DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (a81015259a98)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: sw=2 ts=8 et :
 */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at:
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Code.
 *
 * The Initial Developer of the Original Code is
 *   The Mozilla Foundation
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */


//////////////////////////////////////////////////////////////////////////////
//
// Explanation: See bug 639842. Safely getting GL driver info on X11 is hard, because the only way to do
// that is to create a GL context and call glGetString(), but with bad drivers,
// just creating a GL context may crash.
//
// This file implements the idea to do that in a separate process.
//
// The only non-static function here is fire_glxtest_process(). It creates a pipe, publishes its 'read' end as the
// mozilla::widget::glxtest_pipe global variable, forks, and runs that GLX probe in the child process,
// which runs the glxtest() static function. This creates a X connection, a GLX context, calls glGetString, and writes that
// to the 'write' end of the pipe.

#include <cstdio>
#include <cstdlib>
#include <unistd.h>
#include <GL/gl.h>
#include <GL/glx.h>
#include <dlfcn.h>
#include "nscore.h"

#ifdef __SUNPRO_CC
#include <stdio.h>
#endif

namespace mozilla {
namespace widget {
// the read end of the pipe, which will be used by GfxInfo
extern int glxtest_pipe;
// the PID of the glxtest process, to pass to waitpid()
extern pid_t glxtest_pid;
}
}

// the write end of the pipe, which we're going to write to
static int write_end_of_the_pipe = -1;

// C++ standard collides with C standard in that it doesn't allow casting void* to function pointer types.
// So the work-around is to convert first to size_t.
// http://www.trilithium.com/johan/2004/12/problem-with-dlsym/
template<typename func_ptr_type>
static func_ptr_type cast(void *ptr)
{
  return reinterpret_cast<func_ptr_type>(
           reinterpret_cast<size_t>(ptr)
         );
}

static void fatal_error(const char *str)
{
  write(write_end_of_the_pipe, str, strlen(str));
  write(write_end_of_the_pipe, "\n", 1);
  exit(EXIT_FAILURE);
}

static int
x_error_handler(Display *, XErrorEvent *ev)
{
  enum { bufsize = 1024 };
  char buf[bufsize];
  int length = snprintf(buf, bufsize,
                        "X error occurred in GLX probe, error_code=%d, request_code=%d, minor_code=%d\n",
                        ev->error_code,
                        ev->request_code,
                        ev->minor_code);
  write(write_end_of_the_pipe, buf, length);
  exit(EXIT_FAILURE);
  return 0;
}

static void glxtest()
{
  ///// Open libGL and load needed symbols /////
#ifdef __OpenBSD__
  void *libgl = dlopen("libGL.so", RTLD_LAZY);
#else
  void *libgl = dlopen("libGL.so.1", RTLD_LAZY);
#endif
  if (!libgl)
    fatal_error("Unable to load libGL.so.1");
  
  typedef void* (* PFNGLXGETPROCADDRESS) (const char *);
  PFNGLXGETPROCADDRESS glXGetProcAddress = cast<PFNGLXGETPROCADDRESS>(dlsym(libgl, "glXGetProcAddress"));
  
  if (!glXGetProcAddress)
    fatal_error("Unable to find glXGetProcAddress in libGL.so.1");

  typedef GLXFBConfig* (* PFNGLXQUERYEXTENSION) (Display *, int *, int *);
  PFNGLXQUERYEXTENSION glXQueryExtension = cast<PFNGLXQUERYEXTENSION>(glXGetProcAddress("glXQueryExtension"));

  typedef GLXFBConfig* (* PFNGLXQUERYVERSION) (Display *, int *, int *);
  PFNGLXQUERYVERSION glXQueryVersion = cast<PFNGLXQUERYVERSION>(dlsym(libgl, "glXQueryVersion"));

  typedef GLXFBConfig* (* PFNGLXCHOOSEFBCONFIG) (Display *, int, const int *, int *);
  PFNGLXCHOOSEFBCONFIG glXChooseFBConfig = cast<PFNGLXCHOOSEFBCONFIG>(glXGetProcAddress("glXChooseFBConfig"));

  typedef XVisualInfo* (* PFNGLXGETVISUALFROMFBCONFIG) (Display *, GLXFBConfig);
  PFNGLXGETVISUALFROMFBCONFIG glXGetVisualFromFBConfig = cast<PFNGLXGETVISUALFROMFBCONFIG>(glXGetProcAddress("glXGetVisualFromFBConfig"));

  typedef GLXPixmap (* PFNGLXCREATEPIXMAP) (Display *, GLXFBConfig, Pixmap, const int *);
  PFNGLXCREATEPIXMAP glXCreatePixmap = cast<PFNGLXCREATEPIXMAP>(glXGetProcAddress("glXCreatePixmap"));

  typedef GLXContext (* PFNGLXCREATENEWCONTEXT) (Display *, GLXFBConfig, int, GLXContext, Bool);
  PFNGLXCREATENEWCONTEXT glXCreateNewContext = cast<PFNGLXCREATENEWCONTEXT>(glXGetProcAddress("glXCreateNewContext"));

  typedef Bool (* PFNGLXMAKECURRENT) (Display*, GLXDrawable, GLXContext);
  PFNGLXMAKECURRENT glXMakeCurrent = cast<PFNGLXMAKECURRENT>(glXGetProcAddress("glXMakeCurrent"));

  typedef void (* PFNGLXDESTROYPIXMAP) (Display *, GLXPixmap);
  PFNGLXDESTROYPIXMAP glXDestroyPixmap = cast<PFNGLXDESTROYPIXMAP>(glXGetProcAddress("glXDestroyPixmap"));

  typedef void (* PFNGLXDESTROYCONTEXT) (Display*, GLXContext);
  PFNGLXDESTROYCONTEXT glXDestroyContext = cast<PFNGLXDESTROYCONTEXT>(glXGetProcAddress("glXDestroyContext"));

  typedef GLubyte* (* PFNGLGETSTRING) (GLenum);
  PFNGLGETSTRING glGetString = cast<PFNGLGETSTRING>(glXGetProcAddress("glGetString"));

  if (!glXQueryExtension ||
      !glXQueryVersion ||
      !glXChooseFBConfig ||
      !glXGetVisualFromFBConfig ||
      !glXCreatePixmap ||
      !glXCreateNewContext ||
      !glXMakeCurrent ||
      !glXDestroyPixmap ||
      !glXDestroyContext ||
      !glGetString)
  {
    fatal_error("glXGetProcAddress couldn't find required functions");
  }
  ///// Open a connection to the X server /////
  Display *dpy = XOpenDisplay(NULL);
  if (!dpy)
    fatal_error("Unable to open a connection to the X server");
  
  ///// Check that the GLX extension is present /////
  if (!glXQueryExtension(dpy, NULL, NULL))
    fatal_error("GLX extension missing");
  
  ///// Check that the GLX version is >= 1.3, needed for glXCreatePixmap, bug 659932 /////
  int majorVersion, minorVersion;
  if (!glXQueryVersion(dpy, &majorVersion, &minorVersion))
    fatal_error("Unable to query GLX version");

  if (majorVersion < 1 || (majorVersion == 1 && minorVersion < 3))
    fatal_error("GLX version older than the required 1.3");

  XSetErrorHandler(x_error_handler);

  ///// Get a FBConfig and a visual /////
  int attribs[] = {
    GLX_DRAWABLE_TYPE, GLX_PIXMAP_BIT,
    GLX_X_RENDERABLE, True,
    0
  };
  int numReturned;
  GLXFBConfig *fbConfigs = glXChooseFBConfig(dpy, DefaultScreen(dpy), attribs, &numReturned );
  if (!fbConfigs)
    fatal_error("No FBConfigs found");
  XVisualInfo *vInfo = glXGetVisualFromFBConfig(dpy, fbConfigs[0]);
  if (!vInfo)
    fatal_error("No visual found for first FBConfig");

  ///// Get a Pixmap and a GLXPixmap /////
  Pixmap pixmap = XCreatePixmap(dpy, RootWindow(dpy, vInfo->screen), 4, 4, 32);
  GLXPixmap glxpixmap = glXCreatePixmap(dpy, fbConfigs[0], pixmap, NULL);

  ///// Get a GL context and make it current //////
  GLXContext context = glXCreateNewContext(dpy, fbConfigs[0], GLX_RGBA_TYPE, NULL, True);
  glXMakeCurrent(dpy, glxpixmap, context);

  ///// Look for this symbol to determine texture_from_pixmap support /////
  void* glXBindTexImageEXT = glXGetProcAddress("glXBindTexImageEXT"); 

  ///// Get GL vendor/renderer/versions strings /////
  enum { bufsize = 1024 };
  char buf[bufsize];
  const GLubyte *vendorString = glGetString(GL_VENDOR);
  const GLubyte *rendererString = glGetString(GL_RENDERER);
  const GLubyte *versionString = glGetString(GL_VERSION);
  
  if (!vendorString || !rendererString || !versionString)
    fatal_error("glGetString returned null");

  int length = snprintf(buf, bufsize,
                        "VENDOR\n%s\nRENDERER\n%s\nVERSION\n%s\nTFP\n%s\n",
                        vendorString,
                        rendererString,
                        versionString,
                        glXBindTexImageEXT ? "TRUE" : "FALSE");
  if (length >= bufsize)
    fatal_error("GL strings length too large for buffer size");

  ///// Check that no X error happened /////
  // In case of X errors, our X error handler will exit() now.
  // We really want to make sure that the system is able to create a GL context without generating X errors,
  // as these would crash the application.
  XSync(dpy, False);
  
  ///// Finally write data to the pipe /////
  write(write_end_of_the_pipe, buf, length);

  ///// Clean up. Indeed, the parent process might fail to kill us (e.g. if it doesn't need to check GL info)
  ///// so we might be staying alive for longer than expected, so it's important to consume as little memory as
  ///// possible. Also we want to check that we're able to do that too without generating X errors.
  glXMakeCurrent(dpy, None, NULL); // must release the GL context before destroying it
  glXDestroyContext(dpy, context);
  glXDestroyPixmap(dpy, glxpixmap);
  XFreePixmap(dpy, pixmap);
  XCloseDisplay(dpy);
  dlclose(libgl);
}

/** \returns true in the child glxtest process, false in the parent process */
bool fire_glxtest_process()
{
  int pfd[2];
  if (pipe(pfd) == -1) {
      perror("pipe");
      return false;
  }
  pid_t pid = fork();
  if (pid < 0) {
      perror("fork");
      close(pfd[0]);
      close(pfd[1]);
      return false;
  }
  if (pid == 0) {
      close(pfd[0]);
      write_end_of_the_pipe = pfd[1];
      glxtest();
      close(pfd[1]);
      return true;
  }

  close(pfd[1]);
  mozilla::widget::glxtest_pipe = pfd[0];
  mozilla::widget::glxtest_pid = pid;
  return false;
}