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authorZhang Qiang <qiang.z.zhang@intel.com>2012-05-29 12:22:00 +0800
committerZhang Qiang <qiang.z.zhang@intel.com>2012-05-29 12:22:00 +0800
commit02f0634ac29e19c68279e5544cac963e7f1203b8 (patch)
treeb983472f94ef063cedf866d8ecfb55939171779d /test_micro/source/b_latch.c
parente776056ea09ba0b6d9505ced6913c9190a12d632 (diff)
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diff --git a/test_micro/source/b_latch.c b/test_micro/source/b_latch.c
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+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 2009 Oracle. All rights reserved.
+ *
+ * $Id$
+ */
+
+#include "bench.h"
+
+#ifdef _POSIX_THREADS
+typedef struct {
+ pthread_t id;
+ DB_ENV *dbenv;
+ int iterations;
+ db_mutex_t mutex;
+ int contentions;
+} threadinfo_t;
+
+static void *latch_threadmain __P((void *));
+#endif
+
+static int time_latches __P((DB_ENV *, db_mutex_t, int));
+
+#define LATCH_THREADS_MAX 100
+
+/* Return the environment needed for __mutex_lock(), depending on release.
+ */
+#if DB_VERSION_MAJOR <4 || DB_VERSION_MAJOR == 4 && DB_VERSION_MINOR < 7
+#define ENV_ARG(dbenv) (dbenv)
+#else
+#define ENV_ARG(dbenv) ((dbenv)->env)
+#endif
+
+/*
+ * In the mulithreaded latch test each thread locks and updates this variable.
+ * It detects contention when the value of this counter changes during the
+ * mutex lock call.
+ */
+static int CurrentCounter = 0;
+static int latch_usage __P((void));
+
+static int
+latch_usage()
+{
+ (void)fprintf(stderr, "usage: b_latch [-c number of %s",
+ "lock+unlock pairs] [-n number of threads]\n");
+ return (EXIT_FAILURE);
+}
+
+/*
+ * time_latches --
+ * Repeat acquire and release of an exclusive latch, counting the
+ * number of times that 'someone else' got it just as we tried to.
+ */
+static int time_latches(dbenv, mutex, iterations)
+ DB_ENV *dbenv;
+ db_mutex_t mutex;
+ int iterations;
+{
+ int contended, i, previous;
+
+ contended = 0;
+ for (i = 0; i < iterations; ++i) {
+ previous = CurrentCounter;
+ DB_BENCH_ASSERT(__mutex_lock(ENV_ARG(dbenv), mutex) == 0);
+ if (previous != CurrentCounter)
+ contended++;
+ CurrentCounter++;
+ DB_BENCH_ASSERT(__mutex_unlock(ENV_ARG(dbenv), mutex) == 0);
+ }
+ return (contended);
+}
+
+#ifdef _POSIX_THREADS
+/*
+ * latch_threadmain --
+ * Entry point for multithreaded latching test.
+ *
+ * Currently only supported for POSIX threads.
+ */
+static void *
+latch_threadmain(arg)
+ void *arg;
+{
+ threadinfo_t *info = arg;
+
+ info->contentions = time_latches(info->dbenv,
+ info->mutex, info->iterations);
+
+ return ((void *) 0);
+}
+#endif
+
+/*
+ * b_latch --
+ * Measure the speed of latching and mutex operations.
+ *
+ *
+ */
+int
+b_latch(argc, argv)
+ int argc;
+ char *argv[];
+{
+ extern char *optarg;
+ extern int optind;
+ DB_ENV *dbenv;
+ int ch, count, nthreads;
+#ifdef _POSIX_THREADS
+ threadinfo_t threads[LATCH_THREADS_MAX];
+ int i, ret;
+ void *status;
+#endif
+ db_mutex_t mutex;
+ int contended;
+
+ contended = 0;
+ count = 1000000;
+ nthreads = 0; /* Default to running the test without extra threads */
+ while ((ch = getopt(argc, argv, "c:n:")) != EOF)
+ switch (ch) {
+ case 'c':
+ count = atoi(optarg);
+ break;
+ case 'n':
+ nthreads = atoi(optarg);
+ break;
+ case '?':
+ default:
+ return (latch_usage());
+ }
+ argc -= optind;
+ argv += optind;
+ if (argc != 0 || count < 1 || nthreads < 0 ||
+ nthreads > LATCH_THREADS_MAX)
+ return (latch_usage());
+#ifndef _POSIX_THREADS
+ if (nthreads > 1) {
+ (void)fprintf(stderr,
+ "Sorry, support for -n %d: threads not yet available\n",
+ nthreads);
+ exit(EXIT_FAILURE);
+ }
+#endif
+
+ /* Create the environment. */
+ DB_BENCH_ASSERT(db_env_create(&dbenv, 0) == 0);
+ dbenv->set_errfile(dbenv, stderr);
+#if DB_VERSION_MAJOR == 3 && DB_VERSION_MINOR < 1
+ DB_BENCH_ASSERT(dbenv->open(dbenv, TESTDIR,
+ NULL, DB_CREATE | DB_INIT_LOCK | DB_INIT_LOG |
+ DB_INIT_MPOOL | DB_INIT_TXN | DB_PRIVATE, 0666) == 0);
+#else
+ DB_BENCH_ASSERT(dbenv->open(dbenv, TESTDIR,
+ DB_CREATE | DB_INIT_LOCK | DB_INIT_LOG |
+ DB_INIT_MPOOL | DB_INIT_TXN | DB_PRIVATE, 0666) == 0);
+#endif
+ DB_BENCH_ASSERT(dbenv->mutex_alloc(dbenv, DB_MUTEX_SELF_BLOCK,
+ &mutex) == 0);
+#ifdef _POSIX_THREADS
+ for (i = 0; i < nthreads; i++) {
+ threads[i].dbenv = dbenv;
+ threads[i].mutex = mutex;
+ threads[i].iterations =
+ nthreads <= 1 ? count : count / nthreads;
+ }
+#endif
+
+ /* Start and acquire and release a mutex count times. If there's
+ * posix support and a non-zero number of threads start them.
+ */
+ TIMER_START;
+#ifdef _POSIX_THREADS
+ if (nthreads > 0) {
+ for (i = 0; i < nthreads; i++)
+ DB_BENCH_ASSERT(pthread_create(&threads[i].id,
+ NULL, latch_threadmain, &threads[i]) == 0);
+ for (i = 0; i < nthreads; i++) {
+ ret = pthread_join(threads[i].id, &status);
+ DB_BENCH_ASSERT(ret == 0);
+ contended += threads[i].contentions;
+ }
+
+ } else
+#endif
+ contended = time_latches(dbenv, mutex, count);
+ TIMER_STOP;
+
+ printf("# %d mutex lock-unlock pairs of %d thread%s\n", count,
+ nthreads, nthreads == 1 ? "" : "s");
+ TIMER_DISPLAY(count);
+
+ DB_BENCH_ASSERT(dbenv->mutex_free(dbenv, mutex) == 0);
+ DB_BENCH_ASSERT(dbenv->close(dbenv, 0) == 0);
+ COMPQUIET(contended, 0);
+
+ return (0);
+}