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    .ClientOnlyExtensionString =
  66    "EGL_EXT_client_extensions"
  67    " EGL_EXT_device_base"
  68    " EGL_EXT_device_enumeration"
  69    " EGL_EXT_device_query"
  70    " EGL_EXT_platform_base"
  71    " EGL_KHR_client_get_all_proc_addresses"
  72    " EGL_KHR_debug",
  73
  74    .PlatformExtensionString =
  75 #ifdef HAVE_WAYLAND_PLATFORM
  76    " EGL_EXT_platform_wayland"
  77 #endif
  78 #ifdef HAVE_X11_PLATFORM
  79    " EGL_EXT_platform_x11"
  80 #endif
  81 #ifdef HAVE_DRM_PLATFORM
  82    " EGL_MESA_platform_gbm"
  83 #endif
  84 #ifdef HAVE_SURFACELESS_PLATFORM
  85    " EGL_MESA_platform_surfaceless"
  86 #endif
  87    " EGL_EXT_platform_device"
  88    "",
  89
  90    .ClientExtensionString = NULL,
  91
  92    .debugCallback = NULL,
  93    .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
  94 };
  95
  96
  97 static void
  98 _eglAtExit(void)
  99 {
 100    EGLint i;
 101    for (i = _eglGlobal.NumAtExitCalls - 1; i >= 0; i--)
 102       _eglGlobal.AtExitCalls[i]();
 103 }
 104
 105
 106 void
 107 _eglAddAtExitCall(void (*func)(void))
 108 {
 109    if (func) {
 110       static EGLBoolean registered = EGL_FALSE;
 111
 112       mtx_lock(_eglGlobal.Mutex);
 113
 114       if (!registered) {
 115          atexit(_eglAtExit);
 116          registered = EGL_TRUE;
 117       }
 118
 119       assert(_eglGlobal.NumAtExitCalls < ARRAY_SIZE(_eglGlobal.AtExitCalls));
 120       _eglGlobal.AtExitCalls[_eglGlobal.NumAtExitCalls++] = func;
 121
 122       mtx_unlock(_eglGlobal.Mutex);
 123    }
 124 }
 125
 126 const char *
 127 _eglGetClientExtensionString(void)
 128 {
 129    const char *ret;
 130
 131    mtx_lock(_eglGlobal.Mutex);
 132
 133    if (_eglGlobal.ClientExtensionString == NULL) {
 134       size_t clientLen = strlen(_eglGlobal.ClientOnlyExtensionString);
 135       size_t platformLen = strlen(_eglGlobal.PlatformExtensionString);
 136
 137       _eglGlobal.ClientExtensionString = (char *) malloc(clientLen + platformLen + 1);
 138       if (_eglGlobal.ClientExtensionString != NULL) {
 139          char *ptr = _eglGlobal.ClientExtensionString;
 140
 141          memcpy(ptr, _eglGlobal.ClientOnlyExtensionString, clientLen);
 142          ptr += clientLen;
 143
 144          if (platformLen > 0) {
 145             // Note that if PlatformExtensionString is not empty, then it will
 146             // already have a leading space.
 147             assert(_eglGlobal.PlatformExtensionString[0] == ' ');
 148             memcpy(ptr, _eglGlobal.PlatformExtensionString, platformLen);
 149             ptr += platformLen;
 150          }
 151          *ptr = '\0';
 152       }
 153    }
 154    ret = _eglGlobal.ClientExtensionString;
 155
 156    mtx_unlock(_eglGlobal.Mutex);
 157    return ret;
 158 }
 159
 160 EGLBoolean
 161 _eglPointerIsDereferencable(void *p)
 162 {
 163    uintptr_t addr = (uintptr_t) p;
 164    const long page_size = getpagesize();
 165 #ifdef HAVE_MINCORE
 166    unsigned char valid = 0;
 167
 168    if (p == NULL)
 169       return EGL_FALSE;
 170
 171    /* align addr to page_size */
 172    addr &= ~(page_size - 1);
 173
 174    if (mincore((void *) addr, page_size, &valid) < 0) {
 175       return EGL_FALSE;
 176    }
 177
 178    /* mincore() returns 0 on success, and -1 on failure.  The last parameter
 179     * is a vector of bytes with one entry for each page queried.  mincore
 180     * returns page residency information in the first bit of each byte in the
 181     * vector.
 182     *
 183     * Residency doesn't actually matter when determining whether a pointer is
 184     * dereferenceable, so the output vector can be ignored.  What matters is
 185     * whether mincore succeeds. See:
 186     *
 187     *   http://man7.org/linux/man-pages/man2/mincore.2.html
 188     */
 189    return EGL_TRUE;
 190 #else
 191    // Without mincore(), we just assume that the first page is unmapped.
 192    return addr >= page_size;
 193 #endif
 194 }