From d984f7e8d853f83b8b07326d042bd1d12e83750b Mon Sep 17 00:00:00 2001
From: gVisor bot <gvisor-bot@google.com>
Date: Wed, 7 Dec 2022 14:55:03 -0800
Subject: [PATCH] Test that setting a timerfd to expire in the past makes it
 expire immediately

PiperOrigin-RevId: 493716667
---
 test/syscalls/linux/timerfd.cc | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/test/syscalls/linux/timerfd.cc b/test/syscalls/linux/timerfd.cc
index e067cfd43..da03a3332 100644
--- a/test/syscalls/linux/timerfd.cc
+++ b/test/syscalls/linux/timerfd.cc
@@ -204,6 +204,19 @@ TEST_P(TimerfdTest, SetAbsoluteTime) {
   EXPECT_EQ(1, val);
 }
 
+TEST_P(TimerfdTest, SetToPastExpiresEventually) {
+  auto const tfd = ASSERT_NO_ERRNO_AND_VALUE(TimerfdCreate(GetParam(), 0));
+  struct itimerspec its = {};
+  its.it_value.tv_nsec = 1;
+  ASSERT_THAT(timerfd_settime(tfd.get(), TFD_TIMER_ABSTIME, &its, nullptr),
+              SyscallSucceeds());
+
+  uint64_t val = 0;
+  ASSERT_THAT(ReadFd(tfd.get(), &val, sizeof(uint64_t)),
+              SyscallSucceedsWithValue(sizeof(uint64_t)));
+  ASSERT_EQ(val, 1);
+}
+
 TEST_P(TimerfdTest, IllegalSeek) {
   auto const tfd = ASSERT_NO_ERRNO_AND_VALUE(TimerfdCreate(GetParam(), 0));
   EXPECT_THAT(lseek(tfd.get(), 0, SEEK_SET), SyscallFailsWithErrno(ESPIPE));