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 #include "util/debug.h"
48
49 static mtx_t _eglModuleMutex = _MTX_INITIALIZER_NP;
50 static _EGLDriver *_eglDriver;
51
52 static _EGLDriver *
_eglGetDriver(void)53 _eglGetDriver(void)
54 {
55 mtx_lock(&_eglModuleMutex);
56
57 if (!_eglDriver)
58 _eglDriver = _eglBuiltInDriver();
59
60 mtx_unlock(&_eglModuleMutex);
61
62 return _eglDriver;
63 }
64
65 static _EGLDriver *
_eglMatchAndInitialize(_EGLDisplay * dpy)66 _eglMatchAndInitialize(_EGLDisplay *dpy)
67 {
68 if (_eglGetDriver())
69 if (_eglDriver->API.Initialize(_eglDriver, dpy))
70 return _eglDriver;
71
72 return NULL;
73 }
74
75 /**
76 * Match a display to a driver. The matching is done by finding the first
77 * driver that can initialize the display.
78 */
79 _EGLDriver *
_eglMatchDriver(_EGLDisplay * dpy)80 _eglMatchDriver(_EGLDisplay *dpy)
81 {
82 _EGLDriver *best_drv;
83
84 assert(!dpy->Initialized);
85
86 /* set options */
87 dpy->Options.ForceSoftware =
88 env_var_as_boolean("LIBGL_ALWAYS_SOFTWARE", false);
89
90 best_drv = _eglMatchAndInitialize(dpy);
91 if (!best_drv && !dpy->Options.ForceSoftware) {
92 dpy->Options.ForceSoftware = EGL_TRUE;
93 best_drv = _eglMatchAndInitialize(dpy);
94 }
95
96 if (best_drv) {
97 _eglLog(_EGL_DEBUG, "the best driver is %s",
98 best_drv->Name);
99 dpy->Driver = best_drv;
100 dpy->Initialized = EGL_TRUE;
101 }
102
103 return best_drv;
104 }
105
106 __eglMustCastToProperFunctionPointerType
_eglGetDriverProc(const char * procname)107 _eglGetDriverProc(const char *procname)
108 {
109 if (_eglGetDriver())
110 return _eglDriver->API.GetProcAddress(_eglDriver, procname);
111
112 return NULL;
113 }
114
115 /**
116 * Unload all drivers.
117 */
118 void
_eglUnloadDrivers(void)119 _eglUnloadDrivers(void)
120 {
121 /* this is called at atexit time */
122 free(_eglDriver);
123 _eglDriver = NULL;
124 }
125