X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=gtk2_ardour%2Fsystem_exec.cc;h=90c7294f5533fae89ad0ea37ec60e942818cf6a6;hb=aac5f4c6d67d0ca782f12d355e853d35e58924b9;hp=eb81c5fcb2158d040a11532561b2154d9b37f6a0;hpb=1053529e4fddcd00891cbbc08cf4107e8335f873;p=ardour.git

diff --git a/gtk2_ardour/system_exec.cc b/gtk2_ardour/system_exec.cc
index eb81c5fcb2..90c7294f55 100644
--- a/gtk2_ardour/system_exec.cc
+++ b/gtk2_ardour/system_exec.cc
@@ -38,7 +38,7 @@
 using namespace std;
 void * interposer_thread (void *arg);
 
-static void close_fd (int* fd) { if (!fd) return; if (*fd >= 0) ::close (*fd); *fd = -1; }
+static void close_fd (int& fd) { if (fd >= 0) ::close (fd); fd = -1; }
 
 SystemExec::SystemExec (std::string c, std::string a)
 	: cmd(c)
@@ -414,19 +414,33 @@ void
 SystemExec::terminate ()
 {
 	::pthread_mutex_lock(&write_lock);
+
+	/* close stdin in an attempt to get the child to exit cleanly.
+	 */
+
 	close_stdin();
+
 	if (pid) {
 		::usleep(50000);
 		sched_yield();
 		wait(WNOHANG);
 	}
 
+	/* if pid is non-zero, the child task is still executing (i.e. it did
+	 * not exit in response to stdin being closed). try to kill it.
+	 */
+	
 	if (pid) {
 		::kill(pid, SIGTERM);
 		::usleep(50000);
 		sched_yield();
 		wait(WNOHANG);
 	}
+
+	/* if pid is non-zero, the child task is STILL executing after being
+	 * sent SIGTERM. Act tough ... send SIGKILL
+	 */
+
 	if (pid) {
 		::fprintf(stderr, "Process is still running! trying SIGKILL\n");
 		::kill(pid, SIGKILL);
@@ -442,15 +456,23 @@ int
 SystemExec::wait (int options)
 {
 	int status=0;
+	int ret;
+
 	if (pid==0) return -1;
-	if (pid==::waitpid(pid, &status, options)) {
+
+	ret = waitpid (pid, &status, options);
+
+	if (ret == pid) {
 		if (WEXITSTATUS(status) || WIFSIGNALED(status)) {
 			pid=0;
 		}
 	} else {
-		if (errno == ECHILD) {
-			pid=0;
-		}
+		if (ret != 0) {
+			if (errno == ECHILD) {
+				/* no currently running children, reset pid */
+				pid=0;
+			}
+		} /* else the process is still running */
 	}
 	return status;
 }
@@ -488,18 +510,18 @@ SystemExec::start (int stderr_mode)
 		pid=r;
 
 		/* check if execve was successful. */
-		close_fd(&pok[1]);
+		close_fd(pok[1]);
 		char buf;
 		for ( ;; ) {
 			ssize_t n = ::read(pok[0], &buf, 1 );
 			if ( n==1 ) {
 				/* child process returned from execve */
 				pid=0;
-				close_fd(&pok[0]);
-				close_fd(&pin[1]);
-				close_fd(&pin[0]);
-				close_fd(&pout[1]);
-				close_fd(&pout[0]);
+				close_fd(pok[0]);
+				close_fd(pin[1]);
+				close_fd(pin[0]);
+				close_fd(pout[1]);
+				close_fd(pout[0]);
 				pin[1] = -1;
 				return -3;
 			} else if ( n==-1 ) {
@@ -508,7 +530,7 @@ SystemExec::start (int stderr_mode)
 			}
 			break;
 		}
-		close_fd(&pok[0]);
+		close_fd(pok[0]);
 		/* child started successfully */
 
 #if 0
@@ -524,17 +546,17 @@ SystemExec::start (int stderr_mode)
 		}
 		if (r == 0) {
 			/* 2nd child process - catch stdout */
-			close_fd(&pin[1]);
-			close_fd(&pout[1]);
+			close_fd(pin[1]);
+			close_fd(pout[1]);
 			output_interposer();
 			exit(0);
 		}
-		close_fd(&pout[1]);
-		close_fd(&pin[0]);
-		close_fd(&pout[0]);
+		close_fd(pout[1]);
+		close_fd(pin[0]);
+		close_fd(pout[0]);
 #else /* use pthread */
-		close_fd(&pout[1]);
-		close_fd(&pin[0]);
+		close_fd(pout[1]);
+		close_fd(pin[0]);
 		int rv = pthread_create(&thread_id_tt, NULL, interposer_thread, this);
 
 		thread_active=true;
@@ -548,15 +570,15 @@ SystemExec::start (int stderr_mode)
 	}
 
 	/* child process - exec external process */
-	close_fd(&pok[0]);
+	close_fd(pok[0]);
 	::fcntl(pok[1], F_SETFD, FD_CLOEXEC);
 
-	close_fd(&pin[1]);
+	close_fd(pin[1]);
 	if (pin[0] != STDIN_FILENO) {
 	  ::dup2(pin[0], STDIN_FILENO);
 	}
-	close_fd(&pin[0]);
-	close_fd(&pout[0]);
+	close_fd(pin[0]);
+	close_fd(pout[0]);
 	if (pout[1] != STDOUT_FILENO) {
 		::dup2(pout[1], STDOUT_FILENO);
 	}
@@ -574,7 +596,7 @@ SystemExec::start (int stderr_mode)
 	}
 
 	if (pout[1] != STDOUT_FILENO && pout[1] != STDERR_FILENO) {
-		close_fd(&pout[1]);
+		close_fd(pout[1]);
 	}
 
 	if (nicelevel !=0) {
@@ -601,7 +623,7 @@ SystemExec::start (int stderr_mode)
 	/* if we reach here something went wrong.. */
 	char buf = 0;
 	(void) ::write(pok[1], &buf, 1 );
-	close_fd(&pok[1]);
+	close_fd(pok[1]);
 	exit(-1);
 	return -1;
 }
@@ -614,7 +636,7 @@ SystemExec::output_interposer()
 	ssize_t r;
 	unsigned long l = 1;
 
-  ioctl(rfd, FIONBIO, &l); // set non-blocking I/O
+	ioctl(rfd, FIONBIO, &l); // set non-blocking I/O
 
 	for (;fcntl(rfd, F_GETFL)!=-1;) {
 		r = read(rfd, buf, sizeof(buf));
@@ -636,17 +658,18 @@ void
 SystemExec::close_stdin()
 {
 	if (pin[1]<0) return;
-	close_fd(&pin[0]);
-	close_fd(&pin[1]);
-	close_fd(&pout[0]);
-	close_fd(&pout[1]);
+	close_fd(pin[0]);
+	close_fd(pin[1]);
+	close_fd(pout[0]);
+	close_fd(pout[1]);
 }
 
 int
 SystemExec::write_to_stdin(std::string d, size_t len)
 {
 	const char *data;
-	size_t r,c;
+	ssize_t r;
+	size_t c;
 	::pthread_mutex_lock(&write_lock);
 
 	data=d.c_str();
@@ -661,7 +684,7 @@ SystemExec::write_to_stdin(std::string d, size_t len)
 				sleep(1);
 				continue;
 			}
-			if (r != (len-c)) {
+			if ((size_t) r != (len-c)) {
 				::pthread_mutex_unlock(&write_lock);
 				return c;
 			}