If QEMU fails to start, or crashes early, before libqtest has opened its qtest and QMP sockets, we'll get into an 'accept()' call with a 50 second timeout waiting for a connection that the zombie QEMU process will never initiate.
Use a short 250ms timeout with accept(), but loop 200 times instead, checking whether the process is alive on each iteration. With this qtest detects dead QEMU immediately. socket_accept is renamed to qtest_socket_accept to reflect that it now requires QTestState. Signed-off-by: Daniel P. Berrangé <[email protected]> --- tests/qtest/libqtest.c | 45 ++++++++++++++++++++++++++---------------- 1 file changed, 28 insertions(+), 17 deletions(-) diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c index 05d88476154..9e7a2d43a18 100644 --- a/tests/qtest/libqtest.c +++ b/tests/qtest/libqtest.c @@ -44,13 +44,14 @@ #define MAX_IRQ 256 +#define ACCEPT_TIMEOUT_MS 250 +#define ACCEPT_RETRIES (4 * 50) + #ifndef _WIN32 -# define SOCKET_TIMEOUT 50 # define CMD_EXEC "exec " # define DEV_STDERR "/dev/fd/2" # define DEV_NULL "/dev/null" #else -# define SOCKET_TIMEOUT 50000 # define CMD_EXEC "" # define DEV_STDERR "2" # define DEV_NULL "nul" @@ -116,20 +117,17 @@ static int init_socket(const char *socket_path) return sock; } -static int socket_accept(int sock) +static int qtest_socket_accept(QTestState *s, int sock) { struct sockaddr_un addr; socklen_t addrlen; int ret; - /* - * timeout unit of blocking receive calls is different among platforms. - * It's in seconds on non-Windows platforms but milliseconds on Windows. - */ + size_t i; #ifndef _WIN32 - struct timeval timeout = { .tv_sec = SOCKET_TIMEOUT, - .tv_usec = 0 }; + struct timeval timeout = { .tv_sec = 0, + .tv_usec = ACCEPT_TIMEOUT_MS * 1000ul }; #else - DWORD timeout = SOCKET_TIMEOUT; + DWORD timeout = ACCEPT_TIMEOUT_MS; #endif if (setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, @@ -140,13 +138,26 @@ static int socket_accept(int sock) return -1; } - do { + for (i = 0; i < ACCEPT_RETRIES ; i++) { + if (!qtest_probe_child(s)) { + fprintf(stderr, + "child process unexpectedly exited, skipping socket accept\n"); + goto cleanup; + } + addrlen = sizeof(addr); ret = accept(sock, (struct sockaddr *)&addr, &addrlen); - } while (ret == -1 && errno == EINTR); - if (ret == -1) { - fprintf(stderr, "%s failed: %s\n", __func__, strerror(errno)); + if (ret == -1) { + if (errno == EINTR || errno == EAGAIN) { + continue; + } else { + fprintf(stderr, "%s failed: %s\n", __func__, strerror(errno)); + } + } + return ret; } + + cleanup: close(sock); return ret; @@ -549,9 +560,9 @@ void qtest_connect(QTestState *s) g_autofree gchar *qmp_socket_path = qtest_socket_path("qmp"); g_assert(s->sock >= 0 && s->qmpsock >= 0); - s->fd = socket_accept(s->sock); + s->fd = qtest_socket_accept(s, s->sock); if (s->fd >= 0) { - s->qmp_fd = socket_accept(s->qmpsock); + s->qmp_fd = qtest_socket_accept(s, s->qmpsock); } unlink(socket_path); unlink(qmp_socket_path); @@ -663,7 +674,7 @@ QTestState *qtest_init_with_serial(const char *extra_args, int *sock_fd) qts = qtest_initf("-chardev socket,id=s0,path=%s -serial chardev:s0 %s", sock_path, extra_args); - *sock_fd = socket_accept(sock_fd_init); + *sock_fd = qtest_socket_accept(qts, sock_fd_init); unlink(sock_path); g_free(sock_path); -- 2.55.0
