tests: Add a parallel launch test.

This is designed to reveal libvirt race conditions such as
bug 875741.

This is a "slow test" so it only runs if you do 'make check-slow'.

.gitignore

@@ -419,6 +419,7 @@ Makefile.in
 /tests/guests/ubuntu.img
 /tests/guests/windows.img
 /tests/mount-local/test-parallel-mount-local
+/tests/parallel/test-parallel
 /tests/regressions/rhbz501893
 /tests/regressions/rhbz790721
 /tests/rsync/rsyncd.pid

Makefile.am

@@ -41,6 +41,7 @@ SUBDIRS += tests/guests
 SUBDIRS += tests/c-api
 SUBDIRS += tests/tmpdirs
 SUBDIRS += tests/protocol
+SUBDIRS += tests/parallel
 SUBDIRS += tests/disks
 SUBDIRS += tests/lvm
 SUBDIRS += tests/luks

configure.ac

@@ -1406,6 +1406,7 @@ AC_CONFIG_FILES([Makefile
                  tests/md/Makefile
                  tests/mount-local/Makefile
                  tests/ntfsclone/Makefile
+                 tests/parallel/Makefile
                  tests/protocol/Makefile
                  tests/qemu/Makefile
                  tests/regressions/Makefile

tests/parallel/Makefile.am

@@ -0,0 +1,43 @@
+# libguestfs
+# Copyright (C) 2012 Red Hat Inc.
+#
+# 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+include $(top_srcdir)/subdir-rules.mk
+
+# Don't run this test by default.  However we have to have an empty
+# TESTS rule otherwise you can't run the test from the command line
+# using 'make TESTS=test-parallel check'
+TESTS =
+TESTS_ENVIRONMENT = $(top_builddir)/run --test
+
+check_PROGRAMS = test-parallel
+
+test_parallel_SOURCES = test-parallel.c
+test_parallel_CFLAGS = \
+	-DGUESTFS_WARN_DEPRECATED=1 \
+	-pthread \
+	-I$(top_srcdir)/gnulib/lib -I$(top_builddir)/gnulib/lib \
+	-I$(top_srcdir)/src -I$(top_builddir)/src \
+	$(WARN_CFLAGS) $(WERROR_CFLAGS)
+test_parallel_LDADD = \
+	$(top_builddir)/src/libguestfs.la \
+	$(top_builddir)/gnulib/lib/libgnu.la
+
+#check-valgrind:
+#	$(MAKE) VG="$(top_builddir)/run @VG@" TESTS="test-parallel" check
+
+check-slow:
+	$(MAKE) TESTS="test-parallel" check

tests/parallel/test-parallel.c

@@ -0,0 +1,157 @@
+/* libguestfs
+ * Copyright (C) 2012 Red Hat Inc.
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/* This test is mainly aimed at libvirt: There appear to be a lot of
+ * cases where libvirt is racy when creating transient guests.
+ * Therefore this test simply launches lots of handles in parallel for
+ * many minutes, hoping to reveal problems in libvirt this way.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <signal.h>
+#include <error.h>
+
+#include <pthread.h>
+
+#include "guestfs.h"
+
+#include "ignore-value.h"
+
+#define TOTAL_TIME 600          /* Seconds, excluding launch. */
+#define NR_THREADS 5
+
+#define STREQ(a,b) (strcmp((a),(b)) == 0)
+
+struct thread_state {
+  pthread_t thread;             /* Thread handle. */
+  int exit_status;              /* Thread exit status. */
+};
+static struct thread_state threads[NR_THREADS];
+
+static void *start_thread (void *) __attribute__((noreturn));
+
+static volatile sig_atomic_t quit = 0;
+
+static void
+catch_sigint (int signal)
+{
+  static char cleaning_up[] = "\ngot signal, cleaning up ...\n";
+
+  if (quit == 0) {
+    quit = 1;
+    ignore_value (write (2, cleaning_up, sizeof cleaning_up));
+  }
+}
+
+int
+main (int argc, char *argv[])
+{
+  char *skip;
+  struct sigaction sa;
+  int r;
+  size_t i, errors = 0;
+  void *status;
+
+  srandom (time (NULL));
+
+  /* Allow the test to be skipped by setting an environment variable. */
+  skip = getenv ("SKIP_TEST_PARALLEL");
+  if (skip && STREQ (skip, "1")) {
+    fprintf (stderr, "%s: test skipped because environment variable set.\n",
+             argv[0]);
+    exit (77);
+  }
+
+  memset (&sa, 0, sizeof sa);
+  sa.sa_handler = catch_sigint;
+  sa.sa_flags = SA_RESTART;
+  sigaction (SIGINT, &sa, NULL);
+  sigaction (SIGQUIT, &sa, NULL);
+
+  for (i = 0; i < NR_THREADS; ++i) {
+    /* Start the thread. */
+    r = pthread_create (&threads[i].thread, NULL, start_thread,
+                        &threads[i]);
+    if (r != 0)
+      error (EXIT_FAILURE, r, "pthread_create");
+  }
+
+  /* Wait for the threads to exit. */
+  for (i = 0; i < NR_THREADS; ++i) {
+    r = pthread_join (threads[i].thread, &status);
+    if (r != 0)
+      error (EXIT_FAILURE, r, "pthread_join");
+    if (*(int *)status != 0) {
+      fprintf (stderr, "%zu: thread returned an error\n", i);
+      errors++;
+    }
+  }
+
+  exit (errors == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
+}
+
+/* Run the test in a single thread. */
+static void *
+start_thread (void *statevp)
+{
+  struct thread_state *state = statevp;
+  guestfs_h *g;
+  time_t start_t, t;
+
+  time (&start_t);
+
+  for (;;) {
+    /* Keep testing until we run out of time. */
+    time (&t);
+    if (quit || t - start_t >= TOTAL_TIME)
+      break;
+
+    g = guestfs_create ();
+    if (g == NULL) {
+      perror ("guestfs_create");
+      state->exit_status = 1;
+      pthread_exit (&state->exit_status);
+    }
+
+    if (guestfs_add_drive_opts (g, "/dev/null",
+                                GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
+                                GUESTFS_ADD_DRIVE_OPTS_READONLY, 1,
+                                -1) == -1) {
+    error:
+      guestfs_close (g);
+      state->exit_status = 1;
+      pthread_exit (&state->exit_status);
+    }
+    if (guestfs_launch (g) == -1)
+      goto error;
+
+    if (guestfs_shutdown (g) == -1)
+      goto error;
+
+    guestfs_close (g);
+  }
+
+  /* Test finished successfully. */
+  state->exit_status = 0;
+  pthread_exit (&state->exit_status);
+}