src/glx/glxcurrent.c

   1 /*
   2  * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
   3  * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice including the dates of first publication and
  13  * either this permission notice or a reference to
  14  * http://oss.sgi.com/projects/FreeB/
  15  * shall be included in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  21  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
  22  * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  *
  25  * Except as contained in this notice, the name of Silicon Graphics, Inc.
  26  * shall not be used in advertising or otherwise to promote the sale, use or
  27  * other dealings in this Software without prior written authorization from
  28  * Silicon Graphics, Inc.
  29  */
  30
  31 /**
  32  * \file glxcurrent.c
  33  * Client-side GLX interface for current context management.
  34  */
  35
  36 #include "glxclient.h"
  37 #include "glapi.h"
  38 #include "indirect_init.h"
  39
  40 /*
  41 ** We setup some dummy structures here so that the API can be used
  42 ** even if no context is current.
  43 */
  44
  45 static GLubyte dummyBuffer[__GLX_BUFFER_LIMIT_SIZE];
  46
  47 /*
  48 ** Dummy context used by small commands when there is no current context.
  49 ** All the
  50 ** gl and glx entry points are designed to operate as nop's when using
  51 ** the dummy context structure.
  52 */
  53 static __GLXcontext dummyContext = {
  54    &dummyBuffer[0],
  55    &dummyBuffer[0],
  56    &dummyBuffer[0],
  57    &dummyBuffer[__GLX_BUFFER_LIMIT_SIZE],
  58    sizeof(dummyBuffer),
  59 };
  60
  61
  62 /*
  63 ** All indirect rendering contexts will share the same indirect dispatch table.
  64 */
  65 static __GLapi *IndirectAPI = NULL;
  66
  67
  68 /*
  69  * Current context management and locking
  70  */
  71
  72 #if defined( PTHREADS )
  73
  74 _X_HIDDEN pthread_mutex_t __glXmutex = PTHREAD_MUTEX_INITIALIZER;
  75
  76 # if defined( GLX_USE_TLS )
  77
  78 /**
  79  * Per-thread GLX context pointer.
  80  *
  81  * \c __glXSetCurrentContext is written is such a way that this pointer can
  82  * \b never be \c NULL.  This is important!  Because of this
  83  * \c __glXGetCurrentContext can be implemented as trivial macro.
  84  */
  85 __thread void *__glX_tls_Context __attribute__ ((tls_model("initial-exec")))
  86    = &dummyContext;
  87
  88 _X_HIDDEN void
  89 __glXSetCurrentContext(__GLXcontext * c)
  90 {
  91    __glX_tls_Context = (c != NULL) ? c : &dummyContext;
  92 }
  93
  94 # else
  95
  96 static pthread_once_t once_control = PTHREAD_ONCE_INIT;
  97
  98 /**
  99  * Per-thread data key.
 100  *
 101  * Once \c init_thread_data has been called, the per-thread data key will
 102  * take a value of \c NULL.  As each new thread is created the default
 103  * value, in that thread, will be \c NULL.
 104  */
 105 static pthread_key_t ContextTSD;
 106
 107 /**
 108  * Initialize the per-thread data key.
 109  *
 110  * This function is called \b exactly once per-process (not per-thread!) to
 111  * initialize the per-thread data key.  This is ideally done using the
 112  * \c pthread_once mechanism.
 113  */
 114 static void
 115 init_thread_data(void)
 116 {
 117    if (pthread_key_create(&ContextTSD, NULL) != 0) {
 118       perror("pthread_key_create");
 119       exit(-1);
 120    }
 121 }
 122
 123 _X_HIDDEN void
 124 __glXSetCurrentContext(__GLXcontext * c)
 125 {
 126    pthread_once(&once_control, init_thread_data);
 127    pthread_setspecific(ContextTSD, c);
 128 }
 129
 130 _X_HIDDEN __GLXcontext *
 131 __glXGetCurrentContext(void)
 132 {
 133    void *v;
 134
 135    pthread_once(&once_control, init_thread_data);
 136
 137    v = pthread_getspecific(ContextTSD);
 138    return (v == NULL) ? &dummyContext : (__GLXcontext *) v;
 139 }
 140
 141 # endif /* defined( GLX_USE_TLS ) */
 142
 143 #elif defined( THREADS )
 144
 145 #error Unknown threading method specified.
 146
 147 #else
 148
 149 /* not thread safe */
 150 _X_HIDDEN __GLXcontext *__glXcurrentContext = &dummyContext;
 151
 152 #endif
 153
 154
 155 _X_HIDDEN void
 156 __glXSetCurrentContextNull(void)
 157 {
 158    __glXSetCurrentContext(&dummyContext);
 159 #ifdef GLX_DIRECT_RENDERING
 160    _glapi_set_dispatch(NULL);   /* no-op functions */
 161    _glapi_set_context(NULL);
 162 #endif
 163 }
 164
 165
 166 /************************************************************************/
 167
 168 PUBLIC GLXContext
 169 glXGetCurrentContext(void)
 170 {
 171    GLXContext cx = __glXGetCurrentContext();
 172
 173    if (cx == &dummyContext) {
 174       return NULL;
 175    }
 176    else {
 177       return cx;
 178    }
 179 }
 180
 181 PUBLIC GLXDrawable
 182 glXGetCurrentDrawable(void)
 183 {
 184    GLXContext gc = __glXGetCurrentContext();
 185    return gc->currentDrawable;
 186 }
 187
 188
 189 /************************************************************************/
 190
 191 /**
 192  * Sends a GLX protocol message to the specified display to make the context
 193  * and the drawables current.
 194  *
 195  * \param dpy     Display to send the message to.
 196  * \param opcode  Major opcode value for the display.
 197  * \param gc_id   Context tag for the context to be made current.
 198  * \param draw    Drawable ID for the "draw" drawable.
 199  * \param read    Drawable ID for the "read" drawable.
 200  * \param reply   Space to store the X-server's reply.
 201  *
 202  * \warning
 203  * This function assumes that \c dpy is locked with \c LockDisplay on entry.
 204  */
 205 static Bool
 206 SendMakeCurrentRequest(Display * dpy, CARD8 opcode,
 207                        GLXContextID gc_id, GLXContextTag gc_tag,
 208                        GLXDrawable draw, GLXDrawable read,
 209                        xGLXMakeCurrentReply * reply)
 210 {
 211    Bool ret;
 212
 213
 214    LockDisplay(dpy);
 215
 216    if (draw == read) {
 217       xGLXMakeCurrentReq *req;
 218
 219       GetReq(GLXMakeCurrent, req);
 220       req->reqType = opcode;
 221       req->glxCode = X_GLXMakeCurrent;
 222       req->drawable = draw;
 223       req->context = gc_id;
 224       req->oldContextTag = gc_tag;
 225    }
 226    else {
 227       __GLXdisplayPrivate *priv = __glXInitialize(dpy);
 228
 229       /* If the server can support the GLX 1.3 version, we should
 230        * perfer that.  Not only that, some servers support GLX 1.3 but
 231        * not the SGI extension.
 232        */
 233
 234       if ((priv->majorVersion > 1) || (priv->minorVersion >= 3)) {
 235          xGLXMakeContextCurrentReq *req;
 236
 237          GetReq(GLXMakeContextCurrent, req);
 238          req->reqType = opcode;
 239          req->glxCode = X_GLXMakeContextCurrent;
 240          req->drawable = draw;
 241          req->readdrawable = read;
 242          req->context = gc_id;
 243          req->oldContextTag = gc_tag;
 244       }
 245       else {
 246          xGLXVendorPrivateWithReplyReq *vpreq;
 247          xGLXMakeCurrentReadSGIReq *req;
 248
 249          GetReqExtra(GLXVendorPrivateWithReply,
 250                      sz_xGLXMakeCurrentReadSGIReq -
 251                      sz_xGLXVendorPrivateWithReplyReq, vpreq);
 252          req = (xGLXMakeCurrentReadSGIReq *) vpreq;
 253          req->reqType = opcode;
 254          req->glxCode = X_GLXVendorPrivateWithReply;
 255          req->vendorCode = X_GLXvop_MakeCurrentReadSGI;
 256          req->drawable = draw;
 257          req->readable = read;
 258          req->context = gc_id;
 259          req->oldContextTag = gc_tag;
 260       }
 261    }
 262
 263    ret = _XReply(dpy, (xReply *) reply, 0, False);
 264
 265    UnlockDisplay(dpy);
 266    SyncHandle();
 267
 268    return ret;
 269 }
 270
 271
 272 #ifdef GLX_DIRECT_RENDERING
 273 static __GLXDRIdrawable *
 274 FetchDRIDrawable(Display * dpy, GLXDrawable glxDrawable, GLXContext gc)
 275 {
 276    __GLXdisplayPrivate *const priv = __glXInitialize(dpy);
 277    __GLXDRIdrawable *pdraw;
 278    __GLXscreenConfigs *psc;
 279
 280    if (priv == NULL)
 281       return NULL;
 282
 283    psc = &priv->screenConfigs[gc->screen];
 284    if (psc->drawHash == NULL)
 285       return NULL;
 286
 287    if (__glxHashLookup(psc->drawHash, glxDrawable, (void *) &pdraw) == 0)
 288       return pdraw;
 289
 290    pdraw = psc->driScreen->createDrawable(psc, glxDrawable,
 291                                           glxDrawable, gc->mode);
 292    if (__glxHashInsert(psc->drawHash, glxDrawable, pdraw)) {
 293       (*pdraw->destroyDrawable) (pdraw);
 294       return NULL;
 295    }
 296
 297    return pdraw;
 298 }
 299 #endif /* GLX_DIRECT_RENDERING */
 300
 301 static void
 302 __glXGenerateError(Display * dpy, GLXContext gc, XID resource,
 303                    BYTE errorCode, CARD16 minorCode)
 304 {
 305    xError error;
 306
 307    error.errorCode = errorCode;
 308    error.resourceID = resource;
 309    error.sequenceNumber = dpy->request;
 310    error.type = X_Error;
 311    error.majorCode = gc->majorOpcode;
 312    error.minorCode = minorCode;
 313    _XError(dpy, &error);
 314 }
 315
 316 /**
 317  * Make a particular context current.
 318  *
 319  * \note This is in this file so that it can access dummyContext.
 320  */
 321 static Bool
 322 MakeContextCurrent(Display * dpy, GLXDrawable draw,
 323                    GLXDrawable read, GLXContext gc)
 324 {
 325    xGLXMakeCurrentReply reply;
 326    const GLXContext oldGC = __glXGetCurrentContext();
 327    const CARD8 opcode = __glXSetupForCommand(dpy);
 328    const CARD8 oldOpcode = ((gc == oldGC) || (oldGC == &dummyContext))
 329       ? opcode : __glXSetupForCommand(oldGC->currentDpy);
 330    Bool bindReturnValue;
 331    __GLXattribute *state;
 332
 333    if (!opcode || !oldOpcode) {
 334       return GL_FALSE;
 335    }
 336
 337    /* Make sure that the new context has a nonzero ID.  In the request,
 338     * a zero context ID is used only to mean that we bind to no current
 339     * context.
 340     */
 341    if ((gc != NULL) && (gc->xid == None)) {
 342       return GL_FALSE;
 343    }
 344
 345    if (gc == NULL && (draw != None || read != None)) {
 346       __glXGenerateError(dpy, gc, (draw != None) ? draw : read,
 347                          BadMatch, X_GLXMakeContextCurrent);
 348       return False;
 349    }
 350    if (gc != NULL && (draw == None || read == None)) {
 351       __glXGenerateError(dpy, gc, None, BadMatch, X_GLXMakeContextCurrent);
 352       return False;
 353    }
 354
 355    _glapi_check_multithread();
 356
 357    if (gc != NULL && gc->thread_id != 0 && gc->thread_id != _glthread_GetID()) {
 358       __glXGenerateError(dpy, gc, gc->xid,
 359                          BadAccess, X_GLXMakeContextCurrent);
 360       return False;
 361    }
 362
 363 #ifdef GLX_DIRECT_RENDERING
 364    /* Bind the direct rendering context to the drawable */
 365    if (gc && gc->driContext) {
 366       __GLXDRIdrawable *pdraw = FetchDRIDrawable(dpy, draw, gc);
 367       __GLXDRIdrawable *pread = FetchDRIDrawable(dpy, read, gc);
 368
 369       if ((pdraw == NULL) || (pread == NULL)) {
 370          __glXGenerateError(dpy, gc, (pdraw == NULL) ? draw : read,
 371                             GLXBadDrawable, X_GLXMakeContextCurrent);
 372          return False;
 373       }
 374
 375       bindReturnValue =
 376          (gc->driContext->bindContext) (gc->driContext, pdraw, pread);
 377    }
 378    else if (!gc && oldGC && oldGC->driContext) {
 379       bindReturnValue = True;
 380    }
 381    else
 382 #endif
 383    {
 384       /* Send a glXMakeCurrent request to bind the new context. */
 385       bindReturnValue =
 386          SendMakeCurrentRequest(dpy, opcode, gc ? gc->xid : None,
 387                                 ((dpy != oldGC->currentDpy)
 388                                  || oldGC->isDirect)
 389                                 ? None : oldGC->currentContextTag, draw, read,
 390                                 &reply);
 391    }
 392
 393
 394    if (!bindReturnValue) {
 395       return False;
 396    }
 397
 398 #ifdef GLX_DIRECT_RENDERING
 399    if ((dpy != oldGC->currentDpy || (gc && gc->driContext)) &&
 400        !oldGC->isDirect && oldGC != &dummyContext) {
 401 #else
 402    if ((dpy != oldGC->currentDpy) && oldGC != &dummyContext) {
 403 #endif
 404       xGLXMakeCurrentReply dummy_reply;
 405
 406       /* We are either switching from one dpy to another and have to
 407        * send a request to the previous dpy to unbind the previous
 408        * context, or we are switching away from a indirect context to
 409        * a direct context and have to send a request to the dpy to
 410        * unbind the previous context.
 411        */
 412       (void) SendMakeCurrentRequest(oldGC->currentDpy, oldOpcode, None,
 413                                     oldGC->currentContextTag, None, None,
 414                                     &dummy_reply);
 415    }
 416 #ifdef GLX_DIRECT_RENDERING
 417    else if (oldGC->driContext && oldGC != gc) {
 418       oldGC->driContext->unbindContext(oldGC->driContext);
 419    }
 420 #endif
 421
 422
 423    /* Update our notion of what is current */
 424    __glXLock();
 425    if (gc == oldGC) {
 426       /* Even though the contexts are the same the drawable might have
 427        * changed.  Note that gc cannot be the dummy, and that oldGC
 428        * cannot be NULL, therefore if they are the same, gc is not
 429        * NULL and not the dummy.
 430        */
 431       gc->currentDrawable = draw;
 432       gc->currentReadable = read;
 433    }
 434    else {
 435       if (oldGC != &dummyContext) {
 436          /* Old current context is no longer current to anybody */
 437          oldGC->currentDpy = 0;
 438          oldGC->currentDrawable = None;
 439          oldGC->currentReadable = None;
 440          oldGC->currentContextTag = 0;
 441          oldGC->thread_id = 0;
 442
 443          if (oldGC->xid == None) {
 444             /* We are switching away from a context that was
 445              * previously destroyed, so we need to free the memory
 446              * for the old handle.
 447              */
 448 #ifdef GLX_DIRECT_RENDERING
 449             /* Destroy the old direct rendering context */
 450             if (oldGC->driContext) {
 451                oldGC->driContext->destroyContext(oldGC->driContext,
 452                                                  oldGC->psc,
 453                                                  oldGC->createDpy);
 454                oldGC->driContext = NULL;
 455             }
 456 #endif
 457             __glXFreeContext(oldGC);
 458          }
 459       }
 460       if (gc) {
 461          __glXSetCurrentContext(gc);
 462
 463          gc->currentDpy = dpy;
 464          gc->currentDrawable = draw;
 465          gc->currentReadable = read;
 466          gc->thread_id = _glthread_GetID();
 467
 468 #ifdef GLX_DIRECT_RENDERING
 469          if (!gc->driContext) {
 470 #endif
 471             if (!IndirectAPI)
 472                IndirectAPI = __glXNewIndirectAPI();
 473             _glapi_set_dispatch(IndirectAPI);
 474
 475             state = (__GLXattribute *) (gc->client_state_private);
 476
 477             gc->currentContextTag = reply.contextTag;
 478             if (state->array_state == NULL) {
 479                (void) glGetString(GL_EXTENSIONS);
 480                (void) glGetString(GL_VERSION);
 481                __glXInitVertexArrayState(gc);
 482             }
 483 #ifdef GLX_DIRECT_RENDERING
 484          }
 485          else {
 486             gc->currentContextTag = -1;
 487          }
 488 #endif
 489       }
 490       else {
 491          __glXSetCurrentContextNull();
 492       }
 493    }
 494    __glXUnlock();
 495    return GL_TRUE;
 496 }
 497
 498
 499 PUBLIC Bool
 500 glXMakeCurrent(Display * dpy, GLXDrawable draw, GLXContext gc)
 501 {
 502    return MakeContextCurrent(dpy, draw, draw, gc);
 503 }
 504
 505 PUBLIC
 506 GLX_ALIAS(Bool, glXMakeCurrentReadSGI,
 507           (Display * dpy, GLXDrawable d, GLXDrawable r, GLXContext ctx),
 508           (dpy, d, r, ctx), MakeContextCurrent)
 509
 510 PUBLIC
 511 GLX_ALIAS(Bool, glXMakeContextCurrent,
 512           (Display * dpy, GLXDrawable d, GLXDrawable r,
 513            GLXContext ctx), (dpy, d, r, ctx), MakeContextCurrent)