SDL_dynapi.c File Reference

#include "SDL_config.h"
#include "SDL_dynapi.h"
#include "SDL.h"
#include "SDL_syswm.h"
#include "SDL_vulkan.h"
#include "SDL_dynapi_procs.h"
#include <windows.h>

Include dependency graph for SDL_dynapi.c:

Go to the source code of this file.

Data Structures
struct	SDL_DYNAPI_jump_table

Macros
#define	SDL_DYNAPI_VERSION   1
#define	DISABLE_JUMP_MAGIC   1
#define	SDL_DYNAPI_VARARGS_LOGFN(_static, name, initcall, logname, prio)
#define	SDL_DYNAPI_VARARGS(_static, name, initcall)
#define	SDL_DYNAPI_PROC(rc, fn, params, args, ret)
#define	SDL_DYNAPI_PROC(rc, fn, params, args, ret)   SDL_DYNAPIFN_##fn fn;
#define	SDL_DYNAPI_PROC(rc, fn, params, args, ret)   static rc SDLCALL fn##_DEFAULT params;
#define	SDL_DYNAPI_PROC(rc, fn, params, args, ret)   fn##_DEFAULT,
#define	SDL_DYNAPI_PROC(rc, fn, params, args, ret)
#define	SDL_DYNAPI_PROC_NO_VARARGS   1
#define	SDL_DYNAPI_PROC(rc, fn, params, args, ret)   rc SDLCALL fn params { ret jump_table.fn args; }
#define	SDL_DYNAPI_PROC_NO_VARARGS   1
#define	SDL_DYNAPI_PROC(rc, fn, params, args, ret)   jump_table.fn = fn##_REAL;
#define	WIN32_LEAN_AND_MEAN   1

Typedefs
typedef Sint32(*	SDL_DYNAPI_ENTRYFN) (Uint32 apiver, void *table, Uint32 tablesize)

Functions
static void	SDL_InitDynamicAPI (void)
static Sint32	initialize_jumptable (Uint32 apiver, void *table, Uint32 tablesize)
Sint32	SDL_DYNAPI_entry (Uint32, void *, Uint32)
static SDL_INLINE void *	get_sdlapi_entry (const char *fname, const char *sym)
static void	SDL_InitDynamicAPILocked (void)

Variables
static SDL_DYNAPI_jump_table	jump_table

Macro Definition Documentation

DISABLE_JUMP_MAGIC

#define DISABLE_JUMP_MAGIC   1

Definition at line 61 of file SDL_dynapi.c.

SDL_DYNAPI_PROC [1/7]

#define SDL_DYNAPI_PROC	(		rc,
			fn,
			params,
			args,
			ret
	)

Value:

    typedef rc (SDLCALL *SDL_DYNAPIFN_##fn) params; \
    static rc SDLCALL fn##_DEFAULT params; \
    extern rc SDLCALL fn##_REAL params;

Definition at line 159 of file SDL_dynapi.c.

SDL_DYNAPI_PROC [2/7]

#define SDL_DYNAPI_PROC	(		rc,
			fn,
			params,
			args,
			ret
	)		SDL_DYNAPIFN_##fn fn;

Definition at line 159 of file SDL_dynapi.c.

SDL_DYNAPI_PROC [3/7]

#define SDL_DYNAPI_PROC	(		rc,
			fn,
			params,
			args,
			ret
	)		static rc SDLCALL fn##_DEFAULT params;

Definition at line 159 of file SDL_dynapi.c.

SDL_DYNAPI_PROC [4/7]

#define SDL_DYNAPI_PROC	(		rc,
			fn,
			params,
			args,
			ret
	)		fn##_DEFAULT,

Definition at line 159 of file SDL_dynapi.c.

SDL_DYNAPI_PROC [5/7]

#define SDL_DYNAPI_PROC	(		rc,
			fn,
			params,
			args,
			ret
	)

Value:

    static rc SDLCALL fn##_DEFAULT params { \
        SDL_InitDynamicAPI(); \
        ret jump_table.fn args; \
    }

Definition at line 159 of file SDL_dynapi.c.

SDL_DYNAPI_PROC [6/7]

#define SDL_DYNAPI_PROC	(		rc,
			fn,
			params,
			args,
			ret
	)		rc SDLCALL fn params { ret jump_table.fn args; }

Definition at line 159 of file SDL_dynapi.c.

SDL_DYNAPI_PROC [7/7]

#define SDL_DYNAPI_PROC	(		rc,
			fn,
			params,
			args,
			ret
	)		jump_table.fn = fn##_REAL;

Definition at line 159 of file SDL_dynapi.c.

SDL_DYNAPI_PROC_NO_VARARGS [1/2]

#define SDL_DYNAPI_PROC_NO_VARARGS   1

Definition at line 161 of file SDL_dynapi.c.

SDL_DYNAPI_PROC_NO_VARARGS [2/2]

#define SDL_DYNAPI_PROC_NO_VARARGS   1

Definition at line 161 of file SDL_dynapi.c.

SDL_DYNAPI_VARARGS

#define SDL_DYNAPI_VARARGS	(		_static,
			name,
			initcall
	)

Definition at line 72 of file SDL_dynapi.c.

SDL_DYNAPI_VARARGS_LOGFN

#define SDL_DYNAPI_VARARGS_LOGFN	(		_static,
			name,
			initcall,
			logname,
			prio
	)

Value:

    _static void SDLCALL SDL_Log##logname##name(int category, SDL_PRINTF_FORMAT_STRING 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); \
    }

Definition at line 65 of file SDL_dynapi.c.

SDL_DYNAPI_VERSION

#define SDL_DYNAPI_VERSION   1

Definition at line 49 of file SDL_dynapi.c.

WIN32_LEAN_AND_MEAN

#define WIN32_LEAN_AND_MEAN   1

Definition at line 217 of file SDL_dynapi.c.

Typedef Documentation

SDL_DYNAPI_ENTRYFN

typedef Sint32( * SDL_DYNAPI_ENTRYFN) (Uint32 apiver, void *table, Uint32 tablesize)

Definition at line 203 of file SDL_dynapi.c.

Function Documentation

get_sdlapi_entry()

static SDL_INLINE void* get_sdlapi_entry ( const char *  fname, const char *  sym  )

static

Definition at line 220 of file SDL_dynapi.c.

{
    HANDLE lib = LoadLibraryA(fname);
    void *retval = NULL;
    if (lib) {
        retval = GetProcAddress(lib, sym);
        if (retval == NULL) {
            FreeLibrary(lib);
        }
    }
    return retval;
}

References NULL, and retval.

Referenced by SDL_InitDynamicAPILocked().

initialize_jumptable()

static Sint32 initialize_jumptable ( Uint32  apiver, void *  table, Uint32  tablesize  )

static

Definition at line 174 of file SDL_dynapi.c.

{
    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! */
}

References jump_table, and SDL_DYNAPI_VERSION.

Referenced by SDL_DYNAPI_entry(), and SDL_InitDynamicAPILocked().

SDL_DYNAPI_entry()

Sint32 SDL_DYNAPI_entry	(	Uint32	apiver,
		void *	table,
		Uint32	tablesize
	)

Definition at line 207 of file SDL_dynapi.c.

{
    return initialize_jumptable(apiver, table, tablesize);
}

References initialize_jumptable().

SDL_InitDynamicAPI()

static void SDL_InitDynamicAPI ( void  )

static

Definition at line 297 of file SDL_dynapi.c.

{
    /* 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 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
}

References lock, SDL_FALSE, SDL_InitDynamicAPILocked(), and SDL_TRUE.

SDL_InitDynamicAPILocked()

static void SDL_InitDynamicAPILocked ( void  )

static

Definition at line 268 of file SDL_dynapi.c.

{
    const char *libname = SDL_getenv_REAL("SDL_DYNAMIC_API");
    SDL_DYNAPI_ENTRYFN entry = NULL;  /* 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. */
        }
    }
 
    if (!entry || (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) {
            if (!initialize_jumptable(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. */
}

References get_sdlapi_entry(), initialize_jumptable(), jump_table, NULL, and SDL_DYNAPI_VERSION.

Referenced by SDL_InitDynamicAPI().

Variable Documentation

jump_table

SDL_DYNAPI_jump_table jump_table

static

Initial value:

= {
#define SDL_DYNAPI_PROC(rc,fn,params,args,ret) 
 
}

Definition at line 134 of file SDL_dynapi.c.

Referenced by initialize_jumptable(), and SDL_InitDynamicAPILocked().