tests: Use a pipe for synchronization to avoid potential deadlock

Using signals in the previous way could potentially lead to dead locks
if the SIGCONT was signalled before a listener was registered.

Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
This commit is contained in:
Jonas Ådahl 2012-11-06 08:15:03 +01:00 committed by Kristian Høgsberg
parent 1801cdc41a
commit 3d651dc2ee

View file

@ -22,6 +22,7 @@
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
@ -50,20 +51,6 @@ struct display {
int child_exit_status;
};
static int
sigchld_handler(int signal_number, void *data)
{
struct display *display = data;
int status;
waitpid(-1, &status, 0);
display->child_exit_status = WEXITSTATUS(status);
wl_display_terminate(display->display);
return 0;
}
static void
registry_handle_global(void *data, struct wl_registry *registry,
uint32_t id, const char *interface, uint32_t version)
@ -82,25 +69,37 @@ static const struct wl_registry_listener registry_listener = {
static void
client_alarm_handler(int sig)
{
fprintf(stderr, "Received SIGALRM signal, aborting.\n");
exit(EXIT_FAILURE);
}
static void
client_continue_handler(int sig)
client_sigsegv_handler(int sig)
{
fprintf(stderr, "Received SIGSEGV signal, aborting.\n");
exit(EXIT_FAILURE);
}
static int
client_main(void)
client_main(int fd)
{
struct wl_display *display;
struct wl_registry *registry;
int counter = 0;
bool cont = false;
signal(SIGSEGV, client_sigsegv_handler);
signal(SIGALRM, client_alarm_handler);
signal(SIGCONT, client_continue_handler);
alarm(20);
pause();
alarm(2);
if (read(fd, &cont, sizeof cont) != 1) {
close(fd);
return EXIT_FAILURE;
}
close(fd);
if (!cont)
return EXIT_FAILURE;
display = wl_display_connect(SOCKET_NAME);
client_assert(display);
@ -122,7 +121,31 @@ dummy_bind(struct wl_client *client,
{
}
TEST(queue_destroy_proxy)
static int
sigchld_handler(int signal_number, void *data)
{
struct display *display = data;
int status;
waitpid(-1, &status, 0);
display->child_exit_status = WEXITSTATUS(status);
wl_display_terminate(display->display);
return 0;
}
static void
signal_client(int fd, bool cont)
{
int ret;
ret = write(fd, &cont, sizeof cont);
close(fd);
assert(ret == sizeof cont);
}
TEST(queue)
{
struct display display;
struct wl_event_loop *loop;
@ -135,19 +158,28 @@ TEST(queue_destroy_proxy)
};
unsigned int i;
pid_t pid;
int fds[2];
int ret;
ret = pipe(fds);
assert(ret == 0);
pid = fork();
if (pid == -1) {
perror("fork");
exit(EXIT_FAILURE);
} else if (pid == 0) {
exit(client_main());
close(fds[1]);
exit(client_main(fds[0]));
}
close(fds[0]);
display.child_exit_status = EXIT_FAILURE;
display.display = wl_display_create();
assert(display.display);
if (!display.display) {
signal_client(fds[1], false);
abort();
}
for (i = 0; i < ARRAY_LENGTH(dummy_interfaces); i++)
wl_display_add_global(display.display, dummy_interfaces[i],
@ -160,7 +192,7 @@ TEST(queue_destroy_proxy)
signal_source = wl_event_loop_add_signal(loop, SIGCHLD, sigchld_handler,
&display);
kill(pid, SIGCONT);
signal_client(fds[1], true);
wl_display_run(display.display);
wl_event_source_remove(signal_source);
@ -168,4 +200,3 @@ TEST(queue_destroy_proxy)
assert(display.child_exit_status == EXIT_SUCCESS);
}