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