[spice-streaming-agent,v4,4/5] Use RAII to cleanup stream in case of exception or return

Submitted by Christophe de Dinechin on Nov. 10, 2017, 3:15 p.m.

Details

Message ID 20171110151546.32221-5-christophe@dinechin.org
State New
Headers show
Series "Add a SpiceStream class for stream access" ( rev: 3 ) in Spice

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Commit Message

Christophe de Dinechin Nov. 10, 2017, 3:15 p.m.
From: Christophe de Dinechin <dinechin@redhat.com>

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

Signed-off-by: Christophe de Dinechin <dinechin@redhat.com>
---
 src/spice-streaming-agent.cpp | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

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diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
index 973192b..d46e308 100644
--- a/src/spice-streaming-agent.cpp
+++ b/src/spice-streaming-agent.cpp
@@ -51,6 +51,23 @@  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;
@@ -349,17 +366,14 @@  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(1) < 0) {
                 syslog(LOG_ERR, "FAILED to read command\n");
-                goto done;
+                return;
             }
         }
 
@@ -410,19 +424,13 @@  do_capture(const char *streamport, FILE *f_log)
             //usleep(1);
             if (read_command(0) < 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__);