1 files changed, 161 insertions, 5 deletions

diff --git a/vncviewer/PlatformPixelBuffer.cxx b/vncviewer/PlatformPixelBuffer.cxx
index 522bad3f..4802ba46 100644
--- a/vncviewer/PlatformPixelBuffer.cxx
+++ b/vncviewer/PlatformPixelBuffer.cxx
@@ -1,4 +1,4 @@
-/* Copyright 2011-2014 Pierre Ossman for Cendio AB
+/* Copyright 2011-2016 Pierre Ossman for Cendio AB
  * 
  * This is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -16,13 +16,70 @@
  * USA.
  */
 
+#include <assert.h>
+
+#if !defined(WIN32) && !defined(__APPLE__)
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#endif
+
+#include <FL/Fl.H>
+#include <FL/x.H>
+
+#include <rfb/LogWriter.h>
+#include <rdr/Exception.h>
+
 #include "PlatformPixelBuffer.h"
 
-PlatformPixelBuffer::PlatformPixelBuffer(const rfb::PixelFormat& pf,
-                                         int width, int height,
-                                         rdr::U8* data, int stride) :
-  FullFramePixelBuffer(pf, width, height, data, stride)
+static rfb::LogWriter vlog("PlatformPixelBuffer");
+
+PlatformPixelBuffer::PlatformPixelBuffer(int width, int height) :
+  FullFramePixelBuffer(rfb::PixelFormat(32, 24, false, true,
+                                       255, 255, 255, 16, 8, 0),
+                       width, height, 0, stride),
+  Surface(width, height)
+#if !defined(WIN32) && !defined(__APPLE__)
+  , shminfo(NULL), xim(NULL)
+#endif
 {
+#if !defined(WIN32) && !defined(__APPLE__)
+  if (!setupShm()) {
+    xim = XCreateImage(fl_display, CopyFromParent, 32,
+                       ZPixmap, 0, 0, width, height, 32, 0);
+    if (!xim)
+      throw rdr::Exception("XCreateImage");
+
+    xim->data = (char*)malloc(xim->bytes_per_line * xim->height);
+    if (!xim->data)
+      throw rdr::Exception("malloc");
+
+    vlog.debug("Using standard XImage");
+  }
+
+  data = (rdr::U8*)xim->data;
+  stride = xim->bytes_per_line / (getPF().bpp/8);
+#else
+  FullFramePixelBuffer::data = (rdr::U8*)Surface::data;
+  stride = width;
+#endif
+}
+
+PlatformPixelBuffer::~PlatformPixelBuffer()
+{
+#if !defined(WIN32) && !defined(__APPLE__)
+  if (shminfo) {
+    vlog.debug("Freeing shared memory XImage");
+    shmdt(shminfo->shmaddr);
+    shmctl(shminfo->shmid, IPC_RMID, 0);
+    delete shminfo;
+    shminfo = NULL;
+  }
+
+  // XDestroyImage() will free(xim->data) if appropriate
+  if (xim)
+    XDestroyImage(xim);
+  xim = NULL;
+#endif
 }
 
 void PlatformPixelBuffer::commitBufferRW(const rfb::Rect& r)
@@ -42,5 +99,104 @@ rfb::Rect PlatformPixelBuffer::getDamage(void)
   damage.clear();
   mutex.unlock();
 
+#if !defined(WIN32) && !defined(__APPLE__)
+  GC gc;
+
+  gc = XCreateGC(fl_display, pixmap, 0, NULL);
+  if (shminfo) {
+    XShmPutImage(fl_display, pixmap, gc, xim,
+                 r.tl.x, r.tl.y, r.tl.x, r.tl.y,
+                 r.width(), r.height(), False);
+    // Need to make sure the X server has finished reading the
+    // shared memory before we return
+    XSync(fl_display, False);
+  } else {
+    XPutImage(fl_display, pixmap, gc, xim,
+              r.tl.x, r.tl.y, r.tl.x, r.tl.y, r.width(), r.height());
+  }
+  XFreeGC(fl_display, gc);
+#endif
+
   return r;
 }
+
+#if !defined(WIN32) && !defined(__APPLE__)
+
+static bool caughtError;
+
+static int XShmAttachErrorHandler(Display *dpy, XErrorEvent *error)
+{
+  caughtError = true;
+  return 0;
+}
+
+bool PlatformPixelBuffer::setupShm()
+{
+  int major, minor;
+  Bool pixmaps;
+  XErrorHandler old_handler;
+  const char *display_name = XDisplayName (NULL);
+
+  /* Don't use MIT-SHM on remote displays */
+  if (*display_name && *display_name != ':')
+    return false;
+
+  if (!XShmQueryVersion(fl_display, &major, &minor, &pixmaps))
+    return false;
+
+  shminfo = new XShmSegmentInfo;
+
+  xim = XShmCreateImage(fl_display, CopyFromParent, 32,
+                        ZPixmap, 0, shminfo, width(), height());
+  if (!xim)
+    goto free_shminfo;
+
+  shminfo->shmid = shmget(IPC_PRIVATE,
+                          xim->bytes_per_line * xim->height,
+                          IPC_CREAT|0777);
+  if (shminfo->shmid == -1)
+    goto free_xim;
+
+  shminfo->shmaddr = xim->data = (char*)shmat(shminfo->shmid, 0, 0);
+  shmctl(shminfo->shmid, IPC_RMID, 0); // to avoid memory leakage
+  if (shminfo->shmaddr == (char *)-1)
+    goto free_xim;
+
+  shminfo->readOnly = True;
+
+  // This is the only way we can detect that shared memory won't work
+  // (e.g. because we're accessing a remote X11 server)
+  caughtError = false;
+  old_handler = XSetErrorHandler(XShmAttachErrorHandler);
+
+  if (!XShmAttach(fl_display, shminfo)) {
+    XSetErrorHandler(old_handler);
+    goto free_shmaddr;
+  }
+
+  XSync(fl_display, False);
+
+  XSetErrorHandler(old_handler);
+
+  if (caughtError)
+    goto free_shmaddr;
+
+  vlog.debug("Using shared memory XImage");
+
+  return true;
+
+free_shmaddr:
+  shmdt(shminfo->shmaddr);
+
+free_xim:
+  XDestroyImage(xim);
+  xim = NULL;
+
+free_shminfo:
+  delete shminfo;
+  shminfo = NULL;
+
+  return 0;
+}
+
+#endif