init: Fix signalfd support in WaitToBeReaped()
Add an Epoll::Open() call such that the Epoll::Wait() calls wait for the
signalfd. Rename DiscardSiginfo() into HandleSignal(). Handle Epoll method
call failures. Test whether alive_pids is empty once per loop iteration.
Test: CtsInitTestCases:ServiceStopTest
Change-Id: I16c27aa74d61f889b304f3e59cd3c5255c299ce1
Signed-off-by: Bart Van Assche <bvanassche@google.com>
diff --git a/init/sigchld_handler.cpp b/init/sigchld_handler.cpp
index 0279508..8e9e713 100644
--- a/init/sigchld_handler.cpp
+++ b/init/sigchld_handler.cpp
@@ -138,7 +138,7 @@
}
}
-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)) {
@@ -151,22 +151,37 @@
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); });
- }
- 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;
- }
- if (sigchld_fd >= 0) {
- epoll.Wait(std::max(timeout - t.duration(), 0ms));
+ 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;
+ }
} else {
- std::this_thread::sleep_for(50ms);
+ 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) {
+ auto result = epoll.Wait(std::max(timeout - t.duration(), 0ms));
+ if (result.ok()) {
+ ReapAndRemove(alive_pids);
+ continue;
+ } else {
+ 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";
for (pid_t pid : alive_pids) {