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 "eglstring.h"
  43 #include "egldefines.h"
  44 #include "egldisplay.h"
  45 #include "egldriver.h"
  46 #include "egllog.h"
  47
  48 #ifdef _EGL_BUILT_IN_DRIVER_HAIKU
  49 _EGLDriver* _eglBuiltInDriverHaiku(const char* args);
  50 #endif
  51
  52 typedef struct _egl_module {
  53    char *Name;
  54    _EGLMain_t BuiltIn;
  55    _EGLDriver *Driver;
  56 } _EGLModule;
  57
  58 static mtx_t _eglModuleMutex = _MTX_INITIALIZER_NP;
  59 static _EGLArray *_eglModules;
  60
  61 const struct {
  62    const char *name;
  63    _EGLMain_t main;
  64 } _eglBuiltInDrivers[] = {
  65 #ifdef _EGL_BUILT_IN_DRIVER_DRI2
  66    { "egl_dri2", _eglBuiltInDriverDRI2 },
  67 #endif
  68 #ifdef _EGL_BUILT_IN_DRIVER_HAIKU
  69    { "egl_haiku", _eglBuiltInDriverHaiku },
  70 #endif
  71    { NULL, NULL }
  72 };
  73
  74 /**
  75  * Load a module and create the driver object.
  76  */
  77 static EGLBoolean
  78 _eglLoadModule(_EGLModule *mod)
  79 {
  80    _EGLDriver *drv;
  81
  82    if (mod->Driver)
  83       return EGL_TRUE;
  84
  85    if (!mod->BuiltIn)
  86          return EGL_FALSE;
  87
  88    drv = mod->BuiltIn(NULL);
  89    if (!drv || !drv->Name)
  90       return EGL_FALSE;
  91
  92    mod->Driver = drv;
  93
  94    return EGL_TRUE;
  95 }
  96
  97
  98 /**
  99  * Unload a module.
 100  */
 101 static void
 102 _eglUnloadModule(_EGLModule *mod)
 103 {
 104 #if defined(_EGL_OS_UNIX)
 105    /* destroy the driver */
 106    if (mod->Driver && mod->Driver->Unload)
 107       mod->Driver->Unload(mod->Driver);
 108
 109 #elif defined(_EGL_OS_WINDOWS)
 110    /* XXX Windows unloads DLLs before atexit */
 111 #endif
 112
 113    mod->Driver = NULL;
 114 }
 115
 116
 117 /**
 118  * Add a module to the module array.
 119  */
 120 static _EGLModule *
 121 _eglAddModule(const char *name)
 122 {
 123    _EGLModule *mod;
 124    EGLint i;
 125
 126    if (!_eglModules) {
 127       _eglModules = _eglCreateArray("Module", 8);
 128       if (!_eglModules)
 129          return NULL;
 130    }
 131
 132    /* find duplicates */
 133    for (i = 0; i < _eglModules->Size; i++) {
 134       mod = _eglModules->Elements[i];
 135       if (strcmp(mod->Name, name) == 0)
 136          return mod;
 137    }
 138
 139    /* allocate a new one */
 140    mod = calloc(1, sizeof(*mod));
 141    if (mod) {
 142       mod->Name = _eglstrdup(name);
 143       if (!mod->Name) {
 144          free(mod);
 145          mod = NULL;
 146       }
 147    }
 148    if (mod) {
 149       _eglAppendArray(_eglModules, (void *) mod);
 150       _eglLog(_EGL_DEBUG, "added %s to module array", mod->Name);
 151    }
 152
 153    return mod;
 154 }
 155
 156
 157 /**
 158  * Free a module.
 159  */
 160 static void
 161 _eglFreeModule(void *module)
 162 {
 163    _EGLModule *mod = (_EGLModule *) module;
 164
 165    _eglUnloadModule(mod);
 166    free(mod->Name);
 167    free(mod);
 168 }
 169
 170
 171 /**
 172  * Add the user driver to the module array.
 173  *
 174  * The user driver is specified by EGL_DRIVER.
 175  */
 176 static EGLBoolean
 177 _eglAddUserDriver(void)
 178 {
 179    char *env;
 180
 181    env = getenv("EGL_DRIVER");
 182    if (env) {
 183       EGLint i;
 184
 185       for (i = 0; _eglBuiltInDrivers[i].name; i++) {
 186          if (!strcmp(_eglBuiltInDrivers[i].name, env)) {
 187             _EGLModule *mod = _eglAddModule(env);
 188             if (mod)
 189                mod->BuiltIn = _eglBuiltInDrivers[i].main;
 190
 191             return EGL_TRUE;
 192          }
 193       }
 194    }
 195
 196    return EGL_FALSE;
 197 }
 198
 199
 200 /**
 201  * Add built-in drivers to the module array.
 202  */
 203 static void
 204 _eglAddBuiltInDrivers(void)
 205 {
 206    _EGLModule *mod;
 207    EGLint i;
 208
 209    for (i = 0; _eglBuiltInDrivers[i].name; i++) {
 210       mod = _eglAddModule(_eglBuiltInDrivers[i].name);
 211       if (mod)
 212          mod->BuiltIn = _eglBuiltInDrivers[i].main;
 213    }
 214 }
 215
 216
 217 /**
 218  * Add drivers to the module array.  Drivers will be loaded as they are matched
 219  * to displays.
 220  */
 221 static EGLBoolean
 222 _eglAddDrivers(void)
 223 {
 224    if (_eglModules)
 225       return EGL_TRUE;
 226
 227    if (!_eglAddUserDriver()) {
 228       /*
 229        * Add other drivers only when EGL_DRIVER is not set.  The order here
 230        * decides the priorities.
 231        */
 232       _eglAddBuiltInDrivers();
 233    }
 234
 235    return (_eglModules != NULL);
 236 }
 237
 238
 239 /**
 240  * A helper function for _eglMatchDriver.  It finds the first driver that can
 241  * initialize the display and return.
 242  */
 243 static _EGLDriver *
 244 _eglMatchAndInitialize(_EGLDisplay *dpy)
 245 {
 246    _EGLDriver *drv = NULL;
 247    EGLint i = 0;
 248
 249    if (!_eglAddDrivers()) {
 250       _eglLog(_EGL_WARNING, "failed to find any driver");
 251       return NULL;
 252    }
 253
 254    if (dpy->Driver) {
 255       drv = dpy->Driver;
 256       /* no re-matching? */
 257       if (!drv->API.Initialize(drv, dpy))
 258          drv = NULL;
 259       return drv;
 260    }
 261
 262    while (i < _eglModules->Size) {
 263       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 264
 265       if (!_eglLoadModule(mod)) {
 266          /* remove invalid modules */
 267          _eglEraseArray(_eglModules, i, _eglFreeModule);
 268          continue;
 269       }
 270
 271       if (mod->Driver->API.Initialize(mod->Driver, dpy)) {
 272          drv = mod->Driver;
 273          break;
 274       }
 275       else {
 276          i++;
 277       }
 278    }
 279
 280    return drv;
 281 }
 282
 283
 284 /**
 285  * Match a display to a driver.  The display is initialized unless test_only is
 286  * true.  The matching is done by finding the first driver that can initialize
 287  * the display.
 288  */
 289 _EGLDriver *
 290 _eglMatchDriver(_EGLDisplay *dpy, EGLBoolean test_only)
 291 {
 292    _EGLDriver *best_drv;
 293
 294    assert(!dpy->Initialized);
 295
 296    mtx_lock(&_eglModuleMutex);
 297
 298    /* set options */
 299    dpy->Options.TestOnly = test_only;
 300    dpy->Options.UseFallback = EGL_FALSE;
 301
 302    best_drv = _eglMatchAndInitialize(dpy);
 303    if (!best_drv) {
 304       dpy->Options.UseFallback = EGL_TRUE;
 305       best_drv = _eglMatchAndInitialize(dpy);
 306    }
 307
 308    mtx_unlock(&_eglModuleMutex);
 309
 310    if (best_drv) {
 311       _eglLog(_EGL_DEBUG, "the best driver is %s%s",
 312             best_drv->Name, (test_only) ? " (test only) " : "");
 313       if (!test_only) {
 314          dpy->Driver = best_drv;
 315          dpy->Initialized = EGL_TRUE;
 316       }
 317    }
 318
 319    return best_drv;
 320 }
 321
 322
 323 __eglMustCastToProperFunctionPointerType
 324 _eglGetDriverProc(const char *procname)
 325 {
 326    EGLint i;
 327    _EGLProc proc = NULL;
 328
 329    if (!_eglModules) {
 330       /* load the driver for the default display */
 331       EGLDisplay egldpy = eglGetDisplay(EGL_DEFAULT_DISPLAY);
 332       _EGLDisplay *dpy = _eglLookupDisplay(egldpy);
 333       if (!dpy || !_eglMatchDriver(dpy, EGL_TRUE))
 334          return NULL;
 335    }
 336
 337    for (i = 0; i < _eglModules->Size; i++) {
 338       _EGLModule *mod = (_EGLModule *) _eglModules->Elements[i];
 339
 340       if (!mod->Driver)
 341          break;
 342       proc = mod->Driver->API.GetProcAddress(mod->Driver, procname);
 343       if (proc)
 344          break;
 345    }
 346
 347    return proc;
 348 }
 349
 350
 351 /**
 352  * Unload all drivers.
 353  */
 354 void
 355 _eglUnloadDrivers(void)
 356 {
 357    /* this is called at atexit time */
 358    if (_eglModules) {
 359       _eglDestroyArray(_eglModules, _eglFreeModule);
 360       _eglModules = NULL;
 361    }
 362 }