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
  75    .PlatformExtensionString =
  76 #ifdef HAVE_WAYLAND_PLATFORM
  77    " EGL_EXT_platform_wayland"
  78 #endif
  79 #ifdef HAVE_X11_PLATFORM
  80    " EGL_EXT_platform_x11"
  81 #endif
  82 #ifdef HAVE_DRM_PLATFORM
  83    " EGL_MESA_platform_gbm"
  84 #endif
  85 #ifdef HAVE_SURFACELESS_PLATFORM
  86    " EGL_MESA_platform_surfaceless"
  87 #endif
  88    " EGL_EXT_platform_device"
  89    "",
  90
  91    .ClientExtensionString = NULL,
  92
  93    .debugCallback = NULL,
  94    .debugTypesEnabled = _EGL_DEBUG_BIT_CRITICAL | _EGL_DEBUG_BIT_ERROR,
  95 };
  96
  97
  98 static void
  99 _eglAtExit(void)
 100 {
 101    EGLint i;
 102    for (i = _eglGlobal.NumAtExitCalls - 1; i >= 0; i--)
 103       _eglGlobal.AtExitCalls[i]();
 104 }
 105
 106
 107 void
 108 _eglAddAtExitCall(void (*func)(void))
 109 {
 110    if (func) {
 111       static EGLBoolean registered = EGL_FALSE;
 112
 113       mtx_lock(_eglGlobal.Mutex);
 114
 115       if (!registered) {
 116          atexit(_eglAtExit);
 117          registered = EGL_TRUE;
 118       }
 119
 120       assert(_eglGlobal.NumAtExitCalls < ARRAY_SIZE(_eglGlobal.AtExitCalls));
 121       _eglGlobal.AtExitCalls[_eglGlobal.NumAtExitCalls++] = func;
 122
 123       mtx_unlock(_eglGlobal.Mutex);
 124    }
 125 }
 126
 127 const char *
 128 _eglGetClientExtensionString(void)
 129 {
 130    const char *ret;
 131
 132    mtx_lock(_eglGlobal.Mutex);
 133
 134    if (_eglGlobal.ClientExtensionString == NULL) {
 135       size_t clientLen = strlen(_eglGlobal.ClientOnlyExtensionString);
 136       size_t platformLen = strlen(_eglGlobal.PlatformExtensionString);
 137
 138       _eglGlobal.ClientExtensionString = (char *) malloc(clientLen + platformLen + 1);
 139       if (_eglGlobal.ClientExtensionString != NULL) {
 140          char *ptr = _eglGlobal.ClientExtensionString;
 141
 142          memcpy(ptr, _eglGlobal.ClientOnlyExtensionString, clientLen);
 143          ptr += clientLen;
 144
 145          if (platformLen > 0) {
 146             // Note that if PlatformExtensionString is not empty, then it will
 147             // already have a leading space.
 148             assert(_eglGlobal.PlatformExtensionString[0] == ' ');
 149             memcpy(ptr, _eglGlobal.PlatformExtensionString, platformLen);
 150             ptr += platformLen;
 151          }
 152          *ptr = '\0';
 153       }
 154    }
 155    ret = _eglGlobal.ClientExtensionString;
 156
 157    mtx_unlock(_eglGlobal.Mutex);
 158    return ret;
 159 }
 160
 161 EGLBoolean
 162 _eglPointerIsDereferencable(void *p)
 163 {
 164    uintptr_t addr = (uintptr_t) p;
 165    const long page_size = getpagesize();
 166 #ifdef HAVE_MINCORE
 167    unsigned char valid = 0;
 168
 169    if (p == NULL)
 170       return EGL_FALSE;
 171
 172    /* align addr to page_size */
 173    addr &= ~(page_size - 1);
 174
 175    if (mincore((void *) addr, page_size, &valid) < 0) {
 176       _eglLog(_EGL_DEBUG, "mincore failed: %m");
 177       return EGL_FALSE;
 178    }
 179
 180    /* mincore() returns 0 on success, and -1 on failure.  The last parameter
 181     * is a vector of bytes with one entry for each page queried.  mincore
 182     * returns page residency information in the first bit of each byte in the
 183     * vector.
 184     *
 185     * Residency doesn't actually matter when determining whether a pointer is
 186     * dereferenceable, so the output vector can be ignored.  What matters is
 187     * whether mincore succeeds. See:
 188     *
 189     *   http://man7.org/linux/man-pages/man2/mincore.2.html
 190     */
 191    return EGL_TRUE;
 192 #else
 193    // Without mincore(), we just assume that the first page is unmapped.
 194    return addr >= page_size;
 195 #endif
 196 }