tests/signal_test.cpp - android_bionic - Gitiles

 /*
  * Copyright (C) 2012 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include <signal.h>

 #include <gtest/gtest.h>

 #include <errno.h>

 #include "ScopedSignalHandler.h"

 static size_t SIGNAL_MIN() {
   return 1; // Signals start at 1 (SIGHUP), not 0.
 }

 static size_t SIGNAL_MAX() {
   size_t result = SIGRTMAX;

 #if defined(__BIONIC__) && !defined(__mips__) && !defined(__LP64__)
   // 32-bit bionic's sigset_t is too small for ARM and x86: 32 bits instead of 64.
   // This means you can't refer to any of the real-time signals.
   // See http://b/3038348 and http://b/5828899.
   result = 32;
 #else
   // Otherwise, C libraries should be perfectly capable of using their largest signal.
   if (sizeof(sigset_t) * 8 < static_cast<size_t>(SIGRTMAX)) {
     abort();
   }
 #endif

   return result;
 }

 template <typename Fn>
 static void TestSigSet1(Fn fn) {
   // NULL sigset_t*.
   sigset_t* set_ptr = NULL;
   errno = 0;
   ASSERT_EQ(-1, fn(set_ptr));
   ASSERT_EQ(EINVAL, errno);

   // Non-NULL.
   sigset_t set;
   errno = 0;
   ASSERT_EQ(0, fn(&set));
   ASSERT_EQ(0, errno);
 }

 template <typename Fn>
 static void TestSigSet2(Fn fn) {
   // NULL sigset_t*.
   sigset_t* set_ptr = NULL;
   errno = 0;
   ASSERT_EQ(-1, fn(set_ptr, SIGSEGV));
   ASSERT_EQ(EINVAL, errno);

   sigset_t set;
   sigemptyset(&set);

   // Bad signal number: too small.
   errno = 0;
   ASSERT_EQ(-1, fn(&set, 0));
   ASSERT_EQ(EINVAL, errno);

   // Bad signal number: too high.
   errno = 0;
   ASSERT_EQ(-1, fn(&set, SIGNAL_MAX() + 1));
   ASSERT_EQ(EINVAL, errno);

   // Good signal numbers, low and high ends of range.
   errno = 0;
   ASSERT_EQ(0, fn(&set, SIGNAL_MIN()));
   ASSERT_EQ(0, errno);
   ASSERT_EQ(0, fn(&set, SIGNAL_MAX()));
   ASSERT_EQ(0, errno);
 }

 TEST(signal, sigismember_invalid) {
   TestSigSet2(sigismember);
 }

 TEST(signal, sigaddset_invalid) {
   TestSigSet2(sigaddset);
 }

 TEST(signal, sigdelset_invalid) {
   TestSigSet2(sigdelset);
 }

 TEST(signal, sigemptyset_invalid) {
   TestSigSet1(sigemptyset);
 }

 TEST(signal, sigfillset_invalid) {
   TestSigSet1(sigfillset);
 }

 TEST(signal, raise_invalid) {
   errno = 0;
   ASSERT_EQ(-1, raise(-1));
   ASSERT_EQ(EINVAL, errno);
 }

 static void raise_in_signal_handler_helper(int signal_number) {
   ASSERT_EQ(SIGALRM, signal_number);
   static int count = 0;
   if (++count == 1) {
     raise(SIGALRM);
   }
 }

 TEST(signal, raise_in_signal_handler) {
   ScopedSignalHandler ssh(SIGALRM, raise_in_signal_handler_helper);
   raise(SIGALRM);
 }

 static void HandleSIGALRM(int signal_number) {
   ASSERT_EQ(SIGALRM, signal_number);
 }

 TEST(signal, sigwait) {
   ScopedSignalHandler ssh(SIGALRM, HandleSIGALRM);

   sigset_t wait_set;
   sigemptyset(&wait_set);
   sigaddset(&wait_set, SIGALRM);

   alarm(1);

   int received_signal;
   errno = 0;
   ASSERT_EQ(0, sigwait(&wait_set, &received_signal));
   ASSERT_EQ(0, errno);
   ASSERT_EQ(SIGALRM, received_signal);
 }

 static int g_sigsuspend_test_helper_call_count = 0;

 static void SigSuspendTestHelper(int) {
   ++g_sigsuspend_test_helper_call_count;
 }

 TEST(signal, sigsuspend_sigpending) {
   // Block SIGALRM.
   sigset_t just_SIGALRM;
   sigemptyset(&just_SIGALRM);
   sigaddset(&just_SIGALRM, SIGALRM);
   sigset_t original_set;
   ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));

   ScopedSignalHandler ssh(SIGALRM, SigSuspendTestHelper);

   // There should be no pending signals.
   sigset_t pending;
   sigemptyset(&pending);
   ASSERT_EQ(0, sigpending(&pending));
   for (size_t i = SIGNAL_MIN(); i <= SIGNAL_MAX(); ++i) {
     EXPECT_FALSE(sigismember(&pending, i)) << i;
   }

   // Raise SIGALRM and check our signal handler wasn't called.
   raise(SIGALRM);
   ASSERT_EQ(0, g_sigsuspend_test_helper_call_count);

   // We should now have a pending SIGALRM but nothing else.
   sigemptyset(&pending);
   ASSERT_EQ(0, sigpending(&pending));
   for (size_t i = SIGNAL_MIN(); i <= SIGNAL_MAX(); ++i) {
     EXPECT_EQ((i == SIGALRM), sigismember(&pending, i));
   }

   // Use sigsuspend to block everything except SIGALRM...
   sigset_t not_SIGALRM;
   sigfillset(&not_SIGALRM);
   sigdelset(&not_SIGALRM, SIGALRM);
   ASSERT_EQ(-1, sigsuspend(&not_SIGALRM));
   ASSERT_EQ(EINTR, errno);
   // ...and check that we now receive our pending SIGALRM.
   ASSERT_EQ(1, g_sigsuspend_test_helper_call_count);

   // Restore the original set.
   ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
 }

 static void EmptySignalHandler(int) {}
 static void EmptySignalAction(int, siginfo_t*, void*) {}

 TEST(signal, sigaction) {
   // Both bionic and glibc set SA_RESTORER when talking to the kernel on arm,
   // arm64, x86, and x86-64. The version of glibc we're using also doesn't
   // define SA_RESTORER, but luckily it's the same value everywhere, and mips
   // doesn't use the bit for anything.
   static const unsigned sa_restorer = 0x4000000;

   // See what's currently set for SIGALRM.
   struct sigaction original_sa;
   memset(&original_sa, 0, sizeof(original_sa));
   ASSERT_EQ(0, sigaction(SIGALRM, NULL, &original_sa));
   ASSERT_TRUE(original_sa.sa_handler == NULL);
   ASSERT_TRUE(original_sa.sa_sigaction == NULL);
   ASSERT_EQ(0U, original_sa.sa_flags & ~sa_restorer);

   // Set a traditional sa_handler signal handler.
   struct sigaction sa;
   memset(&sa, 0, sizeof(sa));
   sigaddset(&sa.sa_mask, SIGALRM);
   sa.sa_flags = SA_ONSTACK;
   sa.sa_handler = EmptySignalHandler;
   ASSERT_EQ(0, sigaction(SIGALRM, &sa, NULL));

   // Check that we can read it back.
   memset(&sa, 0, sizeof(sa));
   ASSERT_EQ(0, sigaction(SIGALRM, NULL, &sa));
   ASSERT_TRUE(sa.sa_handler == EmptySignalHandler);
   ASSERT_TRUE((void*) sa.sa_sigaction == (void*) sa.sa_handler);
   ASSERT_EQ(static_cast<unsigned>(SA_ONSTACK), sa.sa_flags & ~sa_restorer);

   // Set a new-style sa_sigaction signal handler.
   memset(&sa, 0, sizeof(sa));
   sigaddset(&sa.sa_mask, SIGALRM);
   sa.sa_flags = SA_ONSTACK | SA_SIGINFO;
   sa.sa_sigaction = EmptySignalAction;
   ASSERT_EQ(0, sigaction(SIGALRM, &sa, NULL));

   // Check that we can read it back.
   memset(&sa, 0, sizeof(sa));
   ASSERT_EQ(0, sigaction(SIGALRM, NULL, &sa));
   ASSERT_TRUE(sa.sa_sigaction == EmptySignalAction);
   ASSERT_TRUE((void*) sa.sa_sigaction == (void*) sa.sa_handler);
   ASSERT_EQ(static_cast<unsigned>(SA_ONSTACK | SA_SIGINFO), sa.sa_flags & ~sa_restorer);

   // Put everything back how it was.
   ASSERT_EQ(0, sigaction(SIGALRM, &original_sa, NULL));
 }

 TEST(signal, sys_signame) {
 #if defined(__BIONIC__)
   ASSERT_TRUE(sys_signame[0] == NULL);
   ASSERT_STREQ("HUP", sys_signame[SIGHUP]);
 #else
   GTEST_LOG_(INFO) << "This test does nothing.\n";
 #endif
 }

 TEST(signal, sys_siglist) {
   ASSERT_TRUE(sys_siglist[0] == NULL);
   ASSERT_STREQ("Hangup", sys_siglist[SIGHUP]);
 }

 TEST(signal, limits) {
   // This comes from the kernel.
   ASSERT_EQ(32, __SIGRTMIN);

   // We reserve a non-zero number at the bottom for ourselves.
   ASSERT_GT(SIGRTMIN, __SIGRTMIN);

   // MIPS has more signals than everyone else.
 #if defined(__mips__)
   ASSERT_EQ(128, __SIGRTMAX);
 #else
   ASSERT_EQ(64, __SIGRTMAX);
 #endif

   // We don't currently reserve any at the top.
   ASSERT_EQ(SIGRTMAX, __SIGRTMAX);
 }

 static int g_sigqueue_signal_handler_call_count = 0;

 static void SigqueueSignalHandler(int signum, siginfo_t* info, void*) {
   ASSERT_EQ(SIGALRM, signum);
   ASSERT_EQ(SIGALRM, info->si_signo);
   ASSERT_EQ(SI_QUEUE, info->si_code);
   ASSERT_EQ(1, info->si_value.sival_int);
   ++g_sigqueue_signal_handler_call_count;
 }

 TEST(signal, sigqueue) {
   ScopedSignalHandler ssh(SIGALRM, SigqueueSignalHandler, SA_SIGINFO);
   sigval_t sigval;
   sigval.sival_int = 1;
   errno = 0;
   ASSERT_EQ(0, sigqueue(getpid(), SIGALRM, sigval));
   ASSERT_EQ(0, errno);
   ASSERT_EQ(1, g_sigqueue_signal_handler_call_count);
 }

 TEST(signal, sigwaitinfo) {
   // Block SIGALRM.
   sigset_t just_SIGALRM;
   sigemptyset(&just_SIGALRM);
   sigaddset(&just_SIGALRM, SIGALRM);
   sigset_t original_set;
   ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));

   // Raise SIGALRM.
   sigval_t sigval;
   sigval.sival_int = 1;
   ASSERT_EQ(0, sigqueue(getpid(), SIGALRM, sigval));

   // Get pending SIGALRM.
   siginfo_t info;
   errno = 0;
   ASSERT_EQ(SIGALRM, sigwaitinfo(&just_SIGALRM, &info));
   ASSERT_EQ(0, errno);
   ASSERT_EQ(SIGALRM, info.si_signo);
   ASSERT_EQ(1, info.si_value.sival_int);

   ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
 }

 TEST(signal, sigtimedwait) {
   // Block SIGALRM.
   sigset_t just_SIGALRM;
   sigemptyset(&just_SIGALRM);
   sigaddset(&just_SIGALRM, SIGALRM);
   sigset_t original_set;
   ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));

   // Raise SIGALRM.
   sigval_t sigval;
   sigval.sival_int = 1;
   ASSERT_EQ(0, sigqueue(getpid(), SIGALRM, sigval));

   // Get pending SIGALRM.
   siginfo_t info;
   struct timespec timeout;
   timeout.tv_sec = 2;
   timeout.tv_nsec = 0;
   errno = 0;
   ASSERT_EQ(SIGALRM, sigtimedwait(&just_SIGALRM, &info, &timeout));
   ASSERT_EQ(0, errno);

   ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
 }

 static int64_t NanoTime() {
   struct timespec t;
   t.tv_sec = t.tv_nsec = 0;
   clock_gettime(CLOCK_MONOTONIC, &t);
   return static_cast<int64_t>(t.tv_sec) * 1000000000LL + t.tv_nsec;
 }

 TEST(signal, sigtimedwait_timeout) {
   // Block SIGALRM.
   sigset_t just_SIGALRM;
   sigemptyset(&just_SIGALRM);
   sigaddset(&just_SIGALRM, SIGALRM);
   sigset_t original_set;
   ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));

   // Wait timeout.
   int64_t start_time = NanoTime();
   siginfo_t info;
   struct timespec timeout;
   timeout.tv_sec = 0;
   timeout.tv_nsec = 1000000;
   errno = 0;
   ASSERT_EQ(-1, sigtimedwait(&just_SIGALRM, &info, &timeout));
   ASSERT_EQ(EAGAIN, errno);
   ASSERT_GE(NanoTime() - start_time, 1000000);

   ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
 }
	/*
	* Copyright (C) 2012 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include <signal.h>

	#include <gtest/gtest.h>

	#include <errno.h>

	#include "ScopedSignalHandler.h"

	static size_t SIGNAL_MIN() {
	return 1; // Signals start at 1 (SIGHUP), not 0.
	}

	static size_t SIGNAL_MAX() {
	size_t result = SIGRTMAX;

	#if defined(__BIONIC__) && !defined(__mips__) && !defined(__LP64__)
	// 32-bit bionic's sigset_t is too small for ARM and x86: 32 bits instead of 64.
	// This means you can't refer to any of the real-time signals.
	// See http://b/3038348 and http://b/5828899.
	result = 32;
	#else
	// Otherwise, C libraries should be perfectly capable of using their largest signal.
	if (sizeof(sigset_t) * 8 < static_cast<size_t>(SIGRTMAX)) {
	abort();
	}
	#endif

	return result;
	}

	template <typename Fn>
	static void TestSigSet1(Fn fn) {
	// NULL sigset_t*.
	sigset_t* set_ptr = NULL;
	errno = 0;
	ASSERT_EQ(-1, fn(set_ptr));
	ASSERT_EQ(EINVAL, errno);

	// Non-NULL.
	sigset_t set;
	errno = 0;
	ASSERT_EQ(0, fn(&set));
	ASSERT_EQ(0, errno);
	}

	template <typename Fn>
	static void TestSigSet2(Fn fn) {
	// NULL sigset_t*.
	sigset_t* set_ptr = NULL;
	errno = 0;
	ASSERT_EQ(-1, fn(set_ptr, SIGSEGV));
	ASSERT_EQ(EINVAL, errno);

	sigset_t set;
	sigemptyset(&set);

	// Bad signal number: too small.
	errno = 0;
	ASSERT_EQ(-1, fn(&set, 0));
	ASSERT_EQ(EINVAL, errno);

	// Bad signal number: too high.
	errno = 0;
	ASSERT_EQ(-1, fn(&set, SIGNAL_MAX() + 1));
	ASSERT_EQ(EINVAL, errno);

	// Good signal numbers, low and high ends of range.
	errno = 0;
	ASSERT_EQ(0, fn(&set, SIGNAL_MIN()));
	ASSERT_EQ(0, errno);
	ASSERT_EQ(0, fn(&set, SIGNAL_MAX()));
	ASSERT_EQ(0, errno);
	}

	TEST(signal, sigismember_invalid) {
	TestSigSet2(sigismember);
	}

	TEST(signal, sigaddset_invalid) {
	TestSigSet2(sigaddset);
	}

	TEST(signal, sigdelset_invalid) {
	TestSigSet2(sigdelset);
	}

	TEST(signal, sigemptyset_invalid) {
	TestSigSet1(sigemptyset);
	}

	TEST(signal, sigfillset_invalid) {
	TestSigSet1(sigfillset);
	}

	TEST(signal, raise_invalid) {
	errno = 0;
	ASSERT_EQ(-1, raise(-1));
	ASSERT_EQ(EINVAL, errno);
	}

	static void raise_in_signal_handler_helper(int signal_number) {
	ASSERT_EQ(SIGALRM, signal_number);
	static int count = 0;
	if (++count == 1) {
	raise(SIGALRM);
	}
	}

	TEST(signal, raise_in_signal_handler) {
	ScopedSignalHandler ssh(SIGALRM, raise_in_signal_handler_helper);
	raise(SIGALRM);
	}

	static void HandleSIGALRM(int signal_number) {
	ASSERT_EQ(SIGALRM, signal_number);
	}

	TEST(signal, sigwait) {
	ScopedSignalHandler ssh(SIGALRM, HandleSIGALRM);

	sigset_t wait_set;
	sigemptyset(&wait_set);
	sigaddset(&wait_set, SIGALRM);

	alarm(1);

	int received_signal;
	errno = 0;
	ASSERT_EQ(0, sigwait(&wait_set, &received_signal));
	ASSERT_EQ(0, errno);
	ASSERT_EQ(SIGALRM, received_signal);
	}

	static int g_sigsuspend_test_helper_call_count = 0;

	static void SigSuspendTestHelper(int) {
	++g_sigsuspend_test_helper_call_count;
	}

	TEST(signal, sigsuspend_sigpending) {
	// Block SIGALRM.
	sigset_t just_SIGALRM;
	sigemptyset(&just_SIGALRM);
	sigaddset(&just_SIGALRM, SIGALRM);
	sigset_t original_set;
	ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));

	ScopedSignalHandler ssh(SIGALRM, SigSuspendTestHelper);

	// There should be no pending signals.
	sigset_t pending;
	sigemptyset(&pending);
	ASSERT_EQ(0, sigpending(&pending));
	for (size_t i = SIGNAL_MIN(); i <= SIGNAL_MAX(); ++i) {
	EXPECT_FALSE(sigismember(&pending, i)) << i;
	}

	// Raise SIGALRM and check our signal handler wasn't called.
	raise(SIGALRM);
	ASSERT_EQ(0, g_sigsuspend_test_helper_call_count);

	// We should now have a pending SIGALRM but nothing else.
	sigemptyset(&pending);
	ASSERT_EQ(0, sigpending(&pending));
	for (size_t i = SIGNAL_MIN(); i <= SIGNAL_MAX(); ++i) {
	EXPECT_EQ((i == SIGALRM), sigismember(&pending, i));
	}

	// Use sigsuspend to block everything except SIGALRM...
	sigset_t not_SIGALRM;
	sigfillset(&not_SIGALRM);
	sigdelset(&not_SIGALRM, SIGALRM);
	ASSERT_EQ(-1, sigsuspend(&not_SIGALRM));
	ASSERT_EQ(EINTR, errno);
	// ...and check that we now receive our pending SIGALRM.
	ASSERT_EQ(1, g_sigsuspend_test_helper_call_count);

	// Restore the original set.
	ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
	}

	static void EmptySignalHandler(int) {}
	static void EmptySignalAction(int, siginfo_t, void) {}

	TEST(signal, sigaction) {
	// Both bionic and glibc set SA_RESTORER when talking to the kernel on arm,
	// arm64, x86, and x86-64. The version of glibc we're using also doesn't
	// define SA_RESTORER, but luckily it's the same value everywhere, and mips
	// doesn't use the bit for anything.
	static const unsigned sa_restorer = 0x4000000;

	// See what's currently set for SIGALRM.
	struct sigaction original_sa;
	memset(&original_sa, 0, sizeof(original_sa));
	ASSERT_EQ(0, sigaction(SIGALRM, NULL, &original_sa));
	ASSERT_TRUE(original_sa.sa_handler == NULL);
	ASSERT_TRUE(original_sa.sa_sigaction == NULL);
	ASSERT_EQ(0U, original_sa.sa_flags & ~sa_restorer);

	// Set a traditional sa_handler signal handler.
	struct sigaction sa;
	memset(&sa, 0, sizeof(sa));
	sigaddset(&sa.sa_mask, SIGALRM);
	sa.sa_flags = SA_ONSTACK;
	sa.sa_handler = EmptySignalHandler;
	ASSERT_EQ(0, sigaction(SIGALRM, &sa, NULL));

	// Check that we can read it back.
	memset(&sa, 0, sizeof(sa));
	ASSERT_EQ(0, sigaction(SIGALRM, NULL, &sa));
	ASSERT_TRUE(sa.sa_handler == EmptySignalHandler);
	ASSERT_TRUE((void) sa.sa_sigaction == (void) sa.sa_handler);
	ASSERT_EQ(static_cast<unsigned>(SA_ONSTACK), sa.sa_flags & ~sa_restorer);

	// Set a new-style sa_sigaction signal handler.
	memset(&sa, 0, sizeof(sa));
	sigaddset(&sa.sa_mask, SIGALRM);
	sa.sa_flags = SA_ONSTACK \| SA_SIGINFO;
	sa.sa_sigaction = EmptySignalAction;
	ASSERT_EQ(0, sigaction(SIGALRM, &sa, NULL));

	// Check that we can read it back.
	memset(&sa, 0, sizeof(sa));
	ASSERT_EQ(0, sigaction(SIGALRM, NULL, &sa));
	ASSERT_TRUE(sa.sa_sigaction == EmptySignalAction);
	ASSERT_TRUE((void) sa.sa_sigaction == (void) sa.sa_handler);
	ASSERT_EQ(static_cast<unsigned>(SA_ONSTACK \| SA_SIGINFO), sa.sa_flags & ~sa_restorer);

	// Put everything back how it was.
	ASSERT_EQ(0, sigaction(SIGALRM, &original_sa, NULL));
	}

	TEST(signal, sys_signame) {
	#if defined(__BIONIC__)
	ASSERT_TRUE(sys_signame[0] == NULL);
	ASSERT_STREQ("HUP", sys_signame[SIGHUP]);
	#else
	GTEST_LOG_(INFO) << "This test does nothing.\n";
	#endif
	}

	TEST(signal, sys_siglist) {
	ASSERT_TRUE(sys_siglist[0] == NULL);
	ASSERT_STREQ("Hangup", sys_siglist[SIGHUP]);
	}

	TEST(signal, limits) {
	// This comes from the kernel.
	ASSERT_EQ(32, __SIGRTMIN);

	// We reserve a non-zero number at the bottom for ourselves.
	ASSERT_GT(SIGRTMIN, __SIGRTMIN);

	// MIPS has more signals than everyone else.
	#if defined(__mips__)
	ASSERT_EQ(128, __SIGRTMAX);
	#else
	ASSERT_EQ(64, __SIGRTMAX);
	#endif

	// We don't currently reserve any at the top.
	ASSERT_EQ(SIGRTMAX, __SIGRTMAX);
	}

	static int g_sigqueue_signal_handler_call_count = 0;

	static void SigqueueSignalHandler(int signum, siginfo_t* info, void*) {
	ASSERT_EQ(SIGALRM, signum);
	ASSERT_EQ(SIGALRM, info->si_signo);
	ASSERT_EQ(SI_QUEUE, info->si_code);
	ASSERT_EQ(1, info->si_value.sival_int);
	++g_sigqueue_signal_handler_call_count;
	}

	TEST(signal, sigqueue) {
	ScopedSignalHandler ssh(SIGALRM, SigqueueSignalHandler, SA_SIGINFO);
	sigval_t sigval;
	sigval.sival_int = 1;
	errno = 0;
	ASSERT_EQ(0, sigqueue(getpid(), SIGALRM, sigval));
	ASSERT_EQ(0, errno);
	ASSERT_EQ(1, g_sigqueue_signal_handler_call_count);
	}

	TEST(signal, sigwaitinfo) {
	// Block SIGALRM.
	sigset_t just_SIGALRM;
	sigemptyset(&just_SIGALRM);
	sigaddset(&just_SIGALRM, SIGALRM);
	sigset_t original_set;
	ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));

	// Raise SIGALRM.
	sigval_t sigval;
	sigval.sival_int = 1;
	ASSERT_EQ(0, sigqueue(getpid(), SIGALRM, sigval));

	// Get pending SIGALRM.
	siginfo_t info;
	errno = 0;
	ASSERT_EQ(SIGALRM, sigwaitinfo(&just_SIGALRM, &info));
	ASSERT_EQ(0, errno);
	ASSERT_EQ(SIGALRM, info.si_signo);
	ASSERT_EQ(1, info.si_value.sival_int);

	ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
	}

	TEST(signal, sigtimedwait) {
	// Block SIGALRM.
	sigset_t just_SIGALRM;
	sigemptyset(&just_SIGALRM);
	sigaddset(&just_SIGALRM, SIGALRM);
	sigset_t original_set;
	ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));

	// Raise SIGALRM.
	sigval_t sigval;
	sigval.sival_int = 1;
	ASSERT_EQ(0, sigqueue(getpid(), SIGALRM, sigval));

	// Get pending SIGALRM.
	siginfo_t info;
	struct timespec timeout;
	timeout.tv_sec = 2;
	timeout.tv_nsec = 0;
	errno = 0;
	ASSERT_EQ(SIGALRM, sigtimedwait(&just_SIGALRM, &info, &timeout));
	ASSERT_EQ(0, errno);

	ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
	}

	static int64_t NanoTime() {
	struct timespec t;
	t.tv_sec = t.tv_nsec = 0;
	clock_gettime(CLOCK_MONOTONIC, &t);
	return static_cast<int64_t>(t.tv_sec) * 1000000000LL + t.tv_nsec;
	}

	TEST(signal, sigtimedwait_timeout) {
	// Block SIGALRM.
	sigset_t just_SIGALRM;
	sigemptyset(&just_SIGALRM);
	sigaddset(&just_SIGALRM, SIGALRM);
	sigset_t original_set;
	ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));

	// Wait timeout.
	int64_t start_time = NanoTime();
	siginfo_t info;
	struct timespec timeout;
	timeout.tv_sec = 0;
	timeout.tv_nsec = 1000000;
	errno = 0;
	ASSERT_EQ(-1, sigtimedwait(&just_SIGALRM, &info, &timeout));
	ASSERT_EQ(EAGAIN, errno);
	ASSERT_GE(NanoTime() - start_time, 1000000);

	ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
	}