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 typedef struct _egl_module {
  48    char *Name;
  49    _EGLMain_t BuiltIn;
  50    _EGLDriver *Driver;
  51 } _EGLModule;
  52
  53 static mtx_t _eglModuleMutex = _MTX_INITIALIZER_NP;
  54 static _EGLArray *_eglModules;
  55
  56 const struct {
  57    const char *name;
  58    _EGLMain_t main;
  59 } _eglBuiltInDrivers[] = {
  60 #ifdef _EGL_BUILT_IN_DRIVER_DRI2
  61    { "egl_dri2", _eglBuiltInDriverDRI2 },
  62 #endif
  63 #ifdef _EGL_BUILT_IN_DRIVER_HAIKU
  64    { "egl_haiku", _eglBuiltInDriverHaiku },
  65 #endif
  66    { NULL, NULL }
  67 };
  68
  69 /**
  70  * Load a module and create the driver object.
  71  */
  72 static EGLBoolean
  73 _eglLoadModule(_EGLModule *mod)
  74 {
  75    _EGLDriver *drv;
  76
  77    if (mod->Driver)
  78       return EGL_TRUE;
  79
  80    if (!mod->BuiltIn)
  81          return EGL_FALSE;
  82
  83    drv = mod->BuiltIn(NULL);
  84    if (!drv || !drv->Name)
  85       return EGL_FALSE;
  86
  87    mod->Driver = drv;
  88
  89    return EGL_TRUE;
  90 }
  91
  92
  93 /**
  94  * Unload a module.
  95  */
  96 static void
  97 _eglUnloadModule(_EGLModule *mod)
  98 {
  99    /* destroy the driver */
 100    if (mod->Driver && mod->Driver->Unload)
 101       mod->Driver->Unload(mod->Driver);
 102
 103    mod->Driver = NULL;
 104 }
 105
 106
 107 /**
 108  * Add a module to the module array.
 109  */
 110 static _EGLModule *
 111 _eglAddModule(const char *name)
 112 {
 113    _EGLModule *mod;
 114    EGLint i;
 115
 116    if (!_eglModules) {
 117       _eglModules = _eglCreateArray("Module", 8);
 118       if (!_eglModules)
 119          return NULL;
 120    }
 121
 122    /* find duplicates */
 123    for (i = 0; i < _eglModules->Size; i++) {
 124       mod = _eglModules->Elements[i];
 125       if (strcmp(mod->Name, name) == 0)
 126          return mod;
 127    }
 128
 129    /* allocate a new one */
 130    mod = calloc(1, sizeof(*mod));
 131    if (mod) {
 132       mod->Name = strdup(name);
 133       if (!mod->Name) {
 134          free(mod);
 135          mod = NULL;
 136       }
 137    }
 138    if (mod) {
 139       _eglAppendArray(_eglModules, (void *) mod);
 140       _eglLog(_EGL_DEBUG, "added %s to module array", mod->Name);
 141    }
 142
 143    return mod;
 144 }
 145
 146
 147 /**
 148  * Free a module.
 149  */
 150 static void
 151 _eglFreeModule(void *module)
 152 {
 153    _EGLModule *mod = (_EGLModule *) module;
 154
 155    _eglUnloadModule(mod);
 156    free(mod->Name);
 157    free(mod);
 158 }
 159
 160
 161 /**
 162  * Add the user driver to the module array.
 163  *
 164  * The user driver is specified by EGL_DRIVER.
 165  */
 166 static EGLBoolean
 167 _eglAddUserDriver(void)
 168 {
 169    char *env;
 170
 171    env = getenv("EGL_DRIVER");
 172    if (env) {
 173       EGLint i;
 174
 175       for (i = 0; _eglBuiltInDrivers[i].name; i++) {
 176          if (!strcmp(_eglBuiltInDrivers[i].name, env)) {
 177             _EGLModule *mod = _eglAddModule(env);
 178             if (mod)
 179                mod->BuiltIn = _eglBuiltInDrivers[i].main;
 180
 181             return EGL_TRUE;
 182          }
 183       }
 184    }
 185
 186    return EGL_FALSE;
 187 }
 188
 189
 190 /**
 191  * Add built-in drivers to the module array.
 192  */
 193 static void
 194 _eglAddBuiltInDrivers(void)
 195 {
 196    _EGLModule *mod;
 197    EGLint i;
 198
 199    for (i = 0; _eglBuiltInDrivers[i].name; i++) {
 200       mod = _eglAddModule(_eglBuiltInDrivers[i].name);
 201       if (mod)
 202          mod->BuiltIn = _eglBuiltInDrivers[i].main;
 203    }
 204 }
 205
 206
 207 /**
 208  * Add drivers to the module array.  Drivers will be loaded as they are matched
 209  * to displays.
 210  */
 211 static EGLBoolean
 212 _eglAddDrivers(void)
 213 {
 214    if (_eglModules)
 215       return EGL_TRUE;
 216
 217    if (!_eglAddUserDriver()) {
 218       /*
 219        * Add other drivers only when EGL_DRIVER is not set.  The order here
 220        * decides the priorities.
 221        */
 222       _eglAddBuiltInDrivers();
 223    }
 224
 225    return (_eglModules != NULL);
 226 }
 227
 228
 229 /**
 230  * A helper function for _eglMatchDriver.  It finds the first driver that can
 231  * initialize the display and return.
 232  */
 233 static _EGLDriver *
 234 _eglMatchAndInitialize(_EGLDisplay *dpy)
 235 {
 236    _EGLDriver *drv = NULL;
 237    EGLint i = 0;
 238
 239    if (!_eglAddDrivers()) {
 240       _eglLog(_EGL_WARNING, "failed to find any driver");
 241       return NULL;
 242    }
 243
 244    if (dpy->Driver) {
 245       drv = dpy->Driver;
 246       /* no re-matching? */
 247       if (!drv->API.Initialize(drv, dpy))
 248          drv = NULL;
 249       return drv;
 250    }
 251
 252    while (i < _eglModules->Size) {
 253       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 254
 255       if (!_eglLoadModule(mod)) {
 256          /* remove invalid modules */
 257          _eglEraseArray(_eglModules, i, _eglFreeModule);
 258          continue;
 259       }
 260
 261       if (mod->Driver->API.Initialize(mod->Driver, dpy)) {
 262          drv = mod->Driver;
 263          break;
 264       }
 265       else {
 266          i++;
 267       }
 268    }
 269
 270    return drv;
 271 }
 272
 273
 274 /**
 275  * Match a display to a driver.  The display is initialized unless test_only is
 276  * true.  The matching is done by finding the first driver that can initialize
 277  * the display.
 278  */
 279 _EGLDriver *
 280 _eglMatchDriver(_EGLDisplay *dpy, EGLBoolean test_only)
 281 {
 282    _EGLDriver *best_drv;
 283
 284    assert(!dpy->Initialized);
 285
 286    mtx_lock(&_eglModuleMutex);
 287
 288    /* set options */
 289    dpy->Options.TestOnly = test_only;
 290    dpy->Options.UseFallback = EGL_FALSE;
 291
 292    best_drv = _eglMatchAndInitialize(dpy);
 293    if (!best_drv) {
 294       dpy->Options.UseFallback = EGL_TRUE;
 295       best_drv = _eglMatchAndInitialize(dpy);
 296    }
 297
 298    mtx_unlock(&_eglModuleMutex);
 299
 300    if (best_drv) {
 301       _eglLog(_EGL_DEBUG, "the best driver is %s%s",
 302             best_drv->Name, (test_only) ? " (test only) " : "");
 303       if (!test_only) {
 304          dpy->Driver = best_drv;
 305          dpy->Initialized = EGL_TRUE;
 306       }
 307    }
 308
 309    return best_drv;
 310 }
 311
 312
 313 __eglMustCastToProperFunctionPointerType
 314 _eglGetDriverProc(const char *procname)
 315 {
 316    EGLint i;
 317    _EGLProc proc = NULL;
 318
 319    if (!_eglModules) {
 320       /* load the driver for the default display */
 321       EGLDisplay egldpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
 322       _EGLDisplay *dpy = _eglLookupDisplay(egldpy);
 323       if (!dpy || !_eglMatchDriver(dpy, EGL_TRUE))
 324          return NULL;
 325    }
 326
 327    for (i = 0; i < _eglModules->Size; i++) {
 328       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 329
 330       if (!mod->Driver)
 331          break;
 332       proc = mod->Driver->API.GetProcAddress(mod->Driver, procname);
 333       if (proc)
 334          break;
 335    }
 336
 337    return proc;
 338 }
 339
 340
 341 /**
 342  * Unload all drivers.
 343  */
 344 void
 345 _eglUnloadDrivers(void)
 346 {
 347    /* this is called at atexit time */
 348    if (_eglModules) {
 349       _eglDestroyArray(_eglModules, _eglFreeModule);
 350       _eglModules = NULL;
 351    }
 352 }