1 #include <u.h>
2 #include <libc.h>
3 #include <thread.h>
4 #include "threadimpl.h"
5
6 Pqueue _threadpq;
7
8 static int
nextID(void)9 nextID(void)
10 {
11 static Lock l;
12 static int id;
13 int i;
14
15 lock(&l);
16 i = ++id;
17 unlock(&l);
18 return i;
19 }
20
21 /*
22 * Create and initialize a new Thread structure attached to a given proc.
23 */
24 static int
newthread(Proc * p,void (* f)(void * arg),void * arg,uint stacksize,char * name,int grp)25 newthread(Proc *p, void (*f)(void *arg), void *arg, uint stacksize, char *name, int grp)
26 {
27 int id;
28 Thread *t;
29
30 if(stacksize < 32)
31 sysfatal("bad stacksize %d", stacksize);
32 t = _threadmalloc(sizeof(Thread), 1);
33 t->stksize = stacksize;
34 t->stk = _threadmalloc(stacksize, 0);
35 memset(t->stk, 0xFE, stacksize);
36 _threadinitstack(t, f, arg);
37 t->grp = grp;
38 if(name)
39 t->cmdname = strdup(name);
40 t->id = nextID();
41 id = t->id;
42 t->next = (Thread*)~0;
43 t->proc = p;
44 _threaddebug(DBGSCHED, "create thread %d.%d name %s", p->pid, t->id, name);
45 lock(&p->lock);
46 p->nthreads++;
47 if(p->threads.head == nil)
48 p->threads.head = t;
49 else
50 *p->threads.tail = t;
51 p->threads.tail = &t->nextt;
52 t->nextt = nil;
53 t->state = Ready;
54 _threadready(t);
55 unlock(&p->lock);
56 return id;
57 }
58
59 /*
60 * Create a new thread and schedule it to run.
61 * The thread grp is inherited from the currently running thread.
62 */
63 int
threadcreate(void (* f)(void * arg),void * arg,uint stacksize)64 threadcreate(void (*f)(void *arg), void *arg, uint stacksize)
65 {
66 return newthread(_threadgetproc(), f, arg, stacksize, nil, threadgetgrp());
67 }
68
69 /*
70 * Create and initialize a new Proc structure with a single Thread
71 * running inside it. Add the Proc to the global process list.
72 */
73 Proc*
_newproc(void (* f)(void * arg),void * arg,uint stacksize,char * name,int grp,int rforkflag)74 _newproc(void (*f)(void *arg), void *arg, uint stacksize, char *name, int grp, int rforkflag)
75 {
76 Proc *p;
77
78 p = _threadmalloc(sizeof *p, 1);
79 p->pid = -1;
80 p->rforkflag = rforkflag;
81 newthread(p, f, arg, stacksize, name, grp);
82
83 lock(&_threadpq.lock);
84 if(_threadpq.head == nil)
85 _threadpq.head = p;
86 else
87 *_threadpq.tail = p;
88 _threadpq.tail = &p->next;
89 unlock(&_threadpq.lock);
90 return p;
91 }
92
93 int
procrfork(void (* f)(void *),void * arg,uint stacksize,int rforkflag)94 procrfork(void (*f)(void *), void *arg, uint stacksize, int rforkflag)
95 {
96 Proc *p;
97 int id;
98
99 p = _threadgetproc();
100 assert(p->newproc == nil);
101 p->newproc = _newproc(f, arg, stacksize, nil, p->thread->grp, rforkflag);
102 id = p->newproc->threads.head->id;
103 _sched();
104 return id;
105 }
106
107 int
proccreate(void (* f)(void *),void * arg,uint stacksize)108 proccreate(void (*f)(void*), void *arg, uint stacksize)
109 {
110 return procrfork(f, arg, stacksize, 0);
111 }
112
113 void
_freeproc(Proc * p)114 _freeproc(Proc *p)
115 {
116 Thread *t, *nextt;
117
118 for(t = p->threads.head; t; t = nextt){
119 if(t->cmdname)
120 free(t->cmdname);
121 assert(t->stk != nil);
122 free(t->stk);
123 nextt = t->nextt;
124 free(t);
125 }
126 free(p);
127 }
128
129 void
_freethread(Thread * t)130 _freethread(Thread *t)
131 {
132 Proc *p;
133 Thread **l;
134
135 p = t->proc;
136 lock(&p->lock);
137 for(l=&p->threads.head; *l; l=&(*l)->nextt){
138 if(*l == t){
139 *l = t->nextt;
140 if(*l == nil)
141 p->threads.tail = l;
142 break;
143 }
144 }
145 unlock(&p->lock);
146 if (t->cmdname)
147 free(t->cmdname);
148 assert(t->stk != nil);
149 free(t->stk);
150 free(t);
151 }
152
153