From 02714e46a8d7c12e701dc288d7a5c232e9eaf572 Mon Sep 17 00:00:00 2001
From: gbeauche <>
Date: Sun, 15 May 2005 17:22:12 +0000
Subject: [PATCH] Fix and factor out ether_exit(). Pitifully, MacOS X 10.2 does
 not make select() a cancellation point when it is passed a NULL timeout.
 Workarounded in receive_func() with a full inline of poll_fd() +
 pthread_testcancel().

---
 BasiliskII/src/Unix/configure.ac   |  2 +-
 BasiliskII/src/Unix/ether_unix.cpp | 55 ++++++++++++++++--------------
 2 files changed, 30 insertions(+), 27 deletions(-)

diff --git a/BasiliskII/src/Unix/configure.ac b/BasiliskII/src/Unix/configure.ac
index fe63d08e..15a8be35 100644
--- a/BasiliskII/src/Unix/configure.ac
+++ b/BasiliskII/src/Unix/configure.ac
@@ -195,7 +195,7 @@ AC_CHECK_LIB(pthread, pthread_create, , [
 if [[ "x$HAVE_PTHREADS" = "xyes" ]]; then
   AC_DEFINE(HAVE_PTHREADS, 1, [Define if pthreads are available.])
 fi
-AC_CHECK_FUNCS(pthread_cancel)
+AC_CHECK_FUNCS(pthread_cancel pthread_testcancel)
 AC_CHECK_FUNCS(pthread_mutexattr_setprotocol)
 AC_CHECK_FUNCS(pthread_mutexattr_settype)
 AC_CHECK_FUNCS(pthread_mutexattr_setpshared)
diff --git a/BasiliskII/src/Unix/ether_unix.cpp b/BasiliskII/src/Unix/ether_unix.cpp
index 06165ddd..e8925460 100644
--- a/BasiliskII/src/Unix/ether_unix.cpp
+++ b/BasiliskII/src/Unix/ether_unix.cpp
@@ -143,14 +143,18 @@ static void stop_thread(void)
 {
 #ifdef HAVE_SLIRP
 	if (slirp_thread_active) {
+#ifdef HAVE_PTHREAD_CANCEL
 		pthread_cancel(slirp_thread);
+#endif
 		pthread_join(slirp_thread, NULL);
 		slirp_thread_active = false;
 	}
 #endif
 
 	if (thread_active) {
+#ifdef HAVE_PTHREAD_CANCEL
 		pthread_cancel(ether_thread);
+#endif
 		pthread_join(ether_thread, NULL);
 		sem_destroy(&int_ack);
 		thread_active = false;
@@ -348,13 +352,8 @@ open_error:
 
 void ether_exit(void)
 {
-	// Stop reception thread
-	if (thread_active) {
-		pthread_cancel(ether_thread);
-		pthread_join(ether_thread, NULL);
-		sem_destroy(&int_ack);
-		thread_active = false;
-	}
+	// Stop reception threads
+	stop_thread();
 
 	// Shut down TUN/TAP interface
 	if (net_if_type == NET_IF_TUNTAP)
@@ -546,6 +545,12 @@ void *slirp_receive_func(void *arg)
 		tv.tv_usec = 16667;
 		if (select(nfds + 1, &rfds, &wfds, &xfds, &tv) >= 0)
 			slirp_select_poll(&rfds, &wfds, &xfds);
+
+#ifdef HAVE_PTHREAD_TESTCANCEL
+		// Explicit cancellation point if select() was not covered
+		// This seems to be the case on MacOS X 10.2
+		pthread_testcancel();
+#endif
 	}
 	return NULL;
 }
@@ -561,24 +566,6 @@ void slirp_output(const uint8 *packet, int len)
 #endif
 
 
-/*
- *  Wait for data to arrive
- */
-
-static inline int poll_fd(int fd)
-{
-#ifdef HAVE_POLL
-	struct pollfd pf = {fd, POLLIN, 0};
-	return poll(&pf, 1, -1);
-#else
-	fd_set rfds;
-	FD_ZERO(&rfds);
-	FD_SET(fd, &rfds);
-	return select(fd + 1, &rfds, NULL, NULL, NULL);
-#endif
-}
-
-
 /*
  *  Packet reception thread
  */
@@ -588,7 +575,23 @@ static void *receive_func(void *arg)
 	for (;;) {
 
 		// Wait for packets to arrive
-		int res = poll_fd(fd);
+#if HAVE_POLL
+		struct pollfd pf = {fd, POLLIN, 0};
+		int res = poll(&pf, 1, -1);
+#else
+		fd_set rfds;
+		FD_ZERO(&rfds);
+		FD_SET(fd, &rfds);
+		// A NULL timeout could cause select() to block indefinitely,
+		// even if it is supposed to be a cancellation point [MacOS X]
+		struct timeval tv = { 0, 20000 };
+		int res = select(fd + 1, &rfds, NULL, NULL, &tv);
+#ifdef HAVE_PTHREAD_TESTCANCEL
+		pthread_testcancel();
+#endif
+		if (res == 0 || (res == -1 && errno == EINTR))
+			continue;
+#endif
 		if (res <= 0)
 			break;