Enginex0
c122ded7bf
Supervisor had zero-delay restart on crash loops — pins CPU core at 100% if daemon keeps dying. Add exponential backoff (500ms to 30s cap, resets after 30s stable). Set nice=10 on daemon child to yield CPU to foreground apps. Evict stale entries from fileLocks and rate limiter ConcurrentHashMaps that grew unbounded. Upload pre-built flashable zips in CI instead of unpacking and re-compressing loose files.
77 lines
2.0 KiB
C++
77 lines
2.0 KiB
C++
// Fork-based supervisor for instant daemon restart
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#include <unistd.h>
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#include <sys/wait.h>
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#include <sys/prctl.h>
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#include <sys/resource.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#include <time.h>
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static volatile sig_atomic_t should_exit = 0;
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static void signal_handler(int sig) {
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should_exit = 1;
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}
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int main(int argc, char *argv[]) {
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if (argc < 2) {
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fprintf(stderr, "Usage: %s <daemon> [args...]\n", argv[0]);
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return 1;
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}
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// Forward termination signals to exit cleanly
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signal(SIGTERM, signal_handler);
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signal(SIGINT, signal_handler);
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const char *daemon_path = argv[1];
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char **daemon_argv = &argv[1];
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int backoff_ms = 500;
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while (!should_exit) {
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struct timespec child_start;
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clock_gettime(CLOCK_MONOTONIC, &child_start);
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pid_t pid = fork();
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if (pid < 0) {
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perror("fork failed");
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usleep(100000); // 100ms backoff on fork failure
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continue;
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}
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if (pid == 0) {
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// Child: become the daemon
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prctl(PR_SET_PDEATHSIG, SIGKILL); // Die if parent dies
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setpriority(PRIO_PROCESS, 0, 10); // lower CPU priority than foreground
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execv(daemon_path, daemon_argv);
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perror("execv failed");
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_exit(127);
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}
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// Parent: wait for child to exit
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int status;
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waitpid(pid, &status, 0);
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if (should_exit) break;
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// Exponential backoff on rapid crashes, reset if child was stable
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struct timespec now;
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clock_gettime(CLOCK_MONOTONIC, &now);
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long lived_ms = (now.tv_sec - child_start.tv_sec) * 1000 +
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(now.tv_nsec - child_start.tv_nsec) / 1000000;
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if (lived_ms > 30000) {
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backoff_ms = 500;
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} else {
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usleep(backoff_ms * 1000);
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if (backoff_ms < 30000) backoff_ms *= 2;
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}
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}
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return 0;
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}
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