synch chan

SVN=127057

src/runtime/proc.c

+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "runtime.h"
+
+static	int32	debug	= 0;
+
+void
+sys·goexit(void)
+{
+//prints("goexit goid=");
+//sys·printint(g->goid);
+//prints("\n");
+	g->status = Gdead;
+	sys·gosched();
+}
+
+void
+sys·newproc(int32 siz, byte* fn, byte* arg0)
+{
+	byte *stk, *sp;
+	G *newg;
+
+//prints("newproc siz=");
+//sys·printint(siz);
+//prints(" fn=");
+//sys·printpointer(fn);
+
+	siz = (siz+7) & ~7;
+	if(siz > 1024) {
+		prints("sys·newproc: too many args: ");
+		sys·printint(siz);
+		prints("\n");
+		sys·panicl(123);
+	}
+
+	newg = mal(sizeof(G));
+	stk = mal(4096);
+	newg->stackguard = stk+160;
+
+	sp = stk + 4096 - 4*8;
+	newg->stackbase = sp;
+
+	sp -= siz;
+	mcpy(sp, (byte*)&arg0, siz);
+
+	sp -= 8;
+	*(byte**)sp = (byte*)sys·goexit;
+
+	sp -= 8;	// retpc used by gogo
+	newg->sched.SP = sp;
+	newg->sched.PC = fn;
+
+	goidgen++;
+	newg->goid = goidgen;
+
+	newg->status = Grunnable;
+	newg->alllink = allg;
+	allg = newg;
+
+//prints(" goid=");
+//sys·printint(newg->goid);
+//prints("\n");
+}
+
+G*
+select(void)
+{
+	G *gp, *bestg;
+
+	bestg = nil;
+	for(gp=allg; gp!=nil; gp=gp->alllink) {
+		if(gp->status != Grunnable)
+			continue;
+		if(bestg == nil || gp->pri < bestg->pri)
+			bestg = gp;
+	}
+	if(bestg != nil)
+		bestg->pri++;
+	return bestg;
+}
+
+void
+gom0init(void)
+{
+	gosave(&m->sched);
+	sys·gosched();
+}
+
+void
+sys·gosched(void)
+{
+	G* gp;
+
+	if(g != m->g0) {
+		if(gosave(&g->sched))
+			return;
+		g = m->g0;
+		gogo(&m->sched);
+	}
+	gp = select();
+	if(gp == nil) {
+//		prints("sched: no more work\n");
+		sys·exit(0);
+	}
+
+	m->curg = gp;
+	g = gp;
+	gogo(&gp->sched);
+}
+
+//
+// the calling sequence for a routine that
+// needs N bytes stack, A args.
+//
+//	N1 = (N+160 > 4096)? N+160: 0
+//	A1 = A
+//
+// if N <= 75
+//	CMPQ	SP, 0(R15)
+//	JHI	4(PC)
+//	MOVQ	$(N1<<0) | (A1<<32)), AX
+//	MOVQ	AX, 0(R14)
+//	CALL	sys·morestack(SB)
+//
+// if N > 75
+//	LEAQ	(-N-75)(SP), AX
+//	CMPQ	AX, 0(R15)
+//	JHI	4(PC)
+//	MOVQ	$(N1<<0) | (A1<<32)), AX
+//	MOVQ	AX, 0(R14)
+//	CALL	sys·morestack(SB)
+//
+
+void
+oldstack(void)
+{
+	Stktop *top;
+	uint32 siz2;
+	byte *sp;
+
+// prints("oldstack m->cret = ");
+// sys·printpointer((void*)m->cret);
+// prints("\n");
+
+	top = (Stktop*)m->curg->stackbase;
+
+	m->curg->stackbase = top->oldbase;
+	m->curg->stackguard = top->oldguard;
+	siz2 = (top->magic>>32) & 0xffffLL;
+
+	sp = (byte*)top;
+	if(siz2 > 0) {
+		siz2 = (siz2+7) & ~7;
+		sp -= siz2;
+		mcpy(top->oldsp+16, sp, siz2);
+	}
+
+	m->morestack.SP = top->oldsp+8;
+	m->morestack.PC = (byte*)(*(uint64*)(top->oldsp+8));
+
+// prints("oldstack sp=");
+// sys·printpointer(m->morestack.SP);
+// prints(" pc=");
+// sys·printpointer(m->morestack.PC);
+// prints("\n");
+
+	gogoret(&m->morestack, m->cret);
+}
+
+void
+newstack(void)
+{
+	int32 siz1, siz2;
+	Stktop *top;
+	byte *stk, *sp;
+	void (*fn)(void);
+
+	siz1 = m->morearg & 0xffffffffLL;
+	siz2 = (m->morearg>>32) & 0xffffLL;
+
+// prints("newstack siz1=");
+// sys·printint(siz1);
+// prints(" siz2=");
+// sys·printint(siz2);
+// prints(" moresp=");
+// sys·printpointer(m->moresp);
+// prints("\n");
+
+	if(siz1 < 4096)
+		siz1 = 4096;
+	stk = mal(siz1 + 1024);
+	stk += 512;
+
+	top = (Stktop*)(stk+siz1-sizeof(*top));
+
+	top->oldbase = m->curg->stackbase;
+	top->oldguard = m->curg->stackguard;
+	top->oldsp = m->moresp;
+	top->magic = m->morearg;
+
+	m->curg->stackbase = (byte*)top;
+	m->curg->stackguard = stk + 160;
+
+	sp = (byte*)top;
+	
+	if(siz2 > 0) {
+		siz2 = (siz2+7) & ~7;
+		sp -= siz2;
+		mcpy(sp, m->moresp+16, siz2);
+	}
+
+	g = m->curg;
+	fn = (void(*)(void))(*(uint64*)m->moresp);
+
+// prints("fn=");
+// sys·printpointer(fn);
+// prints("\n");
+
+	setspgoto(sp, fn, retfromnewstack);
+
+	*(int32*)345 = 123;	// never return
+}
+
+void
+sys·morestack(uint64 u)
+{
+	while(g == m->g0) {
+		// very bad news
+		*(int32*)123 = 123;
+	}
+
+	g = m->g0;
+	m->moresp = (byte*)(&u-1);
+	setspgoto(m->sched.SP, newstack, nil);
+
+	*(int32*)234 = 123;	// never return
+}
+
+G*
+dequeue(WaitQ *q)
+{
+	G *gp;
+
+	gp = q->first;
+	if(gp == nil)
+		return nil;
+	q->first = gp->qlink;
+	return gp;
+}
+
+void
+enqueue(WaitQ *q, G *gp)
+{
+	gp->qlink = nil;
+	if(q->first == nil) {
+		q->first = gp;
+		q->last = gp;
+		return;
+	}
+	q->last->qlink = gp;
+	q->last = gp;
+}