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