The Tor Browser: toolkit/xre/glxtest.cpp@6474c204b198 (annotated)

toolkit/xre/glxtest.cpp@6474c204b198 (annotated)

toolkit/xre/glxtest.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
  * vim: sw=2 ts=8 et :
  */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 //////////////////////////////////////////////////////////////////////////////
 //
 // 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 <dlfcn.h>
 #include "nscore.h"
 #include <fcntl.h>
 #include "stdint.h"
 #ifdef __SUNPRO_CC
 #include <stdio.h>
 #endif
 #include "X11/Xlib.h"
 #include "X11/Xutil.h"
 // stuff from glx.h
 typedef struct __GLXcontextRec *GLXContext;
 typedef XID GLXPixmap;
 typedef XID GLXDrawable;
 /* GLX 1.3 and later */
 typedef struct __GLXFBConfigRec *GLXFBConfig;
 typedef XID GLXFBConfigID;
 typedef XID GLXContextID;
 typedef XID GLXWindow;
 typedef XID GLXPbuffer;
 #define GLX_RGBA        4
 #define GLX_RED_SIZE    8
 #define GLX_GREEN_SIZE  9
 #define GLX_BLUE_SIZE   10
 // stuff from gl.h
 typedef uint8_t GLubyte;
 typedef uint32_t GLenum;
 #define GL_VENDOR       0x1F00
 #define GL_RENDERER     0x1F01
 #define GL_VERSION      0x1F02
 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;
 }
 // glxtest is declared inside extern "C" so that the name is not mangled.
 // The name is used in build/valgrind/x86_64-redhat-linux-gnu.sup to suppress
 // memory leak errors because we run it inside a short lived fork and we don't
 // care about leaking memory
 extern "C" {
 void glxtest()
 {
   // we want to redirect to /dev/null stdout, stderr, and while we're at it,
   // any PR logging file descriptors. To that effect, we redirect all positive
   // file descriptors up to what open() returns here. In particular, 1 is stdout and 2 is stderr.
   int fd = open("/dev/null", O_WRONLY);
   for (int i = 1; i < fd; i++)
     dup2(fd, i);
   close(fd);
   if (getenv("MOZ_AVOID_OPENGL_ALTOGETHER"))
     fatal_error("The MOZ_AVOID_OPENGL_ALTOGETHER environment variable is defined");
   ///// Open libGL and load needed symbols /////
 #ifdef __OpenBSD__
   #define LIBGL_FILENAME "libGL.so"
 #else
   #define LIBGL_FILENAME "libGL.so.1"
 #endif
   void *libgl = dlopen(LIBGL_FILENAME, RTLD_LAZY);
   if (!libgl)
     fatal_error("Unable to load " LIBGL_FILENAME);
   typedef void* (* PFNGLXGETPROCADDRESS) (const char *);
   PFNGLXGETPROCADDRESS glXGetProcAddress = cast<PFNGLXGETPROCADDRESS>(dlsym(libgl, "glXGetProcAddress"));
   if (!glXGetProcAddress)
     fatal_error("Unable to find glXGetProcAddress in " LIBGL_FILENAME);
   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 XVisualInfo* (* PFNGLXCHOOSEVISUAL) (Display *, int, int *);
   PFNGLXCHOOSEVISUAL glXChooseVisual = cast<PFNGLXCHOOSEVISUAL>(glXGetProcAddress("glXChooseVisual"));
   typedef GLXContext (* PFNGLXCREATECONTEXT) (Display *, XVisualInfo *, GLXContext, Bool);
   PFNGLXCREATECONTEXT glXCreateContext = cast<PFNGLXCREATECONTEXT>(glXGetProcAddress("glXCreateContext"));
   typedef Bool (* PFNGLXMAKECURRENT) (Display*, GLXDrawable, GLXContext);
   PFNGLXMAKECURRENT glXMakeCurrent = cast<PFNGLXMAKECURRENT>(glXGetProcAddress("glXMakeCurrent"));
   typedef void (* PFNGLXDESTROYCONTEXT) (Display*, GLXContext);
   PFNGLXDESTROYCONTEXT glXDestroyContext = cast<PFNGLXDESTROYCONTEXT>(glXGetProcAddress("glXDestroyContext"));
   typedef GLubyte* (* PFNGLGETSTRING) (GLenum);
   PFNGLGETSTRING glGetString = cast<PFNGLGETSTRING>(glXGetProcAddress("glGetString"));
   if (!glXQueryExtension ||
       !glXQueryVersion ||
       !glXChooseVisual ||
       !glXCreateContext ||
       !glXMakeCurrent ||
       !glXDestroyContext ||
       !glGetString)
   {
     fatal_error("glXGetProcAddress couldn't find required functions");
   }
   ///// Open a connection to the X server /////
   Display *dpy = XOpenDisplay(nullptr);
   if (!dpy)
     fatal_error("Unable to open a connection to the X server");
   ///// Check that the GLX extension is present /////
   if (!glXQueryExtension(dpy, nullptr, nullptr))
     fatal_error("GLX extension missing");
   XSetErrorHandler(x_error_handler);
   ///// Get a visual /////
    int attribs[] = {
       GLX_RGBA,
       GLX_RED_SIZE, 1,
       GLX_GREEN_SIZE, 1,
       GLX_BLUE_SIZE, 1,
       None };
   XVisualInfo *vInfo = glXChooseVisual(dpy, DefaultScreen(dpy), attribs);
   if (!vInfo)
     fatal_error("No visuals found");
   // using a X11 Window instead of a GLXPixmap does not crash
   // fglrx in indirect rendering. bug 680644
   Window window;
   XSetWindowAttributes swa;
   swa.colormap = XCreateColormap(dpy, RootWindow(dpy, vInfo->screen),
                                  vInfo->visual, AllocNone);
   swa.border_pixel = 0;
   window = XCreateWindow(dpy, RootWindow(dpy, vInfo->screen),
 , 0, 16, 16,
 , vInfo->depth, InputOutput, vInfo->visual,
                        CWBorderPixel | CWColormap, &swa);
   ///// Get a GL context and make it current //////
   GLXContext context = glXCreateContext(dpy, vInfo, nullptr, True);
   glXMakeCurrent(dpy, window, 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");
   ///// 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, nullptr); // must release the GL context before destroying it
   glXDestroyContext(dpy, context);
   XDestroyWindow(dpy, window);
   XFreeColormap(dpy, swa.colormap);
 #ifdef NS_FREE_PERMANENT_DATA // conditionally defined in nscore.h, don't forget to #include it above
   XCloseDisplay(dpy);
 #else
   // This XSync call wanted to be instead:
   //   XCloseDisplay(dpy);
   // but this can cause 1-minute stalls on certain setups using Nouveau, see bug 973192
   XSync(dpy, False);
 #endif
   dlclose(libgl);
   ///// Finally write data to the pipe
   write(write_end_of_the_pipe, buf, length);
 }
 }
 /** \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;
   }
   // The child exits early to avoid running the full shutdown sequence and avoid conflicting with threads
   // we have already spawned (like the profiler).
   if (pid == 0) {
       close(pfd[0]);
       write_end_of_the_pipe = pfd[1];
       glxtest();
       close(pfd[1]);
       _exit(0);
   }
   close(pfd[1]);
   mozilla::widget::glxtest_pipe = pfd[0];
   mozilla::widget::glxtest_pid = pid;
   return false;
 }

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toolkit/xre/glxtest.cpp@6474c204b198 (annotated)

toolkit/xre/glxtest.cpp