From: Brian Paul Date: Wed, 2 Oct 2002 01:51:44 +0000 (+0000) Subject: _glapi_get_proc_address() now always returns a valid dispatch stub function X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=54f3aab0c7fb30dccb41c8c79ba9dc190dbb029e;p=mesa.git _glapi_get_proc_address() now always returns a valid dispatch stub function (provided we're on x86 or SPARC). Later, _glapi_add_entrypoint() will fix-up the dispatch offset (which was -1). This will allow DRI libGL to avoid probing for drivers. --- diff --git a/src/mesa/glapi/glapi.c b/src/mesa/glapi/glapi.c index 78f05534274..b0d26fdcdd9 100644 --- a/src/mesa/glapi/glapi.c +++ b/src/mesa/glapi/glapi.c @@ -1,4 +1,4 @@ -/* $Id: glapi.c,v 1.63 2002/06/29 19:48:16 brianp Exp $ */ +/* $Id: glapi.c,v 1.64 2002/10/02 01:51:44 brianp Exp $ */ /* * Mesa 3-D graphics library @@ -43,6 +43,11 @@ * 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. */ @@ -186,12 +191,10 @@ struct _glapi_table *_glapi_RealDispatch = (struct _glapi_table *) __glapi_noop_ void *_glapi_Context = NULL; -static GLuint MaxDispatchOffset = sizeof(struct _glapi_table) / sizeof(void *) - 1; -static GLboolean GetSizeCalled = GL_FALSE; - static GLboolean DispatchOverride = GL_FALSE; + /* strdup() is actually not a standard ANSI C or POSIX routine. * Irix will not define it if ANSI mode is in effect. */ @@ -437,31 +440,6 @@ _glapi_get_override_dispatch(int layer) } - -/* - * Return size of dispatch table struct as number of functions (or - * slots). - */ -GLuint -_glapi_get_dispatch_table_size(void) -{ - /* return sizeof(struct _glapi_table) / sizeof(void *);*/ - GetSizeCalled = GL_TRUE; - return MaxDispatchOffset + 1; -} - - - -/* - * Get API dispatcher version string. - */ -const char * -_glapi_get_version(void) -{ - return "20020628"; /* YYYYMMDD */ -} - - struct name_address_offset { const char *Name; GLvoid *Address; @@ -469,7 +447,7 @@ struct name_address_offset { }; -/* The code in this file is auto-generated */ +/* The code in this file is auto-generated with Python */ #include "glprocs.h" @@ -513,8 +491,20 @@ get_static_proc_address(const char *funcName) * Extension function management. */ +/* + * Number of extension functions which we can dynamically add at runtime. + */ +#define MAX_EXTENSION_FUNCS 300 + + +/* + * The disptach table size (number of entries) is the sizeof 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) -#define MAX_EXTENSION_FUNCS 1000 static struct name_address_offset ExtEntryTable[MAX_EXTENSION_FUNCS]; static GLuint NumExtEntryPoints = 0; @@ -548,7 +538,7 @@ generate_entrypoint(GLuint functionOffset) * 14: ff a0 10 32 54 76 jmp *0x76543210(%eax) * 14 15 16 17 18 19 */ - static const unsigned char temp[] = { + static const unsigned char insn_template[] = { 0xa1, 0x00, 0x00, 0x00, 0x00, 0x85, 0xc0, 0x74, 0x06, @@ -556,10 +546,10 @@ generate_entrypoint(GLuint functionOffset) 0xe8, 0x00, 0x00, 0x00, 0x00, 0xff, 0xa0, 0x00, 0x00, 0x00, 0x00 }; - unsigned char *code = malloc(sizeof(temp)); + unsigned char *code = malloc(sizeof(insn_template)); unsigned int next_insn; if (code) { - memcpy(code, temp, sizeof(temp)); + memcpy(code, insn_template, sizeof(insn_template)); *(unsigned int *)(code + 0x01) = (unsigned int)&_glapi_Dispatch; *(unsigned int *)(code + 0x0b) = (unsigned int)functionOffset * 4; @@ -619,10 +609,42 @@ generate_entrypoint(GLuint functionOffset) return code; #else return NULL; -#endif +#endif /* USE_*_ASM */ } +/* + * This function inserts a new dispatch offset into the assembly language + * stub that was generated with the preceeding function. + */ +static void +fill_in_entrypoint_offset(void *entrypoint, GLuint offset) +{ +#if defined(USE_X86_ASM) + + unsigned char *code = (unsigned char *) entrypoint; + *(unsigned int *)(code + 0x0b) = offset * 4; + *(unsigned int *)(code + 0x16) = offset * 4; + +#elif defined(USE_SPARC_ASM) + + /* XXX this hasn't been tested! */ + unsigned int *code = (unsigned int *) entrypoint; +#ifdef __sparc_v9__ + code[6] = 0x05000000; /* sethi %hi(8 * glapioffset), %g2 */ + code[7] = 0x8410a000; /* or %g2, %lo(8 * glapioffset), %g2 */ + code[6] |= ((offset * 8) >> 10); + code[7] |= ((offset * 8) & ((1 << 10) - 1)); + __glapi_sparc_icache_flush(&code[6]); +#else /* __sparc_v9__ */ + code[2] = 0xc6006000; /* ld [%g1 + %lo(4*glapioffset)], %g3 */ + code[2] |= (functionOffset * 4); + __glapi_sparc_icache_flush(&code[2]); +#endif /* __sparc_v9__ */ + +#endif /* USE_*_ASM */ +} + /* * Add a new extension function entrypoint. @@ -639,52 +661,54 @@ _glapi_add_entrypoint(const char *funcName, GLuint offset) } } + /* make sure this offset/name pair is legal (this isn't really needed) */ { - /* make sure this offset/name pair is legal */ const char *name = _glapi_get_proc_name(offset); if (name && strcmp(name, funcName) != 0) return GL_FALSE; /* bad name! */ } + /* See if this function has already been dynamically added */ { - /* be sure index and name match known data */ GLuint i; for (i = 0; i < NumExtEntryPoints; i++) { if (strcmp(ExtEntryTable[i].Name, funcName) == 0) { - /* function already registered with api */ + /* function already registered */ if (ExtEntryTable[i].Offset == offset) { return GL_TRUE; /* offsets match */ } + else if (ExtEntryTable[i].Offset == ~0 + && offset < DISPATCH_TABLE_SIZE) { + /* need to patch-up the dispatch code */ + if (offset != ~0) { + fill_in_entrypoint_offset(ExtEntryTable[i].Address, offset); + ExtEntryTable[i].Offset = offset; + } + return GL_TRUE; + } else { return GL_FALSE; /* bad offset! */ } } } - /* Make sure we don't try to add a new entrypoint after someone - * has already called _glapi_get_dispatch_table_size()! If that's - * happened the caller's information would become out of date. - */ - if (GetSizeCalled) - return GL_FALSE; - - /* make sure we have space */ - if (NumExtEntryPoints >= MAX_EXTENSION_FUNCS) { + /* This is a new function, try to add it. */ + if (NumExtEntryPoints >= MAX_EXTENSION_FUNCS || + offset >= DISPATCH_TABLE_SIZE) { + /* No space left */ return GL_FALSE; } else { void *entrypoint = generate_entrypoint(offset); if (!entrypoint) - return GL_FALSE; + return GL_FALSE; /* couldn't generate assembly */ + /* OK! */ ExtEntryTable[NumExtEntryPoints].Name = str_dup(funcName); ExtEntryTable[NumExtEntryPoints].Offset = offset; ExtEntryTable[NumExtEntryPoints].Address = entrypoint; NumExtEntryPoints++; - if (offset > MaxDispatchOffset) - MaxDispatchOffset = offset; - return GL_TRUE; /* success */ } } @@ -694,48 +718,6 @@ _glapi_add_entrypoint(const char *funcName, GLuint offset) } - -#if 0000 /* prototype code for dynamic extension slot allocation */ - -static int NextFreeOffset = 409; /*XXX*/ -#define MAX_DISPATCH_TABLE_SIZE 1000 - -/* - * Dynamically allocate a dispatch slot for an extension entrypoint - * and generate the assembly language dispatch stub. - * Return the dispatch offset for the function or -1 if no room or error. - */ -GLint -_glapi_add_entrypoint2(const char *funcName) -{ - int offset; - - /* first see if extension func is already known */ - offset = _glapi_get_proc_offset(funcName); - if (offset >= 0) - return offset; - - if (NumExtEntryPoints < MAX_EXTENSION_FUNCS - && NextFreeOffset < MAX_DISPATCH_TABLE_SIZE) { - void *entryPoint; - offset = NextFreeOffset; - entryPoint = generate_entrypoint(offset); - if (entryPoint) { - NextFreeOffset++; - ExtEntryTable[NumExtEntryPoints].Name = str_dup(funcName); - ExtEntryTable[NumExtEntryPoints].Offset = offset; - ExtEntryTable[NumExtEntryPoints].Address = entryPoint; - NumExtEntryPoints++; - return offset; - } - } - return -1; -} - -#endif - - - /* * Return offset of entrypoint for named function within dispatch table. */ @@ -771,9 +753,35 @@ _glapi_get_proc_address(const char *funcName) } /* search static functions */ - return get_static_proc_address(funcName); -} + { + const GLvoid *func = get_static_proc_address(funcName); + if (func) + return func; + } + + /* generate new entrypoint - use a temporary dispatch offset of + * ~0 (i.e. -1). Later, when the driver calls _glapi_add_entrypoint() + * we'll put in the proper offset. If that never happens, and the + * user calls this function, he'll segfault. That's what you get + * when you try calling a GL function that doesn't really exist. + */ + if (NumExtEntryPoints < MAX_EXTENSION_FUNCS) { + GLvoid *entrypoint = generate_entrypoint(~0); + if (!entrypoint) + return GL_FALSE; + + ExtEntryTable[NumExtEntryPoints].Name = str_dup(funcName); + ExtEntryTable[NumExtEntryPoints].Offset = ~0; + ExtEntryTable[NumExtEntryPoints].Address = entrypoint; + NumExtEntryPoints++; + return entrypoint; + } + else { + /* no space for new functions! */ + return NULL; + } +} @@ -786,6 +794,8 @@ _glapi_get_proc_name(GLuint offset) { const GLuint n = sizeof(static_functions) / sizeof(struct name_address_offset); GLuint i; + + /* search built-in functions */ for (i = 0; i < n; i++) { if (static_functions[i].Offset == offset) return static_functions[i].Name; @@ -802,6 +812,29 @@ _glapi_get_proc_name(GLuint offset) +/* + * Return size of dispatch table struct as number of functions (or + * slots). + */ +GLuint +_glapi_get_dispatch_table_size(void) +{ + return DISPATCH_TABLE_SIZE; +} + + + +/* + * Get API dispatcher version string. + */ +const char * +_glapi_get_version(void) +{ + return "20021001"; /* YYYYMMDD */ +} + + + /* * Make sure there are no NULL pointers in the given dispatch table. * Intended for debugging purposes. @@ -878,5 +911,13 @@ _glapi_check_table(const struct _glapi_table *table) assert(pointParameterivOffset == offset); assert(_glapi_get_proc_address("glPointParameterivNV") == (void *) &glPointParameterivNV); } + { + 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); + assert(_glapi_get_proc_address("glSetFenceNV") == (void *) &glSetFenceNV); + } #endif }