init: handle property messages asynchronously #2
A previous change moved property_service into its own thread, since
there was otherwise a deadlock whenever a process called by init would
try to set a property. This new thread, however, would send a message
via a blocking socket to init for each property that it received,
since init may need to take action depending on which property it is.
Unfortunately, this means that the deadlock is still possible, the
only difference is the socket's buffer must be filled before init deadlocks.
This change, therefore, adds the following:
1) A lock for instructing init to reboot
2) A lock for waiting on properties
3) A lock for queueing new properties
A previous version of this change was reverted and added locks around
all service operations and allowed the property thread to spawn
services directly. This was complex due to the fact that this code
was not designed to be multi-threaded. It was reverted due to
apparent issues during reboot. This change keeps a queue of processes
pending control messages, which it will then handle in the future. It
is less flexible but safer.
Bug: 146877356
Bug: 148236233
Bug: 150863651
Bug: 151251827
Test: multiple reboot tests, safely restarting hwservicemanager
Merged-In: Ice773436e85d3bf636bb0a892f3f6002bdf996b6
Change-Id: Ice773436e85d3bf636bb0a892f3f6002bdf996b6
(cherry picked from commit 802864c7826ea79f8cc29c52801e08bcfc15db76)
diff --git a/init/Android.bp b/init/Android.bp
index 3bb08db..72a7bfe 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -81,6 +81,7 @@
"-Wextra",
"-Wno-unused-parameter",
"-Werror",
+ "-Wthread-safety",
"-DALLOW_FIRST_STAGE_CONSOLE=0",
"-DALLOW_LOCAL_PROP_OVERRIDE=0",
"-DALLOW_PERMISSIVE_SELINUX=0",
diff --git a/init/action_manager.cpp b/init/action_manager.cpp
index ebca762..b45f5cd 100644
--- a/init/action_manager.cpp
+++ b/init/action_manager.cpp
@@ -41,10 +41,12 @@
}
void ActionManager::QueueEventTrigger(const std::string& trigger) {
+ auto lock = std::lock_guard{event_queue_lock_};
event_queue_.emplace(trigger);
}
void ActionManager::QueuePropertyChange(const std::string& name, const std::string& value) {
+ auto lock = std::lock_guard{event_queue_lock_};
event_queue_.emplace(std::make_pair(name, value));
}
@@ -53,6 +55,7 @@
}
void ActionManager::QueueBuiltinAction(BuiltinFunction func, const std::string& name) {
+ auto lock = std::lock_guard{event_queue_lock_};
auto action = std::make_unique<Action>(true, nullptr, "<Builtin Action>", 0, name,
std::map<std::string, std::string>{});
action->AddCommand(std::move(func), {name}, 0);
@@ -62,15 +65,18 @@
}
void ActionManager::ExecuteOneCommand() {
- // Loop through the event queue until we have an action to execute
- while (current_executing_actions_.empty() && !event_queue_.empty()) {
- for (const auto& action : actions_) {
- if (std::visit([&action](const auto& event) { return action->CheckEvent(event); },
- event_queue_.front())) {
- current_executing_actions_.emplace(action.get());
+ {
+ auto lock = std::lock_guard{event_queue_lock_};
+ // Loop through the event queue until we have an action to execute
+ while (current_executing_actions_.empty() && !event_queue_.empty()) {
+ for (const auto& action : actions_) {
+ if (std::visit([&action](const auto& event) { return action->CheckEvent(event); },
+ event_queue_.front())) {
+ current_executing_actions_.emplace(action.get());
+ }
}
+ event_queue_.pop();
}
- event_queue_.pop();
}
if (current_executing_actions_.empty()) {
@@ -103,6 +109,7 @@
}
bool ActionManager::HasMoreCommands() const {
+ auto lock = std::lock_guard{event_queue_lock_};
return !current_executing_actions_.empty() || !event_queue_.empty();
}
@@ -113,6 +120,7 @@
}
void ActionManager::ClearQueue() {
+ auto lock = std::lock_guard{event_queue_lock_};
// We are shutting down so don't claim the oneshot builtin actions back
current_executing_actions_ = {};
event_queue_ = {};
diff --git a/init/action_manager.h b/init/action_manager.h
index a2b95ac..b6f93d9 100644
--- a/init/action_manager.h
+++ b/init/action_manager.h
@@ -16,9 +16,12 @@
#pragma once
+#include <mutex>
#include <string>
#include <vector>
+#include <android-base/thread_annotations.h>
+
#include "action.h"
#include "builtins.h"
@@ -48,7 +51,9 @@
void operator=(ActionManager const&) = delete;
std::vector<std::unique_ptr<Action>> actions_;
- std::queue<std::variant<EventTrigger, PropertyChange, BuiltinAction>> event_queue_;
+ std::queue<std::variant<EventTrigger, PropertyChange, BuiltinAction>> event_queue_
+ GUARDED_BY(event_queue_lock_);
+ mutable std::mutex event_queue_lock_;
std::queue<const Action*> current_executing_actions_;
std::size_t current_command_;
};
diff --git a/init/init.cpp b/init/init.cpp
index a7518fc..b29dfa3 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -33,7 +33,9 @@
#include <functional>
#include <map>
#include <memory>
+#include <mutex>
#include <optional>
+#include <thread>
#include <vector>
#include <android-base/chrono_utils.h>
@@ -95,14 +97,155 @@
static int signal_fd = -1;
static int property_fd = -1;
-static std::unique_ptr<Timer> waiting_for_prop(nullptr);
-static std::string wait_prop_name;
-static std::string wait_prop_value;
-static std::string shutdown_command;
-static bool do_shutdown = false;
-
static std::unique_ptr<Subcontext> subcontext;
+struct PendingControlMessage {
+ std::string message;
+ std::string name;
+ pid_t pid;
+ int fd;
+};
+static std::mutex pending_control_messages_lock;
+static std::queue<PendingControlMessage> pending_control_messages;
+
+// Init epolls various FDs to wait for various inputs. It previously waited on property changes
+// with a blocking socket that contained the information related to the change, however, it was easy
+// to fill that socket and deadlock the system. Now we use locks to handle the property changes
+// directly in the property thread, however we still must wake the epoll to inform init that there
+// is a change to process, so we use this FD. It is non-blocking, since we do not care how many
+// times WakeEpoll() is called, only that the epoll will wake.
+static int wake_epoll_fd = -1;
+static void InstallInitNotifier(Epoll* epoll) {
+ int sockets[2];
+ if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0, sockets) != 0) {
+ PLOG(FATAL) << "Failed to socketpair() between property_service and init";
+ }
+ int epoll_fd = sockets[0];
+ wake_epoll_fd = sockets[1];
+
+ auto drain_socket = [epoll_fd] {
+ char buf[512];
+ while (read(epoll_fd, buf, sizeof(buf)) > 0) {
+ }
+ };
+
+ if (auto result = epoll->RegisterHandler(epoll_fd, drain_socket); !result.ok()) {
+ LOG(FATAL) << result.error();
+ }
+}
+
+static void WakeEpoll() {
+ constexpr char value[] = "1";
+ write(wake_epoll_fd, value, sizeof(value));
+}
+
+static class PropWaiterState {
+ public:
+ bool StartWaiting(const char* name, const char* value) {
+ auto lock = std::lock_guard{lock_};
+ if (waiting_for_prop_) {
+ return false;
+ }
+ if (GetProperty(name, "") != value) {
+ // Current property value is not equal to expected value
+ wait_prop_name_ = name;
+ wait_prop_value_ = value;
+ waiting_for_prop_.reset(new Timer());
+ } else {
+ LOG(INFO) << "start_waiting_for_property(\"" << name << "\", \"" << value
+ << "\"): already set";
+ }
+ return true;
+ }
+
+ void ResetWaitForProp() {
+ auto lock = std::lock_guard{lock_};
+ ResetWaitForPropLocked();
+ }
+
+ void CheckAndResetWait(const std::string& name, const std::string& value) {
+ auto lock = std::lock_guard{lock_};
+ // We always record how long init waited for ueventd to tell us cold boot finished.
+ // If we aren't waiting on this property, it means that ueventd finished before we even
+ // started to wait.
+ if (name == kColdBootDoneProp) {
+ auto time_waited = waiting_for_prop_ ? waiting_for_prop_->duration().count() : 0;
+ std::thread([time_waited] {
+ SetProperty("ro.boottime.init.cold_boot_wait", std::to_string(time_waited));
+ }).detach();
+ }
+
+ if (waiting_for_prop_) {
+ if (wait_prop_name_ == name && wait_prop_value_ == value) {
+ LOG(INFO) << "Wait for property '" << wait_prop_name_ << "=" << wait_prop_value_
+ << "' took " << *waiting_for_prop_;
+ ResetWaitForPropLocked();
+ WakeEpoll();
+ }
+ }
+ }
+
+ // This is not thread safe because it releases the lock when it returns, so the waiting state
+ // may change. However, we only use this function to prevent running commands in the main
+ // thread loop when we are waiting, so we do not care about false positives; only false
+ // negatives. StartWaiting() and this function are always called from the same thread, so false
+ // negatives are not possible and therefore we're okay.
+ bool MightBeWaiting() {
+ auto lock = std::lock_guard{lock_};
+ return static_cast<bool>(waiting_for_prop_);
+ }
+
+ private:
+ void ResetWaitForPropLocked() {
+ wait_prop_name_.clear();
+ wait_prop_value_.clear();
+ waiting_for_prop_.reset();
+ }
+
+ std::mutex lock_;
+ std::unique_ptr<Timer> waiting_for_prop_{nullptr};
+ std::string wait_prop_name_;
+ std::string wait_prop_value_;
+
+} prop_waiter_state;
+
+bool start_waiting_for_property(const char* name, const char* value) {
+ return prop_waiter_state.StartWaiting(name, value);
+}
+
+void ResetWaitForProp() {
+ prop_waiter_state.ResetWaitForProp();
+}
+
+static class ShutdownState {
+ public:
+ void TriggerShutdown(const std::string& command) {
+ // We can't call HandlePowerctlMessage() directly in this function,
+ // because it modifies the contents of the action queue, which can cause the action queue
+ // to get into a bad state if this function is called from a command being executed by the
+ // action queue. Instead we set this flag and ensure that shutdown happens before the next
+ // command is run in the main init loop.
+ auto lock = std::lock_guard{shutdown_command_lock_};
+ shutdown_command_ = command;
+ do_shutdown_ = true;
+ WakeEpoll();
+ }
+
+ std::optional<std::string> CheckShutdown() {
+ auto lock = std::lock_guard{shutdown_command_lock_};
+ if (do_shutdown_ && !IsShuttingDown()) {
+ do_shutdown_ = false;
+ return shutdown_command_;
+ }
+ return {};
+ }
+
+ private:
+ std::mutex shutdown_command_lock_;
+ std::string shutdown_command_;
+ bool do_shutdown_ = false;
+} shutdown_state;
+
void DumpState() {
ServiceList::GetInstance().DumpState();
ActionManager::GetInstance().DumpState();
@@ -156,39 +299,7 @@
}
}
-bool start_waiting_for_property(const char* name, const char* value) {
- if (waiting_for_prop) {
- return false;
- }
- if (GetProperty(name, "") != value) {
- // Current property value is not equal to expected value
- wait_prop_name = name;
- wait_prop_value = value;
- waiting_for_prop.reset(new Timer());
- } else {
- LOG(INFO) << "start_waiting_for_property(\"" << name << "\", \"" << value
- << "\"): already set";
- }
- return true;
-}
-
-void ResetWaitForProp() {
- wait_prop_name.clear();
- wait_prop_value.clear();
- waiting_for_prop.reset();
-}
-
-static void TriggerShutdown(const std::string& command) {
- // We can't call HandlePowerctlMessage() directly in this function,
- // because it modifies the contents of the action queue, which can cause the action queue
- // to get into a bad state if this function is called from a command being executed by the
- // action queue. Instead we set this flag and ensure that shutdown happens before the next
- // command is run in the main init loop.
- shutdown_command = command;
- do_shutdown = true;
-}
-
-void property_changed(const std::string& name, const std::string& value) {
+void PropertyChanged(const std::string& name, const std::string& value) {
// If the property is sys.powerctl, we bypass the event queue and immediately handle it.
// This is to ensure that init will always and immediately shutdown/reboot, regardless of
// if there are other pending events to process or if init is waiting on an exec service or
@@ -196,26 +307,15 @@
// In non-thermal-shutdown case, 'shutdown' trigger will be fired to let device specific
// commands to be executed.
if (name == "sys.powerctl") {
- TriggerShutdown(value);
+ trigger_shutdown(value);
}
- if (property_triggers_enabled) ActionManager::GetInstance().QueuePropertyChange(name, value);
-
- // We always record how long init waited for ueventd to tell us cold boot finished.
- // If we aren't waiting on this property, it means that ueventd finished before we even started
- // to wait.
- if (name == kColdBootDoneProp) {
- auto time_waited = waiting_for_prop ? waiting_for_prop->duration().count() : 0;
- SetProperty("ro.boottime.init.cold_boot_wait", std::to_string(time_waited));
+ if (property_triggers_enabled) {
+ ActionManager::GetInstance().QueuePropertyChange(name, value);
+ WakeEpoll();
}
- if (waiting_for_prop) {
- if (wait_prop_name == name && wait_prop_value == value) {
- LOG(INFO) << "Wait for property '" << wait_prop_name << "=" << wait_prop_value
- << "' took " << *waiting_for_prop;
- ResetWaitForProp();
- }
- }
+ prop_waiter_state.CheckAndResetWait(name, value);
}
static std::optional<boot_clock::time_point> HandleProcessActions() {
@@ -343,8 +443,46 @@
return true;
}
+bool QueueControlMessage(const std::string& message, const std::string& name, pid_t pid, int fd) {
+ auto lock = std::lock_guard{pending_control_messages_lock};
+ if (pending_control_messages.size() > 100) {
+ LOG(ERROR) << "Too many pending control messages, dropped '" << message << "' for '" << name
+ << "' from pid: " << pid;
+ return false;
+ }
+ pending_control_messages.push({message, name, pid, fd});
+ WakeEpoll();
+ return true;
+}
+
+static void HandleControlMessages() {
+ auto lock = std::unique_lock{pending_control_messages_lock};
+ // Init historically would only execute handle one property message, including control messages
+ // in each iteration of its main loop. We retain this behavior here to prevent starvation of
+ // other actions in the main loop.
+ if (!pending_control_messages.empty()) {
+ auto control_message = pending_control_messages.front();
+ pending_control_messages.pop();
+ lock.unlock();
+
+ bool success = HandleControlMessage(control_message.message, control_message.name,
+ control_message.pid);
+
+ uint32_t response = success ? PROP_SUCCESS : PROP_ERROR_HANDLE_CONTROL_MESSAGE;
+ if (control_message.fd != -1) {
+ TEMP_FAILURE_RETRY(send(control_message.fd, &response, sizeof(response), 0));
+ close(control_message.fd);
+ }
+ lock.lock();
+ }
+ // If we still have items to process, make sure we wake back up to do so.
+ if (!pending_control_messages.empty()) {
+ WakeEpoll();
+ }
+}
+
static Result<void> wait_for_coldboot_done_action(const BuiltinArguments& args) {
- if (!start_waiting_for_property(kColdBootDoneProp, "true")) {
+ if (!prop_waiter_state.StartWaiting(kColdBootDoneProp, "true")) {
LOG(FATAL) << "Could not wait for '" << kColdBootDoneProp << "'";
}
@@ -562,60 +700,6 @@
}
}
-void SendStopSendingMessagesMessage() {
- auto init_message = InitMessage{};
- init_message.set_stop_sending_messages(true);
- if (auto result = SendMessage(property_fd, init_message); !result.ok()) {
- LOG(ERROR) << "Failed to send 'stop sending messages' message: " << result.error();
- }
-}
-
-void SendStartSendingMessagesMessage() {
- auto init_message = InitMessage{};
- init_message.set_start_sending_messages(true);
- if (auto result = SendMessage(property_fd, init_message); !result.ok()) {
- LOG(ERROR) << "Failed to send 'start sending messages' message: " << result.error();
- }
-}
-
-static void HandlePropertyFd() {
- auto message = ReadMessage(property_fd);
- if (!message.ok()) {
- LOG(ERROR) << "Could not read message from property service: " << message.error();
- return;
- }
-
- auto property_message = PropertyMessage{};
- if (!property_message.ParseFromString(*message)) {
- LOG(ERROR) << "Could not parse message from property service";
- return;
- }
-
- switch (property_message.msg_case()) {
- case PropertyMessage::kControlMessage: {
- auto& control_message = property_message.control_message();
- bool success = HandleControlMessage(control_message.msg(), control_message.name(),
- control_message.pid());
-
- uint32_t response = success ? PROP_SUCCESS : PROP_ERROR_HANDLE_CONTROL_MESSAGE;
- if (control_message.has_fd()) {
- int fd = control_message.fd();
- TEMP_FAILURE_RETRY(send(fd, &response, sizeof(response), 0));
- close(fd);
- }
- break;
- }
- case PropertyMessage::kChangedMessage: {
- auto& changed_message = property_message.changed_message();
- property_changed(changed_message.name(), changed_message.value());
- break;
- }
- default:
- LOG(ERROR) << "Unknown message type from property service: "
- << property_message.msg_case();
- }
-}
-
int SecondStageMain(int argc, char** argv) {
if (REBOOT_BOOTLOADER_ON_PANIC) {
InstallRebootSignalHandlers();
@@ -623,7 +707,7 @@
boot_clock::time_point start_time = boot_clock::now();
- trigger_shutdown = TriggerShutdown;
+ trigger_shutdown = [](const std::string& command) { shutdown_state.TriggerShutdown(command); };
SetStdioToDevNull(argv);
InitKernelLogging(argv);
@@ -683,11 +767,8 @@
}
InstallSignalFdHandler(&epoll);
-
+ InstallInitNotifier(&epoll);
StartPropertyService(&property_fd);
- if (auto result = epoll.RegisterHandler(property_fd, HandlePropertyFd); !result.ok()) {
- LOG(FATAL) << "Could not register epoll handler for property fd: " << result.error();
- }
// Make the time that init stages started available for bootstat to log.
RecordStageBoottimes(start_time);
@@ -770,12 +851,12 @@
// By default, sleep until something happens.
auto epoll_timeout = std::optional<std::chrono::milliseconds>{};
- if (do_shutdown && !IsShuttingDown()) {
- do_shutdown = false;
- HandlePowerctlMessage(shutdown_command);
+ auto shutdown_command = shutdown_state.CheckShutdown();
+ if (shutdown_command) {
+ HandlePowerctlMessage(*shutdown_command);
}
- if (!(waiting_for_prop || Service::is_exec_service_running())) {
+ if (!(prop_waiter_state.MightBeWaiting() || Service::is_exec_service_running())) {
am.ExecuteOneCommand();
}
if (!IsShuttingDown()) {
@@ -789,7 +870,7 @@
}
}
- if (!(waiting_for_prop || Service::is_exec_service_running())) {
+ if (!(prop_waiter_state.MightBeWaiting() || Service::is_exec_service_running())) {
// If there's more work to do, wake up again immediately.
if (am.HasMoreCommands()) epoll_timeout = 0ms;
}
@@ -806,6 +887,7 @@
(*function)();
}
}
+ HandleControlMessages();
}
return 0;
diff --git a/init/init.h b/init/init.h
index 4bbca6f..27f64e2 100644
--- a/init/init.h
+++ b/init/init.h
@@ -38,8 +38,9 @@
void ResetWaitForProp();
void SendLoadPersistentPropertiesMessage();
-void SendStopSendingMessagesMessage();
-void SendStartSendingMessagesMessage();
+
+void PropertyChanged(const std::string& name, const std::string& value);
+bool QueueControlMessage(const std::string& message, const std::string& name, pid_t pid, int fd);
int SecondStageMain(int argc, char** argv);
diff --git a/init/property_service.cpp b/init/property_service.cpp
index 730bf6d..8206522 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -92,8 +92,11 @@
static bool persistent_properties_loaded = false;
static int property_set_fd = -1;
+static int from_init_socket = -1;
static int init_socket = -1;
static bool accept_messages = false;
+static std::mutex accept_messages_lock;
+static std::thread property_service_thread;
static PropertyInfoAreaFile property_info_area;
@@ -115,6 +118,16 @@
return 0;
}
+void StartSendingMessages() {
+ auto lock = std::lock_guard{accept_messages_lock};
+ accept_messages = true;
+}
+
+void StopSendingMessages() {
+ auto lock = std::lock_guard{accept_messages_lock};
+ accept_messages = true;
+}
+
bool CanReadProperty(const std::string& source_context, const std::string& name) {
const char* target_context = nullptr;
property_info_area->GetPropertyInfo(name.c_str(), &target_context, nullptr);
@@ -147,17 +160,6 @@
return has_access;
}
-static void SendPropertyChanged(const std::string& name, const std::string& value) {
- auto property_msg = PropertyMessage{};
- auto* changed_message = property_msg.mutable_changed_message();
- changed_message->set_name(name);
- changed_message->set_value(value);
-
- if (auto result = SendMessage(init_socket, property_msg); !result.ok()) {
- LOG(ERROR) << "Failed to send property changed message: " << result.error();
- }
-}
-
static uint32_t PropertySet(const std::string& name, const std::string& value, std::string* error) {
size_t valuelen = value.size();
@@ -195,8 +197,9 @@
}
// If init hasn't started its main loop, then it won't be handling property changed messages
// anyway, so there's no need to try to send them.
+ auto lock = std::lock_guard{accept_messages_lock};
if (accept_messages) {
- SendPropertyChanged(name, value);
+ PropertyChanged(name, value);
}
return PROP_SUCCESS;
}
@@ -373,33 +376,24 @@
static uint32_t SendControlMessage(const std::string& msg, const std::string& name, pid_t pid,
SocketConnection* socket, std::string* error) {
+ auto lock = std::lock_guard{accept_messages_lock};
if (!accept_messages) {
*error = "Received control message after shutdown, ignoring";
return PROP_ERROR_HANDLE_CONTROL_MESSAGE;
}
- auto property_msg = PropertyMessage{};
- auto* control_message = property_msg.mutable_control_message();
- control_message->set_msg(msg);
- control_message->set_name(name);
- control_message->set_pid(pid);
-
// We must release the fd before sending it to init, otherwise there will be a race with init.
// If init calls close() before Release(), then fdsan will see the wrong tag and abort().
int fd = -1;
if (socket != nullptr && SelinuxGetVendorAndroidVersion() > __ANDROID_API_Q__) {
fd = socket->Release();
- control_message->set_fd(fd);
}
- if (auto result = SendMessage(init_socket, property_msg); !result.ok()) {
- // We've already released the fd above, so if we fail to send the message to init, we need
- // to manually free it here.
- if (fd != -1) {
- close(fd);
- }
- *error = "Failed to send control message: " + result.error().message();
- return PROP_ERROR_HANDLE_CONTROL_MESSAGE;
+ bool queue_success = QueueControlMessage(msg, name, pid, fd);
+ if (!queue_success && fd != -1) {
+ uint32_t response = PROP_ERROR_HANDLE_CONTROL_MESSAGE;
+ TEMP_FAILURE_RETRY(send(fd, &response, sizeof(response), 0));
+ close(fd);
}
return PROP_SUCCESS;
@@ -1110,14 +1104,6 @@
persistent_properties_loaded = true;
break;
}
- case InitMessage::kStopSendingMessages: {
- accept_messages = false;
- break;
- }
- case InitMessage::kStartSendingMessages: {
- accept_messages = true;
- break;
- }
default:
LOG(ERROR) << "Unknown message type from init: " << init_message.msg_case();
}
@@ -1157,9 +1143,9 @@
if (socketpair(AF_UNIX, SOCK_SEQPACKET | SOCK_CLOEXEC, 0, sockets) != 0) {
PLOG(FATAL) << "Failed to socketpair() between property_service and init";
}
- *epoll_socket = sockets[0];
+ *epoll_socket = from_init_socket = sockets[0];
init_socket = sockets[1];
- accept_messages = true;
+ StartSendingMessages();
if (auto result = CreateSocket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
false, 0666, 0, 0, {});
@@ -1171,7 +1157,8 @@
listen(property_set_fd, 8);
- std::thread{PropertyServiceThread}.detach();
+ auto new_thread = std::thread{PropertyServiceThread};
+ property_service_thread.swap(new_thread);
}
} // namespace init
diff --git a/init/property_service.h b/init/property_service.h
index 506d116..2d49a36 100644
--- a/init/property_service.h
+++ b/init/property_service.h
@@ -32,5 +32,8 @@
void PropertyInit();
void StartPropertyService(int* epoll_socket);
+void StartSendingMessages();
+void StopSendingMessages();
+
} // namespace init
} // namespace android
diff --git a/init/reboot.cpp b/init/reboot.cpp
index 8d8bd8e..f006df3 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -59,6 +59,7 @@
#include "builtin_arguments.h"
#include "init.h"
#include "mount_namespace.h"
+#include "property_service.h"
#include "reboot_utils.h"
#include "service.h"
#include "service_list.h"
@@ -711,17 +712,12 @@
for (const auto& s : ServiceList::GetInstance()) {
s->UnSetExec();
}
- // We no longer process messages about properties changing coming from property service, so we
- // need to tell property service to stop sending us these messages, otherwise it'll fill the
- // buffers and block indefinitely, causing future property sets, including those that init makes
- // during shutdown in Service::NotifyStateChange() to also block indefinitely.
- SendStopSendingMessagesMessage();
}
static void LeaveShutdown() {
LOG(INFO) << "Leaving shutdown mode";
shutting_down = false;
- SendStartSendingMessagesMessage();
+ StartSendingMessages();
}
static Result<void> UnmountAllApexes() {
@@ -981,6 +977,10 @@
return;
}
+ // We do not want to process any messages (queue'ing triggers, shutdown messages, control
+ // messages, etc) from properties during reboot.
+ StopSendingMessages();
+
if (userspace_reboot) {
HandleUserspaceReboot();
return;