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authordec05eba <dec05eba@protonmail.com>2022-03-31 01:24:27 +0200
committerdec05eba <dec05eba@protonmail.com>2022-03-31 01:24:27 +0200
commit7228d3664764a55018d93b216b917668cfc25a32 (patch)
tree6665438132b96ff1bbab442d9da6f0d274997bd5
parent5a4d8ce21bec9434625ad1a12ce50d979226d4cf (diff)
Create pid file to detect if gpu-screen-recorder is already running and only allow one instance to run at once
-rw-r--r--src/main.cpp74
1 files changed, 74 insertions, 0 deletions
diff --git a/src/main.cpp b/src/main.cpp
index 0b1e677..858755b 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -27,6 +27,7 @@
#include <sys/stat.h>
#include <unistd.h>
+#include <fcntl.h>
#include "../include/sound.hpp"
@@ -632,8 +633,16 @@ static void usage() {
exit(1);
}
+static sig_atomic_t started = 0;
static sig_atomic_t running = 1;
static sig_atomic_t save_replay = 0;
+static const char *pid_file = "/tmp/gpu-screen-recorder";
+
+static void term_handler(int) {
+ if(started)
+ unlink(pid_file);
+ exit(0);
+}
static void int_handler(int) {
running = 0;
@@ -771,10 +780,70 @@ static void save_replay_async(AVCodecContext *video_codec_context, AVCodecContex
});
}
+static bool is_process_running_program(pid_t pid, const char *program_name) {
+ char filepath[256];
+ snprintf(filepath, sizeof(filepath), "/proc/%ld/exe", (long)pid);
+
+ char resolved_path[PATH_MAX];
+ const ssize_t resolved_path_len = readlink(filepath, resolved_path, sizeof(resolved_path) - 1);
+ if(resolved_path_len == -1)
+ return false;
+
+ resolved_path[resolved_path_len] = '\0';
+
+ const int program_name_len = strlen(program_name);
+ return resolved_path_len >= program_name_len && memcmp(resolved_path + resolved_path_len - program_name_len, program_name, program_name_len) == 0;
+}
+
+static void handle_existing_pid_file() {
+ char buffer[256];
+ int fd = open(pid_file, O_RDONLY);
+ if(fd == -1)
+ return;
+
+ ssize_t bytes_read = read(fd, buffer, sizeof(buffer) - 1);
+ if(bytes_read < 0) {
+ perror("failed to read gpu-screen-recorder pid file");
+ exit(1);
+ }
+ buffer[bytes_read] = '\0';
+ close(fd);
+
+ long pid = 0;
+ if(sscanf(buffer, "%ld %120s", &pid, buffer) == 2) {
+ if(is_process_running_program(pid, "gpu-screen-recorder")) {
+ fprintf(stderr, "Error: gpu-screen-recorder is already running\n");
+ exit(1);
+ }
+ } else {
+ fprintf(stderr, "Warning: gpu-screen-recorder pid file is in incorrect format, it's possible that its corrupt. Replacing file and continuing...\n");
+ }
+ unlink(pid_file);
+}
+
+static void handle_new_pid_file(const char *mode) {
+ int fd = open(pid_file, O_WRONLY|O_CREAT|O_TRUNC, 0777);
+ if(fd == -1) {
+ perror("failed to create gpu-screen-recorder pid file");
+ exit(1);
+ }
+
+ char buffer[256];
+ const int buffer_size = snprintf(buffer, sizeof(buffer), "%ld %s", (long)getpid(), mode);
+ if(write(fd, buffer, buffer_size) == -1) {
+ perror("failed to write gpu-screen-recorder pid file");
+ exit(1);
+ }
+ close(fd);
+}
+
int main(int argc, char **argv) {
+ signal(SIGTERM, term_handler);
signal(SIGINT, int_handler);
signal(SIGUSR1, save_replay_handler);
+ handle_existing_pid_file();
+
std::map<std::string, Arg> args = {
{ "-w", Arg { nullptr, false } },
//{ "-s", Arg { nullptr, true } },
@@ -1231,6 +1300,9 @@ int main(int argc, char **argv) {
}, av_format_context, audio_stream, audio_frame_buf, &sound_device, audio_frame, &write_output_mutex);
}
+ handle_new_pid_file(replay_buffer_size_secs == -1 ? "record" : "replay");
+ started = 1;
+
bool redraw = true;
XEvent e;
while (running) {
@@ -1434,4 +1506,6 @@ int main(int argc, char **argv) {
XCompositeUnredirectWindow(dpy, src_window_id, CompositeRedirectAutomatic);
XCloseDisplay(dpy);
}
+
+ unlink(pid_file);
}