Add SysV signal handling
Implement the legacy SysV signal handling functions sighold(),
sigignore(), sigpause(), sigrelse(), and sigset() in terms of the newer
POSIX signal APIs. As of POSIX 2013 the SysV signal APIs are deprecated
but still required.
Change-Id: I4ca40e3d706605a7d1a30dc76c78b2b24586387d
Signed-off-by: Greg Hackmann <ghackmann@google.com>
diff --git a/tests/signal_test.cpp b/tests/signal_test.cpp
index c5128ea..36ac690 100644
--- a/tests/signal_test.cpp
+++ b/tests/signal_test.cpp
@@ -422,3 +422,108 @@
#endif
#endif
+
+TEST(signal, sigignore_EINVAL) {
+ errno = 0;
+ ASSERT_EQ(-1, sigignore(99999));
+ ASSERT_EQ(EINVAL, errno);
+}
+
+TEST(signal, sigignore) {
+ errno = 0;
+ EXPECT_EQ(-1, sigignore(SIGKILL));
+ EXPECT_EQ(errno, EINVAL);
+
+ errno = 0;
+ EXPECT_EQ(-1, sigignore(SIGSTOP));
+ EXPECT_EQ(errno, EINVAL);
+
+ ScopedSignalHandler sigalrm{SIGALRM};
+ ASSERT_EQ(0, sigignore(SIGALRM));
+
+ struct sigaction sa;
+ ASSERT_EQ(0, sigaction(SIGALRM, nullptr, &sa));
+ EXPECT_EQ(SIG_IGN, sa.sa_handler);
+}
+
+TEST(signal, sighold_EINVAL) {
+ errno = 0;
+ ASSERT_EQ(-1, sighold(99999));
+ ASSERT_EQ(EINVAL, errno);
+}
+
+TEST(signal, sigpause_EINVAL) {
+ errno = 0;
+ ASSERT_EQ(-1, sigpause(99999));
+ ASSERT_EQ(EINVAL, errno);
+}
+
+TEST(signal, sigrelse_EINVAL) {
+ errno = 0;
+ ASSERT_EQ(-1, sigpause(99999));
+ ASSERT_EQ(EINVAL, errno);
+}
+
+TEST(signal, sighold_sigpause_sigrelse) {
+ static int sigalrm_handler_call_count;
+ auto sigalrm_handler = [](int) { sigalrm_handler_call_count++; };
+ ScopedSignalHandler sigalrm{SIGALRM, sigalrm_handler};
+ ScopedSignalMask mask;
+ sigset_t set;
+
+ // sighold(SIGALRM) should add SIGALRM to the signal mask ...
+ ASSERT_EQ(0, sighold(SIGALRM));
+ ASSERT_EQ(0, sigprocmask(SIG_SETMASK, 0, &set));
+ EXPECT_TRUE(sigismember(&set, SIGALRM));
+
+ // ... preventing our SIGALRM handler from running ...
+ raise(SIGALRM);
+ ASSERT_EQ(0, sigalrm_handler_call_count);
+ // ... until sigpause(SIGALRM) temporarily unblocks it.
+ ASSERT_EQ(-1, sigpause(SIGALRM));
+ ASSERT_EQ(EINTR, errno);
+ ASSERT_EQ(1, sigalrm_handler_call_count);
+
+ // But sigpause(SIGALRM) shouldn't permanently unblock SIGALRM.
+ ASSERT_EQ(0, sigprocmask(SIG_SETMASK, 0, &set));
+ EXPECT_TRUE(sigismember(&set, SIGALRM));
+
+ ASSERT_EQ(0, sigrelse(SIGALRM));
+ ASSERT_EQ(0, sigprocmask(SIG_SETMASK, 0, &set));
+ EXPECT_FALSE(sigismember(&set, SIGALRM));
+}
+
+TEST(signal, sigset_EINVAL) {
+ errno = 0;
+ ASSERT_EQ(SIG_ERR, sigset(99999, SIG_DFL));
+ ASSERT_EQ(EINVAL, errno);
+}
+
+TEST(signal, sigset) {
+ auto sigalrm_handler = [](int) { };
+ ScopedSignalHandler sigalrm{SIGALRM, sigalrm_handler};
+ ScopedSignalMask mask;
+
+ // block SIGALRM so the next sigset(SIGARLM) call will return SIG_HOLD
+ sigset_t sigalrm_set;
+ sigemptyset(&sigalrm_set);
+ sigaddset(&sigalrm_set, SIGALRM);
+ ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &sigalrm_set, nullptr));
+
+ sigset_t set;
+ ASSERT_EQ(SIG_HOLD, sigset(SIGALRM, sigalrm_handler));
+ ASSERT_EQ(0, sigprocmask(SIG_BLOCK, nullptr, &set));
+ EXPECT_FALSE(sigismember(&set, SIGALRM));
+
+ ASSERT_EQ(sigalrm_handler, sigset(SIGALRM, SIG_IGN));
+ ASSERT_EQ(0, sigprocmask(SIG_BLOCK, nullptr, &set));
+ EXPECT_FALSE(sigismember(&set, SIGALRM));
+
+ ASSERT_EQ(SIG_IGN, sigset(SIGALRM, SIG_DFL));
+ ASSERT_EQ(0, sigprocmask(SIG_BLOCK, nullptr, &set));
+ EXPECT_FALSE(sigismember(&set, SIGALRM));
+
+ ASSERT_EQ(SIG_DFL, sigset(SIGALRM, SIG_HOLD));
+ ASSERT_EQ(0, sigprocmask(SIG_BLOCK, nullptr, &set));
+ EXPECT_TRUE(sigismember(&set, SIGALRM));
+}