Use RAII to cleanup stream in case of exception or return

This lets us get rid of C-style 'goto done' in do_capture.

Signed-off-by: Christophe de Dinechin <dinechin@redhat.com>

1 files changed, 20 insertions, 12 deletions

diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
index 53ffbf0..97581c4 100644
--- a/src/spice-streaming-agent.cpp
+++ b/src/spice-streaming-agent.cpp
@@ -52,6 +52,23 @@ struct SpiceStreamDataMessage
     StreamMsgData msg;
 };
 
+struct Stream
+{
+    Stream(const char *name, int &fd): fd(fd)
+    {
+        fd = open(name, O_RDWR);
+        if (fd < 0)
+            throw std::runtime_error("failed to open streaming device");
+    }
+    ~Stream()
+    {
+        if (fd >= 0)
+            close(fd);
+        fd = -1;
+    }
+    int &fd;
+};
+
 static int streaming_requested;
 static bool quit;
 static int streamfd = -1;
@@ -353,17 +370,14 @@ do_capture(const char *streamport, FILE *f_log)
     if (!capture)
         throw std::runtime_error("cannot find a suitable capture system");
 
-    streamfd = open(streamport, O_RDWR);
-    if (streamfd < 0)
-        // TODO was syslog(LOG_ERR, "Failed to open %s: %s\n", streamport, strerror(errno));
-        throw std::runtime_error("failed to open streaming device");
+    Stream stream(streamport, streamfd);
 
     unsigned int frame_count = 0;
     while (! quit) {
         while (!quit && !streaming_requested) {
             if (read_command(true) < 0) {
                 syslog(LOG_ERR, "FAILED to read command\n");
-                goto done;
+                return;
             }
         }
 
@@ -414,19 +428,13 @@ do_capture(const char *streamport, FILE *f_log)
             //usleep(1);
             if (read_command(false) < 0) {
                 syslog(LOG_ERR, "FAILED to read command\n");
-                goto done;
+                return;
             }
             if (!streaming_requested) {
                 capture->Reset();
             }
         }
     }
-
-done:
-    if (streamfd >= 0) {
-        close(streamfd);
-        streamfd = -1;
-    }
 }
 
 #define arg_error(...) syslog(LOG_ERR, ## __VA_ARGS__);