Implement master-client support.
This introduces a mode where xwl-run can run as master and
spawn client instances to serve each new wayland connection.
diff --git a/xwl.c b/xwl.c
index 83d7ce5..27a3eab 100644
--- a/xwl.c
+++ b/xwl.c
@@ -13,12 +13,16 @@
#endif
#include <assert.h>
+#include <errno.h>
#include <fcntl.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/file.h>
#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
#include <sys/wait.h>
#include <systemd/sd-daemon.h>
#include <unistd.h>
@@ -388,6 +392,7 @@
int xwayland;
pid_t xwayland_pid;
pid_t child_pid;
+ pid_t peer_pid;
xcb_connection_t *connection;
const xcb_query_extension_reply_t *xfixes_extension;
xcb_screen_t *screen;
@@ -489,6 +494,13 @@
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
+#ifndef UNIX_PATH_MAX
+#define UNIX_PATH_MAX 108
+#endif
+
+#define LOCK_SUFFIX ".lock"
+#define LOCK_SUFFIXLEN 5
+
static void xwl_internal_xdg_shell_ping(void *data,
struct zxdg_shell_v6 *xdg_shell,
uint32_t serial) {
@@ -4918,6 +4930,7 @@
static void xwl_usage() {
printf("xwl-run "
+ "[-X] "
"[--scale=SCALE] "
"[--app-id=ID] "
"[--x-display=DISPLAY] "
@@ -4929,6 +4942,16 @@
"PROGRAM [ARGS...]\n");
}
+static void xwl_sigchld_handler(int signal) {
+ while (waitpid(-1, NULL, WNOHANG) > 0)
+ continue;
+}
+
+static void xwl_client_destroy_notify(struct wl_listener *listener,
+ void *data) {
+ exit(0);
+}
+
int main(int argc, char **argv) {
struct xwl xwl = {
.runprog = NULL,
@@ -4950,6 +4973,7 @@
.xwayland = 0,
.xwayland_pid = -1,
.child_pid = -1,
+ .peer_pid = -1,
.connection = NULL,
.xfixes_extension = NULL,
.screen = NULL,
@@ -5008,17 +5032,21 @@
},
.visual_ids = {0},
.colormaps = {0}};
- const char *x = getenv("XWL_X");
const char *scale = getenv("XWL_SCALE");
const char *clipboard_manager = getenv("XWL_CLIPBOARD_MANAGER");
const char *frame_color = getenv("XWL_FRAME_COLOR");
const char *show_window_title = getenv("XWL_SHOW_WINDOW_TITLE");
const char *drm_device = getenv("XWL_DRM_DEVICE");
const char *glamor = getenv("XWL_GLAMOR");
+ const char *socket_name = "wayland-0";
struct wl_event_loop *event_loop;
- int sv[2], ds[2], wm[2];
+ struct wl_listener client_destroy_listener = {.notify =
+ xwl_client_destroy_notify};
+ int sv[2];
pid_t pid;
int xdisplay = -1;
+ int master = 0;
+ int client_fd = -1;
int rv;
int i;
@@ -5033,22 +5061,36 @@
printf("Version: %s\n", VERSION);
return 0;
}
- if (strstr(arg, "-X") == arg) {
- x = "1";
- } else if (strstr(arg, "--scale=") == arg) {
+ if (strstr(arg, "--master") == arg) {
+ master = 1;
+ } else if (strstr(arg, "--socket") == arg) {
+ const char *s = strchr(arg, '=');
+ ++s;
+ socket_name = s;
+ } else if (strstr(arg, "--peer-pid") == arg) {
+ const char *s = strchr(arg, '=');
+ ++s;
+ xwl.peer_pid = atoi(s);
+ } else if (strstr(arg, "--client-fd") == arg) {
+ const char *s = strchr(arg, '=');
+ ++s;
+ client_fd = atoi(s);
+ } else if (strstr(arg, "--scale") == arg) {
const char *s = strchr(arg, '=');
++s;
scale = s;
- } else if (strstr(arg, "--app-id=") == arg) {
+ } else if (strstr(arg, "--app-id") == arg) {
const char *s = strchr(arg, '=');
++s;
xwl.app_id = s;
- } else if (strstr(arg, "--x-display=") == arg) {
+ } else if (strstr(arg, "-X") == arg) {
+ xwl.xwayland = 1;
+ } else if (strstr(arg, "--x-display") == arg) {
const char *s = strchr(arg, '=');
++s;
xdisplay = atoi(s);
// Automatically enable X forwarding if X display is specified.
- x = "1";
+ xwl.xwayland = 1;
} else if (strstr(arg, "--no-exit-with-child") == arg) {
xwl.exit_with_child = 0;
} else if (strstr(arg, "--no-clipboard-manager") == arg) {
@@ -5078,23 +5120,133 @@
}
}
- if (!xwl.runprog || !xwl.runprog[0]) {
- xwl_usage();
- return 1;
+ if (master) {
+ const char *runtime_dir = getenv("XDG_RUNTIME_DIR");
+ char lock_addr[UNIX_PATH_MAX + LOCK_SUFFIXLEN];
+ struct sockaddr_un addr;
+ struct sigaction sa;
+ struct stat sock_stat;
+ int lock_fd;
+ int sock_fd;
+
+ if (!runtime_dir) {
+ fprintf(stderr, "XDG_RUNTIME_DIR not set in the environment\n");
+ exit(1);
+ }
+
+ addr.sun_family = AF_LOCAL;
+ snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/%s", runtime_dir,
+ socket_name);
+
+ snprintf(lock_addr, sizeof(lock_addr), "%s%s", addr.sun_path, LOCK_SUFFIX);
+
+ lock_fd = open(lock_addr, O_CREAT | O_CLOEXEC,
+ (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP));
+ assert(lock_fd >= 0);
+
+ rv = flock(lock_fd, LOCK_EX | LOCK_NB);
+ if (rv < 0) {
+ fprintf(stderr, "unable to lock %s, is another compositor running?\n",
+ lock_addr);
+ exit(1);
+ }
+
+ rv = stat(addr.sun_path, &sock_stat);
+ if (rv >= 0) {
+ if (sock_stat.st_mode & (S_IWUSR | S_IWGRP))
+ unlink(addr.sun_path);
+ } else {
+ assert(errno == ENOENT);
+ }
+
+ sock_fd = socket(PF_LOCAL, SOCK_STREAM, 0);
+ assert(sock_fd >= 0);
+
+ rv = bind(sock_fd, (struct sockaddr *)&addr,
+ offsetof(struct sockaddr_un, sun_path) + strlen(addr.sun_path));
+ assert(rv >= 0);
+
+ rv = listen(sock_fd, 128);
+ assert(rv >= 0);
+
+ sa.sa_handler = xwl_sigchld_handler;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_RESTART;
+ rv = sigaction(SIGCHLD, &sa, NULL);
+ assert(rv >= 0);
+
+ sd_notify(0, "READY=1");
+
+ do {
+ struct ucred ucred;
+ socklen_t length = sizeof(addr);
+
+ client_fd = accept(sock_fd, (struct sockaddr *)&addr, &length);
+ if (client_fd < 0) {
+ fprintf(stderr, "failed to accept: %m\n");
+ continue;
+ }
+
+ ucred.pid = -1;
+ length = sizeof(ucred);
+ rv = getsockopt(client_fd, SOL_SOCKET, SO_PEERCRED, &ucred, &length);
+
+ pid = fork();
+ assert(pid != -1);
+ if (pid == 0) {
+ char client_fd_str[64], peer_pid_str[64];
+ char *args[32];
+ int i = 0, j;
+
+ close(sock_fd);
+ close(lock_fd);
+
+ args[i++] = argv[0];
+ snprintf(peer_pid_str, sizeof(peer_pid_str), "--peer-pid=%d",
+ ucred.pid);
+ args[i++] = peer_pid_str;
+ snprintf(client_fd_str, sizeof(client_fd_str), "--client-fd=%d",
+ client_fd);
+ args[i++] = client_fd_str;
+
+ // forward some flags.
+ for (j = 1; j < argc; ++j) {
+ char *arg = argv[j];
+ if (strstr(arg, "--scale") == arg ||
+ strstr(arg, "--drm-device") == arg) {
+ args[i++] = arg;
+ }
+ }
+
+ args[i++] = NULL;
+
+ execvp(argv[0], args);
+ _exit(EXIT_FAILURE);
+ }
+ close(client_fd);
+ } while (1);
+
+ _exit(EXIT_FAILURE);
}
- if (x)
- xwl.xwayland = !!strcmp(x, "0");
-
- if (scale)
- xwl.scale = MIN(MAX_SCALE, MAX(MIN_SCALE, atof(scale)));
+ if (client_fd == -1) {
+ if (!xwl.runprog || !xwl.runprog[0]) {
+ xwl_usage();
+ return 1;
+ }
+ }
if (xwl.xwayland) {
+ assert(client_fd == -1);
+
xwl.clipboard_manager = 1;
if (clipboard_manager)
xwl.clipboard_manager = !!strcmp(clipboard_manager, "0");
}
+ if (scale)
+ xwl.scale = MIN(MAX_SCALE, MAX(MIN_SCALE, atof(scale)));
+
if (frame_color) {
int r, g, b;
if (sscanf(frame_color, "#%02x%02x%02x", &r, &g, &b) == 3) {
@@ -5109,6 +5261,14 @@
if (drm_device && !access(drm_device, 0))
xwl.drm_device = drm_device;
+ if (xwl.runprog || xwl.xwayland) {
+ // Wayland connection from client.
+ rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, sv);
+ assert(!rv);
+
+ client_fd = sv[0];
+ }
+
xwl.display = wl_display_connect(NULL);
assert(xwl.display);
@@ -5133,81 +5293,81 @@
if (!xwl.viewporter)
xwl.scale = ceil(xwl.scale);
- xwl.sigchld_event_source =
- wl_event_loop_add_signal(event_loop, SIGCHLD, xwl_handle_sigchld, &xwl);
+ xwl.client = wl_client_create(xwl.host_display, client_fd);
- // Wayland connection from client.
- rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, sv);
- assert(!rv);
+ if (xwl.runprog || xwl.xwayland) {
+ xwl.sigchld_event_source =
+ wl_event_loop_add_signal(event_loop, SIGCHLD, xwl_handle_sigchld, &xwl);
- xwl.client = wl_client_create(xwl.host_display, sv[0]);
-
- if (xwl.xwayland) {
- // Xwayland display ready socket.
- rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ds);
- assert(!rv);
-
- xwl.display_event_source = wl_event_loop_add_fd(
- event_loop, ds[0], WL_EVENT_READABLE, xwl_handle_display_event, &xwl);
-
- // X connection to Xwayland.
- rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, wm);
- assert(!rv);
-
- xwl.wm_fd = wm[0];
- }
-
- pid = fork();
- assert(pid != -1);
- if (pid == 0) {
if (xwl.xwayland) {
- char display_str[8], display_fd_str[8], wm_fd_str[8];
- char *args[32];
- int i = 0;
- int fd;
+ int ds[2], wm[2];
- fd = dup(ds[1]);
- snprintf(display_fd_str, sizeof(display_fd_str), "%d", fd);
- fd = dup(wm[1]);
- snprintf(wm_fd_str, sizeof(wm_fd_str), "%d", fd);
+ // Xwayland display ready socket.
+ rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, ds);
+ assert(!rv);
- args[i++] = XWAYLAND_PATH "/Xwayland";
- if (xdisplay > 0) {
- snprintf(display_str, sizeof(display_str), ":%d", xdisplay);
- args[i++] = display_str;
+ xwl.display_event_source = wl_event_loop_add_fd(
+ event_loop, ds[0], WL_EVENT_READABLE, xwl_handle_display_event, &xwl);
+
+ // X connection to Xwayland.
+ rv = socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, wm);
+ assert(!rv);
+
+ xwl.wm_fd = wm[0];
+
+ pid = fork();
+ assert(pid != -1);
+ if (pid == 0) {
+ char display_str[8], display_fd_str[8], wm_fd_str[8];
+ char *args[32];
+ int i = 0;
+ int fd;
+
+ fd = dup(ds[1]);
+ snprintf(display_fd_str, sizeof(display_fd_str), "%d", fd);
+ fd = dup(wm[1]);
+ snprintf(wm_fd_str, sizeof(wm_fd_str), "%d", fd);
+
+ args[i++] = XWAYLAND_PATH "/Xwayland";
+ if (xdisplay > 0) {
+ snprintf(display_str, sizeof(display_str), ":%d", xdisplay);
+ args[i++] = display_str;
+ }
+ args[i++] = "-nolisten";
+ args[i++] = "tcp";
+ args[i++] = "-rootless";
+ if (xwl.drm_device) {
+ // Use DRM and software rendering unless glamor is enabled.
+ if (!glamor || !strcmp(glamor, "0"))
+ args[i++] = "-drm";
+ } else {
+ args[i++] = "-shm";
+ }
+ args[i++] = "-displayfd";
+ args[i++] = display_fd_str;
+ args[i++] = "-wm";
+ args[i++] = wm_fd_str;
+ args[i++] = NULL;
+
+ xwl_execvp(XWAYLAND_PATH "/Xwayland", args, sv[1]);
+ _exit(EXIT_FAILURE);
}
- args[i++] = "-nolisten";
- args[i++] = "tcp";
- args[i++] = "-rootless";
- if (xwl.drm_device) {
- // Use DRM and software rendering unless glamor is enabled.
- if (!glamor || !strcmp(glamor, "0"))
- args[i++] = "-drm";
- } else {
- args[i++] = "-shm";
- }
- args[i++] = "-displayfd";
- args[i++] = display_fd_str;
- args[i++] = "-wm";
- args[i++] = wm_fd_str;
- args[i++] = NULL;
-
- xwl_execvp(XWAYLAND_PATH "/Xwayland", args, sv[1]);
+ close(wm[1]);
+ xwl.xwayland_pid = pid;
} else {
- xwl_execvp(xwl.runprog[0], xwl.runprog, sv[1]);
+ pid = fork();
+ assert(pid != -1);
+ if (pid == 0) {
+ xwl_execvp(xwl.runprog[0], xwl.runprog, sv[1]);
+ _exit(EXIT_FAILURE);
+ }
+ xwl.child_pid = pid;
}
- _exit(EXIT_FAILURE);
- }
-
- if (xwl.xwayland) {
- close(wm[1]);
- xwl.xwayland_pid = pid;
+ close(sv[1]);
} else {
- xwl.child_pid = pid;
+ wl_client_add_destroy_listener(xwl.client, &client_destroy_listener);
}
- close(sv[1]);
-
do {
wl_display_flush_clients(xwl.host_display);
if (xwl.connection) {
