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 #include "util/macros.h"
  44
  45 #ifdef HAVE_MINCORE
  46 #include <unistd.h>
  47 #include <sys/mman.h>
  48 #endif
  49
  50
  51 static mtx_t _eglGlobalMutex = _MTX_INITIALIZER_NP;
  52
  53 struct _egl_global _eglGlobal =
  54 {
  55    .Mutex = &_eglGlobalMutex,
  56    .DisplayList = NULL,
  57    .DeviceList = &_eglSoftwareDevice,
  58    .NumAtExitCalls = 3,
  59    .AtExitCalls = {
  60       /* default AtExitCalls, called in reverse order */
  61       _eglFiniDevice, /* always called last */
  62       _eglUnloadDrivers,
  63       _eglFiniDisplay,
  64    },
  65
  66    .ClientOnlyExtensionString =
  67    "EGL_EXT_client_extensions"
  68    " EGL_EXT_device_base"
  69    " EGL_EXT_device_enumeration"
  70    " EGL_EXT_device_query"
  71    " EGL_EXT_platform_base"
  72    " EGL_KHR_client_get_all_proc_addresses"
  73    " EGL_KHR_debug"
  74    " EGL_MESA_config_select_group",
  75
  76    .PlatformExtensionString =
  77 #ifdef HAVE_WAYLAND_PLATFORM
  78    " EGL_EXT_platform_wayland"
  79 #endif
  80 #ifdef HAVE_X11_PLATFORM
  81    " EGL_EXT_platform_x11"
  82 #endif
  83 #ifdef HAVE_DRM_PLATFORM
  84    " EGL_MESA_platform_gbm"
  85 #endif
  86 #ifdef HAVE_SURFACELESS_PLATFORM
  87    " EGL_MESA_platform_surfaceless"
  88 #endif
  89    " EGL_EXT_platform_device"
  90    "",
  91
  92    .ClientExtensionString = NULL,
  93
  94    .debugCallback = NULL,
  95    .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
  96 };
  97
  98
  99 static void
 100 _eglAtExit(void)
 101 {
 102    EGLint i;
 103    for (i = _eglGlobal.NumAtExitCalls - 1; i >= 0; i--)
 104       _eglGlobal.AtExitCalls[i]();
 105 }
 106
 107
 108 void
 109 _eglAddAtExitCall(void (*func)(void))
 110 {
 111    if (func) {
 112       static EGLBoolean registered = EGL_FALSE;
 113
 114       mtx_lock(_eglGlobal.Mutex);
 115
 116       if (!registered) {
 117          atexit(_eglAtExit);
 118          registered = EGL_TRUE;
 119       }
 120
 121       assert(_eglGlobal.NumAtExitCalls < ARRAY_SIZE(_eglGlobal.AtExitCalls));
 122       _eglGlobal.AtExitCalls[_eglGlobal.NumAtExitCalls++] = func;
 123
 124       mtx_unlock(_eglGlobal.Mutex);
 125    }
 126 }
 127
 128 const char *
 129 _eglGetClientExtensionString(void)
 130 {
 131    const char *ret;
 132
 133    mtx_lock(_eglGlobal.Mutex);
 134
 135    if (_eglGlobal.ClientExtensionString == NULL) {
 136       size_t clientLen = strlen(_eglGlobal.ClientOnlyExtensionString);
 137       size_t platformLen = strlen(_eglGlobal.PlatformExtensionString);
 138
 139       _eglGlobal.ClientExtensionString = (char *) malloc(clientLen + platformLen + 1);
 140       if (_eglGlobal.ClientExtensionString != NULL) {
 141          char *ptr = _eglGlobal.ClientExtensionString;
 142
 143          memcpy(ptr, _eglGlobal.ClientOnlyExtensionString, clientLen);
 144          ptr += clientLen;
 145
 146          if (platformLen > 0) {
 147             // Note that if PlatformExtensionString is not empty, then it will
 148             // already have a leading space.
 149             assert(_eglGlobal.PlatformExtensionString[0] == ' ');
 150             memcpy(ptr, _eglGlobal.PlatformExtensionString, platformLen);
 151             ptr += platformLen;
 152          }
 153          *ptr = '\0';
 154       }
 155    }
 156    ret = _eglGlobal.ClientExtensionString;
 157
 158    mtx_unlock(_eglGlobal.Mutex);
 159    return ret;
 160 }
 161
 162 EGLBoolean
 163 _eglPointerIsDereferencable(void *p)
 164 {
 165 #ifdef HAVE_MINCORE
 166    uintptr_t addr = (uintptr_t) p;
 167    unsigned char valid = 0;
 168    const long page_size = getpagesize();
 169
 170    if (p == NULL)
 171       return EGL_FALSE;
 172
 173    /* align addr to page_size */
 174    addr &= ~(page_size - 1);
 175
 176    if (mincore((void *) addr, page_size, &valid) < 0) {
 177       _eglLog(_EGL_DEBUG, "mincore failed: %m");
 178       return EGL_FALSE;
 179    }
 180
 181    /* mincore() returns 0 on success, and -1 on failure.  The last parameter
 182     * is a vector of bytes with one entry for each page queried.  mincore
 183     * returns page residency information in the first bit of each byte in the
 184     * vector.
 185     *
 186     * Residency doesn't actually matter when determining whether a pointer is
 187     * dereferenceable, so the output vector can be ignored.  What matters is
 188     * whether mincore succeeds. See:
 189     *
 190     *   http://man7.org/linux/man-pages/man2/mincore.2.html
 191     */
 192    return EGL_TRUE;
 193 #else
 194    return p != NULL;
 195 #endif
 196 }