| /* |
| * eventfd-sem by Davide Libenzi (Simple test for eventfd sempahore) |
| * Copyright (C) 2009 Davide Libenzi |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program 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 General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| * |
| * Davide Libenzi <davidel@xmailserver.org> |
| * Reference: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=bcd0b235bf3808dec5115c381cd55568f63b85f0 |
| * Reference: http://www.xmailserver.org/eventfd-sem.c |
| * eventfd: testing improved support for semaphore-like behavior in linux-2.6.30 |
| * |
| */ |
| |
| #include <sys/types.h> |
| #include <sys/syscall.h> |
| #include <sys/stat.h> |
| #include <sys/wait.h> |
| #include <fcntl.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <errno.h> |
| #include <inttypes.h> |
| |
| /* Harness Specific Include Files. */ |
| #include "test.h" |
| #include "usctest.h" |
| #include "linux_syscall_numbers.h" |
| |
| char *TCID = "eventfd2_03"; /* test program identifier */ |
| int TST_TOTAL = 1; /* total number of tests in this file */ |
| |
| #ifndef EFD_SEMLIKE |
| #define EFD_SEMLIKE (1 << 0) |
| #endif |
| |
| /* Dummy function as syscall from linux_syscall_numbers.h uses cleanup(). */ |
| void cleanup() |
| { |
| } |
| |
| static int eventfd2(int count, int flags) |
| { |
| return ltp_syscall(__NR_eventfd2, count, flags); |
| } |
| |
| static void xsem_wait(int fd) |
| { |
| u_int64_t cntr; |
| |
| if (read(fd, &cntr, sizeof(cntr)) != sizeof(cntr)) { |
| perror("reading eventfd"); |
| exit(1); |
| } |
| fprintf(stdout, "[%u] wait completed on %d: count=%" PRIu64 "\n", |
| getpid(), fd, cntr); |
| } |
| |
| static void xsem_post(int fd, int count) |
| { |
| u_int64_t cntr = count; |
| |
| if (write(fd, &cntr, sizeof(cntr)) != sizeof(cntr)) { |
| perror("writing eventfd"); |
| exit(1); |
| } |
| } |
| |
| static void sem_player(int fd1, int fd2) |
| { |
| fprintf(stdout, "[%u] posting 1 on %d\n", getpid(), fd1); |
| xsem_post(fd1, 1); |
| |
| fprintf(stdout, "[%u] waiting on %d\n", getpid(), fd2); |
| xsem_wait(fd2); |
| |
| fprintf(stdout, "[%u] posting 1 on %d\n", getpid(), fd1); |
| xsem_post(fd1, 1); |
| |
| fprintf(stdout, "[%u] waiting on %d\n", getpid(), fd2); |
| xsem_wait(fd2); |
| |
| fprintf(stdout, "[%u] posting 5 on %d\n", getpid(), fd1); |
| xsem_post(fd1, 5); |
| |
| fprintf(stdout, "[%u] waiting 5 times on %d\n", getpid(), fd2); |
| xsem_wait(fd2); |
| xsem_wait(fd2); |
| xsem_wait(fd2); |
| xsem_wait(fd2); |
| xsem_wait(fd2); |
| } |
| |
| static void usage(char const *prg) |
| { |
| fprintf(stderr, "use: %s [-h]\n", prg); |
| } |
| |
| int main(int argc, char **argv) |
| { |
| int c, fd1, fd2, status; |
| pid_t cpid_poster, cpid_waiter; |
| |
| while ((c = getopt(argc, argv, "h")) != -1) { |
| switch (c) { |
| default: |
| usage(argv[0]); |
| return 1; |
| } |
| } |
| if ((tst_kvercmp(2, 6, 27)) < 0) { |
| tst_resm(TCONF, |
| "This test can only run on kernels that are 2.6.27 and higher"); |
| tst_exit(); |
| } |
| if ((fd1 = eventfd2(0, EFD_SEMLIKE)) == -1 || |
| (fd2 = eventfd2(0, EFD_SEMLIKE)) == -1) { |
| perror("eventfd2"); |
| return 1; |
| } |
| if ((cpid_poster = fork()) == 0) { |
| sem_player(fd1, fd2); |
| exit(0); |
| } |
| if ((cpid_waiter = fork()) == 0) { |
| sem_player(fd2, fd1); |
| exit(0); |
| } |
| waitpid(cpid_poster, &status, 0); |
| waitpid(cpid_waiter, &status, 0); |
| |
| tst_exit(); |
| } |