diff options
Diffstat (limited to 'tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c')
| -rw-r--r-- | tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c b/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c new file mode 100644 index 000000000000..7f0c756993af --- /dev/null +++ b/tools/testing/selftests/futex/functional/futex_requeue_pi_signal_restart.c @@ -0,0 +1,223 @@ +/****************************************************************************** + * + * Copyright © International Business Machines Corp., 2006-2008 + * + * 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. + * + * DESCRIPTION + * This test exercises the futex_wait_requeue_pi() signal handling both + * before and after the requeue. The first should be restarted by the + * kernel. The latter should return EWOULDBLOCK to the waiter. + * + * AUTHORS + * Darren Hart <dvhart@linux.intel.com> + * + * HISTORY + * 2008-May-5: Initial version by Darren Hart <dvhart@linux.intel.com> + * + *****************************************************************************/ + +#include <errno.h> +#include <getopt.h> +#include <limits.h> +#include <pthread.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "atomic.h" +#include "futextest.h" +#include "logging.h" + +#define DELAY_US 100 + +futex_t f1 = FUTEX_INITIALIZER; +futex_t f2 = FUTEX_INITIALIZER; +atomic_t requeued = ATOMIC_INITIALIZER; + +int waiter_ret = 0; + +void usage(char *prog) +{ + printf("Usage: %s\n", prog); + printf(" -c Use color\n"); + printf(" -h Display this help message\n"); + printf(" -v L Verbosity level: %d=QUIET %d=CRITICAL %d=INFO\n", + VQUIET, VCRITICAL, VINFO); +} + +int create_rt_thread(pthread_t *pth, void*(*func)(void *), void *arg, + int policy, int prio) +{ + struct sched_param schedp; + pthread_attr_t attr; + int ret; + + pthread_attr_init(&attr); + memset(&schedp, 0, sizeof(schedp)); + + ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED); + if (ret) { + error("pthread_attr_setinheritsched\n", ret); + return -1; + } + + ret = pthread_attr_setschedpolicy(&attr, policy); + if (ret) { + error("pthread_attr_setschedpolicy\n", ret); + return -1; + } + + schedp.sched_priority = prio; + ret = pthread_attr_setschedparam(&attr, &schedp); + if (ret) { + error("pthread_attr_setschedparam\n", ret); + return -1; + } + + ret = pthread_create(pth, &attr, func, arg); + if (ret) { + error("pthread_create\n", ret); + return -1; + } + return 0; +} + +void handle_signal(int signo) +{ + info("signal received %s requeue\n", + requeued.val ? "after" : "prior to"); +} + +void *waiterfn(void *arg) +{ + unsigned int old_val; + int res; + + waiter_ret = RET_PASS; + + info("Waiter running\n"); + info("Calling FUTEX_LOCK_PI on f2=%x @ %p\n", f2, &f2); + old_val = f1; + res = futex_wait_requeue_pi(&f1, old_val, &(f2), NULL, + FUTEX_PRIVATE_FLAG); + if (!requeued.val || errno != EWOULDBLOCK) { + fail("unexpected return from futex_wait_requeue_pi: %d (%s)\n", + res, strerror(errno)); + info("w2:futex: %x\n", f2); + if (!res) + futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG); + waiter_ret = RET_FAIL; + } + + info("Waiter exiting with %d\n", waiter_ret); + pthread_exit(NULL); +} + + +int main(int argc, char *argv[]) +{ + unsigned int old_val; + struct sigaction sa; + pthread_t waiter; + int c, res, ret = RET_PASS; + + while ((c = getopt(argc, argv, "chv:")) != -1) { + switch (c) { + case 'c': + log_color(1); + break; + case 'h': + usage(basename(argv[0])); + exit(0); + case 'v': + log_verbosity(atoi(optarg)); + break; + default: + usage(basename(argv[0])); + exit(1); + } + } + + printf("%s: Test signal handling during requeue_pi\n", + basename(argv[0])); + printf("\tArguments: <none>\n"); + + sa.sa_handler = handle_signal; + sigemptyset(&sa.sa_mask); + sa.sa_flags = 0; + if (sigaction(SIGUSR1, &sa, NULL)) { + error("sigaction\n", errno); + exit(1); + } + + info("m1:f2: %x\n", f2); + info("Creating waiter\n"); + res = create_rt_thread(&waiter, waiterfn, NULL, SCHED_FIFO, 1); + if (res) { + error("Creating waiting thread failed", res); + ret = RET_ERROR; + goto out; + } + + info("Calling FUTEX_LOCK_PI on f2=%x @ %p\n", f2, &f2); + info("m2:f2: %x\n", f2); + futex_lock_pi(&f2, 0, 0, FUTEX_PRIVATE_FLAG); + info("m3:f2: %x\n", f2); + + while (1) { + /* + * signal the waiter before requeue, waiter should automatically + * restart futex_wait_requeue_pi() in the kernel. Wait for the + * waiter to block on f1 again. + */ + info("Issuing SIGUSR1 to waiter\n"); + pthread_kill(waiter, SIGUSR1); + usleep(DELAY_US); + + info("Requeueing waiter via FUTEX_CMP_REQUEUE_PI\n"); + old_val = f1; + res = futex_cmp_requeue_pi(&f1, old_val, &(f2), 1, 0, + FUTEX_PRIVATE_FLAG); + /* + * If res is non-zero, we either requeued the waiter or hit an + * error, break out and handle it. If it is zero, then the + * signal may have hit before the the waiter was blocked on f1. + * Try again. + */ + if (res > 0) { + atomic_set(&requeued, 1); + break; + } else if (res > 0) { + error("FUTEX_CMP_REQUEUE_PI failed\n", errno); + ret = RET_ERROR; + break; + } + } + info("m4:f2: %x\n", f2); + + /* + * Signal the waiter after requeue, waiter should return from + * futex_wait_requeue_pi() with EWOULDBLOCK. Join the thread here so the + * futex_unlock_pi() can't happen before the signal wakeup is detected + * in the kernel. + */ + info("Issuing SIGUSR1 to waiter\n"); + pthread_kill(waiter, SIGUSR1); + info("Waiting for waiter to return\n"); + pthread_join(waiter, NULL); + + info("Calling FUTEX_UNLOCK_PI on mutex=%x @ %p\n", f2, &f2); + futex_unlock_pi(&f2, FUTEX_PRIVATE_FLAG); + info("m5:f2: %x\n", f2); + + out: + if (ret == RET_PASS && waiter_ret) + ret = waiter_ret; + + print_result(ret); + return ret; +} |