tests/signal_test.cpp

/*
 * 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 <gtest/gtest.h>

#include <errno.h>
#include <signal.h>

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);

  int min_signal = SIGHUP;
  int max_signal = SIGRTMAX;

#if defined(__BIONIC__) && !defined(__mips__)
  // 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.
  max_signal = 32;
#else
  // Other C libraries (or bionic for MIPS) are perfectly capable of using their largest signal.
  ASSERT_GE(sizeof(sigset_t) * 8, static_cast<size_t>(SIGRTMAX));
#endif

  // 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, max_signal + 1));
  ASSERT_EQ(EINVAL, errno);

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

class ScopedSignalHandler {
 public:
  ScopedSignalHandler(int signal_number, void (*handler)(int)) : signal_number_(signal_number) {
    sigemptyset(&action_.sa_mask);
    action_.sa_flags = 0;
    action_.sa_handler = handler;
    sigaction(signal_number_, &action_, &old_action_);
  }

  ~ScopedSignalHandler() {
    sigaction(signal_number_, &old_action_, NULL);
  }

 private:
  struct sigaction action_;
  struct sigaction old_action_;
  const int signal_number_;
};

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);
}