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/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <cutils/sockets.h>
#include <cutils/android_reboot.h>
#include <cutils/list.h>
#include "init.h"
#include "util.h"
#include "log.h"
static int signal_fd = -1;
static int signal_recv_fd = -1;
static void sigchld_handler(int s)
{
write(signal_fd, &s, 1);
}
#define CRITICAL_CRASH_THRESHOLD 4 /* if we crash >4 times ... */
#define CRITICAL_CRASH_WINDOW (4*60) /* ... in 4 minutes, goto recovery*/
static int wait_for_one_process(int block)
{
pid_t pid;
int status;
struct service *svc;
struct socketinfo *si;
time_t now;
struct listnode *node;
struct command *cmd;
while ( (pid = waitpid(-1, &status, block ? 0 : WNOHANG)) == -1 && errno == EINTR );
if (pid <= 0) return -1;
INFO("waitpid returned pid %d, status = %08x\n", pid, status);
svc = service_find_by_pid(pid);
if (!svc) {
if (WIFEXITED(status)) {
ERROR("untracked pid %d exited with status %d\n", pid, WEXITSTATUS(status));
} else if (WIFSIGNALED(status)) {
ERROR("untracked pid %d killed by signal %d\n", pid, WTERMSIG(status));
} else if (WIFSTOPPED(status)) {
ERROR("untracked pid %d stopped by signal %d\n", pid, WSTOPSIG(status));
} else {
ERROR("untracked pid %d state changed\n", pid);
}
return 0;
}
NOTICE("process '%s', pid %d exited\n", svc->name, pid);
if (!(svc->flags & SVC_ONESHOT) || (svc->flags & SVC_RESTART)) {
kill(-pid, SIGKILL);
NOTICE("process '%s' killing any children in process group\n", svc->name);
}
/* remove any sockets we may have created */
for (si = svc->sockets; si; si = si->next) {
char tmp[128];
snprintf(tmp, sizeof(tmp), ANDROID_SOCKET_DIR"/%s", si->name);
unlink(tmp);
}
svc->pid = 0;
svc->flags &= (~SVC_RUNNING);
/* oneshot processes go into the disabled state on exit,
* except when manually restarted. */
if ((svc->flags & SVC_ONESHOT) && !(svc->flags & SVC_RESTART)) {
svc->flags |= SVC_DISABLED;
}
/* disabled and reset processes do not get restarted automatically */
if (svc->flags & (SVC_DISABLED | SVC_RESET) ) {
notify_service_state(svc->name, "stopped");
return 0;
}
now = gettime();
if ((svc->flags & SVC_CRITICAL) && !(svc->flags & SVC_RESTART)) {
if (svc->time_crashed + CRITICAL_CRASH_WINDOW >= now) {
if (++svc->nr_crashed > CRITICAL_CRASH_THRESHOLD) {
ERROR("critical process '%s' exited %d times in %d minutes; "
"rebooting into recovery mode\n", svc->name,
CRITICAL_CRASH_THRESHOLD, CRITICAL_CRASH_WINDOW / 60);
android_reboot(ANDROID_RB_RESTART2, 0, "recovery");
return 0;
}
} else {
svc->time_crashed = now;
svc->nr_crashed = 1;
}
}
svc->flags &= (~SVC_RESTART);
svc->flags |= SVC_RESTARTING;
/* Execute all onrestart commands for this service. */
list_for_each(node, &svc->onrestart.commands) {
cmd = node_to_item(node, struct command, clist);
cmd->func(cmd->nargs, cmd->args);
}
notify_service_state(svc->name, "restarting");
return 0;
}
void handle_signal(void)
{
char tmp[32];
/* we got a SIGCHLD - reap and restart as needed */
read(signal_recv_fd, tmp, sizeof(tmp));
while (!wait_for_one_process(0))
;
}
void signal_init(void)
{
int s[2];
struct sigaction act;
memset(&act, 0, sizeof(act));
act.sa_handler = sigchld_handler;
act.sa_flags = SA_NOCLDSTOP;
sigaction(SIGCHLD, &act, 0);
/* create a signalling mechanism for the sigchld handler */
if (socketpair(AF_UNIX, SOCK_STREAM, 0, s) == 0) {
signal_fd = s[0];
signal_recv_fd = s[1];
fcntl(s[0], F_SETFD, FD_CLOEXEC);
fcntl(s[0], F_SETFL, O_NONBLOCK);
fcntl(s[1], F_SETFD, FD_CLOEXEC);
fcntl(s[1], F_SETFL, O_NONBLOCK);
}
handle_signal();
}
int get_signal_fd()
{
return signal_recv_fd;
}
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