Merge "init: Introduce Epoll::SetFirstCallback()" am: 9457a9ab72

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2255998

Change-Id: I37b63a6f46d1034c094de7193690a41caf3d35bc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
This commit is contained in:
Treehugger Robot 2022-10-18 23:56:56 +00:00 committed by Automerger Merge Worker
commit aabaa0aeac
3 changed files with 14 additions and 4 deletions

View file

@ -75,6 +75,10 @@ Result<void> Epoll::UnregisterHandler(int fd) {
return {};
}
void Epoll::SetFirstCallback(std::function<void()> first_callback) {
first_callback_ = std::move(first_callback);
}
Result<std::vector<std::shared_ptr<Epoll::Handler>>> Epoll::Wait(
std::optional<std::chrono::milliseconds> timeout) {
int timeout_ms = -1;
@ -87,6 +91,9 @@ Result<std::vector<std::shared_ptr<Epoll::Handler>>> Epoll::Wait(
if (num_events == -1) {
return ErrnoError() << "epoll_wait failed";
}
if (num_events > 0 && first_callback_) {
first_callback_();
}
std::vector<std::shared_ptr<Handler>> pending_functions;
for (int i = 0; i < num_events; ++i) {
auto& info = *reinterpret_cast<Info*>(ev[i].data.ptr);

View file

@ -42,6 +42,7 @@ class Epoll {
Result<void> Open();
Result<void> RegisterHandler(int fd, Handler handler, uint32_t events = EPOLLIN);
Result<void> UnregisterHandler(int fd);
void SetFirstCallback(std::function<void()> first_callback);
Result<std::vector<std::shared_ptr<Handler>>> Wait(
std::optional<std::chrono::milliseconds> timeout);
@ -53,6 +54,7 @@ class Epoll {
android::base::unique_fd epoll_fd_;
std::map<int, Info> epoll_handlers_;
std::function<void()> first_callback_;
};
} // namespace init

View file

@ -1061,6 +1061,11 @@ int SecondStageMain(int argc, char** argv) {
PLOG(FATAL) << result.error();
}
// We always reap children before responding to the other pending functions. This is to
// prevent a race where other daemons see that a service has exited and ask init to
// start it again via ctl.start before init has reaped it.
epoll.SetFirstCallback(ReapAnyOutstandingChildren);
InstallSignalFdHandler(&epoll);
InstallInitNotifier(&epoll);
StartPropertyService(&property_fd);
@ -1176,10 +1181,6 @@ int SecondStageMain(int argc, char** argv) {
if (!pending_functions.ok()) {
LOG(ERROR) << pending_functions.error();
} else if (!pending_functions->empty()) {
// We always reap children before responding to the other pending functions. This is to
// prevent a race where other daemons see that a service has exited and ask init to
// start it again via ctl.start before init has reaped it.
ReapAnyOutstandingChildren();
for (const auto& function : *pending_functions) {
(*function)();
}