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#include "threadimpl.h"
#define free
Pqueue _threadpq;
static int nextID(void);
/*
* Create and initialize a new Thread structure attached to a given proc.
*/
typedef struct Stack Stack;
struct Stack {
ulong magic;
Thread *thr;
Stack *next;
uchar buf[STKSIZE-12];
};
static Stack *stkfree;
static Lock stklock;
void
_stackfree(void *v)
{
Stack *s;
s = v;
lock(&stklock);
s->thr = nil;
s->magic = 0;
s->next = stkfree;
stkfree = s;
unlock(&stklock);
}
static Stack*
stackalloc(void)
{
char *buf;
Stack *s;
int i;
lock(&stklock);
while(stkfree == nil){
unlock(&stklock);
assert(STKSIZE == sizeof(Stack));
buf = malloc(STKSIZE+128*STKSIZE);
s = (Stack*)(((ulong)buf+STKSIZE)&~(STKSIZE-1));
for(i=0; i<128; i++)
_stackfree(&s[i]);
lock(&stklock);
}
s = stkfree;
stkfree = stkfree->next;
unlock(&stklock);
s->magic = STKMAGIC;
return s;
}
static int
newthread(Proc *p, void (*f)(void *arg), void *arg, uint stacksize, char *name, int grp)
{
int id;
Thread *t;
Stack *s;
if(stacksize < 32)
sysfatal("bad stacksize %d", stacksize);
t = _threadmalloc(sizeof(Thread), 1);
s = stackalloc();
s->thr = t;
t->stk = (char*)s;
t->stksize = STKSIZE;
_threaddebugmemset(s->buf, 0xFE, sizeof s->buf);
_threadinitstack(t, f, arg);
t->proc = p;
t->grp = grp;
if(name)
t->cmdname = strdup(name);
t->id = nextID();
id = t->id;
t->next = (Thread*)~0;
_threaddebug(DBGSCHED, "create thread %d.%d name %s", p->pid, t->id, name);
lock(&p->lock);
p->nthreads++;
if(p->threads.head == nil)
p->threads.head = t;
else{
t->prevt = p->threads.tail;
t->prevt->nextt = t;
}
p->threads.tail = t;
t->state = Ready;
_threadready(t);
unlock(&p->lock);
return id;
}
static int
nextID(void)
{
static Lock l;
static int id;
int i;
lock(&l);
i = ++id;
unlock(&l);
return i;
}
int
procrfork(void (*f)(void *), void *arg, uint stacksize, int rforkflag)
{
Proc *p;
int id;
p = _threadgetproc();
assert(p->newproc == nil);
p->newproc = _newproc(f, arg, stacksize, nil, p->thread->grp, rforkflag);
id = p->newproc->threads.head->id;
_sched();
return id;
}
int
proccreate(void (*f)(void*), void *arg, uint stacksize)
{
return procrfork(f, arg, stacksize, 0);
}
void
_freeproc(Proc *p)
{
Thread *t, *nextt;
for(t = p->threads.head; t; t = nextt){
if(t->cmdname)
free(t->cmdname);
assert(t->stk != nil);
_stackfree((Stack*)t->stk);
nextt = t->nextt;
free(t);
}
free(p);
}
/*
* Create a new thread and schedule it to run.
* The thread grp is inherited from the currently running thread.
*/
int
threadcreate(void (*f)(void *arg), void *arg, uint stacksize)
{
return newthread(_threadgetproc(), f, arg, stacksize, nil, threadgetgrp());
}
/*
* Create and initialize a new Proc structure with a single Thread
* running inside it. Add the Proc to the global process list.
*/
Proc*
_newproc(void (*f)(void *arg), void *arg, uint stacksize, char *name, int grp, int rforkflag)
{
Proc *p;
p = _threadmalloc(sizeof *p, 1);
p->pid = -1;
p->rforkflag = rforkflag;
newthread(p, f, arg, stacksize, name, grp);
lock(&_threadpq.lock);
if(_threadpq.head == nil)
_threadpq.head = p;
else
*_threadpq.tail = p;
_threadpq.tail = &p->next;
unlock(&_threadpq.lock);
return p;
}
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