[Spice-devel] [PATCH spice-streaming-agent v2 4/4] Move all stream-related functions within SpiceStream class

Christophe de Dinechin christophe at dinechin.org
Fri Nov 10 12:53:12 UTC 2017


From: Christophe de Dinechin <dinechin at redhat.com>

This incidentally fixes a race condition processing X events,
where we could possibly start sending cursor events to the
stream before it was actually open.

Signed-off-by: Christophe de Dinechin <dinechin at redhat.com>
---
 src/spice-streaming-agent.cpp | 68 +++++++++++++++++++++++--------------------
 1 file changed, 37 insertions(+), 31 deletions(-)

diff --git a/src/spice-streaming-agent.cpp b/src/spice-streaming-agent.cpp
index 8300cf2..33e0345 100644
--- a/src/spice-streaming-agent.cpp
+++ b/src/spice-streaming-agent.cpp
@@ -51,31 +51,39 @@ struct SpiceStreamDataMessage
     StreamMsgData msg;
 };
 
-struct Stream
+struct SpiceStream
 {
-  Stream(const char *name, int &fd): fd(fd)
+  SpiceStream(const char *name): streamfd(open(name, O_RDWR))
   {
-    fd = open(name, O_RDWR);
-    if (fd < 0)
+    if (streamfd < 0)
       throw std::runtime_error("failed to open streaming device");
   }
-  ~Stream()
+  ~SpiceStream()
   {
-    if (fd >= 0)
-      close(fd);
-    fd = -1;
+    if (streamfd >= 0)
+      close(streamfd);
+    streamfd = -1;
   }
-  int &fd;
+
+  int have_something_to_read(int *pfd, int timeout);
+  int read_command_from_stdin(void);
+  int read_command_from_device(void);
+  int read_command(int blocking);
+  size_t write_all(int fd, const void *buf, const size_t len);
+  int send_format(unsigned w, unsigned h, unsigned c);
+  int send_frame(const void *buf, const unsigned size);
+  void send_cursor(const XFixesCursorImage &image);  
+private:
+  int streamfd;
 };
 
 static int streaming_requested;
 static bool quit;
-static int streamfd = -1;
 static bool stdin_ok;
 static int log_binary = 0;
 static std::mutex stream_mtx;
 
-static int have_something_to_read(int *pfd, int timeout)
+int SpiceStream::have_something_to_read(int *pfd, int timeout)
 {
     int nfds;
     struct pollfd pollfds[2] = {
@@ -97,7 +105,7 @@ static int have_something_to_read(int *pfd, int timeout)
     return *pfd != -1;
 }
 
-static int read_command_from_stdin(void)
+int SpiceStream::read_command_from_stdin(void)
 {
     char buffer[64], *p, *save = NULL;
 
@@ -121,7 +129,7 @@ static int read_command_from_stdin(void)
     return 1;
 }
 
-static int read_command_from_device(void)
+int SpiceStream::read_command_from_device(void)
 {
     StreamDevHeader hdr;
     uint8_t msg[64];
@@ -163,7 +171,7 @@ static int read_command_from_device(void)
     return 1;
 }
 
-static int read_command(int blocking)
+int SpiceStream::read_command(int blocking)
 {
     int fd, n=1;
     int timeout = blocking?-1:0;
@@ -185,8 +193,7 @@ static int read_command(int blocking)
     return n;
 }
 
-static size_t
-write_all(int fd, const void *buf, const size_t len)
+size_t SpiceStream::write_all(int fd, const void *buf, const size_t len)
 {
     size_t written = 0;
     while (written < len) {
@@ -204,7 +211,7 @@ write_all(int fd, const void *buf, const size_t len)
     return written;
 }
 
-static int spice_stream_send_format(unsigned w, unsigned h, unsigned c)
+int SpiceStream::send_format(unsigned w, unsigned h, unsigned c)
 {
 
     SpiceStreamFormatMessage msg;
@@ -225,7 +232,7 @@ static int spice_stream_send_format(unsigned w, unsigned h, unsigned c)
     return EXIT_SUCCESS;
 }
 
-static int spice_stream_send_frame(const void *buf, const unsigned size)
+int SpiceStream::send_frame(const void *buf, const unsigned size)
 {
     SpiceStreamDataMessage msg;
     const size_t msgsize = sizeof(msg);
@@ -304,7 +311,7 @@ static void usage(const char *progname)
     exit(1);
 }
 
-static void send_cursor(const XFixesCursorImage &image)
+void SpiceStream::send_cursor(const XFixesCursorImage &image)
 {
     if (image.width >= 1024 || image.height >= 1024)
         return;
@@ -337,7 +344,7 @@ static void send_cursor(const XFixesCursorImage &image)
     write_all(streamfd, msg.get(), cursor_size);
 }
 
-static void cursor_changes(Display *display, int event_base)
+static void cursor_changes(Display *display, int event_base, SpiceStream *stream)
 {
     unsigned long last_serial = 0;
 
@@ -355,23 +362,25 @@ static void cursor_changes(Display *display, int event_base)
             continue;
 
         last_serial = cursor->cursor_serial;
-        send_cursor(*cursor);
+        stream->send_cursor(*cursor);
     }
 }
 
 static void
-do_capture(const char *streamport, FILE *f_log)
+do_capture(const char *streamport, FILE *f_log, Display *display, int event_base)
 {
     std::unique_ptr<FrameCapture> capture(agent.GetBestFrameCapture());
     if (!capture)
         throw std::runtime_error("cannot find a suitable capture system");
 
-    Stream stream(streamport, streamfd);
+    SpiceStream stream(streamport);
+    std::thread cursor_th(cursor_changes, display, event_base, &stream);
+    cursor_th.detach();
 
     unsigned int frame_count = 0;
     while (! quit) {
         while (!quit && !streaming_requested) {
-            if (read_command(1) < 0) {
+            if (stream.read_command(1) < 0) {
                 syslog(LOG_ERR, "FAILED to read command\n");
                 return;
             }
@@ -406,7 +415,7 @@ do_capture(const char *streamport, FILE *f_log)
 
                 syslog(LOG_DEBUG, "wXh %uX%u  codec=%u\n", width, height, codec);
 
-                if (spice_stream_send_format(width, height, codec) == EXIT_FAILURE)
+                if (stream.send_format(width, height, codec) == EXIT_FAILURE)
                     throw std::runtime_error("FAILED to send format message");
             }
             if (f_log) {
@@ -417,12 +426,12 @@ do_capture(const char *streamport, FILE *f_log)
                     hexdump(frame.buffer, frame.buffer_size, f_log);
                 }
             }
-            if (spice_stream_send_frame(frame.buffer, frame.buffer_size) == EXIT_FAILURE) {
+            if (stream.send_frame(frame.buffer, frame.buffer_size) == EXIT_FAILURE) {
                 syslog(LOG_ERR, "FAILED to send a frame\n");
                 break;
             }
             //usleep(1);
-            if (read_command(0) < 0) {
+            if (stream.read_command(0) < 0) {
                 syslog(LOG_ERR, "FAILED to read command\n");
                 return;
             }
@@ -516,12 +525,9 @@ int main(int argc, char* argv[])
     Window rootwindow = DefaultRootWindow(display);
     XFixesSelectCursorInput(display, rootwindow, XFixesDisplayCursorNotifyMask);
 
-    std::thread cursor_th(cursor_changes, display, event_base);
-    cursor_th.detach();
-
     int ret = EXIT_SUCCESS;
     try {
-        do_capture(streamport, f_log);
+      do_capture(streamport, f_log, display, event_base);
     }
     catch (std::runtime_error &err) {
         syslog(LOG_ERR, "%s\n", err.what());
-- 
2.13.5 (Apple Git-94)



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