Merge "init: Fix signalfd support in WaitToBeReaped()" into main (dfe6c802) · Commits · e / os / android_system_core

init/sigchld_handler.cpp

+26 −11

Original line number	Diff line number	Diff line
		@@ -138,7 +138,7 @@ static void ReapAndRemove(std::vector<pid_t>& alive_pids) {
		}
		}

		static void DiscardSiginfo(int signal_fd) {
		static void HandleSignal(int signal_fd) {
		signalfd_siginfo siginfo;
		ssize_t bytes_read = TEMP_FAILURE_RETRY(read(signal_fd, &siginfo, sizeof(siginfo)));
		if (bytes_read != sizeof(siginfo)) {
		@@ -151,21 +151,36 @@ void WaitToBeReaped(int sigchld_fd, const std::vector<pid_t>& pids,
		std::chrono::milliseconds timeout) {
		Timer t;
		Epoll epoll;
		// The init process passes a valid sigchld_fd argument but unit tests do not.
		if (sigchld_fd >= 0) {
		epoll.RegisterHandler(sigchld_fd, [sigchld_fd]() { DiscardSiginfo(sigchld_fd); });
		if (auto result = epoll.Open(); result.ok()) {
		result =
		epoll.RegisterHandler(sigchld_fd, [sigchld_fd]() { HandleSignal(sigchld_fd); });
		if (!result.ok()) {
		LOG(WARNING) << __func__
		<< " RegisterHandler() failed. Falling back to sleep_for(): "
		<< result.error();
		sigchld_fd = -1;
		}
		std::vector<pid_t> alive_pids(pids.begin(), pids.end());
		while (!alive_pids.empty() && t.duration() < timeout) {
		ReapAndRemove(alive_pids);
		if (alive_pids.empty()) {
		break;
		} else {
		LOG(WARNING) << __func__ << " Epoll::Open() failed. Falling back to sleep_for(): "
		<< result.error();
		sigchld_fd = -1;
		}
		}
		std::vector<pid_t> alive_pids(pids);
		ReapAndRemove(alive_pids);
		while (!alive_pids.empty() && t.duration() < timeout) {
		if (sigchld_fd >= 0) {
		epoll.Wait(std::max(timeout - t.duration(), 0ms));
		auto result = epoll.Wait(std::max(timeout - t.duration(), 0ms));
		if (result.ok()) {
		ReapAndRemove(alive_pids);
		continue;
		} else {
		std::this_thread::sleep_for(50ms);
		LOG(WARNING) << "Epoll::Wait() failed " << result.error();
		}
		}
		std::this_thread::sleep_for(50ms);
		ReapAndRemove(alive_pids);
		}
		LOG(INFO) << "Waiting for " << pids.size() << " pids to be reaped took " << t << " with "
		<< alive_pids.size() << " of them still running";