/* * Mesa 3-D graphics library * Version: 7.1 * * Copyright (C) 1999-2008 Brian Paul All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /* * This file manages the OpenGL API dispatch layer. * The dispatch table (struct _glapi_table) is basically just a list * of function pointers. * There are functions to set/get the current dispatch table for the * current thread and to manage registration/dispatch of dynamically * added extension functions. * * It's intended that this file and the other glapi*.[ch] files are * flexible enough to be reused in several places: XFree86, DRI- * based libGL.so, and perhaps the SGI SI. * * NOTE: There are no dependencies on Mesa in this code. * * Versions (API changes): * 2000/02/23 - original version for Mesa 3.3 and XFree86 4.0 * 2001/01/16 - added dispatch override feature for Mesa 3.5 * 2002/06/28 - added _glapi_set_warning_func(), Mesa 4.1. * 2002/10/01 - _glapi_get_proc_address() will now generate new entrypoints * itself (using offset ~0). _glapi_add_entrypoint() can be * called afterward and it'll fill in the correct dispatch * offset. This allows DRI libGL to avoid probing for DRI * drivers! No changes to the public glapi interface. */ #ifdef HAVE_DIX_CONFIG_H #include #define PUBLIC #else #include "main/glheader.h" #endif #include #include #ifdef DEBUG #include #endif #include "glapi.h" #include "glapioffsets.h" #include "glapitable.h" /***** BEGIN NO-OP DISPATCH *****/ static GLboolean WarnFlag = GL_FALSE; static _glapi_warning_func warning_func; /* * Enable/disable printing of warning messages. */ PUBLIC void _glapi_noop_enable_warnings(GLboolean enable) { WarnFlag = enable; } /* * Register a callback function for reporting errors. */ PUBLIC void _glapi_set_warning_func( _glapi_warning_func func ) { warning_func = func; } static GLboolean warn(void) { #if !defined(_WIN32_WCE) if ((WarnFlag || getenv("MESA_DEBUG") || getenv("LIBGL_DEBUG")) && warning_func) { return GL_TRUE; } else { return GL_FALSE; } #else return GL_FALSE; #endif } #define KEYWORD1 static #define KEYWORD1_ALT static #define KEYWORD2 GLAPIENTRY #define NAME(func) NoOp##func #define F NULL #define DISPATCH(func, args, msg) \ if (warn()) { \ warning_func(NULL, "GL User Error: called without context: %s", #func); \ } #define RETURN_DISPATCH(func, args, msg) \ if (warn()) { \ warning_func(NULL, "GL User Error: called without context: %s", #func); \ } \ return 0 #define DISPATCH_TABLE_NAME __glapi_noop_table #define UNUSED_TABLE_NAME __unused_noop_functions #define TABLE_ENTRY(name) (_glapi_proc) NoOp##name static GLint NoOpUnused(void) { if (warn()) { warning_func(NULL, "GL User Error: calling extension function without a current context\n"); } return 0; } #include "glapitemp.h" /***** END NO-OP DISPATCH *****/ /** * \name Current dispatch and current context control variables * * Depending on whether or not multithreading is support, and the type of * support available, several variables are used to store the current context * pointer and the current dispatch table pointer. In the non-threaded case, * the variables \c _glapi_Dispatch and \c _glapi_Context are used for this * purpose. * * In the "normal" threaded case, the variables \c _glapi_Dispatch and * \c _glapi_Context will be \c NULL if an application is detected as being * multithreaded. Single-threaded applications will use \c _glapi_Dispatch * and \c _glapi_Context just like the case without any threading support. * When \c _glapi_Dispatch and \c _glapi_Context are \c NULL, the thread state * data \c _gl_DispatchTSD and \c ContextTSD are used. Drivers and the * static dispatch functions access these variables via \c _glapi_get_dispatch * and \c _glapi_get_context. * * There is a race condition in setting \c _glapi_Dispatch to \c NULL. It is * possible for the original thread to be setting it at the same instant a new * thread, perhaps running on a different processor, is clearing it. Because * of that, \c ThreadSafe, which can only ever be changed to \c GL_TRUE, is * used to determine whether or not the application is multithreaded. * * In the TLS case, the variables \c _glapi_Dispatch and \c _glapi_Context are * hardcoded to \c NULL. Instead the TLS variables \c _glapi_tls_Dispatch and * \c _glapi_tls_Context are used. Having \c _glapi_Dispatch and * \c _glapi_Context be hardcoded to \c NULL maintains binary compatability * between TLS enabled loaders and non-TLS DRI drivers. */ /*@{*/ #if defined(GLX_USE_TLS) PUBLIC __thread struct _glapi_table * _glapi_tls_Dispatch __attribute__((tls_model("initial-exec"))) = (struct _glapi_table *) __glapi_noop_table; PUBLIC __thread void * _glapi_tls_Context __attribute__((tls_model("initial-exec"))); PUBLIC const struct _glapi_table *_glapi_Dispatch = NULL; PUBLIC const void *_glapi_Context = NULL; #else #if defined(THREADS) static GLboolean ThreadSafe = GL_FALSE; /**< In thread-safe mode? */ _glthread_TSD _gl_DispatchTSD; /**< Per-thread dispatch pointer */ static _glthread_TSD ContextTSD; /**< Per-thread context pointer */ #if defined(WIN32_THREADS) void FreeTSD(_glthread_TSD *p); void FreeAllTSD(void) { FreeTSD(&_gl_DispatchTSD); FreeTSD(&ContextTSD); } #endif /* defined(WIN32_THREADS) */ #endif /* defined(THREADS) */ PUBLIC struct _glapi_table *_glapi_Dispatch = (struct _glapi_table *) __glapi_noop_table; PUBLIC void *_glapi_Context = NULL; #endif /* defined(GLX_USE_TLS) */ /*@}*/ /** * We should call this periodically from a function such as glXMakeCurrent * in order to test if multiple threads are being used. */ void _glapi_check_multithread(void) { #if defined(THREADS) && !defined(GLX_USE_TLS) if (!ThreadSafe) { static unsigned long knownID; static GLboolean firstCall = GL_TRUE; if (firstCall) { knownID = _glthread_GetID(); firstCall = GL_FALSE; } else if (knownID != _glthread_GetID()) { ThreadSafe = GL_TRUE; _glapi_set_dispatch(NULL); _glapi_set_context(NULL); } } else if (!_glapi_get_dispatch()) { /* make sure that this thread's dispatch pointer isn't null */ _glapi_set_dispatch(NULL); } #endif } /** * Set the current context pointer for this thread. * The context pointer is an opaque type which should be cast to * void from the real context pointer type. */ PUBLIC void _glapi_set_context(void *context) { (void) __unused_noop_functions; /* silence a warning */ #if defined(GLX_USE_TLS) _glapi_tls_Context = context; #elif defined(THREADS) _glthread_SetTSD(&ContextTSD, context); _glapi_Context = (ThreadSafe) ? NULL : context; #else _glapi_Context = context; #endif } /** * Get the current context pointer for this thread. * The context pointer is an opaque type which should be cast from * void to the real context pointer type. */ PUBLIC void * _glapi_get_context(void) { #if defined(GLX_USE_TLS) return _glapi_tls_Context; #elif defined(THREADS) if (ThreadSafe) { return _glthread_GetTSD(&ContextTSD); } else { return _glapi_Context; } #else return _glapi_Context; #endif } #if defined(PTHREADS) || defined(GLX_USE_TLS) /** * Perform platform-specific GL API entry-point fixups. */ static void init_glapi_relocs( void ) { #if defined(USE_X86_ASM) && defined(GLX_USE_TLS) && !defined(GLX_X86_READONLY_TEXT) extern unsigned long _x86_get_dispatch(void); char run_time_patch[] = { 0x65, 0xa1, 0, 0, 0, 0 /* movl %gs:0,%eax */ }; GLuint *offset = (GLuint *) &run_time_patch[2]; /* 32-bits for x86/32 */ const GLubyte * const get_disp = (const GLubyte *) run_time_patch; GLubyte * curr_func = (GLubyte *) gl_dispatch_functions_start; *offset = _x86_get_dispatch(); while ( curr_func != (GLubyte *) gl_dispatch_functions_end ) { (void) memcpy( curr_func, get_disp, sizeof(run_time_patch)); curr_func += DISPATCH_FUNCTION_SIZE; } #endif } #endif /* defined(PTHREADS) || defined(GLX_USE_TLS) */ /** * Set the global or per-thread dispatch table pointer. * If the dispatch parameter is NULL we'll plug in the no-op dispatch * table (__glapi_noop_table). */ PUBLIC void _glapi_set_dispatch(struct _glapi_table *dispatch) { #if defined(PTHREADS) || defined(GLX_USE_TLS) static pthread_once_t once_control = PTHREAD_ONCE_INIT; pthread_once( & once_control, init_glapi_relocs ); #endif if (!dispatch) { /* use the no-op functions */ dispatch = (struct _glapi_table *) __glapi_noop_table; } #ifdef DEBUG else { _glapi_check_table(dispatch); } #endif #if defined(GLX_USE_TLS) _glapi_tls_Dispatch = dispatch; #elif defined(THREADS) _glthread_SetTSD(&_gl_DispatchTSD, (void *) dispatch); _glapi_Dispatch = (ThreadSafe) ? NULL : dispatch; #else /*THREADS*/ _glapi_Dispatch = dispatch; #endif /*THREADS*/ } /** * Return pointer to current dispatch table for calling thread. */ PUBLIC struct _glapi_table * _glapi_get_dispatch(void) { struct _glapi_table * api; #if defined(GLX_USE_TLS) api = _glapi_tls_Dispatch; #elif defined(THREADS) api = (ThreadSafe) ? (struct _glapi_table *) _glthread_GetTSD(&_gl_DispatchTSD) : _glapi_Dispatch; #else api = _glapi_Dispatch; #endif return api; } /* * The dispatch table size (number of entries) is the size of the * _glapi_table struct plus the number of dynamic entries we can add. * The extra slots can be filled in by DRI drivers that register new extension * functions. */ #define DISPATCH_TABLE_SIZE (sizeof(struct _glapi_table) / sizeof(void *) + MAX_EXTENSION_FUNCS) /** * Return size of dispatch table struct as number of functions (or * slots). */ PUBLIC GLuint _glapi_get_dispatch_table_size(void) { return DISPATCH_TABLE_SIZE; } /** * Make sure there are no NULL pointers in the given dispatch table. * Intended for debugging purposes. */ void _glapi_check_table(const struct _glapi_table *table) { #ifdef EXTRA_DEBUG const GLuint entries = _glapi_get_dispatch_table_size(); const void **tab = (const void **) table; GLuint i; for (i = 1; i < entries; i++) { assert(tab[i]); } /* Do some spot checks to be sure that the dispatch table * slots are assigned correctly. */ { GLuint BeginOffset = _glapi_get_proc_offset("glBegin"); char *BeginFunc = (char*) &table->Begin; GLuint offset = (BeginFunc - (char *) table) / sizeof(void *); assert(BeginOffset == _gloffset_Begin); assert(BeginOffset == offset); } { GLuint viewportOffset = _glapi_get_proc_offset("glViewport"); char *viewportFunc = (char*) &table->Viewport; GLuint offset = (viewportFunc - (char *) table) / sizeof(void *); assert(viewportOffset == _gloffset_Viewport); assert(viewportOffset == offset); } { GLuint VertexPointerOffset = _glapi_get_proc_offset("glVertexPointer"); char *VertexPointerFunc = (char*) &table->VertexPointer; GLuint offset = (VertexPointerFunc - (char *) table) / sizeof(void *); assert(VertexPointerOffset == _gloffset_VertexPointer); assert(VertexPointerOffset == offset); } { GLuint ResetMinMaxOffset = _glapi_get_proc_offset("glResetMinmax"); char *ResetMinMaxFunc = (char*) &table->ResetMinmax; GLuint offset = (ResetMinMaxFunc - (char *) table) / sizeof(void *); assert(ResetMinMaxOffset == _gloffset_ResetMinmax); assert(ResetMinMaxOffset == offset); } { GLuint blendColorOffset = _glapi_get_proc_offset("glBlendColor"); char *blendColorFunc = (char*) &table->BlendColor; GLuint offset = (blendColorFunc - (char *) table) / sizeof(void *); assert(blendColorOffset == _gloffset_BlendColor); assert(blendColorOffset == offset); } { GLuint secondaryColor3fOffset = _glapi_get_proc_offset("glSecondaryColor3fEXT"); char *secondaryColor3fFunc = (char*) &table->SecondaryColor3fEXT; GLuint offset = (secondaryColor3fFunc - (char *) table) / sizeof(void *); assert(secondaryColor3fOffset == _gloffset_SecondaryColor3fEXT); assert(secondaryColor3fOffset == offset); } { GLuint pointParameterivOffset = _glapi_get_proc_offset("glPointParameterivNV"); char *pointParameterivFunc = (char*) &table->PointParameterivNV; GLuint offset = (pointParameterivFunc - (char *) table) / sizeof(void *); assert(pointParameterivOffset == _gloffset_PointParameterivNV); assert(pointParameterivOffset == offset); } { GLuint setFenceOffset = _glapi_get_proc_offset("glSetFenceNV"); char *setFenceFunc = (char*) &table->SetFenceNV; GLuint offset = (setFenceFunc - (char *) table) / sizeof(void *); assert(setFenceOffset == _gloffset_SetFenceNV); assert(setFenceOffset == offset); } #else (void) table; #endif }