possible fix for #5441 -- ardour hangs on shutdown (trying to stop harvid/xjadeo)

diff --git a/gtk2_ardour/system_exec.cc b/gtk2_ardour/system_exec.cc
index 3af660ef77b60889f362796664bd133099f89a12..309f38b4da30f4ad68090c43468e9f02e4bafbf8 100644 (file)
--- a/gtk2_ardour/system_exec.cc
+++ b/gtk2_ardour/system_exec.cc
@@ -32,6 +32,7 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <sys/socket.h>
+#include <sys/ioctl.h>
 #endif
 
 #include "system_exec.h"
@@ -293,6 +294,10 @@ SystemExec::output_interposer()
 {
        DWORD bytesRead = 0;
        char data[BUFSIZ];
+#if 0 // untested code to set up nonblocking
+       unsigned long l = 1;
+       ioctlsocket(stdoutP[0], FIONBIO, &l);
+#endif
        while(1) {
 #if 0 // for non-blocking pipes..
                DWORD bytesAvail = 0;
@@ -411,14 +416,15 @@ SystemExec::terminate ()
        ::pthread_mutex_lock(&write_lock);
        close_stdin();
        if (pid) {
-               ::usleep(100000);
+               ::usleep(50000);
+               sched_yield();
                wait(WNOHANG);
        }
 
        if (pid) {
-               ::fprintf(stderr, "Child process is running. trying SIGTERM\n");
                ::kill(pid, SIGTERM);
                ::usleep(50000);
+               sched_yield();
                wait(WNOHANG);
        }
        if (pid) {
@@ -482,7 +488,7 @@ SystemExec::start (int stderr_mode)
                ::close(pok[1]);
                char buf;
                for ( ;; ) {
-                       int n = ::read(pok[0], &buf, 1 );
+                       ssize_t n = ::read(pok[0], &buf, 1 );
                        if ( n==1 ) {
                                /* child process returned from execve */
                                pid=0;
@@ -602,7 +608,11 @@ SystemExec::output_interposer()
 {
        int rfd=pout[0];
        char buf[BUFSIZ];
-       size_t r;
+       ssize_t r;
+       unsigned long l = 1;
+
+  ioctl(rfd, FIONBIO, &l); // set non-blocking I/O
+
        for (;fcntl(rfd, F_GETFL)!=-1;) {
                r = read(rfd, buf, sizeof(buf));
                if (r < 0 && (errno == EINTR || errno == EAGAIN)) {