7db93b7cd7
Improves portability by avoiding the non-standard 'uint'. For example
this fixes building with musl libc:
".../kwin_wrapper.c:45:9: error: unknown type name 'uint';
did you mean 'int'?"
119 lines
3.5 KiB
C
119 lines
3.5 KiB
C
/*
|
|
KWin - the KDE window manager
|
|
This file is part of the KDE project.
|
|
|
|
SPDX-FileCopyrightText: 2020 <davidedmundson@kde.org>
|
|
|
|
SPDX-License-Identifier: GPL-2.0-or-later
|
|
*/
|
|
|
|
/**
|
|
* This tiny executable creates a socket, then starts kwin passing it the FD to the wayland socket.
|
|
* The WAYLAND_DISPLAY environment variable gets set here and passed to all spawned kwin instances.
|
|
* On any non-zero kwin exit kwin gets restarted.
|
|
*
|
|
* After restart kwin is relaunched but now with the KWIN_RESTART_COUNT env set to an incrementing counter
|
|
*
|
|
* It's somewhat akin to systemd socket activation, but we also need the lock file, finding the next free socket
|
|
* and so on, hence our own binary.
|
|
*
|
|
* Usage kwin_wayland_wrapper [argForKwin] [argForKwin] ...
|
|
*/
|
|
|
|
#include "wl-socket.h"
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/un.h>
|
|
#include <sys/wait.h>
|
|
#include <unistd.h>
|
|
|
|
char *old_wayland_env = NULL;
|
|
|
|
#define WAYLAND_ENV_NAME "WAYLAND_DISPLAY"
|
|
|
|
pid_t launch_kwin(struct wl_socket *socket, int argc, char **argv)
|
|
{
|
|
printf("Launching kwin\n");
|
|
pid_t pid = fork();
|
|
if (pid == 0) { /* child process */
|
|
char fdString[5]; // long enough string to contain what is probably a 1 digit number.
|
|
snprintf(fdString, sizeof(fdString) - 1, "%d", wl_socket_get_fd(socket));
|
|
|
|
char **args = calloc(argc + 6, sizeof(char *));
|
|
unsigned int pos = 0;
|
|
args[pos++] = (char *)"kwin_wayland"; //process name is the first argument by convention
|
|
args[pos++] = (char *)"--wayland_fd";
|
|
args[pos++] = fdString;
|
|
|
|
// for running in nested wayland, pass the original socket name
|
|
if (old_wayland_env) {
|
|
args[pos++] = (char *)"--wayland-display";
|
|
args[pos++] = old_wayland_env;
|
|
}
|
|
|
|
//copy passed args
|
|
for (int i = 0; i < argc; i++) {
|
|
args[pos++] = argv[i];
|
|
}
|
|
|
|
args[pos++] = NULL;
|
|
|
|
execvp("kwin_wayland", args);
|
|
free(args);
|
|
exit(127); /* if exec fails */
|
|
} else {
|
|
return pid;
|
|
}
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
struct wl_socket *socket = wl_socket_create();
|
|
if (!socket) {
|
|
return -1;
|
|
}
|
|
|
|
// copy the old WAYLAND_DISPLAY as we are about to overwrite it and kwin may need it
|
|
if (getenv(WAYLAND_ENV_NAME)) {
|
|
old_wayland_env = strdup(getenv(WAYLAND_ENV_NAME));
|
|
}
|
|
|
|
setenv(WAYLAND_ENV_NAME, wl_socket_get_display_name(socket), 1);
|
|
|
|
int crashCount = 0;
|
|
while (crashCount < 10) {
|
|
int status;
|
|
|
|
if (crashCount > 0) {
|
|
char restartCountEnv[3];
|
|
snprintf(restartCountEnv, sizeof(restartCountEnv) - 1, "%d", crashCount);
|
|
setenv("KWIN_RESTART_COUNT", restartCountEnv, 1);
|
|
}
|
|
|
|
// forward our own arguments, but drop the first, as that will be our own executable name
|
|
pid_t pid = launch_kwin(socket, argc - 1, &argv[1]);
|
|
if (pid < 0) {
|
|
// failed to launch kwin, we can just quit immediately
|
|
break;
|
|
}
|
|
|
|
waitpid(pid, &status, 0); /* wait for child */
|
|
|
|
if (WIFEXITED(status)) {
|
|
int exit_status = WEXITSTATUS(status);
|
|
fprintf(stderr, "Kwin exited with code %d\n", exit_status);
|
|
break;
|
|
} else if (WIFSIGNALED(status)) {
|
|
// we crashed! Let's go again!
|
|
pid = 0;
|
|
fprintf(stderr, "Compositor crashed, respawning\n");
|
|
}
|
|
crashCount++;
|
|
}
|
|
|
|
wl_socket_destroy(socket);
|
|
free(old_wayland_env);
|
|
return 0;
|
|
}
|