init: Allows shutting down cleanly.
When ro.build.shutdown_timeout is set, init will send a SIGTERM signal to
all services on reboot. The normal shutdown process will continue once
all services have exited or after the shutdown timeout
(ro.build.shutdown_timeout).
If ro.build.shutdown_timeout is not set, we assume a 0s timeout.
Bug: 26216447
Test: manual: Ask to reboot. All services exit cleanly.
Change-Id: If921f6e8d87211e500ac9fa86f3e1eabe02d18cf
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 10f9d81..d2291bb 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -39,6 +39,7 @@
#include <selinux/label.h>
#include <fs_mgr.h>
+#include <android-base/parseint.h>
#include <android-base/stringprintf.h>
#include <cutils/partition_utils.h>
#include <cutils/android_reboot.h>
@@ -53,6 +54,7 @@
#include "log.h"
#include "property_service.h"
#include "service.h"
+#include "signal_handler.h"
#include "util.h"
#define chmod DO_NOT_USE_CHMOD_USE_FCHMODAT_SYMLINK_NOFOLLOW
@@ -62,6 +64,8 @@
// System call provided by bionic but not in any header file.
extern "C" int init_module(void *, unsigned long, const char *);
+static const int kTerminateServiceDelayMicroSeconds = 50000;
+
static int insmod(const char *filename, const char *options) {
std::string module;
if (!read_file(filename, &module)) {
@@ -608,6 +612,42 @@
return -EINVAL;
}
+ std::string timeout = property_get("ro.build.shutdown_timeout");
+ unsigned int delay = 0;
+
+ if (android::base::ParseUint(timeout.c_str(), &delay) && delay > 0) {
+ Timer t;
+ // Ask all services to terminate.
+ ServiceManager::GetInstance().ForEachService(
+ [] (Service* s) { s->Terminate(); });
+
+ while (t.duration() < delay) {
+ ServiceManager::GetInstance().ReapAnyOutstandingChildren();
+
+ int service_count = 0;
+ ServiceManager::GetInstance().ForEachService(
+ [&service_count] (Service* s) {
+ // Count the number of services running.
+ // Exclude the console as it will ignore the SIGTERM signal
+ // and not exit.
+ // Note: SVC_CONSOLE actually means "requires console" but
+ // it is only used by the shell.
+ if (s->pid() != 0 && (s->flags() & SVC_CONSOLE) == 0) {
+ service_count++;
+ }
+ });
+
+ if (service_count == 0) {
+ // All terminable services terminated. We can exit early.
+ break;
+ }
+
+ // Wait a bit before recounting the number or running services.
+ usleep(kTerminateServiceDelayMicroSeconds);
+ }
+ NOTICE("Terminating running services took %.02f seconds", t.duration());
+ }
+
return android_reboot_with_callback(cmd, 0, reboot_target,
callback_on_ro_remount);
}
diff --git a/init/service.cpp b/init/service.cpp
index 40a4bc7..0ddc484 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -19,6 +19,7 @@
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
+#include <sys/wait.h>
#include <termios.h>
#include <unistd.h>
@@ -531,6 +532,17 @@
StopOrReset(SVC_DISABLED);
}
+void Service::Terminate() {
+ flags_ &= ~(SVC_RESTARTING | SVC_DISABLED_START);
+ flags_ |= SVC_DISABLED;
+ if (pid_) {
+ NOTICE("Sending SIGTERM to service '%s' (pid %d)...\n", name_.c_str(),
+ pid_);
+ kill(-pid_, SIGTERM);
+ NotifyStateChange("stopping");
+ }
+}
+
void Service::Restart() {
if (flags_ & SVC_RUNNING) {
/* Stop, wait, then start the service. */
@@ -724,9 +736,9 @@
return nullptr;
}
-void ServiceManager::ForEachService(void (*func)(Service* svc)) const {
+void ServiceManager::ForEachService(std::function<void(Service*)> callback) const {
for (const auto& s : services_) {
- func(s.get());
+ callback(s.get());
}
}
@@ -767,6 +779,53 @@
INFO("\n");
}
+bool ServiceManager::ReapOneProcess() {
+ int status;
+ pid_t pid = TEMP_FAILURE_RETRY(waitpid(-1, &status, WNOHANG));
+ if (pid == 0) {
+ return false;
+ } else if (pid == -1) {
+ ERROR("waitpid failed: %s\n", strerror(errno));
+ return false;
+ }
+
+ Service* svc = FindServiceByPid(pid);
+
+ std::string name;
+ if (svc) {
+ name = android::base::StringPrintf("Service '%s' (pid %d)",
+ svc->name().c_str(), pid);
+ } else {
+ name = android::base::StringPrintf("Untracked pid %d", pid);
+ }
+
+ if (WIFEXITED(status)) {
+ NOTICE("%s exited with status %d\n", name.c_str(), WEXITSTATUS(status));
+ } else if (WIFSIGNALED(status)) {
+ NOTICE("%s killed by signal %d\n", name.c_str(), WTERMSIG(status));
+ } else if (WIFSTOPPED(status)) {
+ NOTICE("%s stopped by signal %d\n", name.c_str(), WSTOPSIG(status));
+ } else {
+ NOTICE("%s state changed", name.c_str());
+ }
+
+ if (!svc) {
+ return true;
+ }
+
+ if (svc->Reap()) {
+ waiting_for_exec = false;
+ RemoveService(*svc);
+ }
+
+ return true;
+}
+
+void ServiceManager::ReapAnyOutstandingChildren() {
+ while (ReapOneProcess()) {
+ }
+}
+
bool ServiceParser::ParseSection(const std::vector<std::string>& args,
std::string* err) {
if (args.size() < 3) {
diff --git a/init/service.h b/init/service.h
index 10eb736..35abde9 100644
--- a/init/service.h
+++ b/init/service.h
@@ -82,6 +82,7 @@
bool Enable();
void Reset();
void Stop();
+ void Terminate();
void Restart();
void RestartIfNeeded(time_t& process_needs_restart);
bool Reap();
@@ -167,17 +168,22 @@
Service* FindServiceByName(const std::string& name) const;
Service* FindServiceByPid(pid_t pid) const;
Service* FindServiceByKeychord(int keychord_id) const;
- void ForEachService(void (*func)(Service* svc)) const;
+ void ForEachService(std::function<void(Service*)> callback) const;
void ForEachServiceInClass(const std::string& classname,
void (*func)(Service* svc)) const;
void ForEachServiceWithFlags(unsigned matchflags,
void (*func)(Service* svc)) const;
+ void ReapAnyOutstandingChildren();
void RemoveService(const Service& svc);
void DumpState() const;
private:
ServiceManager();
+ // Cleans up a child process that exited.
+ // Returns true iff a children was cleaned up.
+ bool ReapOneProcess();
+
static int exec_count_; // Every service needs a unique name.
std::vector<std::unique_ptr<Service>> services_;
};
diff --git a/init/signal_handler.cpp b/init/signal_handler.cpp
index e7d42cb..ea483d4 100644
--- a/init/signal_handler.cpp
+++ b/init/signal_handler.cpp
@@ -37,62 +37,12 @@
static int signal_write_fd = -1;
static int signal_read_fd = -1;
-static std::string DescribeStatus(int status) {
- if (WIFEXITED(status)) {
- return android::base::StringPrintf("exited with status %d", WEXITSTATUS(status));
- } else if (WIFSIGNALED(status)) {
- return android::base::StringPrintf("killed by signal %d", WTERMSIG(status));
- } else if (WIFSTOPPED(status)) {
- return android::base::StringPrintf("stopped by signal %d", WSTOPSIG(status));
- } else {
- return "state changed";
- }
-}
-
-static bool wait_for_one_process() {
- int status;
- pid_t pid = TEMP_FAILURE_RETRY(waitpid(-1, &status, WNOHANG));
- if (pid == 0) {
- return false;
- } else if (pid == -1) {
- ERROR("waitpid failed: %s\n", strerror(errno));
- return false;
- }
-
- Service* svc = ServiceManager::GetInstance().FindServiceByPid(pid);
-
- std::string name;
- if (svc) {
- name = android::base::StringPrintf("Service '%s' (pid %d)", svc->name().c_str(), pid);
- } else {
- name = android::base::StringPrintf("Untracked pid %d", pid);
- }
-
- NOTICE("%s %s\n", name.c_str(), DescribeStatus(status).c_str());
-
- if (!svc) {
- return true;
- }
-
- if (svc->Reap()) {
- waiting_for_exec = false;
- ServiceManager::GetInstance().RemoveService(*svc);
- }
-
- return true;
-}
-
-static void reap_any_outstanding_children() {
- while (wait_for_one_process()) {
- }
-}
-
static void handle_signal() {
// Clear outstanding requests.
char buf[32];
read(signal_read_fd, buf, sizeof(buf));
- reap_any_outstanding_children();
+ ServiceManager::GetInstance().ReapAnyOutstandingChildren();
}
static void SIGCHLD_handler(int) {
@@ -119,7 +69,7 @@
act.sa_flags = SA_NOCLDSTOP;
sigaction(SIGCHLD, &act, 0);
- reap_any_outstanding_children();
+ ServiceManager::GetInstance().ReapAnyOutstandingChildren();
register_epoll_handler(signal_read_fd, handle_signal);
}