diff options
Diffstat (limited to 'mit-pthreads/pthreads/select.c')
| -rw-r--r-- | mit-pthreads/pthreads/select.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/mit-pthreads/pthreads/select.c b/mit-pthreads/pthreads/select.c new file mode 100644 index 00000000000..eaafce31f19 --- /dev/null +++ b/mit-pthreads/pthreads/select.c @@ -0,0 +1,255 @@ +/* ==== select.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. + * + * This code based on code contributed by + * Peter Hofmann <peterh@prz.tu-berlin.d400.de> + * + * Description : Select. + * + * 1.23 94/04/26 proven + * -Started coding this file. + */ + +#ifndef lint +static const char rcsid[] = "$Id$"; +#endif + +#include <string.h> +#include <errno.h> +#include <pthread.h> +#include <sys/types.h> +#include <sys/time.h> + +extern struct pthread_queue fd_wait_select; +static struct timeval zero_timeout = { 0, 0 }; /* Moved by monty */ + +/* ========================================================================== + * select() + */ +int select(int numfds, fd_set *readfds, fd_set *writefds, + fd_set *exceptfds, struct timeval *timeout) +{ + fd_set real_exceptfds, real_readfds, real_writefds; /* mapped fd_sets */ + fd_set * real_readfds_p, * real_writefds_p, * real_exceptfds_p; + fd_set read_locks, write_locks, rdwr_locks; + struct timespec timeout_time, current_time; + int i, j, ret = 0, got_all_locks = 1; + struct pthread_select_data data; + + if (numfds > dtablesize) { + numfds = dtablesize; + } + + data.nfds = 0; + FD_ZERO(&data.readfds); + FD_ZERO(&data.writefds); + FD_ZERO(&data.exceptfds); + + /* Do this first */ + if (timeout) { + machdep_gettimeofday(¤t_time); + timeout_time.tv_sec = current_time.tv_sec + timeout->tv_sec; + if ((timeout_time.tv_nsec = current_time.tv_nsec + + (timeout->tv_usec * 1000)) > 1000000000) { + timeout_time.tv_nsec -= 1000000000; + timeout_time.tv_sec++; + } + } + + FD_ZERO(&read_locks); + FD_ZERO(&write_locks); + FD_ZERO(&rdwr_locks); + FD_ZERO(&real_readfds); + FD_ZERO(&real_writefds); + FD_ZERO(&real_exceptfds); + + /* lock readfds */ + if (readfds || writefds || exceptfds) { + for (i = 0; i < numfds; i++) { + if ((readfds && (FD_ISSET(i, readfds))) || + (exceptfds && FD_ISSET(i, exceptfds))) { + if (writefds && FD_ISSET(i ,writefds)) { + if ((ret = fd_lock(i, FD_RDWR, NULL)) != OK) { + got_all_locks = 0; + break; + } + FD_SET(i, &rdwr_locks); + FD_SET(fd_table[i]->fd.i,&real_writefds); + } else { + if ((ret = fd_lock(i, FD_READ, NULL)) != OK) { + got_all_locks = 0; + break; + } + FD_SET(i, &read_locks); + } + if (readfds && FD_ISSET(i,readfds)) { + FD_SET(fd_table[i]->fd.i, &real_readfds); + } + if (exceptfds && FD_ISSET(i,exceptfds)) { + FD_SET(fd_table[i]->fd.i, &real_exceptfds); + } + if (fd_table[i]->fd.i >= data.nfds) { + data.nfds = fd_table[i]->fd.i + 1; + } + } else { + if (writefds && FD_ISSET(i, writefds)) { + if ((ret = fd_lock(i, FD_WRITE, NULL)) != OK) { + got_all_locks = 0; + break; + } + FD_SET(i, &write_locks); + FD_SET(fd_table[i]->fd.i,&real_writefds); + if (fd_table[i]->fd.i >= data.nfds) { + data.nfds = fd_table[i]->fd.i + 1; + } + } + } + } + } + + if (got_all_locks) + { + memcpy(&data.readfds,&real_readfds,sizeof(fd_set)); + memcpy(&data.writefds,&real_writefds,sizeof(fd_set)); + memcpy(&data.exceptfds,&real_exceptfds,sizeof(fd_set)); + + real_readfds_p = (readfds == NULL) ? NULL : &real_readfds; + real_writefds_p = (writefds == NULL) ? NULL : &real_writefds; + real_exceptfds_p = (exceptfds == NULL) ? NULL : &real_exceptfds; + + pthread_run->sighandled=0; + if ((ret = machdep_sys_select(data.nfds, real_readfds_p, + real_writefds_p, real_exceptfds_p, + &zero_timeout)) == OK) { + pthread_sched_prevent(); + + real_exceptfds_p = (exceptfds == NULL) ? NULL : &data.exceptfds; + real_writefds_p = (writefds == NULL) ? NULL : &data.writefds; + real_readfds_p = (readfds == NULL) ? NULL : &data.readfds; + + pthread_queue_enq(&fd_wait_select, pthread_run); + pthread_run->data.select_data = &data; + SET_PF_WAIT_EVENT(pthread_run); + + if (timeout) { + machdep_gettimeofday(¤t_time); + sleep_schedule(¤t_time, &timeout_time); + + SET_PF_AT_CANCEL_POINT(pthread_run); + pthread_resched_resume(PS_SELECT_WAIT); + CLEAR_PF_AT_CANCEL_POINT(pthread_run); + + /* We're awake */ + if (sleep_cancel(pthread_run) == NOTOK) { + ret = OK; + } + else + { + int count = 0; + for (i = 0; i < numfds; i++) + { + if (real_readfds_p && (FD_ISSET(i, real_readfds_p))) + count++; + if (real_writefds_p && (FD_ISSET(i, real_writefds_p))) + count++; + if (real_exceptfds_p && (FD_ISSET(i, real_exceptfds_p))) + count++; + } + ret = count; + } + /* Moving this after the sleep_cancel() seemed + * to fix intermittent crashes during heavy + * socket use. (mevans) + */ + CLEAR_PF_DONE_EVENT(pthread_run); + } else { + int count = 0; + SET_PF_AT_CANCEL_POINT(pthread_run); + pthread_resched_resume(PS_SELECT_WAIT); + CLEAR_PF_AT_CANCEL_POINT(pthread_run); + CLEAR_PF_DONE_EVENT(pthread_run); + for (i = 0; i < numfds; i++) + { + if (real_readfds_p && (FD_ISSET(i, real_readfds_p))) + count++; + if (real_writefds_p && (FD_ISSET(i, real_writefds_p))) + count++; + if (real_exceptfds_p && (FD_ISSET(i, real_exceptfds_p))) + count++; + } + ret = count; + } + if (pthread_run->sighandled) /* Added by monty */ + { /* We where aborted */ + ret= NOTOK; + SET_ERRNO(EINTR); + } + } else if (ret < 0) { + SET_ERRNO(-ret); + ret = NOTOK; + } + } + + /* clean up the locks */ + for (i = 0; i < numfds; i++) + { /* Changed by monty */ + if (FD_ISSET(i,&read_locks)) fd_unlock(i,FD_READ); + if (FD_ISSET(i,&rdwr_locks)) fd_unlock(i,FD_RDWR); + if (FD_ISSET(i,&write_locks)) fd_unlock(i,FD_WRITE); + } + if (ret > 0) { + if (readfds != NULL) { + for (i = 0; i < numfds; i++) { + if (! (FD_ISSET(i,readfds) && + FD_ISSET(fd_table[i]->fd.i,real_readfds_p))) + FD_CLR(i,readfds); + } + } + if (writefds != NULL) { + for (i = 0; i < numfds; i++) + if (! (FD_ISSET(i,writefds) && + FD_ISSET(fd_table[i]->fd.i,real_writefds_p))) + FD_CLR(i,writefds); + } + if (exceptfds != NULL) { + for (i = 0; i < numfds; i++) + if (! (FD_ISSET(i,exceptfds) && + FD_ISSET(fd_table[i]->fd.i,real_exceptfds_p))) + FD_CLR(i,exceptfds); + } + } else { + if (exceptfds != NULL) FD_ZERO(exceptfds); + if (writefds != NULL) FD_ZERO(writefds); + if (readfds != NULL) FD_ZERO(readfds); + } + + return(ret); +} |