src/egl/main/eglglobals.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 VMware, Inc.
   4  * Copyright 2009-2010 Chia-I Wu <olvaffe@gmail.com>
   5  * Copyright 2010-2011 LunarG, Inc.
   6  * All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the
  10  * "Software"), to deal in the Software without restriction, including
  11  * without limitation the rights to use, copy, modify, merge, publish,
  12  * distribute, sub license, and/or sell copies of the Software, and to
  13  * permit persons to whom the Software is furnished to do so, subject to
  14  * the following conditions:
  15  *
  16  * The above copyright notice and this permission notice (including the
  17  * next paragraph) shall be included in all copies or substantial portions
  18  * of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  25  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  26  * DEALINGS IN THE SOFTWARE.
  27  *
  28  **************************************************************************/
  29
  30
  31 #include <stdlib.h>
  32 #include <stdio.h>
  33 #include <string.h>
  34 #include <assert.h>
  35 #include "c11/threads.h"
  36
  37 #include "eglglobals.h"
  38 #include "egldisplay.h"
  39 #include "egldriver.h"
  40 #include "egllog.h"
  41
  42 #ifdef HAVE_MINCORE
  43 #include <unistd.h>
  44 #include <sys/mman.h>
  45 #endif
  46
  47
  48 static mtx_t _eglGlobalMutex = _MTX_INITIALIZER_NP;
  49
  50 struct _egl_global _eglGlobal =
  51 {
  52    .Mutex = &_eglGlobalMutex,
  53    .DisplayList = NULL,
  54    .NumAtExitCalls = 2,
  55    .AtExitCalls = {
  56       /* default AtExitCalls, called in reverse order */
  57       _eglUnloadDrivers, /* always called last */
  58       _eglFiniDisplay
  59    },
  60
  61    .ClientOnlyExtensionString =
  62    "EGL_EXT_client_extensions"
  63    " EGL_EXT_platform_base"
  64    " EGL_KHR_client_get_all_proc_addresses"
  65    " EGL_KHR_debug",
  66
  67    .PlatformExtensionString =
  68 #ifdef HAVE_WAYLAND_PLATFORM
  69    " EGL_EXT_platform_wayland"
  70 #endif
  71 #ifdef HAVE_X11_PLATFORM
  72    " EGL_EXT_platform_x11"
  73 #endif
  74 #ifdef HAVE_DRM_PLATFORM
  75    " EGL_MESA_platform_gbm"
  76 #endif
  77 #ifdef HAVE_SURFACELESS_PLATFORM
  78    " EGL_MESA_platform_surfaceless"
  79 #endif
  80    "",
  81
  82    .ClientExtensionString = NULL,
  83
  84    .debugCallback = NULL,
  85    .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
  86 };
  87
  88
  89 static void
  90 _eglAtExit(void)
  91 {
  92    EGLint i;
  93    for (i = _eglGlobal.NumAtExitCalls - 1; i >= 0; i--)
  94       _eglGlobal.AtExitCalls[i]();
  95 }
  96
  97
  98 void
  99 _eglAddAtExitCall(void (*func)(void))
 100 {
 101    if (func) {
 102       static EGLBoolean registered = EGL_FALSE;
 103
 104       mtx_lock(_eglGlobal.Mutex);
 105
 106       if (!registered) {
 107          atexit(_eglAtExit);
 108          registered = EGL_TRUE;
 109       }
 110
 111       assert(_eglGlobal.NumAtExitCalls < ARRAY_SIZE(_eglGlobal.AtExitCalls));
 112       _eglGlobal.AtExitCalls[_eglGlobal.NumAtExitCalls++] = func;
 113
 114       mtx_unlock(_eglGlobal.Mutex);
 115    }
 116 }
 117
 118 const char *
 119 _eglGetClientExtensionString(void)
 120 {
 121    const char *ret;
 122
 123    mtx_lock(_eglGlobal.Mutex);
 124
 125    if (_eglGlobal.ClientExtensionString == NULL) {
 126       size_t clientLen = strlen(_eglGlobal.ClientOnlyExtensionString);
 127       size_t platformLen = strlen(_eglGlobal.PlatformExtensionString);
 128
 129       _eglGlobal.ClientExtensionString = (char *) malloc(clientLen + platformLen + 1);
 130       if (_eglGlobal.ClientExtensionString != NULL) {
 131          char *ptr = _eglGlobal.ClientExtensionString;
 132
 133          memcpy(ptr, _eglGlobal.ClientOnlyExtensionString, clientLen);
 134          ptr += clientLen;
 135
 136          if (platformLen > 0) {
 137             // Note that if PlatformExtensionString is not empty, then it will
 138             // already have a leading space.
 139             assert(_eglGlobal.PlatformExtensionString[0] == ' ');
 140             memcpy(ptr, _eglGlobal.PlatformExtensionString, platformLen);
 141             ptr += platformLen;
 142          }
 143          *ptr = '\0';
 144       }
 145    }
 146    ret = _eglGlobal.ClientExtensionString;
 147
 148    mtx_unlock(_eglGlobal.Mutex);
 149    return ret;
 150 }
 151
 152 EGLBoolean
 153 _eglPointerIsDereferencable(void *p)
 154 {
 155 #ifdef HAVE_MINCORE
 156    uintptr_t addr = (uintptr_t) p;
 157    unsigned char valid = 0;
 158    const long page_size = getpagesize();
 159
 160    if (p == NULL)
 161       return EGL_FALSE;
 162
 163    /* align addr to page_size */
 164    addr &= ~(page_size - 1);
 165
 166    if (mincore((void *) addr, page_size, &valid) < 0) {
 167       _eglLog(_EGL_DEBUG, "mincore failed: %m");
 168       return EGL_FALSE;
 169    }
 170
 171    /* mincore() returns 0 on success, and -1 on failure.  The last parameter
 172     * is a vector of bytes with one entry for each page queried.  mincore
 173     * returns page residency information in the first bit of each byte in the
 174     * vector.
 175     *
 176     * Residency doesn't actually matter when determining whether a pointer is
 177     * dereferenceable, so the output vector can be ignored.  What matters is
 178     * whether mincore succeeds. See:
 179     *
 180     *   http://man7.org/linux/man-pages/man2/mincore.2.html
 181     */
 182    return EGL_TRUE;
 183 #else
 184    return p != NULL;
 185 #endif
 186 }