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