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 #ifdef PTHREADS
  37 #include <pthread.h>
  38 #endif
  39
  40 #include "glxclient.h"
  41 #ifdef GLX_USE_APPLEGL
  42 #include <stdlib.h>
  43
  44 #include "apple_glx.h"
  45 #include "apple_glx_context.h"
  46 #else
  47 #include "glapi.h"
  48 #include "indirect_init.h"
  49 #endif
  50
  51 /*
  52 ** We setup some dummy structures here so that the API can be used
  53 ** even if no context is current.
  54 */
  55
  56 static GLubyte dummyBuffer[__GLX_BUFFER_LIMIT_SIZE];
  57
  58 /*
  59 ** Dummy context used by small commands when there is no current context.
  60 ** All the
  61 ** gl and glx entry points are designed to operate as nop's when using
  62 ** the dummy context structure.
  63 */
  64 static __GLXcontext dummyContext = {
  65    &dummyBuffer[0],
  66    &dummyBuffer[0],
  67    &dummyBuffer[0],
  68    &dummyBuffer[__GLX_BUFFER_LIMIT_SIZE],
  69    sizeof(dummyBuffer),
  70 };
  71
  72
  73 #ifndef GLX_USE_APPLEGL
  74 /*
  75 ** All indirect rendering contexts will share the same indirect dispatch table.
  76 */
  77 static __GLapi *IndirectAPI = NULL;
  78 #endif
  79
  80 /*
  81  * Current context management and locking
  82  */
  83
  84 #if defined( PTHREADS )
  85
  86 _X_HIDDEN pthread_mutex_t __glXmutex = PTHREAD_MUTEX_INITIALIZER;
  87
  88 # if defined( GLX_USE_TLS )
  89
  90 /**
  91  * Per-thread GLX context pointer.
  92  *
  93  * \c __glXSetCurrentContext is written is such a way that this pointer can
  94  * \b never be \c NULL.  This is important!  Because of this
  95  * \c __glXGetCurrentContext can be implemented as trivial macro.
  96  */
  97 __thread void *__glX_tls_Context __attribute__ ((tls_model("initial-exec")))
  98    = &dummyContext;
  99
 100 _X_HIDDEN void
 101 __glXSetCurrentContext(__GLXcontext * c)
 102 {
 103    __glX_tls_Context = (c != NULL) ? c : &dummyContext;
 104 }
 105
 106 # else
 107
 108 static pthread_once_t once_control = PTHREAD_ONCE_INIT;
 109
 110 /**
 111  * Per-thread data key.
 112  *
 113  * Once \c init_thread_data has been called, the per-thread data key will
 114  * take a value of \c NULL.  As each new thread is created the default
 115  * value, in that thread, will be \c NULL.
 116  */
 117 static pthread_key_t ContextTSD;
 118
 119 /**
 120  * Initialize the per-thread data key.
 121  *
 122  * This function is called \b exactly once per-process (not per-thread!) to
 123  * initialize the per-thread data key.  This is ideally done using the
 124  * \c pthread_once mechanism.
 125  */
 126 static void
 127 init_thread_data(void)
 128 {
 129    if (pthread_key_create(&ContextTSD, NULL) != 0) {
 130       perror("pthread_key_create");
 131       exit(-1);
 132    }
 133 }
 134
 135 _X_HIDDEN void
 136 __glXSetCurrentContext(__GLXcontext * c)
 137 {
 138    pthread_once(&once_control, init_thread_data);
 139    pthread_setspecific(ContextTSD, c);
 140 }
 141
 142 _X_HIDDEN __GLXcontext *
 143 __glXGetCurrentContext(void)
 144 {
 145    void *v;
 146
 147    pthread_once(&once_control, init_thread_data);
 148
 149    v = pthread_getspecific(ContextTSD);
 150    return (v == NULL) ? &dummyContext : (__GLXcontext *) v;
 151 }
 152
 153 # endif /* defined( GLX_USE_TLS ) */
 154
 155 #elif defined( THREADS )
 156
 157 #error Unknown threading method specified.
 158
 159 #else
 160
 161 /* not thread safe */
 162 _X_HIDDEN __GLXcontext *__glXcurrentContext = &dummyContext;
 163
 164 #endif
 165
 166
 167 _X_HIDDEN void
 168 __glXSetCurrentContextNull(void)
 169 {
 170    __glXSetCurrentContext(&dummyContext);
 171 #ifndef GLX_USE_APPLEGL
 172 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
 173    _glapi_set_dispatch(NULL);   /* no-op functions */
 174    _glapi_set_context(NULL);
 175 #endif
 176 #endif
 177 }
 178
 179
 180 /************************************************************************/
 181
 182 _X_EXPORT GLXContext
 183 glXGetCurrentContext(void)
 184 {
 185    GLXContext cx = __glXGetCurrentContext();
 186
 187    if (cx == &dummyContext) {
 188       return NULL;
 189    }
 190    else {
 191       return cx;
 192    }
 193 }
 194
 195 _X_EXPORT GLXDrawable
 196 glXGetCurrentDrawable(void)
 197 {
 198    GLXContext gc = __glXGetCurrentContext();
 199    return gc->currentDrawable;
 200 }
 201
 202
 203 #ifndef GLX_USE_APPLEGL
 204 /************************************************************************/
 205
 206 /**
 207  * Sends a GLX protocol message to the specified display to make the context
 208  * and the drawables current.
 209  *
 210  * \param dpy     Display to send the message to.
 211  * \param opcode  Major opcode value for the display.
 212  * \param gc_id   Context tag for the context to be made current.
 213  * \param draw    Drawable ID for the "draw" drawable.
 214  * \param read    Drawable ID for the "read" drawable.
 215  * \param reply   Space to store the X-server's reply.
 216  *
 217  * \warning
 218  * This function assumes that \c dpy is locked with \c LockDisplay on entry.
 219  */
 220 static Bool
 221 SendMakeCurrentRequest(Display * dpy, CARD8 opcode,
 222                        GLXContextID gc_id, GLXContextTag gc_tag,
 223                        GLXDrawable draw, GLXDrawable read,
 224                        xGLXMakeCurrentReply * reply)
 225 {
 226    Bool ret;
 227
 228
 229    LockDisplay(dpy);
 230
 231    if (draw == read) {
 232       xGLXMakeCurrentReq *req;
 233
 234       GetReq(GLXMakeCurrent, req);
 235       req->reqType = opcode;
 236       req->glxCode = X_GLXMakeCurrent;
 237       req->drawable = draw;
 238       req->context = gc_id;
 239       req->oldContextTag = gc_tag;
 240    }
 241    else {
 242       __GLXdisplayPrivate *priv = __glXInitialize(dpy);
 243
 244       /* If the server can support the GLX 1.3 version, we should
 245        * perfer that.  Not only that, some servers support GLX 1.3 but
 246        * not the SGI extension.
 247        */
 248
 249       if ((priv->majorVersion > 1) || (priv->minorVersion >= 3)) {
 250          xGLXMakeContextCurrentReq *req;
 251
 252          GetReq(GLXMakeContextCurrent, req);
 253          req->reqType = opcode;
 254          req->glxCode = X_GLXMakeContextCurrent;
 255          req->drawable = draw;
 256          req->readdrawable = read;
 257          req->context = gc_id;
 258          req->oldContextTag = gc_tag;
 259       }
 260       else {
 261          xGLXVendorPrivateWithReplyReq *vpreq;
 262          xGLXMakeCurrentReadSGIReq *req;
 263
 264          GetReqExtra(GLXVendorPrivateWithReply,
 265                      sz_xGLXMakeCurrentReadSGIReq -
 266                      sz_xGLXVendorPrivateWithReplyReq, vpreq);
 267          req = (xGLXMakeCurrentReadSGIReq *) vpreq;
 268          req->reqType = opcode;
 269          req->glxCode = X_GLXVendorPrivateWithReply;
 270          req->vendorCode = X_GLXvop_MakeCurrentReadSGI;
 271          req->drawable = draw;
 272          req->readable = read;
 273          req->context = gc_id;
 274          req->oldContextTag = gc_tag;
 275       }
 276    }
 277
 278    ret = _XReply(dpy, (xReply *) reply, 0, False);
 279
 280    UnlockDisplay(dpy);
 281    SyncHandle();
 282
 283    return ret;
 284 }
 285
 286
 287 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
 288 static __GLXDRIdrawable *
 289 FetchDRIDrawable(Display * dpy, GLXDrawable glxDrawable, GLXContext gc)
 290 {
 291    __GLXdisplayPrivate *const priv = __glXInitialize(dpy);
 292    __GLXDRIdrawable *pdraw;
 293    struct glx_screen *psc;
 294
 295    if (priv == NULL)
 296       return NULL;
 297
 298    psc = priv->screens[gc->screen];
 299    if (priv->drawHash == NULL)
 300       return NULL;
 301
 302    if (__glxHashLookup(priv->drawHash, glxDrawable, (void *) &pdraw) == 0)
 303       return pdraw;
 304
 305    pdraw = psc->driScreen->createDrawable(psc, glxDrawable,
 306                                           glxDrawable, gc->config);
 307    if (__glxHashInsert(priv->drawHash, glxDrawable, pdraw)) {
 308       (*pdraw->destroyDrawable) (pdraw);
 309       return NULL;
 310    }
 311
 312    return pdraw;
 313 }
 314 #endif /* GLX_DIRECT_RENDERING */
 315
 316 static void
 317 __glXGenerateError(Display * dpy, GLXContext gc, XID resource,
 318                    BYTE errorCode, CARD16 minorCode)
 319 {
 320    xError error;
 321
 322    error.errorCode = errorCode;
 323    error.resourceID = resource;
 324    error.sequenceNumber = dpy->request;
 325    error.type = X_Error;
 326    error.majorCode = gc->majorOpcode;
 327    error.minorCode = minorCode;
 328    _XError(dpy, &error);
 329 }
 330
 331 #endif /* GLX_USE_APPLEGL */
 332
 333 /**
 334  * Make a particular context current.
 335  *
 336  * \note This is in this file so that it can access dummyContext.
 337  */
 338 static Bool
 339 MakeContextCurrent(Display * dpy, GLXDrawable draw,
 340                    GLXDrawable read, GLXContext gc)
 341 {
 342    const GLXContext oldGC = __glXGetCurrentContext();
 343 #ifdef GLX_USE_APPLEGL
 344    bool error = apple_glx_make_current_context(dpy,
 345                    (oldGC && oldGC != &dummyContext) ? oldGC->driContext : NULL,
 346                    gc ? gc->driContext : NULL, draw);
 347
 348    apple_glx_diagnostic("%s: error %s\n", __func__, error ? "YES" : "NO");
 349    if(error)
 350       return GL_FALSE;
 351 #else
 352    xGLXMakeCurrentReply reply;
 353    const CARD8 opcode = __glXSetupForCommand(dpy);
 354    const CARD8 oldOpcode = ((gc == oldGC) || (oldGC == &dummyContext))
 355       ? opcode : __glXSetupForCommand(oldGC->currentDpy);
 356    Bool bindReturnValue;
 357    __GLXattribute *state;
 358
 359    if (!opcode || !oldOpcode) {
 360       return GL_FALSE;
 361    }
 362
 363    /* Make sure that the new context has a nonzero ID.  In the request,
 364     * a zero context ID is used only to mean that we bind to no current
 365     * context.
 366     */
 367    if ((gc != NULL) && (gc->xid == None)) {
 368       return GL_FALSE;
 369    }
 370
 371    if (gc == NULL && (draw != None || read != None)) {
 372       __glXGenerateError(dpy, gc, (draw != None) ? draw : read,
 373                          BadMatch, X_GLXMakeContextCurrent);
 374       return False;
 375    }
 376    if (gc != NULL && (draw == None || read == None)) {
 377       __glXGenerateError(dpy, gc, None, BadMatch, X_GLXMakeContextCurrent);
 378       return False;
 379    }
 380
 381    _glapi_check_multithread();
 382
 383    if (gc != NULL && gc->thread_id != 0 && gc->thread_id != _glthread_GetID()) {
 384       __glXGenerateError(dpy, gc, gc->xid,
 385                          BadAccess, X_GLXMakeContextCurrent);
 386       return False;
 387    }
 388
 389 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
 390    /* Bind the direct rendering context to the drawable */
 391    if (gc && gc->driContext) {
 392       __GLXDRIdrawable *pdraw = FetchDRIDrawable(dpy, draw, gc);
 393       __GLXDRIdrawable *pread = FetchDRIDrawable(dpy, read, gc);
 394
 395       if ((pdraw == NULL) || (pread == NULL)) {
 396          __glXGenerateError(dpy, gc, (pdraw == NULL) ? draw : read,
 397                             GLXBadDrawable, X_GLXMakeContextCurrent);
 398          return False;
 399       }
 400
 401       bindReturnValue =
 402          (gc->driContext->bindContext) (gc, pdraw, pread);
 403    }
 404    else if (!gc && oldGC && oldGC->driContext) {
 405       bindReturnValue = True;
 406    }
 407    else
 408 #endif
 409    {
 410       /* Send a glXMakeCurrent request to bind the new context. */
 411       bindReturnValue =
 412          SendMakeCurrentRequest(dpy, opcode, gc ? gc->xid : None,
 413                                 ((dpy != oldGC->currentDpy)
 414                                  || oldGC->isDirect)
 415                                 ? None : oldGC->currentContextTag, draw, read,
 416                                 &reply);
 417    }
 418
 419
 420    if (!bindReturnValue) {
 421       return False;
 422    }
 423
 424 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
 425    if ((dpy != oldGC->currentDpy || (gc && gc->driContext)) &&
 426        !oldGC->isDirect && oldGC != &dummyContext) {
 427 #else
 428    if ((dpy != oldGC->currentDpy) && oldGC != &dummyContext) {
 429 #endif
 430       xGLXMakeCurrentReply dummy_reply;
 431
 432       /* We are either switching from one dpy to another and have to
 433        * send a request to the previous dpy to unbind the previous
 434        * context, or we are switching away from a indirect context to
 435        * a direct context and have to send a request to the dpy to
 436        * unbind the previous context.
 437        */
 438       (void) SendMakeCurrentRequest(oldGC->currentDpy, oldOpcode, None,
 439                                     oldGC->currentContextTag, None, None,
 440                                     &dummy_reply);
 441    }
 442 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
 443    else if (oldGC->driContext && oldGC != gc) {
 444       oldGC->driContext->unbindContext(oldGC);
 445    }
 446 #endif
 447
 448 #endif /* GLX_USE_APPLEGL */
 449
 450    /* Update our notion of what is current */
 451    __glXLock();
 452    if (gc == oldGC) {
 453       /* Even though the contexts are the same the drawable might have
 454        * changed.  Note that gc cannot be the dummy, and that oldGC
 455        * cannot be NULL, therefore if they are the same, gc is not
 456        * NULL and not the dummy.
 457        */
 458       if(gc) {
 459         gc->currentDrawable = draw;
 460         gc->currentReadable = read;
 461       }
 462    }
 463    else {
 464       if (oldGC != &dummyContext) {
 465          /* Old current context is no longer current to anybody */
 466          oldGC->currentDpy = 0;
 467          oldGC->currentDrawable = None;
 468          oldGC->currentReadable = None;
 469          oldGC->currentContextTag = 0;
 470          oldGC->thread_id = 0;
 471
 472          if (oldGC->xid == None) {
 473             /* We are switching away from a context that was
 474              * previously destroyed, so we need to free the memory
 475              * for the old handle.
 476              */
 477             oldGC->vtable->destroy(oldGC);
 478          }
 479       }
 480       if (gc) {
 481          __glXSetCurrentContext(gc);
 482
 483          gc->currentDpy = dpy;
 484          gc->currentDrawable = draw;
 485          gc->currentReadable = read;
 486 #ifndef GLX_USE_APPLEGL
 487          gc->thread_id = _glthread_GetID();
 488
 489 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
 490          if (!gc->driContext) {
 491 #endif
 492             if (!IndirectAPI)
 493                IndirectAPI = __glXNewIndirectAPI();
 494             _glapi_set_dispatch(IndirectAPI);
 495
 496             state = (__GLXattribute *) (gc->client_state_private);
 497
 498             gc->currentContextTag = reply.contextTag;
 499             if (state->array_state == NULL) {
 500                (void) glGetString(GL_EXTENSIONS);
 501                (void) glGetString(GL_VERSION);
 502                __glXInitVertexArrayState(gc);
 503             }
 504 #if defined(GLX_DIRECT_RENDERING) && !defined(GLX_USE_APPLEGL)
 505          }
 506          else {
 507             gc->currentContextTag = -1;
 508          }
 509 #endif
 510 #endif /* GLX_USE_APPLEGL */
 511       }
 512       else {
 513          __glXSetCurrentContextNull();
 514       }
 515    }
 516    __glXUnlock();
 517    return GL_TRUE;
 518 }
 519
 520
 521 _X_EXPORT Bool
 522 glXMakeCurrent(Display * dpy, GLXDrawable draw, GLXContext gc)
 523 {
 524    return MakeContextCurrent(dpy, draw, draw, gc);
 525 }
 526
 527 _X_EXPORT
 528 GLX_ALIAS(Bool, glXMakeCurrentReadSGI,
 529           (Display * dpy, GLXDrawable d, GLXDrawable r, GLXContext ctx),
 530           (dpy, d, r, ctx), MakeContextCurrent)
 531
 532 _X_EXPORT
 533 GLX_ALIAS(Bool, glXMakeContextCurrent,
 534           (Display * dpy, GLXDrawable d, GLXDrawable r,
 535            GLXContext ctx), (dpy, d, r, ctx), MakeContextCurrent)