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
  42 #include "util/macros.h"
  43
  44 #ifdef HAVE_MINCORE
  45 #include <unistd.h>
  46 #include <sys/mman.h>
  47 #endif
  48
  49
  50 static mtx_t _eglGlobalMutex = _MTX_INITIALIZER_NP;
  51
  52 struct _egl_global _eglGlobal =
  53 {
  54    .Mutex = &_eglGlobalMutex,
  55    .DisplayList = NULL,
  56    .DeviceList = &_eglSoftwareDevice,
  57    .NumAtExitCalls = 3,
  58    .AtExitCalls = {
  59       /* default AtExitCalls, called in reverse order */
  60       _eglFiniDevice, /* always called last */
  61       _eglUnloadDrivers,
  62       _eglFiniDisplay,
  63    },
  64
  65 #if USE_LIBGLVND
  66    .ClientOnlyExtensionString =
  67 #else
  68    .ClientExtensionString =
  69 #endif
  70    "EGL_EXT_client_extensions"
  71    " EGL_EXT_device_base"
  72    " EGL_EXT_device_enumeration"
  73    " EGL_EXT_device_query"
  74    " EGL_EXT_platform_base"
  75    " EGL_KHR_client_get_all_proc_addresses"
  76    " EGL_KHR_debug"
  77
  78 #if USE_LIBGLVND
  79    ,
  80    .PlatformExtensionString =
  81 #else
  82    " "
  83 #endif
  84
  85    "EGL_EXT_platform_device"
  86 #ifdef HAVE_WAYLAND_PLATFORM
  87    " EGL_EXT_platform_wayland"
  88 #endif
  89 #ifdef HAVE_X11_PLATFORM
  90    " EGL_EXT_platform_x11"
  91 #endif
  92 #ifdef HAVE_DRM_PLATFORM
  93    " EGL_MESA_platform_gbm"
  94 #endif
  95 #ifdef HAVE_SURFACELESS_PLATFORM
  96    " EGL_MESA_platform_surfaceless"
  97 #endif
  98    "",
  99
 100    .debugCallback = NULL,
 101    .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
 102 };
 103
 104
 105 static void
 106 _eglAtExit(void)
 107 {
 108    EGLint i;
 109    for (i = _eglGlobal.NumAtExitCalls - 1; i >= 0; i--)
 110       _eglGlobal.AtExitCalls[i]();
 111 }
 112
 113
 114 void
 115 _eglAddAtExitCall(void (*func)(void))
 116 {
 117    if (func) {
 118       static EGLBoolean registered = EGL_FALSE;
 119
 120       mtx_lock(_eglGlobal.Mutex);
 121
 122       if (!registered) {
 123          atexit(_eglAtExit);
 124          registered = EGL_TRUE;
 125       }
 126
 127       assert(_eglGlobal.NumAtExitCalls < ARRAY_SIZE(_eglGlobal.AtExitCalls));
 128       _eglGlobal.AtExitCalls[_eglGlobal.NumAtExitCalls++] = func;
 129
 130       mtx_unlock(_eglGlobal.Mutex);
 131    }
 132 }
 133
 134 EGLBoolean
 135 _eglPointerIsDereferencable(void *p)
 136 {
 137    uintptr_t addr = (uintptr_t) p;
 138    const long page_size = getpagesize();
 139 #ifdef HAVE_MINCORE
 140    unsigned char valid = 0;
 141
 142    if (p == NULL)
 143       return EGL_FALSE;
 144
 145    /* align addr to page_size */
 146    addr &= ~(page_size - 1);
 147
 148    if (mincore((void *) addr, page_size, &valid) < 0) {
 149       return EGL_FALSE;
 150    }
 151
 152    /* mincore() returns 0 on success, and -1 on failure.  The last parameter
 153     * is a vector of bytes with one entry for each page queried.  mincore
 154     * returns page residency information in the first bit of each byte in the
 155     * vector.
 156     *
 157     * Residency doesn't actually matter when determining whether a pointer is
 158     * dereferenceable, so the output vector can be ignored.  What matters is
 159     * whether mincore succeeds. See:
 160     *
 161     *   http://man7.org/linux/man-pages/man2/mincore.2.html
 162     */
 163    return EGL_TRUE;
 164 #else
 165    // Without mincore(), we just assume that the first page is unmapped.
 166    return addr >= page_size;
 167 #endif
 168 }