diff options
Diffstat (limited to 'lib/libthr/tests/umtx_op_test.c')
| -rw-r--r-- | lib/libthr/tests/umtx_op_test.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/lib/libthr/tests/umtx_op_test.c b/lib/libthr/tests/umtx_op_test.c new file mode 100644 index 000000000000..8f964f9a923b --- /dev/null +++ b/lib/libthr/tests/umtx_op_test.c @@ -0,0 +1,105 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2020 Kyle Evans <kevans@FreeBSD.org> + * + * 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. + */ + +#include <sys/types.h> +#include <sys/umtx.h> + +#include <pthread.h> + +#include <atf-c.h> + +/* + * This is an implementation detail of _umtx_op(2), pulled from + * sys/kern/kern_umtx.c. The relevant bug observed that requests above the + * batch size would not function as intended, so it's important that this + * reflects the BATCH_SIZE configured there. + */ +#define UMTX_OP_BATCH_SIZE 128 +#define THREAD_COUNT ((UMTX_OP_BATCH_SIZE * 3) / 2) + +static pthread_mutex_t static_mutex = PTHREAD_MUTEX_INITIALIZER; + +static int batched_waiting; + +static void * +batching_threadfunc(void *arg) +{ + + pthread_mutex_lock(&static_mutex); + ++batched_waiting; + pthread_mutex_unlock(&static_mutex); + _umtx_op(arg, UMTX_OP_WAIT_UINT_PRIVATE, 0, NULL, NULL); + + return (NULL); +} + +ATF_TC(batching); +ATF_TC_HEAD(batching, tc) +{ + atf_tc_set_md_var(tc, "descr", + "Checks batching of UMTX_OP_NWAKE_PRIVATE"); +} +ATF_TC_BODY(batching, tc) +{ + uintptr_t addrs[THREAD_COUNT]; + uint32_t vals[THREAD_COUNT]; + pthread_t threads[THREAD_COUNT]; + + for (int i = 0; i < THREAD_COUNT; i++) { + addrs[i] = (uintptr_t)&vals[i]; + vals[i] = 0; + pthread_create(&threads[i], NULL, batching_threadfunc, + &vals[i]); + } + + pthread_mutex_lock(&static_mutex); + while (batched_waiting != THREAD_COUNT) { + pthread_mutex_unlock(&static_mutex); + pthread_yield(); + pthread_mutex_lock(&static_mutex); + } + + /* + * Spin for another .50 seconds to make sure they're all safely in the + * kernel. + */ + usleep(500000); + + pthread_mutex_unlock(&static_mutex); + _umtx_op(addrs, UMTX_OP_NWAKE_PRIVATE, THREAD_COUNT, NULL, NULL); + + for (int i = 0; i < THREAD_COUNT; i++) { + ATF_REQUIRE_EQ(0, pthread_join(threads[i], NULL)); + } +} + +ATF_TP_ADD_TCS(tp) +{ + + ATF_TP_ADD_TC(tp, batching); + return (atf_no_error()); +} |