (result, total, NULL, 0); +#else + /* Since `pthread_cond_wait'/`pthread_cond_timedwait' are cancellation + points we must be careful. We added entries to the waiting lists + which we must remove. So defer cancellation for now. */ + pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &oldstate); + while (total > 0) + pthread_cond_wait (&cond, &__aio_requests_mutex); + + /* Now it's time to restore the cancellation state. */ + pthread_setcancelstate (oldstate, NULL); + + /* Release the conditional variable. */ + if (pthread_cond_destroy (&cond) != 0) + /* This must never happen. */ + abort (); +#endif + + /* If any of the I/O requests failed, return -1 and set errno. */ + if (result != 0) + { + __set_errno (result == EINTR ? EINTR : EIO); + result = -1; + } + } + else + { + struct async_waitlist *waitlist; + + waitlist = (struct async_waitlist *) + malloc (sizeof (struct async_waitlist) + + (nent * sizeof (struct waitlist))); + + if (waitlist == NULL) + { + __set_errno (EAGAIN); + result = -1; + } + else + { + total = 0; + + for (cnt = 0; cnt < nent; ++cnt) + { + assert (requests[cnt] == NULL || list[cnt] != NULL); + + if (requests[cnt] != NULL + && list[cnt]->aio_lio_opcode != LIO_NOP) + { +#ifndef DONT_NEED_AIO_MISC_COND + waitlist->list[cnt].cond = NULL; +#endif + waitlist->list[cnt].result = NULL; + waitlist->list[cnt].next = requests[cnt]->waiting; + waitlist->list[cnt].counterp = &waitlist->counter; + waitlist->list[cnt].sigevp = &waitlist->sigev; + requests[cnt]->waiting = &waitlist->list[cnt]; + ++total; + } + } + + waitlist->counter = total; + waitlist->sigev = *sig; + } + } + + /* Release the mutex. */ + pthread_mutex_unlock (&__aio_requests_mutex); + + return result; +} + + +#if SHLIB_COMPAT (librt, GLIBC_2_1, GLIBC_2_4) int -lio_listio (int mode, - struct aiocb *const list[], int nent, - struct sigevent *sig) +attribute_compat_text_section +__lio_listio_21 (int mode, struct aiocb *const list[], int nent, + struct sigevent *sig) { - __set_errno (ENOSYS); - return -1; + /* Check arguments. */ + if (mode != LIO_WAIT && mode != LIO_NOWAIT) + { + __set_errno (EINVAL); + return -1; + } + + return lio_listio_internal (mode | LIO_NO_INDIVIDUAL_EVENT, list, nent, sig); } +compat_symbol (librt, __lio_listio_21, lio_listio, GLIBC_2_1); +#endif -stub_warning (lio_listio) + +int +__lio_listio_item_notify (int mode, struct aiocb *const list[], int nent, + struct sigevent *sig) +{ + /* Check arguments. */ + if (mode != LIO_WAIT && mode != LIO_NOWAIT) + { + __set_errno (EINVAL); + return -1; + } + + return lio_listio_internal (mode, list, nent, sig); +} +versioned_symbol (librt, __lio_listio_item_notify, lio_listio, GLIBC_2_4); |