SDL_thread.h File Reference

#include "SDL_stdinc.h"
#include "SDL_error.h"
#include "SDL_atomic.h"
#include "SDL_mutex.h"
#include "begin_code.h"
#include "close_code.h"

Go to the source code of this file.

Typedefs
typedef struct SDL_Thread	SDL_Thread
typedef unsigned long	SDL_threadID
typedef unsigned int	SDL_TLSID

Enumerations
enum	SDL_ThreadPriority { SDL_THREAD_PRIORITY_LOW, SDL_THREAD_PRIORITY_NORMAL, SDL_THREAD_PRIORITY_HIGH }

Functions
typedef	int (SDLCALL *SDL_ThreadFunction)(void *data)
DECLSPEC SDL_Thread *SDLCALL	SDL_CreateThread (SDL_ThreadFunction fn, const char *name, void *data)
DECLSPEC const char *SDLCALL	SDL_GetThreadName (SDL_Thread *thread)
DECLSPEC SDL_threadID SDLCALL	SDL_ThreadID (void)
DECLSPEC SDL_threadID SDLCALL	SDL_GetThreadID (SDL_Thread *thread)
DECLSPEC int SDLCALL	SDL_SetThreadPriority (SDL_ThreadPriority priority)
DECLSPEC void SDLCALL	SDL_WaitThread (SDL_Thread *thread, int *status)
DECLSPEC SDL_TLSID SDLCALL	SDL_TLSCreate (void)
	Create an identifier that is globally visible to all threads but refers to data that is thread-specific. More...
DECLSPEC void *SDLCALL	SDL_TLSGet (SDL_TLSID id)
	Get the value associated with a thread local storage ID for the current thread. More...
DECLSPEC int SDLCALL	SDL_TLSSet (SDL_TLSID id, const void *value, void(*destructor)(void *))
	Set the value associated with a thread local storage ID for the current thread. More...

Detailed Description

Header for the SDL thread management routines.

Enumeration Type Documentation

enum SDL_ThreadPriority

The SDL thread priority.

Note

On many systems you require special privileges to set high priority.

Function Documentation

typedef int

(

SDLCALL *

SDL_ThreadFunction

)

The function passed to SDL_CreateThread(). It is passed a void* user context parameter and returns an int.

DECLSPEC SDL_Thread* SDLCALL SDL_CreateThread	(	SDL_ThreadFunction	fn,
		const char *	name,
		void *	data
	)

Create a thread.

Thread naming is a little complicated: Most systems have very small limits for the string length (BeOS has 32 bytes, Linux currently has 16, Visual C++ 6.0 has nine!), and possibly other arbitrary rules. You'll have to see what happens with your system's debugger. The name should be UTF-8 (but using the naming limits of C identifiers is a better bet). There are no requirements for thread naming conventions, so long as the string is null-terminated UTF-8, but these guidelines are helpful in choosing a name:

http://stackoverflow.com/questions/149932/naming-conventions-for-threads

If a system imposes requirements, SDL will try to munge the string for it (truncate, etc), but the original string contents will be available from SDL_GetThreadName().

DECLSPEC SDL_threadID SDLCALL SDL_GetThreadID

(

SDL_Thread *

thread

)

Get the thread identifier for the specified thread.

Equivalent to SDL_ThreadID() if the specified thread is NULL.

DECLSPEC const char* SDLCALL SDL_GetThreadName

(

SDL_Thread *

thread

)

Get the thread name, as it was specified in SDL_CreateThread(). This function returns a pointer to a UTF-8 string that names the specified thread, or NULL if it doesn't have a name. This is internal memory, not to be free()'d by the caller, and remains valid until the specified thread is cleaned up by SDL_WaitThread().

DECLSPEC int SDLCALL SDL_SetThreadPriority

(

SDL_ThreadPriority

priority

)

Set the priority for the current thread

DECLSPEC SDL_threadID SDLCALL SDL_ThreadID

(

void

)

Get the thread identifier for the current thread.

DECLSPEC SDL_TLSID SDLCALL SDL_TLSCreate

(

void

)

Create an identifier that is globally visible to all threads but refers to data that is thread-specific.

Returns

The newly created thread local storage identifier, or 0 on error

*  static SDL_SpinLock tls_lock;
*  static SDL_TLSID thread_local_storage;
* 
*  void SetMyThreadData(void *value)
*  {
*      if (!thread_local_storage) {
*          SDL_AtomicLock(&tls_lock);
*          if (!thread_local_storage) {
*              thread_local_storage = SDL_TLSCreate();
*          }
*          SDL_AtomicUnLock(&tls_lock);
*      }
*      SDL_TLSSet(thread_local_storage, value);
*  }
*  
*  void *GetMyThreadData(void)
*  {
*      return SDL_TLSGet(thread_local_storage);
*  }
*  

See Also

SDL_TLSGet()

SDL_TLSSet()

DECLSPEC void* SDLCALL SDL_TLSGet

(

SDL_TLSID

id

)

Get the value associated with a thread local storage ID for the current thread.

Parameters

id	The thread local storage ID

Returns

The value associated with the ID for the current thread, or NULL if no value has been set.

See Also

SDL_TLSCreate()

SDL_TLSSet()

DECLSPEC int SDLCALL SDL_TLSSet	(	SDL_TLSID	id,
		const void *	value,
		void(*)(void *)	destructor
	)

Set the value associated with a thread local storage ID for the current thread.

Parameters

id	The thread local storage ID
value	The value to associate with the ID for the current thread
destructor	A function called when the thread exits, to free the value.

Returns

0 on success, -1 on error

See Also

SDL_TLSCreate()

SDL_TLSGet()

DECLSPEC void SDLCALL SDL_WaitThread	(	SDL_Thread *	thread,
		int *	status
	)

Wait for a thread to finish.

The return code for the thread function is placed in the area pointed to by status, if status is not NULL.