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 FindVisualAndDepth(Display* aDisplay, VisualID aVisualID, Visual** aVisual,
  15                         int* aDepth) {
  16   const Screen* screen = DefaultScreenOfDisplay(aDisplay);
  17
  18   for (int d = 0; d < screen->ndepths; d++) {
  19     Depth* d_info = &screen->depths[d];
  20     for (int v = 0; v < d_info->nvisuals; v++) {
  21       Visual* visual = &d_info->visuals[v];
  22       if (visual->visualid == aVisualID) {
  23         *aVisual = visual;
  24         *aDepth = d_info->depth;
  25         return;
  26       }
  27     }
  28   }
  29
  30   NS_ASSERTION(aVisualID == X11None, "VisualID not on Screen.");
  31   *aVisual = nullptr;
  32   *aDepth = 0;
  33 }
  34
  35 void FinishX(Display* aDisplay) {
  36   unsigned long lastRequest = NextRequest(aDisplay) - 1;
  37   if (lastRequest == LastKnownRequestProcessed(aDisplay)) return;
  38
  39   XSync(aDisplay, X11False);
  40 }
  41
  42 ScopedXErrorHandler::ErrorEvent* ScopedXErrorHandler::sXErrorPtr;
  43
  44 int ScopedXErrorHandler::ErrorHandler(Display*, XErrorEvent* ev) {
  45   // only record the error if no error was previously recorded.
  46   // this means that in case of multiple errors, it's the first error that we
  47   // report.
  48   if (!sXErrorPtr->mError.error_code) sXErrorPtr->mError = *ev;
  49   return 0;
  50 }
  51
  52 ScopedXErrorHandler::ScopedXErrorHandler(bool aAllowOffMainThread) {
  53   if (!aAllowOffMainThread) {
  54     // Off main thread usage is not safe in general, but OMTC GL layers uses
  55     // this with the main thread blocked, which makes it safe.
  56     NS_WARNING_ASSERTION(
  57         NS_IsMainThread(),
  58         "ScopedXErrorHandler being called off main thread, may cause issues");
  59   }
  60   // let sXErrorPtr point to this object's mXError object, but don't reset this
  61   // mXError object! think of the case of nested ScopedXErrorHandler's.
  62   mOldXErrorPtr = sXErrorPtr;
  63   sXErrorPtr = &mXError;
  64   mOldErrorHandler = XSetErrorHandler(ErrorHandler);
  65 }
  66
  67 ScopedXErrorHandler::~ScopedXErrorHandler() {
  68   sXErrorPtr = mOldXErrorPtr;
  69   XSetErrorHandler(mOldErrorHandler);
  70 }
  71
  72 bool ScopedXErrorHandler::SyncAndGetError(Display* dpy, XErrorEvent* ev) {
  73   FinishX(dpy);
  74
  75   bool retval = mXError.mError.error_code != 0;
  76   if (ev) *ev = mXError.mError;
  77   mXError = ErrorEvent();  // reset
  78   return retval;
  79 }
  80
  81 }  // namespace mozilla