#!/bin/sh # # SPDX-License-Identifier: BSD-2-Clause # # Copyright (c) 2019 Dell EMC Isilon # # 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. # # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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. # # No problems seen. cat > /tmp/sem_post.c < #include #include #include #include #include #include #include #include static sem_t semaphore; static void * threadfunc(void *data __unused) { for (;;) { usleep(arc4random() % 100); if (sem_wait(&semaphore) == -1) err(1, "sem_wait"); usleep(arc4random() % 100); if (arc4random() % 100 < 3) sleep(1); if (sem_post(&semaphore) == -1) err(1, "sem_post"); } return (NULL); } int main(void) { pthread_t mythread; time_t start; int r; // initialize semaphore and set value to 1 if (sem_init(&semaphore, 0, 1) == -1) err(1, "sem_init"); r = pthread_create(&mythread, NULL, threadfunc, NULL); if (r != 0) errc(1, r, "pthread_create"); usleep(50); alarm(300); start = time(NULL); while (time(NULL) - start < 120) { usleep(arc4random() % 100); if (sem_wait(&semaphore) == -1) err(1, "sem_wait"); usleep(arc4random() % 100); if (arc4random() % 100 < 3) sleep(1); if (sem_post(&semaphore) == -1) err(1, "sem_post"); } if ((r = pthread_kill(mythread, SIGINT)) != 0) errc(1, r, "pthread_kill"); if ((r = pthread_join(mythread, NULL)) != 0) errc(1, r, "pthread_join"); return (0); } EOF cc -o /tmp/sem_post -Wall -Wextra -O2 /tmp/sem_post.c -lpthread || exit 1 (cd ../testcases/swap; ./swap -t 3m -i 30 -h -l 100) & sleep 20 for i in `jot 128`; do /tmp/sem_post > /dev/null & done while pgrep -q sem_post; do sleep .5; done while pkill swap; do :; done wait rm -f /tmp/sem_post /tmp/sem_post.c exit 0