fix possible freeze on exit if exiting quickly after start

This commit is contained in:
dec05eba
2024-05-13 21:22:29 +02:00
parent 133c3a22b9
commit c01eb53513

View File

@@ -79,7 +79,7 @@ static int send_msg_to_server(int server_fd, gsr_kms_request *request) {
return sendmsg(server_fd, &response_message, 0);
}
static int recv_msg_from_server(int server_fd, gsr_kms_response *response) {
static int recv_msg_from_server(int server_pid, int server_fd, gsr_kms_response *response) {
struct iovec iov;
iov.iov_base = response;
iov.iov_len = sizeof(*response);
@@ -93,11 +93,26 @@ static int recv_msg_from_server(int server_fd, gsr_kms_response *response) {
response_message.msg_control = cmsgbuf;
response_message.msg_controllen = sizeof(cmsgbuf);
int res = recvmsg(server_fd, &response_message, MSG_WAITALL);
if(res <= 0)
return res;
int res = 0;
for(;;) {
res = recvmsg(server_fd, &response_message, MSG_DONTWAIT);
if(res <= 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
// If we are replacing the connection and closing the application at the same time
// then recvmsg can get stuck (because the server died), so we prevent that by doing
// non-blocking recvmsg and checking if the server died
int status = 0;
int wait_result = waitpid(server_pid, &status, WNOHANG);
if(wait_result != 0) {
res = -1;
break;
}
usleep(1000);
} else {
break;
}
}
if(response->num_fds > 0) {
if(res > 0 && response->num_fds > 0) {
struct cmsghdr *cmsg = CMSG_FIRSTHDR(&response_message);
if(cmsg) {
int *fds = (int*)CMSG_DATA(cmsg);
@@ -371,7 +386,7 @@ int gsr_kms_client_replace_connection(gsr_kms_client *self) {
return -1;
}
const int recv_res = recv_msg_from_server(self->socket_pair[GSR_SOCKET_PAIR_LOCAL], &response);
const int recv_res = recv_msg_from_server(self->kms_server_pid, self->socket_pair[GSR_SOCKET_PAIR_LOCAL], &response);
if(recv_res == 0) {
fprintf(stderr, "gsr warning: gsr_kms_client_replace_connection: kms server shut down\n");
return -1;
@@ -404,7 +419,7 @@ int gsr_kms_client_get_kms(gsr_kms_client *self, gsr_kms_response *response) {
return -1;
}
const int recv_res = recv_msg_from_server(self->socket_pair[GSR_SOCKET_PAIR_LOCAL], response);
const int recv_res = recv_msg_from_server(self->kms_server_pid, self->socket_pair[GSR_SOCKET_PAIR_LOCAL], response);
if(recv_res == 0) {
fprintf(stderr, "gsr warning: gsr_kms_client_get_kms: kms server shut down\n");
strcpy(response->err_msg, "failed to receive");