Fix raise(3) so it works in signal handlers.

We could special-case raise(3) in non-threaded programs, but the more
conservative course is to make pthread_kill(3) work in signal handlers
at the cost of a race shared by other C libraries.

Change-Id: I59fb23d03bdabf403435e731704b33acdf3e0234

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index 239092ca2..98bc4e5a5 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -252,6 +252,24 @@ TEST(pthread, pthread_kill__invalid_signal) {
   ASSERT_EQ(EINVAL, pthread_kill(pthread_self(), -1));
 }
 
+static void pthread_kill__in_signal_handler_helper(int signal_number) {
+  static int count = 0;
+  ASSERT_EQ(SIGALRM, signal_number);
+  if (++count == 1) {
+    // Can we call pthread_kill from a signal handler?
+    ASSERT_EQ(0, pthread_kill(pthread_self(), SIGALRM));
+  }
+}
+
+TEST(pthread, pthread_kill__in_signal_handler) {
+  struct sigaction action;
+  sigemptyset(&action.sa_mask);
+  action.sa_flags = 0;
+  action.sa_handler = pthread_kill__in_signal_handler_helper;
+  sigaction(SIGALRM, &action, NULL);
+  ASSERT_EQ(0, pthread_kill(pthread_self(), SIGALRM));
+}
+
 TEST(pthread, pthread_detach__no_such_thread) {
   pthread_t dead_thread;
   MakeDeadThread(dead_thread);