src/mesa/state_tracker/st_context.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 #include "main/accum.h"
  30 #include "main/api_exec.h"
  31 #include "main/context.h"
  32 #include "main/debug_output.h"
  33 #include "main/glthread.h"
  34 #include "main/samplerobj.h"
  35 #include "main/shaderobj.h"
  36 #include "main/version.h"
  37 #include "main/vtxfmt.h"
  38 #include "main/hash.h"
  39 #include "program/prog_cache.h"
  40 #include "vbo/vbo.h"
  41 #include "glapi/glapi.h"
  42 #include "st_manager.h"
  43 #include "st_context.h"
  44 #include "st_debug.h"
  45 #include "st_cb_bitmap.h"
  46 #include "st_cb_blit.h"
  47 #include "st_cb_bufferobjects.h"
  48 #include "st_cb_clear.h"
  49 #include "st_cb_compute.h"
  50 #include "st_cb_condrender.h"
  51 #include "st_cb_copyimage.h"
  52 #include "st_cb_drawpixels.h"
  53 #include "st_cb_rasterpos.h"
  54 #include "st_cb_drawtex.h"
  55 #include "st_cb_eglimage.h"
  56 #include "st_cb_fbo.h"
  57 #include "st_cb_feedback.h"
  58 #include "st_cb_memoryobjects.h"
  59 #include "st_cb_msaa.h"
  60 #include "st_cb_perfmon.h"
  61 #include "st_cb_perfquery.h"
  62 #include "st_cb_program.h"
  63 #include "st_cb_queryobj.h"
  64 #include "st_cb_readpixels.h"
  65 #include "st_cb_semaphoreobjects.h"
  66 #include "st_cb_texture.h"
  67 #include "st_cb_xformfb.h"
  68 #include "st_cb_flush.h"
  69 #include "st_cb_syncobj.h"
  70 #include "st_cb_strings.h"
  71 #include "st_cb_texturebarrier.h"
  72 #include "st_cb_viewport.h"
  73 #include "st_atom.h"
  74 #include "st_draw.h"
  75 #include "st_extensions.h"
  76 #include "st_gen_mipmap.h"
  77 #include "st_pbo.h"
  78 #include "st_program.h"
  79 #include "st_sampler_view.h"
  80 #include "st_shader_cache.h"
  81 #include "st_vdpau.h"
  82 #include "st_texture.h"
  83 #include "st_util.h"
  84 #include "pipe/p_context.h"
  85 #include "util/u_cpu_detect.h"
  86 #include "util/u_inlines.h"
  87 #include "util/u_upload_mgr.h"
  88 #include "util/u_vbuf.h"
  89 #include "util/u_memory.h"
  90 #include "cso_cache/cso_context.h"
  91 #include "compiler/glsl/glsl_parser_extras.h"
  92
  93
  94 DEBUG_GET_ONCE_BOOL_OPTION(mesa_mvp_dp4, "MESA_MVP_DP4", FALSE)
  95
  96
  97 /**
  98  * Called via ctx->Driver.Enable()
  99  */
 100 static void
 101 st_Enable(struct gl_context *ctx, GLenum cap, GLboolean state)
 102 {
 103    struct st_context *st = st_context(ctx);
 104
 105    switch (cap) {
 106    case GL_DEBUG_OUTPUT:
 107    case GL_DEBUG_OUTPUT_SYNCHRONOUS:
 108       st_update_debug_callback(st);
 109       break;
 110    case GL_BLACKHOLE_RENDER_INTEL:
 111       st->pipe->set_frontend_noop(st->pipe, ctx->IntelBlackholeRender);
 112       break;
 113    default:
 114       break;
 115    }
 116 }
 117
 118
 119 /**
 120  * Called via ctx->Driver.QueryMemoryInfo()
 121  */
 122 static void
 123 st_query_memory_info(struct gl_context *ctx, struct gl_memory_info *out)
 124 {
 125    struct pipe_screen *screen = st_context(ctx)->pipe->screen;
 126    struct pipe_memory_info info;
 127
 128    assert(screen->query_memory_info);
 129    if (!screen->query_memory_info)
 130       return;
 131
 132    screen->query_memory_info(screen, &info);
 133
 134    out->total_device_memory = info.total_device_memory;
 135    out->avail_device_memory = info.avail_device_memory;
 136    out->total_staging_memory = info.total_staging_memory;
 137    out->avail_staging_memory = info.avail_staging_memory;
 138    out->device_memory_evicted = info.device_memory_evicted;
 139    out->nr_device_memory_evictions = info.nr_device_memory_evictions;
 140 }
 141
 142
 143 static uint64_t
 144 st_get_active_states(struct gl_context *ctx)
 145 {
 146    struct st_program *vp =
 147       st_program(ctx->VertexProgram._Current);
 148    struct st_program *tcp =
 149       st_program(ctx->TessCtrlProgram._Current);
 150    struct st_program *tep =
 151       st_program(ctx->TessEvalProgram._Current);
 152    struct st_program *gp =
 153       st_program(ctx->GeometryProgram._Current);
 154    struct st_program *fp =
 155       st_program(ctx->FragmentProgram._Current);
 156    struct st_program *cp =
 157       st_program(ctx->ComputeProgram._Current);
 158    uint64_t active_shader_states = 0;
 159
 160    if (vp)
 161       active_shader_states |= vp->affected_states;
 162    if (tcp)
 163       active_shader_states |= tcp->affected_states;
 164    if (tep)
 165       active_shader_states |= tep->affected_states;
 166    if (gp)
 167       active_shader_states |= gp->affected_states;
 168    if (fp)
 169       active_shader_states |= fp->affected_states;
 170    if (cp)
 171       active_shader_states |= cp->affected_states;
 172
 173    /* Mark non-shader-resource shader states as "always active". */
 174    return active_shader_states | ~ST_ALL_SHADER_RESOURCES;
 175 }
 176
 177
 178 void
 179 st_invalidate_buffers(struct st_context *st)
 180 {
 181    st->dirty |= ST_NEW_BLEND |
 182                 ST_NEW_DSA |
 183                 ST_NEW_FB_STATE |
 184                 ST_NEW_SAMPLE_STATE |
 185                 ST_NEW_SAMPLE_SHADING |
 186                 ST_NEW_FS_STATE |
 187                 ST_NEW_POLY_STIPPLE |
 188                 ST_NEW_VIEWPORT |
 189                 ST_NEW_RASTERIZER |
 190                 ST_NEW_SCISSOR |
 191                 ST_NEW_WINDOW_RECTANGLES;
 192 }
 193
 194
 195 static inline bool
 196 st_vp_uses_current_values(const struct gl_context *ctx)
 197 {
 198    const uint64_t inputs = ctx->VertexProgram._Current->info.inputs_read;
 199    return _mesa_draw_current_bits(ctx) & inputs;
 200 }
 201
 202
 203 /**
 204  * Called via ctx->Driver.UpdateState()
 205  */
 206 static void
 207 st_invalidate_state(struct gl_context *ctx)
 208 {
 209    GLbitfield new_state = ctx->NewState;
 210    struct st_context *st = st_context(ctx);
 211
 212    if (new_state & _NEW_BUFFERS) {
 213       st_invalidate_buffers(st);
 214    } else {
 215       /* These set a subset of flags set by _NEW_BUFFERS, so we only have to
 216        * check them when _NEW_BUFFERS isn't set.
 217        */
 218       if (new_state & _NEW_PROGRAM)
 219          st->dirty |= ST_NEW_RASTERIZER;
 220
 221       if (new_state & _NEW_FOG)
 222          st->dirty |= ST_NEW_FS_STATE;
 223    }
 224
 225    if (new_state & (_NEW_LIGHT |
 226                     _NEW_POINT))
 227       st->dirty |= ST_NEW_RASTERIZER;
 228
 229    if ((new_state & _NEW_LIGHT) &&
 230        (st->lower_flatshade || st->lower_two_sided_color))
 231       st->dirty |= ST_NEW_FS_STATE;
 232
 233    if (new_state & _NEW_PROJECTION &&
 234        st_user_clip_planes_enabled(ctx))
 235       st->dirty |= ST_NEW_CLIP_STATE;
 236
 237    if (new_state & _NEW_PIXEL)
 238       st->dirty |= ST_NEW_PIXEL_TRANSFER;
 239
 240    if (new_state & _NEW_CURRENT_ATTRIB && st_vp_uses_current_values(ctx))
 241       st->dirty |= ST_NEW_VERTEX_ARRAYS;
 242
 243    if (st->clamp_frag_depth_in_shader && (new_state & _NEW_VIEWPORT)) {
 244       if (ctx->GeometryProgram._Current)
 245          st->dirty |= ST_NEW_GS_CONSTANTS;
 246       else if (ctx->TessEvalProgram._Current)
 247          st->dirty |= ST_NEW_TES_CONSTANTS;
 248       else
 249          st->dirty |= ST_NEW_VS_CONSTANTS;
 250       st->dirty |= ST_NEW_FS_CONSTANTS;
 251    }
 252
 253    /* Update the vertex shader if ctx->Light._ClampVertexColor was changed. */
 254    if (st->clamp_vert_color_in_shader && (new_state & _NEW_LIGHT)) {
 255       st->dirty |= ST_NEW_VS_STATE;
 256       if (st->ctx->API == API_OPENGL_COMPAT && ctx->Version >= 32) {
 257          st->dirty |= ST_NEW_GS_STATE | ST_NEW_TES_STATE;
 258       }
 259    }
 260
 261    /* Which shaders are dirty will be determined manually. */
 262    if (new_state & _NEW_PROGRAM) {
 263       st->gfx_shaders_may_be_dirty = true;
 264       st->compute_shader_may_be_dirty = true;
 265       /* This will mask out unused shader resources. */
 266       st->active_states = st_get_active_states(ctx);
 267    }
 268
 269    if (new_state & _NEW_TEXTURE_OBJECT) {
 270       st->dirty |= st->active_states &
 271                    (ST_NEW_SAMPLER_VIEWS |
 272                     ST_NEW_SAMPLERS |
 273                     ST_NEW_IMAGE_UNITS);
 274       if (ctx->FragmentProgram._Current &&
 275           ctx->FragmentProgram._Current->ExternalSamplersUsed) {
 276          st->dirty |= ST_NEW_FS_STATE;
 277       }
 278    }
 279 }
 280
 281
 282 /*
 283  * In some circumstances (such as running google-chrome) the state
 284  * tracker may try to delete a resource view from a context different
 285  * than when it was created.  We don't want to do that.
 286  *
 287  * In that situation, st_texture_release_all_sampler_views() calls this
 288  * function to transfer the sampler view reference to this context (expected
 289  * to be the context which created the view.)
 290  */
 291 void
 292 st_save_zombie_sampler_view(struct st_context *st,
 293                             struct pipe_sampler_view *view)
 294 {
 295    struct st_zombie_sampler_view_node *entry;
 296
 297    assert(view->context == st->pipe);
 298
 299    entry = MALLOC_STRUCT(st_zombie_sampler_view_node);
 300    if (!entry)
 301       return;
 302
 303    entry->view = view;
 304
 305    /* We need a mutex since this function may be called from one thread
 306     * while free_zombie_resource_views() is called from another.
 307     */
 308    simple_mtx_lock(&st->zombie_sampler_views.mutex);
 309    list_addtail(&entry->node, &st->zombie_sampler_views.list.node);
 310    simple_mtx_unlock(&st->zombie_sampler_views.mutex);
 311 }
 312
 313
 314 /*
 315  * Since OpenGL shaders may be shared among contexts, we can wind up
 316  * with variants of a shader created with different contexts.
 317  * When we go to destroy a gallium shader, we want to free it with the
 318  * same context that it was created with, unless the driver reports
 319  * PIPE_CAP_SHAREABLE_SHADERS = TRUE.
 320  */
 321 void
 322 st_save_zombie_shader(struct st_context *st,
 323                       enum pipe_shader_type type,
 324                       struct pipe_shader_state *shader)
 325 {
 326    struct st_zombie_shader_node *entry;
 327
 328    /* we shouldn't be here if the driver supports shareable shaders */
 329    assert(!st->has_shareable_shaders);
 330
 331    entry = MALLOC_STRUCT(st_zombie_shader_node);
 332    if (!entry)
 333       return;
 334
 335    entry->shader = shader;
 336    entry->type = type;
 337
 338    /* We need a mutex since this function may be called from one thread
 339     * while free_zombie_shaders() is called from another.
 340     */
 341    simple_mtx_lock(&st->zombie_shaders.mutex);
 342    list_addtail(&entry->node, &st->zombie_shaders.list.node);
 343    simple_mtx_unlock(&st->zombie_shaders.mutex);
 344 }
 345
 346
 347 /*
 348  * Free any zombie sampler views that may be attached to this context.
 349  */
 350 static void
 351 free_zombie_sampler_views(struct st_context *st)
 352 {
 353    struct st_zombie_sampler_view_node *entry, *next;
 354
 355    if (list_is_empty(&st->zombie_sampler_views.list.node)) {
 356       return;
 357    }
 358
 359    simple_mtx_lock(&st->zombie_sampler_views.mutex);
 360
 361    LIST_FOR_EACH_ENTRY_SAFE(entry, next,
 362                             &st->zombie_sampler_views.list.node, node) {
 363       list_del(&entry->node);  // remove this entry from the list
 364
 365       assert(entry->view->context == st->pipe);
 366       pipe_sampler_view_reference(&entry->view, NULL);
 367
 368       free(entry);
 369    }
 370
 371    assert(list_is_empty(&st->zombie_sampler_views.list.node));
 372
 373    simple_mtx_unlock(&st->zombie_sampler_views.mutex);
 374 }
 375
 376
 377 /*
 378  * Free any zombie shaders that may be attached to this context.
 379  */
 380 static void
 381 free_zombie_shaders(struct st_context *st)
 382 {
 383    struct st_zombie_shader_node *entry, *next;
 384
 385    if (list_is_empty(&st->zombie_shaders.list.node)) {
 386       return;
 387    }
 388
 389    simple_mtx_lock(&st->zombie_shaders.mutex);
 390
 391    LIST_FOR_EACH_ENTRY_SAFE(entry, next,
 392                             &st->zombie_shaders.list.node, node) {
 393       list_del(&entry->node);  // remove this entry from the list
 394
 395       switch (entry->type) {
 396       case PIPE_SHADER_VERTEX:
 397          st->pipe->bind_vs_state(st->pipe, NULL);
 398          st->pipe->delete_vs_state(st->pipe, entry->shader);
 399          break;
 400       case PIPE_SHADER_FRAGMENT:
 401          st->pipe->bind_fs_state(st->pipe, NULL);
 402          st->pipe->delete_fs_state(st->pipe, entry->shader);
 403          break;
 404       case PIPE_SHADER_GEOMETRY:
 405          st->pipe->bind_gs_state(st->pipe, NULL);
 406          st->pipe->delete_gs_state(st->pipe, entry->shader);
 407          break;
 408       case PIPE_SHADER_TESS_CTRL:
 409          st->pipe->bind_tcs_state(st->pipe, NULL);
 410          st->pipe->delete_tcs_state(st->pipe, entry->shader);
 411          break;
 412       case PIPE_SHADER_TESS_EVAL:
 413          st->pipe->bind_tes_state(st->pipe, NULL);
 414          st->pipe->delete_tes_state(st->pipe, entry->shader);
 415          break;
 416       case PIPE_SHADER_COMPUTE:
 417          st->pipe->bind_compute_state(st->pipe, NULL);
 418          st->pipe->delete_compute_state(st->pipe, entry->shader);
 419          break;
 420       default:
 421          unreachable("invalid shader type in free_zombie_shaders()");
 422       }
 423       free(entry);
 424    }
 425
 426    assert(list_is_empty(&st->zombie_shaders.list.node));
 427
 428    simple_mtx_unlock(&st->zombie_shaders.mutex);
 429 }
 430
 431
 432 /*
 433  * This function is called periodically to free any zombie objects
 434  * which are attached to this context.
 435  */
 436 void
 437 st_context_free_zombie_objects(struct st_context *st)
 438 {
 439    free_zombie_sampler_views(st);
 440    free_zombie_shaders(st);
 441 }
 442
 443
 444 static void
 445 st_destroy_context_priv(struct st_context *st, bool destroy_pipe)
 446 {
 447    uint i;
 448
 449    st_destroy_atoms(st);
 450    st_destroy_draw(st);
 451    st_destroy_clear(st);
 452    st_destroy_bitmap(st);
 453    st_destroy_drawpix(st);
 454    st_destroy_drawtex(st);
 455    st_destroy_perfmon(st);
 456    st_destroy_pbo_helpers(st);
 457    st_destroy_bound_texture_handles(st);
 458    st_destroy_bound_image_handles(st);
 459
 460    for (i = 0; i < ARRAY_SIZE(st->state.frag_sampler_views); i++) {
 461       pipe_sampler_view_reference(&st->state.vert_sampler_views[i], NULL);
 462       pipe_sampler_view_reference(&st->state.frag_sampler_views[i], NULL);
 463    }
 464
 465    /* free glReadPixels cache data */
 466    st_invalidate_readpix_cache(st);
 467    util_throttle_deinit(st->pipe->screen, &st->throttle);
 468
 469    cso_destroy_context(st->cso_context);
 470
 471    if (st->pipe && destroy_pipe)
 472       st->pipe->destroy(st->pipe);
 473
 474    free(st);
 475 }
 476
 477
 478 static void
 479 st_init_driver_flags(struct st_context *st)
 480 {
 481    struct gl_driver_flags *f = &st->ctx->DriverFlags;
 482
 483    f->NewArray = ST_NEW_VERTEX_ARRAYS;
 484    f->NewRasterizerDiscard = ST_NEW_RASTERIZER;
 485    f->NewTileRasterOrder = ST_NEW_RASTERIZER;
 486    f->NewUniformBuffer = ST_NEW_UNIFORM_BUFFER;
 487    f->NewDefaultTessLevels = ST_NEW_TESS_STATE;
 488
 489    /* Shader resources */
 490    f->NewTextureBuffer = ST_NEW_SAMPLER_VIEWS;
 491    if (st->has_hw_atomics)
 492       f->NewAtomicBuffer = ST_NEW_HW_ATOMICS | ST_NEW_CS_ATOMICS;
 493    else
 494       f->NewAtomicBuffer = ST_NEW_ATOMIC_BUFFER;
 495    f->NewShaderStorageBuffer = ST_NEW_STORAGE_BUFFER;
 496    f->NewImageUnits = ST_NEW_IMAGE_UNITS;
 497
 498    f->NewShaderConstants[MESA_SHADER_VERTEX] = ST_NEW_VS_CONSTANTS;
 499    f->NewShaderConstants[MESA_SHADER_TESS_CTRL] = ST_NEW_TCS_CONSTANTS;
 500    f->NewShaderConstants[MESA_SHADER_TESS_EVAL] = ST_NEW_TES_CONSTANTS;
 501    f->NewShaderConstants[MESA_SHADER_GEOMETRY] = ST_NEW_GS_CONSTANTS;
 502    f->NewShaderConstants[MESA_SHADER_FRAGMENT] = ST_NEW_FS_CONSTANTS;
 503    f->NewShaderConstants[MESA_SHADER_COMPUTE] = ST_NEW_CS_CONSTANTS;
 504
 505    f->NewWindowRectangles = ST_NEW_WINDOW_RECTANGLES;
 506    f->NewFramebufferSRGB = ST_NEW_FB_STATE;
 507    f->NewScissorRect = ST_NEW_SCISSOR;
 508    f->NewScissorTest = ST_NEW_SCISSOR | ST_NEW_RASTERIZER;
 509
 510    if (st->lower_alpha_test)
 511       f->NewAlphaTest = ST_NEW_FS_STATE;
 512    else
 513       f->NewAlphaTest = ST_NEW_DSA;
 514
 515    f->NewBlend = ST_NEW_BLEND;
 516    f->NewBlendColor = ST_NEW_BLEND_COLOR;
 517    f->NewColorMask = ST_NEW_BLEND;
 518    f->NewDepth = ST_NEW_DSA;
 519    f->NewLogicOp = ST_NEW_BLEND;
 520    f->NewStencil = ST_NEW_DSA;
 521    f->NewMultisampleEnable = ST_NEW_BLEND | ST_NEW_RASTERIZER |
 522                              ST_NEW_SAMPLE_STATE | ST_NEW_SAMPLE_SHADING;
 523    f->NewSampleAlphaToXEnable = ST_NEW_BLEND;
 524    f->NewSampleMask = ST_NEW_SAMPLE_STATE;
 525    f->NewSampleLocations = ST_NEW_SAMPLE_STATE;
 526    f->NewSampleShading = ST_NEW_SAMPLE_SHADING;
 527
 528    /* This depends on what the gallium driver wants. */
 529    if (st->force_persample_in_shader) {
 530       f->NewMultisampleEnable |= ST_NEW_FS_STATE;
 531       f->NewSampleShading |= ST_NEW_FS_STATE;
 532    } else {
 533       f->NewSampleShading |= ST_NEW_RASTERIZER;
 534    }
 535
 536    f->NewClipControl = ST_NEW_VIEWPORT | ST_NEW_RASTERIZER;
 537    f->NewClipPlane = ST_NEW_CLIP_STATE;
 538
 539    if (st->clamp_frag_color_in_shader) {
 540       f->NewFragClamp = ST_NEW_FS_STATE;
 541    } else {
 542       f->NewFragClamp = ST_NEW_RASTERIZER;
 543    }
 544
 545    if (st->clamp_frag_depth_in_shader) {
 546       f->NewClipControl |= ST_NEW_VS_STATE | ST_NEW_GS_STATE |
 547                            ST_NEW_TES_STATE;
 548
 549       f->NewDepthClamp = ST_NEW_FS_STATE | ST_NEW_VS_STATE |
 550                          ST_NEW_GS_STATE | ST_NEW_TES_STATE;
 551    } else {
 552       f->NewDepthClamp = ST_NEW_RASTERIZER;
 553    }
 554
 555    if (st->lower_ucp)
 556       f->NewClipPlaneEnable = ST_NEW_VS_STATE;
 557    else
 558       f->NewClipPlaneEnable = ST_NEW_RASTERIZER;
 559
 560    f->NewLineState = ST_NEW_RASTERIZER;
 561    f->NewPolygonState = ST_NEW_RASTERIZER;
 562    f->NewPolygonStipple = ST_NEW_POLY_STIPPLE;
 563    f->NewViewport = ST_NEW_VIEWPORT;
 564    f->NewNvConservativeRasterization = ST_NEW_RASTERIZER;
 565    f->NewNvConservativeRasterizationParams = ST_NEW_RASTERIZER;
 566    f->NewIntelConservativeRasterization = ST_NEW_RASTERIZER;
 567 }
 568
 569
 570 static struct st_context *
 571 st_create_context_priv(struct gl_context *ctx, struct pipe_context *pipe,
 572                        const struct st_config_options *options, bool no_error)
 573 {
 574    struct pipe_screen *screen = pipe->screen;
 575    uint i;
 576    struct st_context *st = ST_CALLOC_STRUCT( st_context);
 577
 578    st->options = *options;
 579
 580    ctx->st = st;
 581
 582    st->ctx = ctx;
 583    st->pipe = pipe;
 584    st->dirty = ST_ALL_STATES_MASK;
 585
 586    st->can_bind_const_buffer_as_vertex =
 587       screen->get_param(screen, PIPE_CAP_CAN_BIND_CONST_BUFFER_AS_VERTEX);
 588
 589    /* st/mesa always uploads zero-stride vertex attribs, and other user
 590     * vertex buffers are only possible with a compatibility profile.
 591     * So tell the u_vbuf module that user VBOs are not possible with the Core
 592     * profile, so that u_vbuf is bypassed completely if there is nothing else
 593     * to do.
 594     */
 595    unsigned cso_flags;
 596    switch (ctx->API) {
 597    case API_OPENGL_CORE:
 598       cso_flags = CSO_NO_USER_VERTEX_BUFFERS;
 599       break;
 600    case API_OPENGLES:
 601    case API_OPENGLES2:
 602       cso_flags = CSO_NO_64B_VERTEX_BUFFERS;
 603       break;
 604    default:
 605       cso_flags = 0;
 606       break;
 607    }
 608
 609    st->cso_context = cso_create_context(pipe, cso_flags);
 610
 611    st_init_atoms(st);
 612    st_init_clear(st);
 613    st_init_pbo_helpers(st);
 614
 615    /* Choose texture target for glDrawPixels, glBitmap, renderbuffers */
 616    if (pipe->screen->get_param(pipe->screen, PIPE_CAP_NPOT_TEXTURES))
 617       st->internal_target = PIPE_TEXTURE_2D;
 618    else
 619       st->internal_target = PIPE_TEXTURE_RECT;
 620
 621    /* Setup vertex element info for 'struct st_util_vertex'.
 622     */
 623    {
 624       STATIC_ASSERT(sizeof(struct st_util_vertex) == 9 * sizeof(float));
 625
 626       memset(&st->util_velems, 0, sizeof(st->util_velems));
 627       st->util_velems.velems[0].src_offset = 0;
 628       st->util_velems.velems[0].vertex_buffer_index = 0;
 629       st->util_velems.velems[0].src_format = PIPE_FORMAT_R32G32B32_FLOAT;
 630       st->util_velems.velems[1].src_offset = 3 * sizeof(float);
 631       st->util_velems.velems[1].vertex_buffer_index = 0;
 632       st->util_velems.velems[1].src_format = PIPE_FORMAT_R32G32B32A32_FLOAT;
 633       st->util_velems.velems[2].src_offset = 7 * sizeof(float);
 634       st->util_velems.velems[2].vertex_buffer_index = 0;
 635       st->util_velems.velems[2].src_format = PIPE_FORMAT_R32G32_FLOAT;
 636    }
 637
 638    /* Need these flags:
 639     */
 640    ctx->FragmentProgram._MaintainTexEnvProgram = GL_TRUE;
 641    ctx->VertexProgram._MaintainTnlProgram = GL_TRUE;
 642
 643    if (no_error)
 644       ctx->Const.ContextFlags |= GL_CONTEXT_FLAG_NO_ERROR_BIT_KHR;
 645
 646    ctx->Const.PackedDriverUniformStorage =
 647       screen->get_param(screen, PIPE_CAP_PACKED_UNIFORMS);
 648
 649    ctx->Const.BitmapUsesRed =
 650       screen->is_format_supported(screen, PIPE_FORMAT_R8_UNORM,
 651                                   PIPE_TEXTURE_2D, 0, 0,
 652                                   PIPE_BIND_SAMPLER_VIEW);
 653
 654    st->has_stencil_export =
 655       screen->get_param(screen, PIPE_CAP_SHADER_STENCIL_EXPORT);
 656    st->has_etc1 = screen->is_format_supported(screen, PIPE_FORMAT_ETC1_RGB8,
 657                                               PIPE_TEXTURE_2D, 0, 0,
 658                                               PIPE_BIND_SAMPLER_VIEW);
 659    st->has_etc2 = screen->is_format_supported(screen, PIPE_FORMAT_ETC2_RGB8,
 660                                               PIPE_TEXTURE_2D, 0, 0,
 661                                               PIPE_BIND_SAMPLER_VIEW);
 662    st->has_astc_2d_ldr =
 663       screen->is_format_supported(screen, PIPE_FORMAT_ASTC_4x4_SRGB,
 664                                   PIPE_TEXTURE_2D, 0, 0, PIPE_BIND_SAMPLER_VIEW);
 665    st->has_astc_5x5_ldr =
 666       screen->is_format_supported(screen, PIPE_FORMAT_ASTC_5x5_SRGB,
 667                                   PIPE_TEXTURE_2D, 0, 0, PIPE_BIND_SAMPLER_VIEW);
 668    st->prefer_blit_based_texture_transfer = screen->get_param(screen,
 669                               PIPE_CAP_PREFER_BLIT_BASED_TEXTURE_TRANSFER);
 670    st->force_persample_in_shader =
 671       screen->get_param(screen, PIPE_CAP_SAMPLE_SHADING) &&
 672       !screen->get_param(screen, PIPE_CAP_FORCE_PERSAMPLE_INTERP);
 673    st->has_shareable_shaders = screen->get_param(screen,
 674                                                  PIPE_CAP_SHAREABLE_SHADERS);
 675    st->needs_texcoord_semantic =
 676       screen->get_param(screen, PIPE_CAP_TGSI_TEXCOORD);
 677    st->apply_texture_swizzle_to_border_color =
 678       !!(screen->get_param(screen, PIPE_CAP_TEXTURE_BORDER_COLOR_QUIRK) &
 679          (PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_NV50 |
 680           PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_R600));
 681    st->has_time_elapsed =
 682       screen->get_param(screen, PIPE_CAP_QUERY_TIME_ELAPSED);
 683    st->has_half_float_packing =
 684       screen->get_param(screen, PIPE_CAP_TGSI_PACK_HALF_FLOAT);
 685    st->has_multi_draw_indirect =
 686       screen->get_param(screen, PIPE_CAP_MULTI_DRAW_INDIRECT);
 687    st->has_single_pipe_stat =
 688       screen->get_param(screen, PIPE_CAP_QUERY_PIPELINE_STATISTICS_SINGLE);
 689    st->has_indep_blend_func =
 690       screen->get_param(screen, PIPE_CAP_INDEP_BLEND_FUNC);
 691    st->needs_rgb_dst_alpha_override =
 692       screen->get_param(screen, PIPE_CAP_RGB_OVERRIDE_DST_ALPHA_BLEND);
 693    st->lower_flatshade =
 694       !screen->get_param(screen, PIPE_CAP_FLATSHADE);
 695    st->lower_alpha_test =
 696       !screen->get_param(screen, PIPE_CAP_ALPHA_TEST);
 697    st->lower_point_size =
 698       !screen->get_param(screen, PIPE_CAP_POINT_SIZE_FIXED);
 699    st->lower_two_sided_color =
 700       !screen->get_param(screen, PIPE_CAP_TWO_SIDED_COLOR);
 701    st->lower_ucp =
 702       !screen->get_param(screen, PIPE_CAP_CLIP_PLANES);
 703    st->allow_st_finalize_nir_twice = screen->finalize_nir != NULL;
 704
 705    st->has_hw_atomics =
 706       screen->get_shader_param(screen, PIPE_SHADER_FRAGMENT,
 707                                PIPE_SHADER_CAP_MAX_HW_ATOMIC_COUNTERS)
 708       ? true : false;
 709
 710    util_throttle_init(&st->throttle,
 711                       screen->get_param(screen,
 712                                         PIPE_CAP_MAX_TEXTURE_UPLOAD_MEMORY_BUDGET));
 713
 714    /* GL limits and extensions */
 715    st_init_limits(pipe->screen, &ctx->Const, &ctx->Extensions);
 716    st_init_extensions(pipe->screen, &ctx->Const,
 717                       &ctx->Extensions, &st->options, ctx->API);
 718
 719    /* FIXME: add support for geometry and tessellation shaders for
 720     * lower_point_size
 721     */
 722    assert(!ctx->Extensions.OES_geometry_shader || !st->lower_point_size);
 723    assert(!ctx->Extensions.ARB_tessellation_shader || !st->lower_point_size);
 724
 725    /* FIXME: add support for geometry and tessellation shaders for
 726     * lower_ucp
 727     */
 728    assert(!ctx->Extensions.OES_geometry_shader || !st->lower_ucp);
 729    assert(!ctx->Extensions.ARB_tessellation_shader || !st->lower_ucp);
 730
 731    if (st_have_perfmon(st)) {
 732       ctx->Extensions.AMD_performance_monitor = GL_TRUE;
 733    }
 734
 735    if (st_have_perfquery(st)) {
 736       ctx->Extensions.INTEL_performance_query = GL_TRUE;
 737    }
 738
 739    /* Enable shader-based fallbacks for ARB_color_buffer_float if needed. */
 740    if (screen->get_param(screen, PIPE_CAP_VERTEX_COLOR_UNCLAMPED)) {
 741       if (!screen->get_param(screen, PIPE_CAP_VERTEX_COLOR_CLAMPED)) {
 742          st->clamp_vert_color_in_shader = GL_TRUE;
 743       }
 744
 745       if (!screen->get_param(screen, PIPE_CAP_FRAGMENT_COLOR_CLAMPED)) {
 746          st->clamp_frag_color_in_shader = GL_TRUE;
 747       }
 748
 749       /* For drivers which cannot do color clamping, it's better to just
 750        * disable ARB_color_buffer_float in the core profile, because
 751        * the clamping is deprecated there anyway. */
 752       if (ctx->API == API_OPENGL_CORE &&
 753           (st->clamp_frag_color_in_shader || st->clamp_vert_color_in_shader)) {
 754          st->clamp_vert_color_in_shader = GL_FALSE;
 755          st->clamp_frag_color_in_shader = GL_FALSE;
 756          ctx->Extensions.ARB_color_buffer_float = GL_FALSE;
 757       }
 758    }
 759
 760    if (screen->get_param(screen, PIPE_CAP_DEPTH_CLIP_DISABLE) == 2)
 761       st->clamp_frag_depth_in_shader = true;
 762
 763    /* called after _mesa_create_context/_mesa_init_point, fix default user
 764     * settable max point size up
 765     */
 766    ctx->Point.MaxSize = MAX2(ctx->Const.MaxPointSize,
 767                              ctx->Const.MaxPointSizeAA);
 768    /* For vertex shaders, make sure not to emit saturate when SM 3.0
 769     * is not supported
 770     */
 771    ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].EmitNoSat =
 772       !screen->get_param(screen, PIPE_CAP_VERTEX_SHADER_SATURATE);
 773
 774    ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].PositionAlwaysInvariant = options->vs_position_always_invariant;
 775
 776    enum pipe_shader_ir preferred_ir = (enum pipe_shader_ir)
 777       screen->get_shader_param(screen, PIPE_SHADER_VERTEX,
 778                                PIPE_SHADER_CAP_PREFERRED_IR);
 779    ctx->Const.UseNIRGLSLLinker = preferred_ir == PIPE_SHADER_IR_NIR;
 780
 781    if (ctx->Const.GLSLVersion < 400) {
 782       for (i = 0; i < MESA_SHADER_STAGES; i++)
 783          ctx->Const.ShaderCompilerOptions[i].EmitNoIndirectSampler = true;
 784    }
 785
 786    /* Set which shader types can be compiled at link time. */
 787    st->shader_has_one_variant[MESA_SHADER_VERTEX] =
 788          st->has_shareable_shaders &&
 789          !st->clamp_frag_depth_in_shader &&
 790          !st->clamp_vert_color_in_shader &&
 791          !st->lower_point_size &&
 792          !st->lower_ucp;
 793
 794    st->shader_has_one_variant[MESA_SHADER_FRAGMENT] =
 795          st->has_shareable_shaders &&
 796          !st->lower_flatshade &&
 797          !st->lower_alpha_test &&
 798          !st->clamp_frag_color_in_shader &&
 799          !st->clamp_frag_depth_in_shader &&
 800          !st->force_persample_in_shader &&
 801          !st->lower_two_sided_color;
 802
 803    st->shader_has_one_variant[MESA_SHADER_TESS_CTRL] = st->has_shareable_shaders;
 804    st->shader_has_one_variant[MESA_SHADER_TESS_EVAL] =
 805          st->has_shareable_shaders &&
 806          !st->clamp_frag_depth_in_shader &&
 807          !st->clamp_vert_color_in_shader;
 808    st->shader_has_one_variant[MESA_SHADER_GEOMETRY] =
 809          st->has_shareable_shaders &&
 810          !st->clamp_frag_depth_in_shader &&
 811          !st->clamp_vert_color_in_shader;
 812    st->shader_has_one_variant[MESA_SHADER_COMPUTE] = st->has_shareable_shaders;
 813
 814    st->bitmap.cache.empty = true;
 815
 816    _mesa_override_extensions(ctx);
 817    _mesa_compute_version(ctx);
 818
 819    if (ctx->Version == 0) {
 820       /* This can happen when a core profile was requested, but the driver
 821        * does not support some features of GL 3.1 or later.
 822        */
 823       st_destroy_context_priv(st, false);
 824       return NULL;
 825    }
 826
 827    /* This must be done after extensions are initialized to enable persistent
 828     * mappings immediately.
 829     */
 830    _vbo_CreateContext(ctx, true);
 831
 832    _mesa_initialize_dispatch_tables(ctx);
 833    _mesa_initialize_vbo_vtxfmt(ctx);
 834    st_init_driver_flags(st);
 835
 836    /* Initialize context's winsys buffers list */
 837    list_inithead(&st->winsys_buffers);
 838
 839    list_inithead(&st->zombie_sampler_views.list.node);
 840    simple_mtx_init(&st->zombie_sampler_views.mutex, mtx_plain);
 841    list_inithead(&st->zombie_shaders.list.node);
 842    simple_mtx_init(&st->zombie_shaders.mutex, mtx_plain);
 843
 844    return st;
 845 }
 846
 847
 848 static void
 849 st_emit_string_marker(struct gl_context *ctx, const GLchar *string, GLsizei len)
 850 {
 851    struct st_context *st = ctx->st;
 852    st->pipe->emit_string_marker(st->pipe, string, len);
 853 }
 854
 855
 856 static void
 857 st_set_background_context(struct gl_context *ctx,
 858                           struct util_queue_monitoring *queue_info)
 859 {
 860    struct st_context *st = ctx->st;
 861    struct st_manager *smapi =
 862       (struct st_manager *) st->iface.st_context_private;
 863
 864    assert(smapi->set_background_context);
 865    smapi->set_background_context(&st->iface, queue_info);
 866 }
 867
 868
 869 static void
 870 st_get_device_uuid(struct gl_context *ctx, char *uuid)
 871 {
 872    struct pipe_screen *screen = st_context(ctx)->pipe->screen;
 873
 874    assert(GL_UUID_SIZE_EXT >= PIPE_UUID_SIZE);
 875    memset(uuid, 0, GL_UUID_SIZE_EXT);
 876    screen->get_device_uuid(screen, uuid);
 877 }
 878
 879
 880 static void
 881 st_get_driver_uuid(struct gl_context *ctx, char *uuid)
 882 {
 883    struct pipe_screen *screen = st_context(ctx)->pipe->screen;
 884
 885    assert(GL_UUID_SIZE_EXT >= PIPE_UUID_SIZE);
 886    memset(uuid, 0, GL_UUID_SIZE_EXT);
 887    screen->get_driver_uuid(screen, uuid);
 888 }
 889
 890
 891 static void
 892 st_init_driver_functions(struct pipe_screen *screen,
 893                          struct dd_function_table *functions)
 894 {
 895    _mesa_init_sampler_object_functions(functions);
 896
 897    st_init_draw_functions(functions);
 898    st_init_blit_functions(functions);
 899    st_init_bufferobject_functions(screen, functions);
 900    st_init_clear_functions(functions);
 901    st_init_bitmap_functions(functions);
 902    st_init_copy_image_functions(functions);
 903    st_init_drawpixels_functions(functions);
 904    st_init_rasterpos_functions(functions);
 905
 906    st_init_drawtex_functions(functions);
 907
 908    st_init_eglimage_functions(functions);
 909
 910    st_init_fbo_functions(functions);
 911    st_init_feedback_functions(functions);
 912    st_init_memoryobject_functions(functions);
 913    st_init_msaa_functions(functions);
 914    st_init_perfmon_functions(functions);
 915    st_init_perfquery_functions(functions);
 916    st_init_program_functions(functions);
 917    st_init_query_functions(functions);
 918    st_init_cond_render_functions(functions);
 919    st_init_readpixels_functions(functions);
 920    st_init_semaphoreobject_functions(functions);
 921    st_init_texture_functions(functions);
 922    st_init_texture_barrier_functions(functions);
 923    st_init_flush_functions(screen, functions);
 924    st_init_string_functions(functions);
 925    st_init_viewport_functions(functions);
 926    st_init_compute_functions(functions);
 927
 928    st_init_xformfb_functions(functions);
 929    st_init_syncobj_functions(functions);
 930
 931    st_init_vdpau_functions(functions);
 932
 933    if (screen->get_param(screen, PIPE_CAP_STRING_MARKER))
 934       functions->EmitStringMarker = st_emit_string_marker;
 935
 936    functions->Enable = st_Enable;
 937    functions->UpdateState = st_invalidate_state;
 938    functions->QueryMemoryInfo = st_query_memory_info;
 939    functions->SetBackgroundContext = st_set_background_context;
 940    functions->GetDriverUuid = st_get_driver_uuid;
 941    functions->GetDeviceUuid = st_get_device_uuid;
 942
 943    /* GL_ARB_get_program_binary */
 944    functions->GetProgramBinaryDriverSHA1 = st_get_program_binary_driver_sha1;
 945
 946    enum pipe_shader_ir preferred_ir = (enum pipe_shader_ir)
 947       screen->get_shader_param(screen, PIPE_SHADER_VERTEX,
 948                                PIPE_SHADER_CAP_PREFERRED_IR);
 949    if (preferred_ir == PIPE_SHADER_IR_NIR) {
 950       functions->ShaderCacheSerializeDriverBlob =  st_serialise_nir_program;
 951       functions->ProgramBinarySerializeDriverBlob =
 952          st_serialise_nir_program_binary;
 953       functions->ProgramBinaryDeserializeDriverBlob =
 954          st_deserialise_nir_program;
 955    } else {
 956       functions->ShaderCacheSerializeDriverBlob =  st_serialise_tgsi_program;
 957       functions->ProgramBinarySerializeDriverBlob =
 958          st_serialise_tgsi_program_binary;
 959       functions->ProgramBinaryDeserializeDriverBlob =
 960          st_deserialise_tgsi_program;
 961    }
 962 }
 963
 964
 965 struct st_context *
 966 st_create_context(gl_api api, struct pipe_context *pipe,
 967                   const struct gl_config *visual,
 968                   struct st_context *share,
 969                   const struct st_config_options *options,
 970                   bool no_error)
 971 {
 972    struct gl_context *ctx;
 973    struct gl_context *shareCtx = share ? share->ctx : NULL;
 974    struct dd_function_table funcs;
 975    struct st_context *st;
 976
 977    util_cpu_detect();
 978
 979    memset(&funcs, 0, sizeof(funcs));
 980    st_init_driver_functions(pipe->screen, &funcs);
 981
 982    ctx = calloc(1, sizeof(struct gl_context));
 983    if (!ctx)
 984       return NULL;
 985
 986    if (!_mesa_initialize_context(ctx, api, visual, shareCtx, &funcs)) {
 987       free(ctx);
 988       return NULL;
 989    }
 990
 991    st_debug_init();
 992
 993    if (pipe->screen->get_disk_shader_cache)
 994       ctx->Cache = pipe->screen->get_disk_shader_cache(pipe->screen);
 995
 996    /* XXX: need a capability bit in gallium to query if the pipe
 997     * driver prefers DP4 or MUL/MAD for vertex transformation.
 998     */
 999    if (debug_get_option_mesa_mvp_dp4())
1000       ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].OptimizeForAOS = GL_TRUE;
1001
1002    st = st_create_context_priv(ctx, pipe, options, no_error);
1003    if (!st) {
1004       _mesa_destroy_context(ctx);
1005    }
1006
1007    return st;
1008 }
1009
1010
1011 /**
1012  * When we destroy a context, we must examine all texture objects to
1013  * find/release any sampler views created by that context.
1014  *
1015  * This callback is called per-texture object.  It releases all the
1016  * texture's sampler views which belong to the context.
1017  */
1018 static void
1019 destroy_tex_sampler_cb(GLuint id, void *data, void *userData)
1020 {
1021    struct gl_texture_object *texObj = (struct gl_texture_object *) data;
1022    struct st_context *st = (struct st_context *) userData;
1023
1024    st_texture_release_context_sampler_view(st, st_texture_object(texObj));
1025 }
1026
1027 static void
1028 destroy_framebuffer_attachment_sampler_cb(GLuint id, void *data, void *userData)
1029 {
1030    struct gl_framebuffer* glfb = (struct gl_framebuffer*) data;
1031    struct st_context *st = (struct st_context *) userData;
1032
1033     for (unsigned i = 0; i < BUFFER_COUNT; i++) {
1034       struct gl_renderbuffer_attachment *att = &glfb->Attachment[i];
1035       if (att->Texture) {
1036         st_texture_release_context_sampler_view(st, st_texture_object(att->Texture));
1037       }
1038    }
1039 }
1040
1041 void
1042 st_destroy_context(struct st_context *st)
1043 {
1044    struct gl_context *ctx = st->ctx;
1045    struct st_framebuffer *stfb, *next;
1046    struct gl_framebuffer *save_drawbuffer;
1047    struct gl_framebuffer *save_readbuffer;
1048
1049    /* Save the current context and draw/read buffers*/
1050    GET_CURRENT_CONTEXT(save_ctx);
1051    if (save_ctx) {
1052       save_drawbuffer = save_ctx->WinSysDrawBuffer;
1053       save_readbuffer = save_ctx->WinSysReadBuffer;
1054    } else {
1055       save_drawbuffer = save_readbuffer = NULL;
1056    }
1057
1058    /*
1059     * We need to bind the context we're deleting so that
1060     * _mesa_reference_texobj_() uses this context when deleting textures.
1061     * Similarly for framebuffer objects, etc.
1062     */
1063    _mesa_make_current(ctx, NULL, NULL);
1064
1065    /* This must be called first so that glthread has a chance to finish */
1066    _mesa_glthread_destroy(ctx);
1067
1068    _mesa_HashWalk(ctx->Shared->TexObjects, destroy_tex_sampler_cb, st);
1069
1070    /* For the fallback textures, free any sampler views belonging to this
1071     * context.
1072     */
1073    for (unsigned i = 0; i < NUM_TEXTURE_TARGETS; i++) {
1074       struct st_texture_object *stObj =
1075          st_texture_object(ctx->Shared->FallbackTex[i]);
1076       if (stObj) {
1077          st_texture_release_context_sampler_view(st, stObj);
1078       }
1079    }
1080
1081    st_context_free_zombie_objects(st);
1082
1083    simple_mtx_destroy(&st->zombie_sampler_views.mutex);
1084    simple_mtx_destroy(&st->zombie_shaders.mutex);
1085
1086    st_release_program(st, &st->fp);
1087    st_release_program(st, &st->gp);
1088    st_release_program(st, &st->vp);
1089    st_release_program(st, &st->tcp);
1090    st_release_program(st, &st->tep);
1091    st_release_program(st, &st->cp);
1092
1093    /* release framebuffer in the winsys buffers list */
1094    LIST_FOR_EACH_ENTRY_SAFE_REV(stfb, next, &st->winsys_buffers, head) {
1095       st_framebuffer_reference(&stfb, NULL);
1096    }
1097
1098    _mesa_HashWalk(ctx->Shared->FrameBuffers, destroy_framebuffer_attachment_sampler_cb, st);
1099
1100    pipe_sampler_view_reference(&st->pixel_xfer.pixelmap_sampler_view, NULL);
1101    pipe_resource_reference(&st->pixel_xfer.pixelmap_texture, NULL);
1102
1103    _vbo_DestroyContext(ctx);
1104
1105    st_destroy_program_variants(st);
1106
1107    /* Do not release debug_output yet because it might be in use by other threads.
1108     * These threads will be terminated by _mesa_free_context_data and
1109     * st_destroy_context_priv.
1110     */
1111    _mesa_free_context_data(ctx, false);
1112
1113    /* This will free the st_context too, so 'st' must not be accessed
1114     * afterwards. */
1115    st_destroy_context_priv(st, true);
1116    st = NULL;
1117
1118    _mesa_destroy_debug_output(ctx);
1119
1120    free(ctx);
1121
1122    if (save_ctx == ctx) {
1123       /* unbind the context we just deleted */
1124       _mesa_make_current(NULL, NULL, NULL);
1125    } else {
1126       /* Restore the current context and draw/read buffers (may be NULL) */
1127       _mesa_make_current(save_ctx, save_drawbuffer, save_readbuffer);
1128    }
1129 }