0d8919aa0e1cce345a6780db81de2e974ae2b05e
[mesa.git] / 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 #include "util/debug.h"
48
49 static mtx_t _eglModuleMutex = _MTX_INITIALIZER_NP;
50 static _EGLDriver *_eglDriver;
51
52 static _EGLDriver *
53 _eglGetDriver(void)
54 {
55 mtx_lock(&_eglModuleMutex);
56
57 if (!_eglDriver) {
58 _eglDriver = calloc(1, sizeof(*_eglDriver));
59 if (!_eglDriver) {
60 mtx_unlock(&_eglModuleMutex);
61 return NULL;
62 }
63 _eglInitDriver(_eglDriver);
64 }
65
66 mtx_unlock(&_eglModuleMutex);
67
68 return _eglDriver;
69 }
70
71 static _EGLDriver *
72 _eglMatchAndInitialize(_EGLDisplay *disp)
73 {
74 if (_eglGetDriver())
75 if (_eglDriver->API.Initialize(_eglDriver, disp))
76 return _eglDriver;
77
78 return NULL;
79 }
80
81 /**
82 * Match a display to a driver. The matching is done by finding the first
83 * driver that can initialize the display.
84 */
85 _EGLDriver *
86 _eglMatchDriver(_EGLDisplay *disp)
87 {
88 _EGLDriver *best_drv;
89
90 assert(!disp->Initialized);
91
92 /* set options */
93 disp->Options.ForceSoftware =
94 env_var_as_boolean("LIBGL_ALWAYS_SOFTWARE", false);
95
96 best_drv = _eglMatchAndInitialize(disp);
97 if (!best_drv && !disp->Options.ForceSoftware) {
98 disp->Options.ForceSoftware = EGL_TRUE;
99 best_drv = _eglMatchAndInitialize(disp);
100 }
101
102 if (best_drv) {
103 disp->Driver = best_drv;
104 disp->Initialized = EGL_TRUE;
105 }
106
107 return best_drv;
108 }
109
110 __eglMustCastToProperFunctionPointerType
111 _eglGetDriverProc(const char *procname)
112 {
113 if (_eglGetDriver() && _eglDriver->API.GetProcAddress)
114 return _eglDriver->API.GetProcAddress(_eglDriver, procname);
115
116 return NULL;
117 }
118
119 /**
120 * Unload all drivers.
121 */
122 void
123 _eglUnloadDrivers(void)
124 {
125 /* this is called at atexit time */
126 free(_eglDriver);
127 _eglDriver = NULL;
128 }