gfx/src/X11Util.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: sw=2 ts=8 et :
   3  */
   4 /* This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   7
   8 #include "X11Util.h"
   9 #include "nsDebug.h"                    // for NS_ASSERTION, etc
  10 #include "MainThreadUtils.h"            // for NS_IsMainThread
  11
  12 namespace mozilla {
  13
  14 void
  15 FindVisualAndDepth(Display* aDisplay, VisualID aVisualID,
  16                    Visual** aVisual, int* aDepth)
  17 {
  18     const Screen* screen = DefaultScreenOfDisplay(aDisplay);
  19
  20     for (int d = 0; d < screen->ndepths; d++) {
  21         Depth *d_info = &screen->depths[d];
  22         for (int v = 0; v < d_info->nvisuals; v++) {
  23             Visual* visual = &d_info->visuals[v];
  24             if (visual->visualid == aVisualID) {
  25                 *aVisual = visual;
  26                 *aDepth = d_info->depth;
  27                 return;
  28             }
  29         }
  30     }
  31
  32     NS_ASSERTION(aVisualID == None, "VisualID not on Screen.");
  33     *aVisual = nullptr;
  34     *aDepth = 0;
  35     return;
  36 }
  37
  38 void
  39 FinishX(Display* aDisplay)
  40 {
  41   unsigned long lastRequest = NextRequest(aDisplay) - 1;
  42   if (lastRequest == LastKnownRequestProcessed(aDisplay))
  43     return;
  44
  45   XSync(aDisplay, False);
  46 }
  47
  48 ScopedXErrorHandler::ErrorEvent* ScopedXErrorHandler::sXErrorPtr;
  49
  50 int
  51 ScopedXErrorHandler::ErrorHandler(Display *, XErrorEvent *ev)
  52 {
  53     // only record the error if no error was previously recorded.
  54     // this means that in case of multiple errors, it's the first error that we report.
  55     if (!sXErrorPtr->mError.error_code)
  56       sXErrorPtr->mError = *ev;
  57     return 0;
  58 }
  59
  60 ScopedXErrorHandler::ScopedXErrorHandler()
  61 {
  62     // Off main thread usage is not safe in general, but OMTC GL layers uses this
  63     // with the main thread blocked, which makes it safe.
  64     NS_WARN_IF_FALSE(NS_IsMainThread(), "ScopedXErrorHandler being called off main thread, may cause issues");
  65     // let sXErrorPtr point to this object's mXError object, but don't reset this mXError object!
  66     // think of the case of nested ScopedXErrorHandler's.
  67     mOldXErrorPtr = sXErrorPtr;
  68     sXErrorPtr = &mXError;
  69     mOldErrorHandler = XSetErrorHandler(ErrorHandler);
  70 }
  71
  72 ScopedXErrorHandler::~ScopedXErrorHandler()
  73 {
  74     sXErrorPtr = mOldXErrorPtr;
  75     XSetErrorHandler(mOldErrorHandler);
  76 }
  77
  78 bool
  79 ScopedXErrorHandler::SyncAndGetError(Display *dpy, XErrorEvent *ev)
  80 {
  81     FinishX(dpy);
  82
  83     bool retval = mXError.mError.error_code != 0;
  84     if (ev)
  85         *ev = mXError.mError;
  86     mXError = ErrorEvent(); // reset
  87     return retval;
  88 }
  89
  90 } // namespace mozilla