Implemented the Dynamic API magic.
--HG-- extra : rebase_source : 38f639089d3d142895d5cf106919a0bfbb65c5ed
This commit is contained in:
Ryan C. Gordon
parent
82edee6971
commit
63256a2384
21 changed files with 1808 additions and 1 deletions
302
src/dynapi/SDL_dynapi.c
Normal file
302
src/dynapi/SDL_dynapi.c
Normal file
|
|
@ -0,0 +1,302 @@
|
|||
/*
|
||||
Simple DirectMedia Layer
|
||||
Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>
|
||||
|
||||
This software is provided 'as-is', without any express or implied
|
||||
warranty. In no event will the authors be held liable for any damages
|
||||
arising from the use of this software.
|
||||
|
||||
Permission is granted to anyone to use this software for any purpose,
|
||||
including commercial applications, and to alter it and redistribute it
|
||||
freely, subject to the following restrictions:
|
||||
|
||||
1. The origin of this software must not be misrepresented; you must not
|
||||
claim that you wrote the original software. If you use this software
|
||||
in a product, an acknowledgment in the product documentation would be
|
||||
appreciated but is not required.
|
||||
2. Altered source versions must be plainly marked as such, and must not be
|
||||
misrepresented as being the original software.
|
||||
3. This notice may not be removed or altered from any source distribution.
|
||||
*/
|
||||
|
||||
#include "SDL_config.h"
|
||||
#include "SDL_dynapi.h"
|
||||
|
||||
#if SDL_DYNAMIC_API
|
||||
|
||||
#include "SDL.h"
|
||||
|
||||
/* !!! FIXME: Shouldn't these be included in SDL.h? */
|
||||
#include "SDL_shape.h"
|
||||
#include "SDL_syswm.h"
|
||||
|
||||
/* This is the version of the dynamic API. This doesn't match the SDL version
|
||||
and should not change until there's been a major revamp in API/ABI.
|
||||
So 2.0.5 adds functions over 2.0.4? This number doesn't change;
|
||||
the sizeof (jump_table) changes instead. But 2.1.0 changes how a function
|
||||
works in an incompatible way or removes a function? This number changes,
|
||||
since sizeof (jump_table) isn't sufficient anymore. It's likely
|
||||
we'll forget to bump every time we add a function, so this is the
|
||||
failsafe switch for major API change decisions. Respect it and use it
|
||||
sparingly. */
|
||||
#define SDL_DYNAPI_VERSION 1
|
||||
|
||||
static void SDL_InitDynamicAPI(void);
|
||||
|
||||
|
||||
/* BE CAREFUL CALLING ANY SDL CODE IN HERE, IT WILL BLOW UP.
|
||||
Even self-contained stuff might call SDL_Error and break everything. */
|
||||
|
||||
|
||||
/* behold, the macro salsa! */
|
||||
|
||||
/* !!! FIXME: ...disabled...until we write it. :) */
|
||||
#define DISABLE_JUMP_MAGIC 1
|
||||
|
||||
#if DISABLE_JUMP_MAGIC
|
||||
/* Can't use the macro for varargs nonsense. This is atrocious. */
|
||||
#define SDL_DYNAPI_VARARGS_LOGFN(_static, name, initcall, logname, prio) \
|
||||
_static void SDL_Log##logname##name(int category, const char *fmt, ...) { \
|
||||
va_list ap; initcall; va_start(ap, fmt); \
|
||||
jump_table.SDL_LogMessageV(category, SDL_LOG_PRIORITY_##prio, fmt, ap); \
|
||||
va_end(ap); \
|
||||
}
|
||||
|
||||
#define SDL_DYNAPI_VARARGS(_static, name, initcall) \
|
||||
_static int SDL_SetError##name(const char *fmt, ...) { \
|
||||
char buf[512]; /* !!! FIXME: dynamic allocation */ \
|
||||
va_list ap; initcall; va_start(ap, fmt); \
|
||||
jump_table.SDL_vsnprintf(buf, sizeof (buf), fmt, ap); \
|
||||
va_end(ap); \
|
||||
return jump_table.SDL_SetError("%s", buf); \
|
||||
} \
|
||||
_static int SDL_sscanf##name(const char *buf, const char *fmt, ...) { \
|
||||
int retval; va_list ap; initcall; va_start(ap, fmt); \
|
||||
retval = jump_table.SDL_vsscanf(buf, fmt, ap); \
|
||||
va_end(ap); \
|
||||
return retval; \
|
||||
} \
|
||||
_static int SDL_snprintf##name(char *buf, size_t buflen, const char *fmt, ...) { \
|
||||
int retval; va_list ap; initcall; va_start(ap, fmt); \
|
||||
retval = jump_table.SDL_vsnprintf(buf, buflen, fmt, ap); \
|
||||
va_end(ap); \
|
||||
return retval; \
|
||||
} \
|
||||
_static void SDL_Log##name(const char *fmt, ...) { \
|
||||
va_list ap; initcall; va_start(ap, fmt); \
|
||||
jump_table.SDL_LogMessageV(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO, fmt, ap); \
|
||||
va_end(ap); \
|
||||
} \
|
||||
_static void SDL_LogMessage##name(int category, SDL_LogPriority priority, const char *fmt, ...) { \
|
||||
va_list ap; initcall; va_start(ap, fmt); \
|
||||
jump_table.SDL_LogMessageV(category, priority, fmt, ap); \
|
||||
va_end(ap); \
|
||||
} \
|
||||
SDL_DYNAPI_VARARGS_LOGFN(_static, name, initcall, Verbose, VERBOSE) \
|
||||
SDL_DYNAPI_VARARGS_LOGFN(_static, name, initcall, Debug, DEBUG) \
|
||||
SDL_DYNAPI_VARARGS_LOGFN(_static, name, initcall, Info, INFO) \
|
||||
SDL_DYNAPI_VARARGS_LOGFN(_static, name, initcall, Warn, WARN) \
|
||||
SDL_DYNAPI_VARARGS_LOGFN(_static, name, initcall, Error, ERROR) \
|
||||
SDL_DYNAPI_VARARGS_LOGFN(_static, name, initcall, Critical, CRITICAL)
|
||||
#endif
|
||||
|
||||
|
||||
/* Typedefs for function pointers for jump table, and predeclare funcs */
|
||||
/* The DEFAULT funcs will init jump table and then call real function. */
|
||||
/* The REAL funcs are the actual functions, name-mangled to not clash. */
|
||||
#define SDL_DYNAPI_PROC(rc,fn,params,args,ret) \
|
||||
typedef rc (*SDL_DYNAPIFN_##fn) params; \
|
||||
static rc fn##_DEFAULT params; \
|
||||
extern rc fn##_REAL params;
|
||||
#include "SDL_dynapi_procs.h"
|
||||
#undef SDL_DYNAPI_PROC
|
||||
|
||||
/* The jump table! */
|
||||
typedef struct {
|
||||
#define SDL_DYNAPI_PROC(rc,fn,params,args,ret) SDL_DYNAPIFN_##fn fn;
|
||||
#include "SDL_dynapi_procs.h"
|
||||
#undef SDL_DYNAPI_PROC
|
||||
} SDL_DYNAPI_jump_table;
|
||||
|
||||
/* Predeclare the default functions for initializing the jump table. */
|
||||
#define SDL_DYNAPI_PROC(rc,fn,params,args,ret) static rc fn##_DEFAULT params;
|
||||
#include "SDL_dynapi_procs.h"
|
||||
#undef SDL_DYNAPI_PROC
|
||||
|
||||
/* The actual jump table. */
|
||||
static SDL_DYNAPI_jump_table jump_table = {
|
||||
#define SDL_DYNAPI_PROC(rc,fn,params,args,ret) fn##_DEFAULT,
|
||||
#include "SDL_dynapi_procs.h"
|
||||
#undef SDL_DYNAPI_PROC
|
||||
};
|
||||
|
||||
/* Default functions init the function table then call right thing. */
|
||||
#if DISABLE_JUMP_MAGIC
|
||||
#define SDL_DYNAPI_PROC(rc,fn,params,args,ret) \
|
||||
static rc fn##_DEFAULT params { \
|
||||
SDL_InitDynamicAPI(); \
|
||||
ret jump_table.fn args; \
|
||||
}
|
||||
#define SDL_DYNAPI_PROC_NO_VARARGS 1
|
||||
#include "SDL_dynapi_procs.h"
|
||||
#undef SDL_DYNAPI_PROC
|
||||
#undef SDL_DYNAPI_PROC_NO_VARARGS
|
||||
SDL_DYNAPI_VARARGS(static, _DEFAULT, SDL_InitDynamicAPI())
|
||||
#else
|
||||
/* !!! FIXME: need the jump magic. */
|
||||
#error Write me.
|
||||
#endif
|
||||
|
||||
/* Public API functions to jump into the jump table. */
|
||||
#if DISABLE_JUMP_MAGIC
|
||||
#define SDL_DYNAPI_PROC(rc,fn,params,args,ret) \
|
||||
rc fn params { ret jump_table.fn args; }
|
||||
#define SDL_DYNAPI_PROC_NO_VARARGS 1
|
||||
#include "SDL_dynapi_procs.h"
|
||||
#undef SDL_DYNAPI_PROC
|
||||
#undef SDL_DYNAPI_PROC_NO_VARARGS
|
||||
SDL_DYNAPI_VARARGS(,,)
|
||||
#else
|
||||
/* !!! FIXME: need the jump magic. */
|
||||
#error Write me.
|
||||
#endif
|
||||
|
||||
|
||||
|
||||
/* Here's the exported entry point that fills in the jump table. */
|
||||
/* Use specific types when an "int" might suffice to keep this sane. */
|
||||
typedef Sint32 (SDLCALL *SDL_DYNAPI_ENTRYFN)(Uint32 apiver, void *table, Uint32 tablesize);
|
||||
extern DECLSPEC Sint32 SDLCALL SDL_DYNAPI_entry(Uint32, void *, Uint32);
|
||||
|
||||
Sint32
|
||||
SDL_DYNAPI_entry(Uint32 apiver, void *table, Uint32 tablesize)
|
||||
{
|
||||
SDL_DYNAPI_jump_table *output_jump_table = (SDL_DYNAPI_jump_table *) table;
|
||||
|
||||
if (apiver != SDL_DYNAPI_VERSION) {
|
||||
/* !!! FIXME: can maybe handle older versions? */
|
||||
return -1; /* not compatible. */
|
||||
} else if (tablesize > sizeof (jump_table)) {
|
||||
return -1; /* newer version of SDL with functions we can't provide. */
|
||||
}
|
||||
|
||||
/* Init our jump table first. */
|
||||
#define SDL_DYNAPI_PROC(rc,fn,params,args,ret) jump_table.fn = fn##_REAL;
|
||||
#include "SDL_dynapi_procs.h"
|
||||
#undef SDL_DYNAPI_PROC
|
||||
|
||||
/* Then the external table... */
|
||||
if (output_jump_table != &jump_table) {
|
||||
jump_table.SDL_memcpy(output_jump_table, &jump_table, tablesize);
|
||||
}
|
||||
|
||||
/* Safe to call SDL functions now; jump table is initialized! */
|
||||
|
||||
return 0; /* success! */
|
||||
}
|
||||
|
||||
|
||||
/* Obviously we can't use SDL_LoadObject() to load SDL. :) */
|
||||
/* Also obviously, we never close the loaded library. */
|
||||
#if defined(_WINDOWS)
|
||||
#ifndef WIN32_LEAN_AND_MEAN
|
||||
#define WIN32_LEAN_AND_MEAN 1
|
||||
#endif
|
||||
#include <windows.h>
|
||||
static SDL_INLINE void *get_sdlapi_entry(const char *fname, const char *sym)
|
||||
{
|
||||
HANDLE lib = LoadLibraryA(fname);
|
||||
return lib ? GetProcAddress(lib, sym) : NULL;
|
||||
}
|
||||
|
||||
#elif defined(__HAIKU__)
|
||||
#include <os/kernel/image.h>
|
||||
static SDL_INLINE void *get_sdlapi_entry(const char *fname, const char *sym)
|
||||
{
|
||||
image_id lib = load_add_on(fname);
|
||||
void *retval = NULL;
|
||||
if ((lib < 0) || (get_image_symbol(lib, sym, B_SYMBOL_TYPE_TEXT, &retval) != B_NO_ERROR)) {
|
||||
retval = NULL;
|
||||
}
|
||||
return retval;
|
||||
}
|
||||
#elif defined(unix) || defined(__APPLE__)
|
||||
#include <dlfcn.h>
|
||||
static SDL_INLINE void *get_sdlapi_entry(const char *fname, const char *sym)
|
||||
{
|
||||
void *lib = dlopen(fname, RTLD_NOW | RTLD_LOCAL);
|
||||
return lib ? dlsym(lib, sym) : NULL;
|
||||
}
|
||||
#else
|
||||
#error Please define your platform.
|
||||
#endif
|
||||
|
||||
|
||||
static void
|
||||
SDL_InitDynamicAPILocked(void)
|
||||
{
|
||||
const char *libname = SDL_getenv_REAL("SDL_DYNAMIC_API");
|
||||
SDL_DYNAPI_ENTRYFN entry = SDL_DYNAPI_entry; /* funcs from here by default. */
|
||||
|
||||
if (libname) {
|
||||
entry = (SDL_DYNAPI_ENTRYFN) get_sdlapi_entry(libname, "SDL_DYNAPI_entry");
|
||||
if (!entry) {
|
||||
/* !!! FIXME: fail to startup here instead? */
|
||||
/* !!! FIXME: definitely warn user. */
|
||||
/* Just fill in the function pointers from this library. */
|
||||
entry = SDL_DYNAPI_entry;
|
||||
}
|
||||
}
|
||||
|
||||
if (entry(SDL_DYNAPI_VERSION, &jump_table, sizeof (jump_table)) < 0) {
|
||||
/* !!! FIXME: fail to startup here instead? */
|
||||
/* !!! FIXME: definitely warn user. */
|
||||
/* Just fill in the function pointers from this library. */
|
||||
if (entry != SDL_DYNAPI_entry) {
|
||||
if (!SDL_DYNAPI_entry(SDL_DYNAPI_VERSION, &jump_table, sizeof (jump_table))) {
|
||||
/* !!! FIXME: now we're screwed. Should definitely abort now. */
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* we intentionally never close the newly-loaded lib, of course. */
|
||||
}
|
||||
|
||||
static void
|
||||
SDL_InitDynamicAPI(void)
|
||||
{
|
||||
/* So the theory is that every function in the jump table defaults to
|
||||
* calling this function, and then replaces itself with a version that
|
||||
* doesn't call this function anymore. But it's possible that, in an
|
||||
* extreme corner case, you can have a second thread hit this function
|
||||
* while the jump table is being initialized by the first.
|
||||
* In this case, a spinlock is really painful compared to what spinlocks
|
||||
* _should_ be used for, but this would only happen once, and should be
|
||||
* insanely rare, as you would have to spin a thread outside of SDL (as
|
||||
* SDL_CreateThread() would also call this function before building the
|
||||
* new thread).
|
||||
*/
|
||||
static volatile SDL_bool already_initialized = SDL_FALSE;
|
||||
|
||||
/* SDL_AtomicLock calls SDL mutex functions to emulate if
|
||||
SDL_ATOMIC_DISABLED, which we can't do here, so in such a
|
||||
configuration, you're on your own. */
|
||||
#if !SDL_ATOMIC_DISABLED
|
||||
static SDL_SpinLock lock = 0;
|
||||
SDL_AtomicLock_REAL(&lock);
|
||||
#endif
|
||||
|
||||
if (!already_initialized) {
|
||||
SDL_InitDynamicAPILocked();
|
||||
already_initialized = SDL_TRUE;
|
||||
}
|
||||
|
||||
#if !SDL_ATOMIC_DISABLED
|
||||
SDL_AtomicUnlock_REAL(&lock);
|
||||
#endif
|
||||
}
|
||||
|
||||
#endif /* SDL_DYNAMIC_API */
|
||||
|
||||
/* vi: set ts=4 sw=4 expandtab: */
|
||||
|
||||
Loading…
Add table
Add a link
Reference in a new issue