Commit af58f17a authored by Ken Thompson's avatar Ken Thompson

synch chan

SVN=127057
parent 52620034
// 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;
}
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