asm.cpp

mini http server,可以集成嵌入到程序中,实现简单的web功能

/*____________________________________________________________________________*\
 *

 Copyright (c) 1997-2003 John Roy, Holger Zimmermann. All rights reserved.

 These sources, libraries and applications are
 FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
 as long as the following conditions are adhered to.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:

 1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer. 

 2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in
    the documentation and/or other materials provided with the
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 3. The name of the author may not be used to endorse or promote products
    derived from this software without specific prior written permission.

 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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 IN NO EVENT SHALL THE AUTHORS OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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 *____________________________________________________________________________*|
 *
 * $Source: /cvsroot/pi3web/Pi3Web_200/Source/Platform/Asm.cpp,v $
 * $Date: 2003/05/13 18:42:13 $
 *
 Description:
	Assemly language implementation of low level user-context threading
	functions

\*____________________________________________________________________________*/
//$SourceTop:$

#include "OSConfig.h"

#if defined(CONFIG_MULTITHREADED) && defined(CONFIG_MT_USER)

/* ---
	Make sure this architecure is supported
--- */
#if !defined(CONFIG_ASM_I386) && \
	!defined(CONFIG_ASM_SPARC) && \
	!defined(CONFIG_ASM_MIPS) && \
	!defined(CONFIG_ASM_HP)
#	error Unsupported Machine Architecture
#endif

#include "UserSync.h"

/* ---
This is global because it needs to be referenced after the
stack and base pointers have been changed and wiped out automatic variables
--- */
static void **__ppCurrentThread;

/*____________________________________________________________________________*\
 *
 Function:	StackContextSwitch()
 Synopsis:
 Description:
	This is a very specical function. It swaps out the stack and so does
	a 'return' into another thread.

	-	Assumes the current thread has been initializated, wrt to runnable
	state and reason it is yielding.

	-	Saves the current context for the thread and adds it the scheduler.

	-	Finds the next runnable thread and restores its context.

	- 	If a new thread has been created then it is used as the
	next thread to run and its BeginThread() (via __Pi_BeginThread() )
	is run. When its BeginThread() returns it is not restored as a runnable
	thread and effectively that thread of execution terminates.

	- 	If a thread is exiting then
	its stack is restored and an exception or setjmp() is done immediately
	afterwards to unwind its stack. This is achieved by calling the function
	__Pi_UnwindThreadStack.
	At the stack base (__Pi_BeginThread()) this
	exception is caught, the thread object cleaned up wrt outstanding locks,
	and the thread marked terminated. The return from (__Pi_BeginThread()) back
	to StackContextSwitch() causes the next thread to be scheduled.

\*____________________________________________________________________________*/
void __Pi_StackContextSwitch(
		void **ppCurrentThread,
		void *pNextThread,
		int iAction )
{
#if	defined(CONFIG_ASM_I386)
	/* make it easy to spot in ASM */
	size_t *__pContext = (size_t *)0x3737;

#elif defined(CONFIG_ASM_SPARC) || defined(CONFIG_ASM_MIPS) || defined(CONFIG_ASM_HP)
	/* make it easy to spot in ASM */
	register size_t *__pContext = (size_t *)0x3737;

#endif
	size_t tFrameSize;
	__ppCurrentThread = ppCurrentThread;

	__pContext = __Pi_GetThreadContext( *__ppCurrentThread );

	/* --- 
	Save some machine registers in this thread's context object.
	--- */
#if	defined(CONFIG_ASM_I386)		/* Intel 386 series */
	/* assume eax==__pContext */
#	if	defined(CONFIG_ASM_I386_WIN32) 
		__asm mov	eax, (-4)[ebp];			// eax = __pContext;
		__asm mov	0[eax], esp; 
		__asm mov	4[eax], ebp; 
		__asm mov	12[eax], ebx; 
		__asm mov	16[eax], ecx; 
		__asm mov	20[eax], edx; 
		__asm mov	24[eax], esi; 
		__asm mov	28[eax], edi; 
#	elif	defined(CONFIG_ASM_I386_WIN16)
		asm	{
			push	ds
			push	si
			push	di
			push	ax
			push	cx
			push	es
			push	bx
			push	dx

			les	bx,dword ptr [bp-6]
			mov	word ptr es:[bx+0],sp
			mov	word ptr es:[bx+2],bp
			}
		#	else
		asm( "movl	-4(%ebp), %eax" );		// eax = __pContext
		asm( "movl	%esp, 0(%eax)" ); 
		asm( "movl	%ebp, 4(%eax)" ); 
		asm( "movl	%ebx, 12(%eax)" ); 
		asm( "movl	%ecx, 16(%eax)" ); 
		asm( "movl	%edx, 20(%eax)" ); 
		asm( "movl	%esi, 24(%eax)" ); 
		asm( "movl	%edi, 28(%eax)" ); 
#	endif 
#elif defined(CONFIG_ASM_SPARC)		/* Sparc chip */
	/* assume %l0 == __pContext; */
	asm( "st	%sp, [%l0]" ); 
	asm( "st	%fp, [%l0+4]" ); 
	asm( "st	%o7, [%l0+8]" ); 
	asm( "st	%i7, [%l0+12]" ); 
#elif defined(CONFIG_ASM_MIPS)		/* IRIX on MIPS */
	/* assume $16 == __pContext; */
	asm( "sw	$sp, 0($16)" ); 
	asm( "sw	$fp, 4($16)" ); 
	asm( "sw	$gp, 8($16)" );  
	asm( "sw	$17, 12($16)" );
	asm( "sw	$18, 16($16)" );
	asm( "sw	$19, 20($16)" );
	asm( "sw	$20, 24($16)" );
	asm( "sw	$21, 28($16)" );
	asm( "sw	$22, 32($16)" );
	asm( "sw	$23, 36($16)" );
	asm( "sw	$31, 40($16)" );
#endif

	__Pi_AddLatentThread( *__ppCurrentThread );

	/* --- new thread ? --- */
	if ( iAction==SCHED_BEGIN )
		{
		/*
		** A new thread has been primed, begin execution of that thread
		*/
		tFrameSize = (size_t) __pContext[1] - /* assumes the stack */
							(size_t) __pContext[0];  /* grows down */

		*__ppCurrentThread = pNextThread;
		pNextThread = 0;
		__pContext = __Pi_GetThreadContext( *__ppCurrentThread );

		__pContext[1] = __pContext[0];
		__pContext[0] = __pContext[1] - tFrameSize;

		/* ---
		Setup base of stack for new thread
		--- */
#	if	defined(CONFIG_ASM_I386)
#		if defined(CONFIG_ASM_I386_WIN32)
		__asm mov	eax, (-4)[ebp];			// eax = __pContext;
		__asm mov	esp, 0[eax];
		__asm mov	ebp, 4[eax];
#		elif defined(CONFIG_ASM_I386_WIN16)
		asm {
			les	bx,dword ptr [bp-6]
			mov	sp, es:[bx+0]
			mov	bp, es:[bx+2]
			};
#		else
		asm( "movl	-4(%ebp), %eax" );		// eax = __pContext
		asm( "movl	0(%eax), %esp" );
		asm( "movl	4(%eax), %ebp" ); 
#		endif
#	elif defined(CONFIG_ASM_SPARC)
		asm( "mov	0, %o7" ); 
		asm( "mov	0, %i7" ); 
		asm( "ld	[%l0+0], %sp" ); 
		asm( "ld	[%l0+4], %fp" ); 
#	elif defined(CONFIG_ASM_MIPS)
		asm( "lw	$sp, 0($16)" ); 
		asm( "lw	$fp, 4($16)" ); 
		asm( "sw	$gp, 16($fp)" ); 
#	endif
		pNextThread = 0;
		__Pi_BeginThread( *__ppCurrentThread );
		}
	else if ( iAction==SCHED_EXIT )	/* --- an exiting thread exists --- */
		{
		/*
		** A thread has been scheduled for termination, swap in the thread
		** by adjusting the current stack to its stack, but kill an 
		** exception or other stack unwinding contruct immediately, then
		** schedule the next thread. Thus terminating this thread
		*/
		*__ppCurrentThread = pNextThread;
		pNextThread = 0;
		__pContext = __Pi_GetThreadContext( *__ppCurrentThread );
#if	defined(CONFIG_ASM_I386)
#	if	defined(CONFIG_ASM_I386_WIN32)
		__asm mov	esp, 0[eax];
		__asm mov	ebp, 4[eax];
		__asm mov	ebx, 12[eax];
		__asm mov	ecx, 16[eax];
		__asm mov	edx, 20[eax];
		__asm mov	esi, 24[eax];
		__asm mov	edi, 28[eax];
		__asm mov	eax, 8[eax];
#	elif	defined(CONFIG_ASM_I386_WIN16)
		asm {
			les	bx,dword ptr [bp-6]
			mov	sp, word ptr es:[bx+0]
			mov	bp, word ptr es:[bx+2]
			pop	dx
			pop	bx
			pop	es
			pop	cx
			pop	ax
			pop	di
			pop	si
			pop	ds
			}
#	else
		asm( "movl	-4(%ebp), %eax" );		// eax = __pContext
		asm( "movl	0(%eax), %esp" ); 
		asm( "movl	4(%eax), %ebp" ); 
		asm( "movl	12(%eax), %ebx" );	
		asm( "movl	16(%eax), %ecx" );	
		asm( "movl	20(%eax), %edx" );	
		asm( "movl	24(%eax), %esi" );	
		asm( "movl	28(%eax), %edi" );	
		asm( "movl	8(%eax), %eax" );	
#	endif 
#elif defined(CONFIG_ASM_SPARC)
		asm( "ld	[%l0+8], %o7" ); 
		asm( "ld	[%l0+12], %i7" ); 
		asm( "ld	[%l0+0], %sp" ); 
		asm( "ld	[%l0+4], %fp" ); 
#elif defined(CONFIG_ASM_MIPS)
		asm( "lw	$sp, 0($16)" ); 
		asm( "lw	$fp, 4($16)" ); 
		asm( "lw	$gp, 8($16)" ); 
		asm( "lw	$17, 12($16)" );
		asm( "lw	$18, 16($16)" );
		asm( "lw	$19, 20($16)" );
		asm( "lw	$20, 24($16)" );
		asm( "lw	$21, 28($16)" );
		asm( "lw	$22, 32($16)" );
		asm( "lw	$23, 36($16)" );
		asm( "lw	$31, 40($16)" );
#endif
		__Pi_UnwindThreadStack( *__ppCurrentThread );
		}

	/* --- select the next thread to run --- */
/*	if ( pNextThread ) : temp. see UserSync.cpp ___pPlaceHolder */
	if ( 0 )
		{
		*__ppCurrentThread = pNextThread;
		}
	else
		{
		*__ppCurrentThread = __Pi_SelectNextRunnableThread();
		};

	__pContext = __Pi_GetThreadContext( *__ppCurrentThread );
#if	defined(CONFIG_ASM_I386)
#	if	defined(CONFIG_ASM_I386_WIN32)
		__asm mov	esp, 0[eax];
		__asm mov	ebp, 4[eax];
		__asm mov	ebx, 12[eax];
		__asm mov	ecx, 16[eax];
		__asm mov	edx, 20[eax];
		__asm mov	esi, 24[eax];
		__asm mov	edi, 28[eax];
		__asm mov	eax, 8[eax];
#	elif	defined(CONFIG_ASM_I386_WIN16)
		asm {
			les	bx,dword ptr [bp-6]
			mov	sp, word ptr es:[bx+0]
			mov	bp, word ptr es:[bx+2]
			pop	dx
			pop	bx
			pop	es
			pop	cx
			pop	ax
			pop	di
			pop	si
			pop	ds
			};
#	else
		asm( "movl	-4(%ebp), %eax" );		// eax = __pContext
		asm( "movl	0(%eax), %esp" ); 
		asm( "movl	4(%eax), %ebp" ); 
		asm( "movl	12(%eax), %ebx" );	
		asm( "movl	16(%eax), %ecx" );	
		asm( "movl	20(%eax), %edx" );	
		asm( "movl	24(%eax), %esi" );	
		asm( "movl	28(%eax), %edi" );	
		asm( "movl	8(%eax), %eax" );	
#	endif 
#elif defined(CONFIG_ASM_SPARC)
	asm( "ld	[%l0+8], %o7" ); 
	asm( "ld	[%l0+12], %i7" ); 
	asm( "ld	[%l0+0], %sp" ); 
	asm( "ld	[%l0+4], %fp" ); 
#elif defined(CONFIG_ASM_MIPS)
	asm( "lw	$sp, 0($16)" ); 
	asm( "lw	$fp, 4($16)" ); 
 	asm( "lw	$gp, 8($16)" ); 
	asm( "lw	$17, 12($16)" );
	asm( "lw	$18, 16($16)" );
	asm( "lw	$19, 20($16)" );
	asm( "lw	$20, 24($16)" );
	asm( "lw	$21, 28($16)" );
	asm( "lw	$22, 32($16)" );
	asm( "lw	$23, 36($16)" );
	asm( "lw	$31, 40($16)" );
#endif
}

/*____________________________________________________________________________*\
 *
 Function:
 Synopsis:
 Description:
	Only used for Win16.
\*____________________________________________________________________________*/
void *__Pi_GetCurrentStackPtr()
{
	size_t *__pStackPtr = 0;
#if	defined(CONFIG_ASM_I386_WIN16)
	asm {
		mov word ptr [bp-6], sp
		};
#endif
	return __pStackPtr;
}

#endif /* defined(CONFIG_MULTITHREADED) && defined(CONFIG_MT_USER) */