125 lines
3.4 KiB
C++
125 lines
3.4 KiB
C++
/*
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* Copyright (C) 2010 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <errno.h>
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#include <fcntl.h>
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#include <signal.h>
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#include <stdio.h>
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#include <sys/socket.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <unistd.h>
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#include <android-base/stringprintf.h>
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#include <cutils/android_reboot.h>
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#include <cutils/list.h>
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#include <cutils/sockets.h>
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#include "action.h"
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#include "init.h"
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#include "log.h"
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#include "service.h"
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#include "util.h"
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static int signal_write_fd = -1;
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static int signal_read_fd = -1;
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static std::string DescribeStatus(int status) {
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if (WIFEXITED(status)) {
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return android::base::StringPrintf("exited with status %d", WEXITSTATUS(status));
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} else if (WIFSIGNALED(status)) {
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return android::base::StringPrintf("killed by signal %d", WTERMSIG(status));
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} else if (WIFSTOPPED(status)) {
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return android::base::StringPrintf("stopped by signal %d", WSTOPSIG(status));
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} else {
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return "state changed";
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}
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}
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static bool wait_for_one_process() {
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int status;
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pid_t pid = TEMP_FAILURE_RETRY(waitpid(-1, &status, WNOHANG));
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if (pid == 0) {
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return false;
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} else if (pid == -1) {
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ERROR("waitpid failed: %s\n", strerror(errno));
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return false;
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}
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Service* svc = ServiceManager::GetInstance().FindServiceByPid(pid);
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std::string name;
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if (svc) {
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name = android::base::StringPrintf("Service '%s' (pid %d)", svc->name().c_str(), pid);
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} else {
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name = android::base::StringPrintf("Untracked pid %d", pid);
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}
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NOTICE("%s %s\n", name.c_str(), DescribeStatus(status).c_str());
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if (!svc) {
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return true;
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}
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if (svc->Reap()) {
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waiting_for_exec = false;
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ServiceManager::GetInstance().RemoveService(*svc);
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}
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return true;
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}
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static void reap_any_outstanding_children() {
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while (wait_for_one_process()) {
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}
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}
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static void handle_signal() {
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// Clear outstanding requests.
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char buf[32];
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read(signal_read_fd, buf, sizeof(buf));
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reap_any_outstanding_children();
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}
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static void SIGCHLD_handler(int) {
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if (TEMP_FAILURE_RETRY(write(signal_write_fd, "1", 1)) == -1) {
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ERROR("write(signal_write_fd) failed: %s\n", strerror(errno));
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}
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}
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void signal_handler_init() {
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// Create a signalling mechanism for SIGCHLD.
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int s[2];
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if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0, s) == -1) {
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ERROR("socketpair failed: %s\n", strerror(errno));
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exit(1);
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}
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signal_write_fd = s[0];
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signal_read_fd = s[1];
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// Write to signal_write_fd if we catch SIGCHLD.
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struct sigaction act;
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memset(&act, 0, sizeof(act));
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act.sa_handler = SIGCHLD_handler;
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act.sa_flags = SA_NOCLDSTOP;
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sigaction(SIGCHLD, &act, 0);
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reap_any_outstanding_children();
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register_epoll_handler(signal_read_fd, handle_signal);
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}
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