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
  41 #include "util/macros.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 = 2,
  57    .AtExitCalls = {
  58       /* default AtExitCalls, called in reverse order */
  59       _eglFiniDevice, /* always called last */
  60       _eglFiniDisplay,
  61    },
  62
  63 #if USE_LIBGLVND
  64    .ClientOnlyExtensionString =
  65 #else
  66    .ClientExtensionString =
  67 #endif
  68    "EGL_EXT_client_extensions"
  69    " EGL_EXT_device_base"
  70    " EGL_EXT_device_enumeration"
  71    " EGL_EXT_device_query"
  72    " EGL_EXT_platform_base"
  73    " EGL_KHR_client_get_all_proc_addresses"
  74    " EGL_KHR_debug"
  75
  76 #if USE_LIBGLVND
  77    ,
  78    .PlatformExtensionString =
  79 #else
  80    " "
  81 #endif
  82
  83    "EGL_EXT_platform_device"
  84 #ifdef HAVE_WAYLAND_PLATFORM
  85    " EGL_EXT_platform_wayland"
  86    " EGL_KHR_platform_wayland"
  87 #endif
  88 #ifdef HAVE_X11_PLATFORM
  89    " EGL_EXT_platform_x11"
  90    " EGL_KHR_platform_x11"
  91 #endif
  92 #ifdef HAVE_DRM_PLATFORM
  93    " EGL_MESA_platform_gbm"
  94    " EGL_KHR_platform_gbm"
  95 #endif
  96    " EGL_MESA_platform_surfaceless"
  97    "",
  98
  99    .debugCallback = NULL,
 100    .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
 101 };
 102
 103
 104 static void
 105 _eglAtExit(void)
 106 {
 107    EGLint i;
 108    for (i = _eglGlobal.NumAtExitCalls - 1; i >= 0; i--)
 109       _eglGlobal.AtExitCalls[i]();
 110 }
 111
 112
 113 void
 114 _eglAddAtExitCall(void (*func)(void))
 115 {
 116    if (func) {
 117       static EGLBoolean registered = EGL_FALSE;
 118
 119       mtx_lock(_eglGlobal.Mutex);
 120
 121       if (!registered) {
 122          atexit(_eglAtExit);
 123          registered = EGL_TRUE;
 124       }
 125
 126       assert(_eglGlobal.NumAtExitCalls < ARRAY_SIZE(_eglGlobal.AtExitCalls));
 127       _eglGlobal.AtExitCalls[_eglGlobal.NumAtExitCalls++] = func;
 128
 129       mtx_unlock(_eglGlobal.Mutex);
 130    }
 131 }
 132
 133 EGLBoolean
 134 _eglPointerIsDereferencable(void *p)
 135 {
 136    uintptr_t addr = (uintptr_t) p;
 137    const long page_size = getpagesize();
 138 #ifdef HAVE_MINCORE
 139    unsigned char valid = 0;
 140
 141    if (p == NULL)
 142       return EGL_FALSE;
 143
 144    /* align addr to page_size */
 145    addr &= ~(page_size - 1);
 146
 147    if (mincore((void *) addr, page_size, &valid) < 0) {
 148       return EGL_FALSE;
 149    }
 150
 151    /* mincore() returns 0 on success, and -1 on failure.  The last parameter
 152     * is a vector of bytes with one entry for each page queried.  mincore
 153     * returns page residency information in the first bit of each byte in the
 154     * vector.
 155     *
 156     * Residency doesn't actually matter when determining whether a pointer is
 157     * dereferenceable, so the output vector can be ignored.  What matters is
 158     * whether mincore succeeds. See:
 159     *
 160     *   http://man7.org/linux/man-pages/man2/mincore.2.html
 161     */
 162    return EGL_TRUE;
 163 #else
 164    // Without mincore(), we just assume that the first page is unmapped.
 165    return addr >= page_size;
 166 #endif
 167 }