windows-nt/Source/XPSP1/NT/base/crts/crtw32/startup/threadex.c
2020-09-26 16:20:57 +08:00

327 lines
9.9 KiB
C

/***
*threadex.c - Extended versions of Begin (Create) and End (Exit) a Thread
*
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* This source contains the _beginthreadex() and _endthreadex()
* routines which are used to start and terminate a thread. These
* routines are more like the Win32 APIs CreateThread() and ExitThread()
* than the original functions _beginthread() & _endthread() were.
*
*Revision History:
* 02-16-94 SKS Original version, based on thread.c which contains
* _beginthread() and _endthread().
* 02-17-94 SKS Changed error return from -1 to 0, fix some comments.
* 06-10-94 SKS Pass the thrdaddr value directly to CreateThread().
* Do *NOT* store the thread handle into the per-thread
* data block of the child thread. (It is not needed.)
* The thread data structure may have been freed by the
* child thread before the parent thread returns from the
* call to CreateThread(). Watch that synchronization!
* 01-10-95 CFW Debug CRT allocs.
* 04-18-95 SKS Add 5 MIPS per-thread variables.
* 05-02-95 SKS Call _initptd for initialization of per-thread data.
* 02-03-98 GJF Changes for Win64: use uintptr_t type for anything with
* a HANDLE value.
* 02-02-00 GB Modified threadstartex() to prevent leaking of ptd
* allocated during call to getptd while ATTACHing THREAD
* in dlls.
* 05-31-00 PML Don't pass NULL thrdaddr into CreateThread, since a
* non-NULL lpThreadId is required on Win9x.
* 08-04-00 PML Set EINVAL error if thread start address null in
* _beginthreadex (VS7#118688).
*
*******************************************************************************/
#ifdef _MT
#include <cruntime.h>
#include <oscalls.h>
#include <internal.h>
#include <mtdll.h>
#include <msdos.h>
#include <malloc.h>
#include <process.h>
#include <stddef.h>
#include <rterr.h>
#include <dbgint.h>
#include <errno.h>
/*
* Startup code for new thread.
*/
static unsigned long WINAPI _threadstartex(void *);
/*
* declare pointers to per-thread FP initialization and termination routines
*/
_PVFV _FPmtinit;
_PVFV _FPmtterm;
/***
*_beginthreadex() - Create a child thread
*
*Purpose:
* Create a child thread.
*
*Entry:
* *** Same parameters as the Win32 API CreateThread() ***
* security = security descriptor for the new thread
* stacksize = size of stack
* initialcode = pointer to thread's startup code address
* must be a __stdcall function returning an unsigned.
* argument = argument to be passed to new thread
* createflag = flag to create thread in a suspended state
* thrdaddr = points to an int to receive the ID of the new thread
*
*Exit:
* *** Same as the Win32 API CreateThread() ***
*
* success = handle for new thread if successful
*
* failure = 0 in case of error, errno and _doserrno are set
*
*Exceptions:
*
*Notes:
* This routine is more like the Win32 API CreateThread() than it
* is like the C run-time routine _beginthread(). Ditto for
* _endthreadex() and the Win32 API ExitThread() versus _endthread().
*
* Differences between _beginthread/_endthread and the "ex" versions:
*
* 1) _beginthreadex takes the 3 extra parameters to CreateThread
* which are lacking in _beginthread():
* A) security descriptor for the new thread
* B) initial thread state (running/asleep)
* C) pointer to return ID of newly created thread
*
* 2) The routine passed to _beginthread() must be __cdecl and has
* no return code, but the routine passed to _beginthreadex()
* must be __stdcall and returns a thread exit code. _endthread
* likewise takes no parameter and calls ExitThread() with a
* parameter of zero, but _endthreadex() takes a parameter as
* thread exit code.
*
* 3) _endthread implicitly closes the handle to the thread, but
* _endthreadex does not!
*
* 4) _beginthread returns -1 for failure, _beginthreadex returns
* 0 for failure (just like CreateThread).
*
*******************************************************************************/
uintptr_t __cdecl _beginthreadex (
void *security,
unsigned stacksize,
unsigned (__stdcall * initialcode) (void *),
void * argument,
unsigned createflag,
unsigned *thrdaddr
)
{
_ptiddata ptd; /* pointer to per-thread data */
uintptr_t thdl; /* thread handle */
unsigned long errcode = 0L; /* Return from GetLastError() */
unsigned dummyid; /* dummy returned thread ID */
if ( initialcode == NULL ) {
errno = EINVAL;
return( (uintptr_t)0 );
}
/*
* Allocate and initialize a per-thread data structure for the to-
* be-created thread.
*/
if ( (ptd = _calloc_crt(1, sizeof(struct _tiddata))) == NULL )
goto error_return;
/*
* Initialize the per-thread data
*/
_initptd(ptd);
ptd->_initaddr = (void *) initialcode;
ptd->_initarg = argument;
ptd->_thandle = (uintptr_t)(-1);
/*
* Make sure non-NULL thrdaddr is passed to CreateThread
*/
if ( thrdaddr == NULL )
thrdaddr = &dummyid;
/*
* Create the new thread using the parameters supplied by the caller.
*/
if ( (thdl = (uintptr_t)
CreateThread( security,
stacksize,
_threadstartex,
(LPVOID)ptd,
createflag,
thrdaddr))
== (uintptr_t)0 )
{
errcode = GetLastError();
goto error_return;
}
/*
* Good return
*/
return(thdl);
/*
* Error return
*/
error_return:
/*
* Either ptd is NULL, or it points to the no-longer-necessary block
* calloc-ed for the _tiddata struct which should now be freed up.
*/
_free_crt(ptd);
/*
* Map the error, if necessary.
*
* Note: this routine returns 0 for failure, just like the Win32
* API CreateThread, but _beginthread() returns -1 for failure.
*/
if ( errcode != 0L )
_dosmaperr(errcode);
return( (uintptr_t)0 );
}
/***
*_threadstartex() - New thread begins here
*
*Purpose:
* The new thread begins execution here. This routine, in turn,
* passes control to the user's code.
*
*Entry:
* void *ptd = pointer to _tiddata structure for this thread
*
*Exit:
* Never returns - terminates thread!
*
*Exceptions:
*
*******************************************************************************/
static unsigned long WINAPI _threadstartex (
void * ptd
)
{
_ptiddata _ptd; /* pointer to per-thread data */
/*
* Check if ptd is initialised during THREAD_ATTACH call to dll mains
*/
if ( ( _ptd = TlsGetValue(__tlsindex)) == NULL)
{
/*
* Stash the pointer to the per-thread data stucture in TLS
*/
if ( !TlsSetValue(__tlsindex, ptd) )
_amsg_exit(_RT_THREAD);
/*
* Set the thread ID field -- parent thread cannot set it after
* CreateThread() returns since the child thread might have run
* to completion and already freed its per-thread data block!
*/
((_ptiddata) ptd)->_tid = GetCurrentThreadId();
}
else
{
_ptd->_initaddr = ((_ptiddata) ptd)->_initaddr;
_ptd->_initarg = ((_ptiddata) ptd)->_initarg;
_free_crt(ptd);
ptd = _ptd;
}
/*
* Call fp initialization, if necessary
*/
if ( _FPmtinit != NULL )
(*_FPmtinit)();
/*
* Guard call to user code with a _try - _except statement to
* implement runtime errors and signal support
*/
__try {
_endthreadex (
( (unsigned (WINAPI *)(void *))(((_ptiddata)ptd)->_initaddr) )
( ((_ptiddata)ptd)->_initarg ) ) ;
}
__except ( _XcptFilter(GetExceptionCode(), GetExceptionInformation()) )
{
/*
* Should never reach here
*/
_exit( GetExceptionCode() );
} /* end of _try - _except */
/*
* Never executed!
*/
return(0L);
}
/***
*_endthreadex() - Terminate the calling thread
*
*Purpose:
*
*Entry:
* Thread exit code
*
*Exit:
* Never returns!
*
*Exceptions:
*
*******************************************************************************/
void __cdecl _endthreadex (
unsigned retcode
)
{
_ptiddata ptd; /* pointer to thread's _tiddata struct */
/*
* Call fp termination, if necessary
*/
if ( _FPmtterm != NULL )
(*_FPmtterm)();
if ( (ptd = _getptd()) == NULL )
_amsg_exit(_RT_THREAD);
/*
* Free up the _tiddata structure & its subordinate buffers
* _freeptd() will also clear the value for this thread
* of the TLS variable __tlsindex.
*/
_freeptd(ptd);
/*
* Terminate the thread
*/
ExitThread(retcode);
}
#endif /* _MT */