src/egl/main/egldriver.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 /**
  32  * Functions for choosing and opening/loading device drivers.
  33  */
  34
  35
  36 #include <assert.h>
  37 #include <string.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include "c11/threads.h"
  41
  42 #include "egldefines.h"
  43 #include "egldisplay.h"
  44 #include "egldriver.h"
  45 #include "egllog.h"
  46
  47 static mtx_t _eglModuleMutex = _MTX_INITIALIZER_NP;
  48 static _EGLDriver *_eglDriver;
  49
  50 static _EGLDriver *
  51 _eglGetDriver(void)
  52 {
  53    mtx_lock(&_eglModuleMutex);
  54
  55    if (!_eglDriver) {
  56       _eglDriver = calloc(1, sizeof(*_eglDriver));
  57       if (!_eglDriver)
  58          return NULL;
  59       _eglInitDriver(_eglDriver);
  60    }
  61
  62    mtx_unlock(&_eglModuleMutex);
  63
  64    return _eglDriver;
  65 }
  66
  67 static _EGLDriver *
  68 _eglMatchAndInitialize(_EGLDisplay *dpy)
  69 {
  70    if (_eglGetDriver())
  71       if (_eglDriver->API.Initialize(_eglDriver, dpy))
  72          return _eglDriver;
  73
  74    return NULL;
  75 }
  76
  77 /**
  78  * Match a display to a driver.  The display is initialized unless test_only is
  79  * true.  The matching is done by finding the first driver that can initialize
  80  * the display.
  81  */
  82 _EGLDriver *
  83 _eglMatchDriver(_EGLDisplay *dpy, EGLBoolean test_only)
  84 {
  85    _EGLDriver *best_drv;
  86
  87    assert(!dpy->Initialized);
  88
  89    /* set options */
  90    dpy->Options.TestOnly = test_only;
  91    dpy->Options.UseFallback = EGL_FALSE;
  92
  93    best_drv = _eglMatchAndInitialize(dpy);
  94    if (!best_drv) {
  95       dpy->Options.UseFallback = EGL_TRUE;
  96       best_drv = _eglMatchAndInitialize(dpy);
  97    }
  98
  99    if (best_drv) {
 100       _eglLog(_EGL_DEBUG, "the best driver is %s%s",
 101             best_drv->Name, (test_only) ? " (test only) " : "");
 102       if (!test_only) {
 103          dpy->Driver = best_drv;
 104          dpy->Initialized = EGL_TRUE;
 105       }
 106    }
 107
 108    return best_drv;
 109 }
 110
 111 __eglMustCastToProperFunctionPointerType
 112 _eglGetDriverProc(const char *procname)
 113 {
 114    if (_eglGetDriver())
 115       return _eglDriver->API.GetProcAddress(_eglDriver, procname);
 116
 117    return NULL;
 118 }
 119
 120 /**
 121  * Unload all drivers.
 122  */
 123 void
 124 _eglUnloadDrivers(void)
 125 {
 126    /* this is called at atexit time */
 127    free(_eglDriver);
 128    _eglDriver = NULL;
 129 }