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