[libvirt] PATCH: 4/4: Test the event loop impl
Daniel P. Berrange
berrange at redhat.com
Mon May 11 11:25:08 UTC 2009
This patch adds a new test case to validate the various wierd scenarios that
can occur when adding/removing/updating watches & timers in the event loop.
In particular it checks
- Handling of watches marked as deleted before virEventRunOnce
- Handling of watches marked as deleted during dispatch of poll() results
- Correct interrupt of main thread if watches change during poll() sleep
These are the 3 problems we've been hitting with all these issues. I've
tested they all fail prior to this patch
http://www.redhat.com/archives/libvir-list/2009-March/msg00246.html
and now all 3 pass
Daniel
diff -r d5dc15adcbea tests/.cvsignore
--- a/tests/.cvsignore Fri May 08 11:58:19 2009 +0100
+++ b/tests/.cvsignore Fri May 08 15:51:11 2009 +0100
@@ -16,6 +16,7 @@ nodeinfotest
statstest
qparamtest
seclabeltest
+eventtest
*.gcda
*.gcno
*.exe
diff -r d5dc15adcbea tests/Makefile.am
--- a/tests/Makefile.am Fri May 08 11:58:19 2009 +0100
+++ b/tests/Makefile.am Fri May 08 15:51:11 2009 +0100
@@ -125,6 +125,11 @@ if WITH_SECDRIVER_SELINUX
TESTS += seclabeltest
endif
+if WITH_LIBVIRTD
+noinst_PROGRAMS += eventtest
+TESTS += eventtest
+endif
+
TESTS += nodedevxml2xmltest
path_add = $$abs_top_builddir/src$(PATH_SEPARATOR)$$abs_top_builddir/qemud
@@ -226,4 +231,10 @@ qparamtest_SOURCES = \
qparamtest.c testutils.h testutils.c
qparamtest_LDADD = $(LDADDS)
+if WITH_LIBVIRTD
+eventtest_SOURCES = \
+ eventtest.c testutils.h testutils.c ../qemud/event.c
+eventtest_LDADD = -lrt $(LDADDS)
+endif
+
CLEANFILES = *.cov *.gcov .libs/*.gcda .libs/*.gcno *.gcno *.gcda
diff -r d5dc15adcbea tests/eventtest.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/eventtest.c Fri May 08 15:51:11 2009 +0100
@@ -0,0 +1,444 @@
+/*
+ * eventtest.c: Test the libvirtd event loop impl
+ *
+ * Copyright (C) 2009 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Author: Daniel P. Berrange <berrange at redhat.com>
+ */
+
+#include <config.h>
+
+#include <stdlib.h>
+#include <signal.h>
+#include <time.h>
+
+#include "testutils.h"
+#include "internal.h"
+#include "threads.h"
+#include "logging.h"
+#include "../qemud/event.h"
+
+#define NUM_FDS 5
+#define NUM_TIME 5
+
+static struct handleInfo {
+ int pipeFD[2];
+ int fired;
+ int watch;
+ int error;
+ int delete;
+} handles[NUM_FDS];
+
+static struct timerInfo {
+ int timeout;
+ int timer;
+ int fired;
+ int error;
+ int delete;
+} timers[NUM_TIME];
+
+enum {
+ EV_ERROR_NONE,
+ EV_ERROR_WATCH,
+ EV_ERROR_FD,
+ EV_ERROR_EVENT,
+ EV_ERROR_DATA,
+};
+
+static void
+testPipeReader(int watch, int fd, int events, void *data)
+{
+ struct handleInfo *info = data;
+ char one;
+
+ info->fired = 1;
+
+ if (watch != info->watch) {
+ info->error = EV_ERROR_WATCH;
+ return;
+ }
+
+ if (fd != info->pipeFD[0]) {
+ info->error = EV_ERROR_FD;
+ return;
+ }
+
+ if (!(events & VIR_EVENT_HANDLE_READABLE)) {
+ info->error = EV_ERROR_EVENT;
+ return;
+ }
+ if (read(fd, &one, 1) != 1) {
+ info->error = EV_ERROR_DATA;
+ return;
+ }
+ info->error = EV_ERROR_NONE;
+
+ if (info->delete != -1)
+ virEventRemoveHandleImpl(info->delete);
+}
+
+
+static void
+testTimer(int timer, void *data)
+{
+ struct timerInfo *info = data;
+
+ info->fired = 1;
+
+ if (timer != info->timer) {
+ info->error = EV_ERROR_WATCH;
+ return;
+ }
+
+ info->error = EV_ERROR_NONE;
+
+ if (info->delete != -1)
+ virEventRemoveTimeoutImpl(info->delete);
+}
+
+static pthread_mutex_t eventThreadMutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t eventThreadRunCond = PTHREAD_COND_INITIALIZER;
+static int eventThreadRunOnce = 0;
+static pthread_cond_t eventThreadJobCond = PTHREAD_COND_INITIALIZER;
+static int eventThreadJobDone = 0;
+
+
+static void *eventThreadLoop(void *data ATTRIBUTE_UNUSED) {
+ while (1) {
+ pthread_mutex_lock(&eventThreadMutex);
+ while (!eventThreadRunOnce) {
+ pthread_cond_wait(&eventThreadRunCond, &eventThreadMutex);
+ }
+ eventThreadRunOnce = 0;
+ pthread_mutex_unlock(&eventThreadMutex);
+
+ virEventRunOnce();
+
+ pthread_mutex_lock(&eventThreadMutex);
+ eventThreadJobDone = 1;
+ pthread_cond_signal(&eventThreadJobCond);
+ pthread_mutex_unlock(&eventThreadMutex);
+ }
+}
+
+
+static int
+verifyFired(int handle, int timer)
+{
+ int handleFired = 0;
+ int timerFired = 0;
+ int i;
+ for (i = 0 ; i < NUM_FDS ; i++) {
+ if (handles[i].fired) {
+ if (i != handle) {
+ fprintf(stderr, "FAIL Handle %d fired, but expected %d\n", i, handle);
+ return EXIT_FAILURE;
+ } else {
+ if (handles[i].error != EV_ERROR_NONE) {
+ fprintf(stderr, "FAIL Handle %d fired, but had error %d\n", i,
+ handles[i].error);
+ return EXIT_FAILURE;
+ }
+ handleFired = 1;
+ }
+ } else {
+ if (i == handle) {
+ fprintf(stderr, "FAIL Handle %d should have fired, but didn't\n", handle);
+ return EXIT_FAILURE;
+ }
+ }
+ }
+ if (handleFired != 1 && handle != -1) {
+ fprintf(stderr, "FAIL Something wierd happened, expecting handle %d\n", handle);
+ return EXIT_FAILURE;
+ }
+
+
+ for (i = 0 ; i < NUM_TIME ; i++) {
+ if (timers[i].fired) {
+ if (i != timer) {
+ fprintf(stderr, "FAIL Timer %d fired, but expected %d\n", i, timer);
+ return EXIT_FAILURE;
+ } else {
+ if (timers[i].error != EV_ERROR_NONE) {
+ fprintf(stderr, "FAIL Timer %d fired, but had error %d\n", i,
+ timers[i].error);
+ return EXIT_FAILURE;
+ }
+ timerFired = 1;
+ }
+ } else {
+ if (i == timer) {
+ fprintf(stderr, "FAIL Timer %d should have fired, but didn't\n", timer);
+ return EXIT_FAILURE;
+ }
+ }
+ }
+ if (timerFired != 1 && timer != -1) {
+ fprintf(stderr, "FAIL Something wierd happened, expecting timer %d\n", timer);
+ return EXIT_FAILURE;
+ }
+ return EXIT_SUCCESS;
+}
+
+static void
+startJob(const char *msg, int *test)
+{
+ fprintf(stderr, "%2d: %s ", (*test)++, msg);
+ eventThreadRunOnce = 1;
+ eventThreadJobDone = 0;
+ pthread_cond_signal(&eventThreadRunCond);
+ pthread_mutex_unlock(&eventThreadMutex);
+ sched_yield();
+ pthread_mutex_lock(&eventThreadMutex);
+}
+
+static int
+finishJob(int handle, int timer)
+{
+ struct timespec waitTime;
+ int rc;
+ clock_gettime(CLOCK_REALTIME, &waitTime);
+ waitTime.tv_sec += 5;
+ rc = 0;
+ while (!eventThreadJobDone && rc == 0)
+ rc = pthread_cond_timedwait(&eventThreadJobCond, &eventThreadMutex, &waitTime);
+ if (rc != 0) {
+ fprintf(stderr, "FAIL Timed out waiting for pipe event\n");
+ return EXIT_FAILURE;
+ }
+
+ if (verifyFired(handle, timer) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+
+ fprintf(stderr, "OK\n");
+ return EXIT_SUCCESS;
+}
+
+static void
+resetAll(void)
+{
+ int i;
+ for (i = 0 ; i < NUM_FDS ; i++) {
+ handles[i].fired = 0;
+ handles[i].error = EV_ERROR_NONE;
+ }
+ for (i = 0 ; i < NUM_TIME ; i++) {
+ timers[i].fired = 0;
+ timers[i].error = EV_ERROR_NONE;
+ }
+}
+
+static int
+mymain(int argc, char **argv)
+{
+ int ret = 0;
+ char *progname;
+ int i;
+ pthread_t eventThread;
+ char one = '1';
+ int test = 1;
+
+ progname = argv[0];
+
+ if (argc > 1) {
+ fprintf(stderr, "Usage: %s\n", progname);
+ return EXIT_FAILURE;
+ }
+
+ for (i = 0 ; i < NUM_FDS ; i++) {
+ if (pipe(handles[i].pipeFD) < 0) {
+ fprintf(stderr, "Cannot create pipe: %d", errno);
+ return EXIT_FAILURE;
+ }
+ }
+
+ if (virThreadInitialize() < 0)
+ return EXIT_FAILURE;
+ char *debugEnv = getenv("LIBVIRT_DEBUG");
+ if (debugEnv && *debugEnv && *debugEnv != '0') {
+ if (STREQ(debugEnv, "2") || STREQ(debugEnv, "info"))
+ virLogSetDefaultPriority(VIR_LOG_INFO);
+ else if (STREQ(debugEnv, "3") || STREQ(debugEnv, "warning"))
+ virLogSetDefaultPriority(VIR_LOG_WARN);
+ else if (STREQ(debugEnv, "4") || STREQ(debugEnv, "error"))
+ virLogSetDefaultPriority(VIR_LOG_ERROR);
+ else
+ virLogSetDefaultPriority(VIR_LOG_DEBUG);
+ }
+
+ virEventInit();
+
+ for (i = 0 ; i < NUM_FDS ; i++) {
+ handles[i].delete = -1;
+ handles[i].watch =
+ virEventAddHandleImpl(handles[i].pipeFD[0],
+ VIR_EVENT_HANDLE_READABLE,
+ testPipeReader,
+ &handles[i], NULL);
+ }
+
+ for (i = 0 ; i < NUM_TIME ; i++) {
+ timers[i].delete = -1;
+ timers[i].timeout = -1;
+ timers[i].timer =
+ virEventAddTimeoutImpl(timers[i].timeout,
+ testTimer,
+ &timers[i], NULL);
+ }
+
+ pthread_create(&eventThread, NULL, eventThreadLoop, NULL);
+
+ pthread_mutex_lock(&eventThreadMutex);
+
+ /* First time, is easy - just try triggering one of our
+ * registered handles */
+ startJob("Simple write", &test);
+ ret = write(handles[1].pipeFD[1], &one, 1);
+ if (finishJob(1, -1) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+
+ resetAll();
+
+ /* Now lets delete one before starting poll(), and
+ * try triggering another handle */
+ virEventRemoveHandleImpl(handles[0].watch);
+ startJob("Deleted before poll", &test);
+ ret = write(handles[1].pipeFD[1], &one, 1);
+ if (finishJob(1, -1) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+
+ resetAll();
+
+ /* Next lets delete *during* poll, which should interrupt
+ * the loop with no event showing */
+
+ /* NB: this case is subject to a bit of a race condition.
+ * We yield & sleep, and pray that the other thread gets
+ * scheduled before we run EventRemoveHandleImpl */
+ startJob("Interrupted during poll", &test);
+ pthread_mutex_unlock(&eventThreadMutex);
+ sched_yield();
+ usleep(100 * 1000);
+ pthread_mutex_lock(&eventThreadMutex);
+ virEventRemoveHandleImpl(handles[1].watch);
+ if (finishJob(-1, -1) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+
+ resetAll();
+
+ /* Getting more fun, lets delete a later handle during dispatch */
+
+ /* NB: this case is subject to a bit of a race condition.
+ * Only 1 time in 3 does the 2nd write get triggered by
+ * before poll() exits for the first write(). We don't
+ * see a hard failure in other cases, so nothing to worry
+ * about */
+ startJob("Deleted during dispatch", &test);
+ handles[2].delete = handles[3].watch;
+ ret = write(handles[2].pipeFD[1], &one, 1);
+ ret = write(handles[3].pipeFD[1], &one, 1);
+ if (finishJob(2, -1) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+
+ resetAll();
+
+ /* Extreme fun, lets delete ourselves during dispatch */
+ startJob("Deleted during dispatch", &test);
+ handles[2].delete = handles[2].watch;
+ ret = write(handles[2].pipeFD[1], &one, 1);
+ if (finishJob(2, -1) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+
+ resetAll();
+
+
+
+ /* Run a timer on its own */
+ virEventUpdateTimeoutImpl(timers[1].timer, 100);
+ startJob("Firing a timer", &test);
+ if (finishJob(-1, 1) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+ virEventUpdateTimeoutImpl(timers[1].timer, -1);
+
+ resetAll();
+
+ /* Now lets delete one before starting poll(), and
+ * try triggering another timer */
+ virEventUpdateTimeoutImpl(timers[1].timer, 100);
+ virEventRemoveTimeoutImpl(timers[0].timer);
+ startJob("Deleted before poll", &test);
+ if (finishJob(-1, 1) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+ virEventUpdateTimeoutImpl(timers[1].timer, -1);
+
+ resetAll();
+
+ /* Next lets delete *during* poll, which should interrupt
+ * the loop with no event showing */
+
+ /* NB: this case is subject to a bit of a race condition.
+ * We yield & sleep, and pray that the other thread gets
+ * scheduled before we run EventRemoveTimeoutImpl */
+ startJob("Interrupted during poll", &test);
+ pthread_mutex_unlock(&eventThreadMutex);
+ sched_yield();
+ usleep(100 * 1000);
+ pthread_mutex_lock(&eventThreadMutex);
+ virEventRemoveTimeoutImpl(timers[1].timer);
+ if (finishJob(-1, -1) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+
+ resetAll();
+
+ /* Getting more fun, lets delete a later timer during dispatch */
+
+ /* NB: this case is subject to a bit of a race condition.
+ * Only 1 time in 3 does the 2nd write get triggered by
+ * before poll() exits for the first write(). We don't
+ * see a hard failure in other cases, so nothing to worry
+ * about */
+ virEventUpdateTimeoutImpl(timers[2].timer, 100);
+ virEventUpdateTimeoutImpl(timers[3].timer, 100);
+ startJob("Deleted during dispatch", &test);
+ timers[2].delete = timers[3].timer;
+ if (finishJob(-1, 2) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+ virEventUpdateTimeoutImpl(timers[2].timer, -1);
+
+ resetAll();
+
+ /* Extreme fun, lets delete ourselves during dispatch */
+ virEventUpdateTimeoutImpl(timers[2].timer, 100);
+ startJob("Deleted during dispatch", &test);
+ timers[2].delete = timers[2].timer;
+ if (finishJob(-1, 2) != EXIT_SUCCESS)
+ return EXIT_FAILURE;
+
+ for (i = 0 ; i < NUM_FDS ; i++)
+ virEventRemoveHandleImpl(handles[i].watch);
+ for (i = 0 ; i < NUM_TIME ; i++)
+ virEventRemoveTimeoutImpl(timers[i].timer);
+
+
+ //pthread_kill(eventThread, SIGTERM);
+
+ return EXIT_SUCCESS;
+}
+
+
+VIRT_TEST_MAIN(mymain)
diff -r d5dc15adcbea tests/testutils.h
--- a/tests/testutils.h Fri May 08 11:58:19 2009 +0100
+++ b/tests/testutils.h Fri May 08 15:51:11 2009 +0100
@@ -11,6 +11,8 @@
#ifndef __VIT_TEST_UTILS_H__
#define __VIT_TEST_UTILS_H__
+#include <stdio.h>
+
double virtTestCountAverage(double *items,
int nitems);
--
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