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 "egldevice.h"
  39 #include "egldisplay.h"
  40 #include "egldriver.h"
  41 #include "egllog.h"
  42
  43 #ifdef HAVE_MINCORE
  44 #include <unistd.h>
  45 #include <sys/mman.h>
  46 #endif
  47
  48
  49 static mtx_t _eglGlobalMutex = _MTX_INITIALIZER_NP;
  50
  51 struct _egl_global _eglGlobal =
  52 {
  53    .Mutex = &_eglGlobalMutex,
  54    .DisplayList = NULL,
  55    .DeviceList = &_eglSoftwareDevice,
  56    .NumAtExitCalls = 3,
  57    .AtExitCalls = {
  58       /* default AtExitCalls, called in reverse order */
  59       _eglFiniDevice, /* always called last */
  60       _eglUnloadDrivers,
  61       _eglFiniDisplay,
  62    },
  63
  64    .ClientOnlyExtensionString =
  65    "EGL_EXT_client_extensions"
  66    " EGL_EXT_platform_base"
  67    " EGL_KHR_client_get_all_proc_addresses"
  68    " EGL_KHR_debug",
  69
  70    .PlatformExtensionString =
  71 #ifdef HAVE_WAYLAND_PLATFORM
  72    " EGL_EXT_platform_wayland"
  73 #endif
  74 #ifdef HAVE_X11_PLATFORM
  75    " EGL_EXT_platform_x11"
  76 #endif
  77 #ifdef HAVE_DRM_PLATFORM
  78    " EGL_MESA_platform_gbm"
  79 #endif
  80 #ifdef HAVE_SURFACELESS_PLATFORM
  81    " EGL_MESA_platform_surfaceless"
  82 #endif
  83    "",
  84
  85    .ClientExtensionString = NULL,
  86
  87    .debugCallback = NULL,
  88    .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
  89 };
  90
  91
  92 static void
  93 _eglAtExit(void)
  94 {
  95    EGLint i;
  96    for (i = _eglGlobal.NumAtExitCalls - 1; i >= 0; i--)
  97       _eglGlobal.AtExitCalls[i]();
  98 }
  99
 100
 101 void
 102 _eglAddAtExitCall(void (*func)(void))
 103 {
 104    if (func) {
 105       static EGLBoolean registered = EGL_FALSE;
 106
 107       mtx_lock(_eglGlobal.Mutex);
 108
 109       if (!registered) {
 110          atexit(_eglAtExit);
 111          registered = EGL_TRUE;
 112       }
 113
 114       assert(_eglGlobal.NumAtExitCalls < ARRAY_SIZE(_eglGlobal.AtExitCalls));
 115       _eglGlobal.AtExitCalls[_eglGlobal.NumAtExitCalls++] = func;
 116
 117       mtx_unlock(_eglGlobal.Mutex);
 118    }
 119 }
 120
 121 const char *
 122 _eglGetClientExtensionString(void)
 123 {
 124    const char *ret;
 125
 126    mtx_lock(_eglGlobal.Mutex);
 127
 128    if (_eglGlobal.ClientExtensionString == NULL) {
 129       size_t clientLen = strlen(_eglGlobal.ClientOnlyExtensionString);
 130       size_t platformLen = strlen(_eglGlobal.PlatformExtensionString);
 131
 132       _eglGlobal.ClientExtensionString = (char *) malloc(clientLen + platformLen + 1);
 133       if (_eglGlobal.ClientExtensionString != NULL) {
 134          char *ptr = _eglGlobal.ClientExtensionString;
 135
 136          memcpy(ptr, _eglGlobal.ClientOnlyExtensionString, clientLen);
 137          ptr += clientLen;
 138
 139          if (platformLen > 0) {
 140             // Note that if PlatformExtensionString is not empty, then it will
 141             // already have a leading space.
 142             assert(_eglGlobal.PlatformExtensionString[0] == ' ');
 143             memcpy(ptr, _eglGlobal.PlatformExtensionString, platformLen);
 144             ptr += platformLen;
 145          }
 146          *ptr = '\0';
 147       }
 148    }
 149    ret = _eglGlobal.ClientExtensionString;
 150
 151    mtx_unlock(_eglGlobal.Mutex);
 152    return ret;
 153 }
 154
 155 EGLBoolean
 156 _eglPointerIsDereferencable(void *p)
 157 {
 158 #ifdef HAVE_MINCORE
 159    uintptr_t addr = (uintptr_t) p;
 160    unsigned char valid = 0;
 161    const long page_size = getpagesize();
 162
 163    if (p == NULL)
 164       return EGL_FALSE;
 165
 166    /* align addr to page_size */
 167    addr &= ~(page_size - 1);
 168
 169    if (mincore((void *) addr, page_size, &valid) < 0) {
 170       _eglLog(_EGL_DEBUG, "mincore failed: %m");
 171       return EGL_FALSE;
 172    }
 173
 174    /* mincore() returns 0 on success, and -1 on failure.  The last parameter
 175     * is a vector of bytes with one entry for each page queried.  mincore
 176     * returns page residency information in the first bit of each byte in the
 177     * vector.
 178     *
 179     * Residency doesn't actually matter when determining whether a pointer is
 180     * dereferenceable, so the output vector can be ignored.  What matters is
 181     * whether mincore succeeds. See:
 182     *
 183     *   http://man7.org/linux/man-pages/man2/mincore.2.html
 184     */
 185    return EGL_TRUE;
 186 #else
 187    return p != NULL;
 188 #endif
 189 }