[luad] add an Erlang-style supervisior to the daemon

This commit is contained in:
Bart Van Der Meerssche 2011-02-12 19:34:10 +01:00
parent 36746544ee
commit 7e99548842
1 changed files with 65 additions and 10 deletions

View File

@ -36,6 +36,9 @@
#define DAEMON_VARRUN "/var/run" #define DAEMON_VARRUN "/var/run"
#define SUP_ALLOWED_RESTARTS 10
#define SUP_MAX_SECONDS 60
#include <pwd.h> #include <pwd.h>
#include <grp.h> #include <grp.h>
#include <unistd.h> #include <unistd.h>
@ -44,6 +47,7 @@
#include <errno.h> #include <errno.h>
#include <string.h> #include <string.h>
#include <stdio.h> #include <stdio.h>
#include <time.h>
#include <sys/types.h> #include <sys/types.h>
#include <sys/time.h> #include <sys/time.h>
#include <sys/unistd.h> #include <sys/unistd.h>
@ -64,6 +68,42 @@
#include <lua5.1/lauxlib.h> #include <lua5.1/lauxlib.h>
#endif #endif
struct restart_s {
int i;
time_t time[SUP_ALLOWED_RESTARTS];
};
static void restart_init(struct restart_s *restart) {
restart->i = 0;
int i;
for (i = 0; i < SUP_ALLOWED_RESTARTS; i++) {
restart->time[i] = 0;
}
}
static void restart_add(struct restart_s *restart, time_t new_restart) {
restart->time[restart->i++] = new_restart;
restart->i %= SUP_ALLOWED_RESTARTS;
}
static int restart_max(struct restart_s *restart) {
int i, total;
for (i = 0; i < SUP_ALLOWED_RESTARTS; i++) {
if (restart->time[i] > time(NULL) - SUP_MAX_SECONDS) {
total++;
}
}
if (total == SUP_ALLOWED_RESTARTS) {
return 1;
}
else {
return 0;
}
}
static void sigterm(int signo) static void sigterm(int signo)
{ {
daemon_log(LOG_INFO, "Caught a SIGTERM. Exiting... "); daemon_log(LOG_INFO, "Caught a SIGTERM. Exiting... ");
@ -292,19 +332,34 @@ int main(int argc, char *argv[])
daemon_retval_send(0); daemon_retval_send(0);
daemon_log(LOG_INFO, "Sucessfully started with DEAMON=%s and DAEMON_PATH=%s", daemon_log_ident, runtime_path); daemon_log(LOG_INFO, "Sucessfully started with DEAMON=%s and DAEMON_PATH=%s", daemon_log_ident, runtime_path);
/* Derive the Lua daemon path from the C daemon one */
asprintf(&luad_path, "%s%s", (const char *)argv[0], ".lua");
/* Erlang-style supervisor */
struct restart_s restart;
restart_init(&restart);
while(1) {
/* Stop when allowed number of restarts have occurred in specified time window */
if (restart_max(&restart)) {
daemon_log(LOG_ERR, "%d restarts within a %d sec window", SUP_ALLOWED_RESTARTS, SUP_MAX_SECONDS);
break;
}
/* Create a new Lua environment */ /* Create a new Lua environment */
L = luaL_newstate(); L = luaL_newstate();
/* And load the standard libraries into the Lua environment */ /* And load the standard libraries into the Lua environment */
luaL_openlibs(L); luaL_openlibs(L);
/* Derive the Lua daemon path from the C daemon one */
asprintf(&luad_path, "%s%s", (const char *)argv[0], ".lua");
/* Tunnel through the wormhole into Lua neverland. This call should never return. */ /* Tunnel through the wormhole into Lua neverland. This call should never return. */
if (luaL_dofile(L, (const char *)luad_path)) { if (luaL_dofile(L, (const char *)luad_path)) {
daemon_log(LOG_ERR, "Lua returned with error message: %s", lua_tostring(L,-1)); daemon_log(LOG_ERR, "%s", lua_tostring(L,-1));
} }
/* Clean up the Lua state */ /* Clean up the Lua state */
lua_close(L); lua_close(L);
/* Wait for one second before restarting the Lua daemon */
sleep(1);
restart_add(&restart, time(NULL));
}
/* Do a cleanup */ /* Do a cleanup */
finish: finish: