tContinue fighting pthreads. Clean up thread library a bit too. - plan9port - [fork] Plan 9 from user space
HTML git clone git://src.adamsgaard.dk/plan9port
DIR Log
DIR Files
DIR Refs
DIR README
DIR LICENSE
---
DIR commit 7966faa931bfa9cf4ca53dd2d5b6e1eb0f174411
DIR parent c6687d4591964cb13df87f55ec4770e778a4a55c
HTML Author: rsc <devnull@localhost>
Date: Thu, 23 Sep 2004 03:01:36 +0000
Continue fighting pthreads.
Clean up thread library a bit too.
Diffstat:
M src/libthread/chanprint.c | 4 +++-
M src/libthread/create.c | 227 ++++++++++++++++---------------
M src/libthread/debug.c | 4 ++--
M src/libthread/exec-unix.c | 14 +++++++++++++-
D src/libthread/exec.c | 82 -------------------------------
M src/libthread/exit.c | 31 +------------------------------
M src/libthread/id.c | 8 ++++----
M src/libthread/iocall.c | 5 ++++-
M src/libthread/ioproc.c | 5 ++++-
M src/libthread/main.c | 152 ++++++++++---------------------
M src/libthread/mkfile | 4 ++--
M src/libthread/note.c | 6 +++++-
M src/libthread/proctab.c | 2 +-
M src/libthread/ref.c | 6 ++++++
D src/libthread/rendez.c | 38 -------------------------------
M src/libthread/sched.c | 355 ++++++++++++++++---------------
A src/libthread/sleep.c | 38 +++++++++++++++++++++++++++++++
M src/libthread/texec.c | 11 ++++++++---
M src/libthread/threadimpl.h | 110 ++++++++++++++-----------------
M src/libthread/ucontext.c | 13 +++++++------
20 files changed, 500 insertions(+), 615 deletions(-)
---
DIR diff --git a/src/libthread/chanprint.c b/src/libthread/chanprint.c
t@@ -1,4 +1,6 @@
-#include "threadimpl.h"
+#include <u.h>
+#include <libc.h>
+#include <thread.h>
int
chanprint(Channel *c, char *fmt, ...)
DIR diff --git a/src/libthread/create.c b/src/libthread/create.c
t@@ -1,45 +1,46 @@
#include "threadimpl.h"
-Pqueue _threadpq;
-int _threadprocs;
-int __pthread_nonstandard_stacks;
+Pqueue _threadpq; /* list of all procs */
+int _threadnprocs; /* count of procs */
-static int nextID(void);
+static int newthreadid(void);
+static int newprocid(void);
/*
* Create and initialize a new Thread structure attached to a given proc.
*/
-void
-_stackfree(void *v)
-{
- free(v);
-}
-
-static int
-newthread(Proc *p, void (*f)(void *arg), void *arg, uint stacksize, char *name, int grp)
+int
+_newthread(Proc *p, void (*f)(void *arg), void *arg, uint stacksize,
+ char *name, int grp)
{
int id;
Thread *t;
- char *s;
- __pthread_nonstandard_stacks = 1;
- if(stacksize < 32)
- sysfatal("bad stacksize %d", stacksize);
t = _threadmalloc(sizeof(Thread), 1);
- t->lastfd = -1;
- s = _threadmalloc(stacksize, 0);
- t->stk = (uchar*)s;
- t->stksize = stacksize;
- _threaddebugmemset(s, 0xFE, stacksize);
- _threadinitstack(t, f, arg);
t->proc = p;
t->grp = grp;
+ t->id = id = newthreadid();
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);
+ t->name = strdup(name);
+ _threaddebug(DBGSCHED, "create thread %d.%d name %s", p->id, id, name);
+
+ /*
+ * Allocate and clear stack.
+ */
+ if(stacksize < 1024)
+ sysfatal("bad stacksize %d", stacksize);
+ t->stk = _threadmalloc(stacksize, 0);
+ t->stksize = stacksize;
+ _threaddebugmemset(t->stk, 0xFE, stacksize);
+
+ /*
+ * Set up t->context to call f(arg).
+ */
+ _threadinitstack(t, f, arg);
+
+ /*
+ * Add thread to proc.
+ */
lock(&p->lock);
p->nthreads++;
if(p->threads.head == nil)
t@@ -49,120 +50,134 @@ newthread(Proc *p, void (*f)(void *arg), void *arg, uint stacksize, char *name,
t->prevt->nextt = t;
}
p->threads.tail = t;
+ t->next = (Thread*)~0;
+
+ /*
+ * Mark thread as ready to run.
+ */
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)
+/*
+ * Free a Thread structure.
+ */
+void
+_threadfree(Thread *t)
{
- 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;
+ free(t->stk);
+ free(t->name);
+ free(t);
}
-int
-proccreate(void (*f)(void*), void *arg, uint stacksize)
+/*
+ * 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)
{
Proc *p;
- p = _threadgetproc();
- if(p->idle){
- fprint(2, "cannot create procs once there is an idle thread\n");
- werrstr("cannot create procs once there is an idle thread");
- return -1;
- }
- return procrfork(f, arg, stacksize, 0);
+ /*
+ * Allocate.
+ */
+ p = _threadmalloc(sizeof *p, 1);
+ p->id = newprocid();
+
+ /*
+ * Add to list. Record if we're now multiprocess.
+ */
+ lock(&_threadpq.lock);
+ if(_threadpq.head == nil)
+ _threadpq.head = p;
+ else
+ *_threadpq.tail = p;
+ _threadpq.tail = &p->next;
+ if(_threadnprocs == 1)
+ _threadmultiproc();
+ _threadnprocs++;
+ unlock(&_threadpq.lock);
+
+ return p;
}
-void
-_freeproc(Proc *p)
+/*
+ * Allocate a new thread running f(arg) on a stack of size stacksize.
+ * Return the thread id. The thread group inherits from the current thread.
+ */
+int
+threadcreate(void (*f)(void*), void *arg, uint stacksize)
{
- Thread *t, *nextt;
-
- for(t = p->threads.head; t; t = nextt){
- if(t->cmdname)
- free(t->cmdname);
- assert(t->stk != nil);
- _stackfree(t->stk);
- nextt = t->nextt;
- free(t);
- }
- free(p);
+ return _newthread(_threadgetproc(), f, arg, stacksize, nil, threadgetgrp());
}
/*
- * Create a new thread and schedule it to run.
- * The thread grp is inherited from the currently running thread.
+ * Allocate a new idle thread. Only allowed in a single-proc program.
*/
int
-threadcreate(void (*f)(void *arg), void *arg, uint stacksize)
+threadcreateidle(void (*f)(void *arg), void *arg, uint stacksize)
{
- return newthread(_threadgetproc(), f, arg, stacksize, nil, threadgetgrp());
+ int id;
+
+ assert(_threadnprocs == 1);
+
+ id = threadcreate(f, arg, stacksize);
+ _threaddebug(DBGSCHED, "idle is %d", id);
+ _threadsetidle(id);
+ return id;
}
+/*
+ * Threadcreate, but do it inside a fresh proc.
+ */
int
-threadcreateidle(void (*f)(void *arg), void *arg, uint stacksize)
+proccreate(void (*f)(void*), void *arg, uint stacksize)
{
int id;
+ Proc *p, *np;
- if(_threadprocs!=1){
- fprint(2, "cannot have idle thread in multi-proc program\n");
- werrstr("cannot have idle thread in multi-proc program");
- return -1;
- }
- id = newthread(_threadgetproc(), f, arg, stacksize, nil, threadgetgrp());
- _threaddebug(DBGSCHED, "idle is %d", id);
- _threadidle();
+ p = _threadgetproc();
+ np = _newproc();
+ p->newproc = np;
+ p->schedfn = _threadstartproc;
+ id = _newthread(np, f, arg, stacksize, nil, p->thread->grp);
+ _sched(); /* call into scheduler to create proc XXX */
return id;
}
/*
- * Create and initialize a new Proc structure with a single Thread
- * running inside it. Add the Proc to the global process list.
+ * Allocate a new thread id.
*/
-Proc*
-_newproc(void (*f)(void *arg), void *arg, uint stacksize, char *name, int grp, int rforkflag)
+static int
+newthreadid(void)
{
- Proc *p;
+ static Lock l;
+ static int id;
+ int i;
- p = _threadmalloc(sizeof *p, 1);
- p->pid = -1;
- p->rforkflag = rforkflag;
- newthread(p, f, arg, stacksize, name, grp);
+ lock(&l);
+ i = ++id;
+ unlock(&l);
+ return i;
+}
- lock(&_threadpq.lock);
- if(_threadpq.head == nil)
- _threadpq.head = p;
- else
- *_threadpq.tail = p;
- _threadpq.tail = &p->next;
+/*
+ * Allocate a new proc id.
+ */
+static int
+newprocid(void)
+{
+ static Lock l;
+ static int id;
+ int i;
- if(_threadprocs == 1)
- _threadmultiproc();
- _threadprocs++;
- unlock(&_threadpq.lock);
- return p;
+ lock(&l);
+ i = ++id;
+ unlock(&l);
+ return i;
}
DIR diff --git a/src/libthread/debug.c b/src/libthread/debug.c
t@@ -19,9 +19,9 @@ __threaddebug(ulong flag, char *fmt, ...)
if(p==nil)
fmtprint(&f, "noproc ");
else if(p->thread)
- fmtprint(&f, "%d.%d ", p->pid, p->thread->id);
+ fmtprint(&f, "%d.%d ", p->id, p->thread->id);
else
- fmtprint(&f, "%d._ ", p->pid);
+ fmtprint(&f, "%d._ ", p->id);
va_start(arg, fmt);
fmtvprint(&f, fmt, arg);
DIR diff --git a/src/libthread/exec-unix.c b/src/libthread/exec-unix.c
t@@ -10,9 +10,20 @@ _threadexec(Channel *pidc, int fd[3], char *prog, char *args[], int freeargs)
int pfd[2];
int n, pid;
char exitstr[ERRMAX];
+ static int firstexec = 1;
+ static Lock lk;
_threaddebug(DBGEXEC, "threadexec %s", prog);
-
+
+ if(firstexec){
+ lock(&lk);
+ if(firstexec){
+ firstexec = 0;
+ _threadfirstexec();
+ }
+ unlock(&lk);
+ }
+
/*
* We want threadexec to behave like exec; if exec succeeds,
* never return, and if it fails, return with errstr set.
t@@ -41,6 +52,7 @@ _threadexec(Channel *pidc, int fd[3], char *prog, char *args[], int freeargs)
efork(fd, pfd, prog, args);
_exit(0);
default:
+ _threadafterexec();
if(freeargs)
free(args);
break;
DIR diff --git a/src/libthread/exec.c b/src/libthread/exec.c
t@@ -1,82 +0,0 @@
-#include "threadimpl.h"
-
-#define PIPEMNT "/mnt/temp"
-
-void
-procexec(Channel *pidc, int fd[3], char *prog, char *args[])
-{
- int n;
- Proc *p;
- Thread *t;
-
- _threaddebug(DBGEXEC, "procexec %s", prog);
- /* must be only thread in proc */
- p = _threadgetproc();
- t = p->thread;
- if(p->threads.head != t || p->threads.head->nextt != nil){
- werrstr("not only thread in proc");
- Bad:
- if(pidc)
- sendul(pidc, ~0);
- return;
- }
-
- /*
- * We want procexec to behave like exec; if exec succeeds,
- * never return, and if it fails, return with errstr set.
- * Unfortunately, the exec happens in another proc since
- * we have to wait for the exec'ed process to finish.
- * To provide the semantics, we open a pipe with the
- * write end close-on-exec and hand it to the proc that
- * is doing the exec. If the exec succeeds, the pipe will
- * close so that our read below fails. If the exec fails,
- * then the proc doing the exec sends the errstr down the
- * pipe to us.
- */
- if(bind("#|", PIPEMNT, MREPL) < 0)
- goto Bad;
- if((p->exec.fd[0] = open(PIPEMNT "/data", OREAD)) < 0){
- unmount(nil, PIPEMNT);
- goto Bad;
- }
- if((p->exec.fd[1] = open(PIPEMNT "/data1", OWRITE|OCEXEC)) < 0){
- close(p->exec.fd[0]);
- unmount(nil, PIPEMNT);
- goto Bad;
- }
- unmount(nil, PIPEMNT);
-
- /* exec in parallel via the scheduler */
- assert(p->needexec==0);
- p->exec.prog = prog;
- p->exec.args = args;
- p->exec.stdfd = fd;
- p->needexec = 1;
- _sched();
-
- close(p->exec.fd[1]);
- if((n = read(p->exec.fd[0], p->exitstr, ERRMAX-1)) > 0){ /* exec failed */
- p->exitstr[n] = '\0';
- errstr(p->exitstr, ERRMAX);
- close(p->exec.fd[0]);
- goto Bad;
- }
- close(p->exec.fd[0]);
- close(fd[0]);
- if(fd[1] != fd[0])
- close(fd[1]);
- if(fd[2] != fd[1] && fd[2] != fd[0])
- close(fd[2]);
- if(pidc)
- sendul(pidc, t->ret);
-
- /* wait for exec'ed program, then exit */
- _schedexecwait();
-}
-
-void
-procexecl(Channel *pidc, int fd[3], char *f, ...)
-{
- procexec(pidc, fd, f, &f+1);
-}
-
DIR diff --git a/src/libthread/exit.c b/src/libthread/exit.c
t@@ -26,42 +26,13 @@ threadexits(char *exitstr)
void
threadexitsall(char *exitstr)
{
- Proc *p;
- int *pid;
- int i, npid, mypid;
-
_threaddebug(DBGSCHED, "threadexitsall %s", exitstr);
if(exitstr == nil)
exitstr = "";
_threadexitsallstatus = exitstr;
_threaddebug(DBGSCHED, "_threadexitsallstatus set to %p", _threadexitsallstatus);
- mypid = _threadgetpid();
-
- /*
- * signal others.
- * copying all the pids first avoids other thread's
- * teardown procedures getting in the way.
- */
- lock(&_threadpq.lock);
- npid = 0;
- for(p=_threadpq.head; p; p=p->next)
- npid++;
- pid = _threadmalloc(npid*sizeof(pid[0]), 0);
- npid = 0;
- for(p = _threadpq.head; p; p=p->next)
- pid[npid++] = p->pid;
- unlock(&_threadpq.lock);
- for(i=0; i<npid; i++){
- _threaddebug(DBGSCHED, "threadexitsall kill %d", pid[i]);
- if(pid[i]==0 || pid[i]==-1)
- fprint(2, "bad pid in threadexitsall: %d\n", pid[i]);
- else if(pid[i] != mypid){
- kill(pid[i], SIGTERM);
- }
- }
-
/* leave */
- exits(0);
+ _threadexitallproc(exitstr);
}
Channel*
DIR diff --git a/src/libthread/id.c b/src/libthread/id.c
t@@ -60,10 +60,10 @@ threadsetname(char *fmt, ...)
p = _threadgetproc();
t = p->thread;
- if (t->cmdname)
- free(t->cmdname);
+ if(t->name)
+ free(t->name);
va_start(arg, fmt);
- t->cmdname = vsmprint(fmt, arg);
+ t->name = vsmprint(fmt, arg);
va_end(arg);
/* Plan 9 only
t@@ -85,7 +85,7 @@ threadsetname(char *fmt, ...)
char*
threadgetname(void)
{
- return _threadgetproc()->thread->cmdname;
+ return _threadgetproc()->thread->name;
}
void**
DIR diff --git a/src/libthread/iocall.c b/src/libthread/iocall.c
t@@ -1,4 +1,7 @@
-#include "threadimpl.h"
+#include <u.h>
+#include <libc.h>
+#include <thread.h>
+#include "ioproc.h"
long
iocall(Ioproc *io, long (*op)(va_list*), ...)
DIR diff --git a/src/libthread/ioproc.c b/src/libthread/ioproc.c
t@@ -1,4 +1,7 @@
-#include "threadimpl.h"
+#include <u.h>
+#include <libc.h>
+#include <thread.h>
+#include "ioproc.h"
enum
{
DIR diff --git a/src/libthread/main.c b/src/libthread/main.c
t@@ -1,135 +1,79 @@
-#include <u.h>
-#include <signal.h>
+/*
+ * Thread library.
+ */
+
#include "threadimpl.h"
typedef struct Mainarg Mainarg;
struct Mainarg
{
- int argc;
- char **argv;
+ int argc;
+ char **argv;
};
-int mainstacksize;
-int _threadnotefd;
-int _threadpasserpid;
-static void mainlauncher(void*);
+int mainstacksize;
extern void (*_sysfatal)(char*, va_list);
-void
-_threadstatus(int x)
-{
- USED(x);
- threadstatus();
-}
-
-void
-_threaddie(int x)
-{
- extern char *_threadexitsallstatus;
- USED(x);
-
- if(_threadexitsallstatus)
- _exits(_threadexitsallstatus);
-}
-
-int
-main(int argc, char **argv)
-{
- Mainarg *a;
- Proc *p;
-
-//_threaddebuglevel = (DBGSCHED|DBGCHAN|DBGREND)^~0;
- _systhreadinit();
- _qlockinit(_threadsleep, _threadwakeup);
- _sysfatal = _threadsysfatal;
- notify(_threadnote);
- if(mainstacksize == 0)
- mainstacksize = 32*1024;
-
- a = _threadmalloc(sizeof *a, 1);
- a->argc = argc;
- a->argv = argv;
- p = _newproc(mainlauncher, a, mainstacksize, "threadmain", 0, 0);
- _scheduler(p);
- abort(); /* not reached */
- return 0;
-}
-
static void
mainlauncher(void *arg)
{
Mainarg *a;
a = arg;
+ _threadmaininit();
threadmain(a->argc, a->argv);
threadexits("threadmain");
}
-void
-_threadsignal(void)
-{
-}
-
-void
-_threadsignalpasser(void)
-{
-}
-
int
-_schedfork(Proc *p)
+main(int argc, char **argv)
{
- int pid;
- lock(&p->lock);
- pid = ffork(RFMEM|RFNOWAIT, _scheduler, p);
- p->pid = pid;
- unlock(&p->lock);
- return pid;
-
-}
+ Mainarg a;
+ Proc *p;
-void
-_schedexit(Proc *p)
-{
- char ex[ERRMAX];
- Proc **l;
+ /*
+ * XXX Do daemonize hack here.
+ */
+
+ /*
+ * Instruct QLock et al. to use our scheduling functions
+ * so that they can operate at the thread level.
+ */
+ _qlockinit(_threadsleep, _threadwakeup);
- lock(&_threadpq.lock);
- for(l=&_threadpq.head; *l; l=&(*l)->next){
- if(*l == p){
- *l = p->next;
- if(*l == nil)
- _threadpq.tail = l;
- break;
- }
- }
- _threadprocs--;
- unlock(&_threadpq.lock);
+ /*
+ * Install our own _threadsysfatal which takes down
+ * the whole conglomeration of procs.
+ */
+ _sysfatal = _threadsysfatal;
- strncpy(ex, p->exitstr, sizeof ex);
- ex[sizeof ex-1] = '\0';
- free(p);
- _exits(ex);
-}
+ /*
+ * XXX Install our own jump handler.
+ */
-int
-nrand(int n)
-{
- return random()%n;
-}
+ /*
+ * Install our own signal handlers.
+ */
+ notify(_threadnote);
-void
-_systhreadinit(void)
-{
+ /*
+ * Construct the initial proc running mainlauncher(&a).
+ */
+ if(mainstacksize == 0)
+ mainstacksize = 32*1024;
+ a.argc = argc;
+ a.argv = argv;
+ p = _newproc();
+ _newthread(p, mainlauncher, &a, mainstacksize, "threadmain", 0);
+ _threadscheduler(p);
+ abort(); /* not reached */
+ return 0;
}
+/*
+ * No-op function here so that sched.o drags in main.o.
+ */
void
-threadstats(void)
+_threadlinkmain(void)
{
- extern int _threadnrendez, _threadhighnrendez,
- _threadnalt, _threadhighnentry;
- fprint(2, "*** THREAD LIBRARY STATS ***\n");
- fprint(2, "nrendez %d high simultaneous %d\n",
- _threadnrendez, _threadhighnrendez);
- fprint(2, "nalt %d high simultaneous entry %d\n",
- _threadnalt, _threadhighnentry);
}
DIR diff --git a/src/libthread/mkfile b/src/libthread/mkfile
t@@ -28,11 +28,11 @@ OFILES=\
memset.$O\
memsetd.$O\
note.$O\
- proctab.$O\
+ pthread.$O\
read9pmsg.$O\
ref.$O\
- rendez.$O\
sched.$O\
+ sleep.$O\
HFILES=\
$PLAN9/include/thread.h\
DIR diff --git a/src/libthread/note.c b/src/libthread/note.c
t@@ -65,6 +65,8 @@ delayednotes(Proc *p, void *v)
}
if(i==NFN){
_threaddebug(DBGNOTE, "Unhandled note %s, proc %p\n", n->s, p);
+ if(strcmp(n->s, "sys: child") == 0)
+ noted(NCONT);
fprint(2, "unhandled note %s, pid %d\n", n->s, p->pid);
if(v != nil)
noted(NDFLT);
t@@ -85,7 +87,9 @@ _threadnote(void *v, char *s)
Note *n;
_threaddebug(DBGNOTE, "Got note %s", s);
- if(strncmp(s, "sys:", 4) == 0 && strcmp(s, "sys: write on closed pipe") != 0)
+ if(strncmp(s, "sys:", 4) == 0
+ && strcmp(s, "sys: write on closed pipe") != 0
+ && strcmp(s, "sys: child") != 0)
noted(NDFLT);
// if(_threadexitsallstatus){
DIR diff --git a/src/libthread/proctab.c b/src/libthread/proctab.c
t@@ -46,7 +46,7 @@ __threadgetproc(int rm)
if(!multi)
return theproc;
- pid = _threadgetpid();
+ pid = getpid();
lock(&ptablock);
h = ((unsigned)pid)%PTABHASH;
DIR diff --git a/src/libthread/ref.c b/src/libthread/ref.c
t@@ -1,3 +1,9 @@
+/*
+ * Atomic reference counts - used by applications.
+ *
+ * We use locks to avoid the assembly of the Plan 9 versions.
+ */
+
#include "threadimpl.h"
void
DIR diff --git a/src/libthread/rendez.c b/src/libthread/rendez.c
t@@ -1,38 +0,0 @@
-#include "threadimpl.h"
-
-int _threadhighnrendez;
-int _threadnrendez;
-
-void
-_threadsleep(_Procrend *r)
-{
- Thread *t;
-
- t = _threadgetproc()->thread;
- r->arg = t;
- t->nextstate = Rendezvous;
- t->inrendez = 1;
- unlock(r->l);
- _sched();
- t->inrendez = 0;
- lock(r->l);
-}
-
-void
-_threadwakeup(_Procrend *r)
-{
- Thread *t;
-
- t = r->arg;
- while(t->state == Running)
- sleep(0);
- lock(&t->proc->lock);
- if(t->state == Dead){
- unlock(&t->proc->lock);
- return;
- }
- assert(t->state == Rendezvous && t->inrendez);
- t->state = Ready;
- _threadready(t);
- unlock(&t->proc->lock);
-}
DIR diff --git a/src/libthread/sched.c b/src/libthread/sched.c
t@@ -1,76 +1,59 @@
-#include <u.h>
-#include <signal.h>
-#include <errno.h>
+/*
+ * Thread scheduler.
+ */
#include "threadimpl.h"
-static Thread *runthread(Proc*);
-
-static char *_psstate[] = {
- "Dead",
- "Running",
- "Ready",
- "Rendezvous",
-};
-
-static char*
-psstate(int s)
-{
- if(s < 0 || s >= nelem(_psstate))
- return "unknown";
- return _psstate[s];
-}
-
-void
-needstack(int howmuch)
-{
- Proc *p;
- Thread *t;
-
- p = _threadgetproc();
- if(p == nil || (t=p->thread) == nil)
- return;
- if((ulong)&howmuch < (ulong)t->stk+howmuch){ /* stack overflow waiting to happen */
- fprint(2, "stack overflow: stack at 0x%lux, limit at 0x%lux, need 0x%lux\n", (ulong)&p, (ulong)t->stk, howmuch);
- abort();
- }
-}
+static Thread *runthread(Proc*);
+static void schedexit(Proc*);
+/*
+ * Main scheduling loop.
+ */
void
-_scheduler(void *arg)
+_threadscheduler(void *arg)
{
Proc *p;
Thread *t;
p = arg;
- lock(&p->lock);
- p->pid = _threadgetpid();
- _threadsetproc(p);
+
+ _threadlinkmain();
+ _threadinitproc(p);
for(;;){
+ /*
+ * Clean up zombie children.
+ */
+ _threadwaitkids(p);
+
+ /*
+ * Find next thread to run.
+ */
+ _threaddebug(DBGSCHED, "runthread");
t = runthread(p);
- if(t == nil){
- _threaddebug(DBGSCHED, "all threads gone; exiting");
- _threaddelproc();
- _schedexit(p);
- }
- _threaddebug(DBGSCHED, "running %d.%d", t->proc->pid, t->id);
- p->thread = t;
- if(t->moribund){
- _threaddebug(DBGSCHED, "%d.%d marked to die");
- goto Moribund;
+ if(t == nil)
+ schedexit(p);
+
+ /*
+ * If it's ready, run it (might instead be marked to die).
+ */
+ lock(&p->lock);
+ if(t->state == Ready){
+ _threaddebug(DBGSCHED, "running %d.%d", p->id, t->id);
+ t->state = Running;
+ t->nextstate = Ready;
+ p->thread = t;
+ unlock(&p->lock);
+ _swaplabel(&p->context, &t->context);
+ lock(&p->lock);
+ p->thread = nil;
}
- t->state = Running;
- t->nextstate = Ready;
- unlock(&p->lock);
- _swaplabel(&p->sched, &t->sched);
-
- lock(&p->lock);
- p->thread = nil;
+ /*
+ * If thread needs to die, kill it.
+ */
if(t->moribund){
- Moribund:
- if(t->moribund != 1)
- fprint(2, "moribund %d\n", t->moribund);
+ _threaddebug(DBGSCHED, "moribund %d.%d", p->id, t->id);
assert(t->moribund == 1);
t->state = Dead;
if(t->prevt)
t@@ -82,40 +65,37 @@ _scheduler(void *arg)
else
p->threads.tail = t->prevt;
unlock(&p->lock);
- if(t->inrendez){
- abort();
- // _threadflagrendez(t);
- // _threadbreakrendez();
- }
- _stackfree(t->stk);
- free(t->cmdname);
- free(t); /* XXX how do we know there are no references? */
+ _threadfree(t);
p->nthreads--;
t = nil;
- lock(&p->lock);
continue;
}
-/*
- if(p->needexec){
- t->ret = _schedexec(&p->exec);
- p->needexec = 0;
- }
-*/
- if(p->newproc){
- t->ret = _schedfork(p->newproc);
- if(t->ret < 0){
-//fprint(2, "_schedfork: %r\n");
- abort();
- }
- p->newproc = nil;
+ unlock(&p->lock);
+
+ /*
+ * If there is a request to run a function on the
+ * scheduling stack, do so.
+ */
+ if(p->schedfn){
+ _threaddebug(DBGSCHED, "schedfn");
+ p->schedfn(p);
+ p->schedfn = nil;
+ _threaddebug(DBGSCHED, "schedfn ended");
}
+
+ /*
+ * Move the thread along.
+ */
t->state = t->nextstate;
+ _threaddebug(DBGSCHED, "moveon %d.%d", p->id, t->id);
if(t->state == Ready)
_threadready(t);
- unlock(&p->lock);
}
}
+/*
+ * Called by thread to give up control of processor to scheduler.
+ */
int
_sched(void)
{
t@@ -125,166 +105,195 @@ _sched(void)
p = _threadgetproc();
t = p->thread;
assert(t != nil);
- _swaplabel(&t->sched, &p->sched);
+ _swaplabel(&t->context, &p->context);
return p->nsched++;
}
+/*
+ * Called by thread to yield the processor to other threads.
+ * Returns number of other threads run between call and return.
+ */
+int
+yield(void)
+{
+ Proc *p;
+ int nsched;
+
+ p = _threadgetproc();
+ nsched = p->nsched;
+ return _sched() - nsched;
+}
+
+/*
+ * Choose the next thread to run.
+ */
static Thread*
runthread(Proc *p)
{
- Channel *c;
Thread *t;
Tqueue *q;
- Waitmsg *w;
- int e, sent;
+ /*
+ * No threads left?
+ */
if(p->nthreads==0 || (p->nthreads==1 && p->idle))
return nil;
- q = &p->ready;
-relock:
+
lock(&p->readylock);
- if(p->nsched%128 == 0){
- /* clean up children */
- e = errno;
- if((c = _threadwaitchan) != nil){
- if(c->n <= c->s){
- sent = 0;
- for(;;){
- if((w = p->waitmsg) != nil)
- p->waitmsg = nil;
- else
- w = waitnohang();
- if(w == nil)
- break;
- if(sent == 0){
- unlock(&p->readylock);
- sent = 1;
- }
- if(nbsendp(c, w) != 1)
- break;
- }
- p->waitmsg = w;
- if(sent)
- goto relock;
- }
- }else{
- while((w = waitnohang()) != nil)
- free(w);
- }
- errno = e;
- }
+ q = &p->ready;
if(q->head == nil){
+ /*
+ * Is this a single-process program with an idle thread?
+ */
if(p->idle){
- if(p->idle->state != Ready){
- fprint(2, "everyone is asleep\n");
- exits("everyone is asleep");
- }
+ /*
+ * The idle thread had better be ready!
+ */
+ if(p->idle->state != Ready)
+ sysfatal("all threads are asleep");
+
+ /*
+ * Run the idle thread.
+ */
unlock(&p->readylock);
_threaddebug(DBGSCHED, "running idle thread", p->nthreads);
return p->idle;
}
- _threaddebug(DBGSCHED, "sleeping for more work (%d threads)", p->nthreads);
+ /*
+ * Wait until one of our threads is readied (by another proc!).
+ */
q->asleep = 1;
p->rend.l = &p->readylock;
_procsleep(&p->rend);
+
+ /*
+ * Maybe we were awakened to exit?
+ */
if(_threadexitsallstatus)
_exits(_threadexitsallstatus);
+
+ assert(q->head != nil);
}
+
t = q->head;
q->head = t->next;
unlock(&p->readylock);
- return t;
-}
-long
-threadstack(void)
-{
- Proc *p;
- Thread *t;
-
- p = _threadgetproc();
- t = p->thread;
- return (ulong)&p - (ulong)t->stk;
+ return t;
}
+/*
+ * Add a newly-ready thread to its proc's run queue.
+ */
void
_threadready(Thread *t)
{
Tqueue *q;
+ /*
+ * The idle thread does not go on the run queue.
+ */
if(t == t->proc->idle){
_threaddebug(DBGSCHED, "idle thread is ready");
return;
}
assert(t->state == Ready);
- _threaddebug(DBGSCHED, "readying %d.%d", t->proc->pid, t->id);
+ _threaddebug(DBGSCHED, "readying %d.%d", t->proc->id, t->id);
+
+ /*
+ * Add thread to run queue.
+ */
q = &t->proc->ready;
lock(&t->proc->readylock);
+
t->next = nil;
- if(q->head==nil)
+ if(q->head == nil)
q->head = t;
else
q->tail->next = t;
q->tail = t;
+
+ /*
+ * Wake proc scheduler if it is sleeping.
+ */
if(q->asleep){
assert(q->asleep == 1);
q->asleep = 0;
- /* lock passes to runthread */
_procwakeup(&t->proc->rend);
}
unlock(&t->proc->readylock);
- if(_threadexitsallstatus)
- _exits(_threadexitsallstatus);
}
+/*
+ * Mark the given thread as the idle thread.
+ * Since the idle thread was just created, it is sitting
+ * somewhere on the ready queue.
+ */
void
-_threadidle(void)
+_threadsetidle(int id)
{
Tqueue *q;
- Thread *t, *idle;
+ Thread *t, **l, *last;
Proc *p;
p = _threadgetproc();
- q = &p->ready;
+
lock(&p->readylock);
- assert(q->tail);
- idle = q->tail;
- if(q->head == idle){
- q->head = nil;
- q->tail = nil;
- }else{
- for(t=q->head; t->next!=q->tail; t=t->next)
- ;
- t->next = nil;
- q->tail = t;
- }
- p->idle = idle;
- _threaddebug(DBGSCHED, "p->idle is %d\n", idle->id);
- unlock(&p->readylock);
-}
-int
-yield(void)
-{
- Proc *p;
- int nsched;
+ /*
+ * Find thread on ready queue.
+ */
+ q = &p->ready;
+ for(l=&q->head, last=nil; (t=*l) != nil; l=&t->next, last=t)
+ if(t->id == id)
+ break;
+ assert(t != nil);
- p = _threadgetproc();
- nsched = p->nsched;
- return _sched() - nsched;
+ /*
+ * Remove it from ready queue.
+ */
+ *l = t->next;
+ if(t == q->head)
+ q->head = t->next;
+ if(t->next == nil)
+ q->tail = last;
+
+ /*
+ * Set as idle thread.
+ */
+ p->idle = t;
+ _threaddebug(DBGSCHED, "p->idle is %d\n", t->id);
+ unlock(&p->readylock);
}
-void
-threadstatus(void)
+static void
+schedexit(Proc *p)
{
- Proc *p;
- Thread *t;
+ char ex[ERRMAX];
+ int n;
+ Proc **l;
- p = _threadgetproc();
- for(t=p->threads.head; t; t=t->nextt)
- fprint(2, "[%3d] %s userpc=%lux\n",
- t->id, psstate(t->state), t->userpc);
+ _threaddebug(DBGSCHED, "exiting proc %d", p->id);
+ lock(&_threadpq.lock);
+ for(l=&_threadpq.head; *l; l=&(*l)->next){
+ if(*l == p){
+ *l = p->next;
+ if(*l == nil)
+ _threadpq.tail = l;
+ break;
+ }
+ }
+ n = --_threadnprocs;
+ unlock(&_threadpq.lock);
+
+ strncpy(ex, p->exitstr, sizeof ex);
+ ex[sizeof ex-1] = '\0';
+ free(p);
+ if(n == 0)
+ _threadexitallproc(ex);
+ else
+ _threadexitproc(ex);
}
-
+
DIR diff --git a/src/libthread/sleep.c b/src/libthread/sleep.c
t@@ -0,0 +1,38 @@
+#include "threadimpl.h"
+
+int _threadhighnrendez;
+int _threadnrendez;
+
+void
+_threadsleep(_Procrend *r)
+{
+ Thread *t;
+
+ t = _threadgetproc()->thread;
+ r->arg = t;
+ t->nextstate = Rendezvous;
+ t->asleep = 1;
+ unlock(r->l);
+ _sched();
+ t->asleep = 0;
+ lock(r->l);
+}
+
+void
+_threadwakeup(_Procrend *r)
+{
+ Thread *t;
+
+ t = r->arg;
+ while(t->state == Running)
+ sleep(0);
+ lock(&t->proc->lock);
+ if(t->state == Dead){
+ unlock(&t->proc->lock);
+ return;
+ }
+ assert(t->state == Rendezvous && t->asleep);
+ t->state = Ready;
+ _threadready(t);
+ unlock(&t->proc->lock);
+}
DIR diff --git a/src/libthread/texec.c b/src/libthread/texec.c
t@@ -5,11 +5,16 @@ extern int _threaddebuglevel;
void
doexec(void *v)
{
+ int fd[3];
char **argv = v;
-print("doexec\n");
- procexec(nil, argv[0], argv);
+ fd[0] = dup(0, -1);
+ fd[1] = dup(1, -1);
+ fd[2] = dup(2, -1);
+ threadexec(nil, fd, argv[0], argv);
+ print("exec failed: %r\n");
sendp(threadwaitchan(), nil);
+ threadexits(nil);
}
void
t@@ -28,7 +33,7 @@ threadmain(int argc, char **argv)
proccreate(doexec, argv, 8192);
w = recvp(c);
if(w == nil)
- print("exec failed: %r\n");
+ print("exec/recvp failed: %r\n");
else
print("%d %lud %lud %lud %s\n", w->pid, w->time[0], w->time[1], w->time[2], w->msg);
threadexits(nil);
DIR diff --git a/src/libthread/threadimpl.h b/src/libthread/threadimpl.h
t@@ -7,31 +7,28 @@
* _threadgetproc()->thread is always a live pointer.
* p->threads, p->ready, and _threadrgrp also contain
* live thread pointers. These may only be consulted
- * while holding p->lock or _threadrgrp.lock; in procs
- * other than p, the pointers are only guaranteed to be live
- * while the lock is still being held.
+ * while holding p->lock; in procs other than p, the
+ * pointers are only guaranteed to be live while the lock
+ * is still being held.
*
* Thread structures can only be freed by the proc
* they belong to. Threads marked with t->inrendez
* need to be extracted from the _threadrgrp before
* being freed.
- *
- * _threadrgrp.lock cannot be acquired while holding p->lock.
*/
+#include <u.h>
#include <assert.h>
-#include <lib9.h>
+#include <libc.h>
#include <thread.h>
#include "label.h"
typedef struct Thread Thread;
-typedef struct Proc Proc;
+typedef struct Proc Proc;
typedef struct Tqueue Tqueue;
typedef struct Pqueue Pqueue;
-typedef struct Rgrp Rgrp;
typedef struct Execargs Execargs;
-/* must match list in sched.c */
typedef enum
{
Dead,
t@@ -50,17 +47,9 @@ typedef enum
enum
{
- RENDHASH = 10009,
- Printsize = 2048,
NPRIV = 8,
};
-struct Rgrp
-{
- Lock lock;
- Thread *hash[RENDHASH];
-};
-
struct Tqueue /* Thread queue */
{
int asleep;
t@@ -68,27 +57,38 @@ struct Tqueue /* Thread queue */
Thread *tail;
};
+struct Pqueue { /* Proc queue */
+ Lock lock;
+ Proc *head;
+ Proc **tail;
+};
+
struct Thread
{
Lock lock; /* protects thread data structure */
- Label sched; /* for context switches */
- int id; /* thread id */
+
+ int asleep; /* thread is in _threadsleep */
+ Label context; /* for context switches */
int grp; /* thread group */
+ int id; /* thread id */
int moribund; /* thread needs to die */
- State state; /* run state */
- State nextstate; /* next run state */
- uchar *stk; /* top of stack (lowest address of stack) */
- uint stksize; /* stack size */
+ char *name; /* name of thread */
Thread *next; /* next on ready queue */
-
- Proc *proc; /* proc of this thread */
Thread *nextt; /* next on list of threads in this proc */
+ State nextstate; /* next run state */
+ Proc *proc; /* proc of this thread */
Thread *prevt; /* prev on list of threads in this proc */
int ret; /* return value for Exec, Fork */
+ State state; /* run state */
+ uchar *stk; /* top of stack (lowest address of stack) */
+ uint stksize; /* stack size */
+ void* udata[NPRIV]; /* User per-thread data pointer */
- char *cmdname; /* ptr to name of thread */
+ /*
+ * for debugging only
+ * (could go away without impacting correct behavior):
+ */
- int inrendez;
Channel *altc;
_Procrend altrend;
t@@ -96,10 +96,7 @@ struct Thread
Alt *alt; /* pointer to current alt structure (debugging) */
ulong userpc;
Channel *c;
- pthread_cond_t cond;
- void* udata[NPRIV]; /* User per-thread data pointer */
- int lastfd;
};
struct Execargs
t@@ -113,12 +110,13 @@ struct Execargs
struct Proc
{
Lock lock;
- Label sched; /* for context switches */
- Proc *link; /* in proctab */
- int pid; /* process id */
+
+ Label context; /* for context switches */
+ Proc *link; /* in ptab */
int splhi; /* delay notes */
Thread *thread; /* running thread */
Thread *idle; /* idle thread */
+ int id;
int needexec;
Execargs exec; /* exec argument */
t@@ -131,13 +129,15 @@ struct Proc
Tqueue ready; /* Runnable threads */
Lock readylock;
- char printbuf[Printsize];
int blocked; /* In a rendezvous */
int pending; /* delayed note pending */
int nonotes; /* delay notes */
uint nextID; /* ID of most recently created thread */
Proc *next; /* linked list of Procs */
+
+ void (*schedfn)(Proc*); /* function to call in scheduler */
+
_Procrend rend; /* sleep here for more ready threads */
void *arg; /* passed between shared and unshared stk */
t@@ -147,29 +147,17 @@ struct Proc
void* udata; /* User per-proc data pointer */
int nsched;
-};
-
-struct Pqueue { /* Proc queue */
- Lock lock;
- Proc *head;
- Proc **tail;
-};
-struct Ioproc
-{
- int tid;
- Channel *c, *creply;
- int inuse;
- long (*op)(va_list*);
- va_list arg;
- long ret;
- char err[ERRMAX];
- Ioproc *next;
+ /*
+ * for debugging only
+ */
+ int pid; /* process id */
+ int pthreadid; /* pthread id */
};
void _swaplabel(Label*, Label*);
-void _freeproc(Proc*);
-Proc* _newproc(void(*)(void*), void*, uint, char*, int, int);
+Proc* _newproc(void);
+int _newthread(Proc*, void(*)(void*), void*, uint, char*, int);
int _procsplhi(void);
void _procsplx(int);
int _sched(void);
t@@ -177,7 +165,8 @@ int _schedexec(Execargs*);
void _schedexecwait(void);
void _schedexit(Proc*);
int _schedfork(Proc*);
-void _scheduler(void*);
+void _threadfree(Thread*);
+void _threadscheduler(void*);
void _systhreadinit(void);
void _threadassert(char*);
void __threaddebug(ulong, char*, ...);
t@@ -186,12 +175,15 @@ void _threadexitsall(char*);
Proc* _threadgetproc(void);
extern void _threadmultiproc(void);
Proc* _threaddelproc(void);
+void _threadinitproc(Proc*);
+void _threadwaitkids(Proc*);
void _threadsetproc(Proc*);
void _threadinitstack(Thread*, void(*)(void*), void*);
+void _threadlinkmain(void);
void* _threadmalloc(long, int);
void _threadnote(void*, char*);
void _threadready(Thread*);
-void _threadidle(void);
+void _threadsetidle(int);
void _threadsleep(_Procrend*);
void _threadwakeup(_Procrend*);
void _threadsignal(void);
t@@ -200,13 +192,15 @@ long _xdec(long*);
void _xinc(long*);
void _threadremove(Proc*, Thread*);
void threadstatus(void);
+void _threadstartproc(Proc*);
+void _threadexitproc(char*);
+void _threadexitallproc(char*);
+extern int _threadnprocs;
extern int _threaddebuglevel;
extern char* _threadexitsallstatus;
extern Pqueue _threadpq;
extern Channel* _threadwaitchan;
-extern Rgrp _threadrgrp;
-extern void _stackfree(void*);
#define DBGAPPL (1 << 0)
#define DBGSCHED (1 << 16)
t@@ -216,8 +210,6 @@ extern void _stackfree(void*);
#define DBGNOTE (1 << 20)
#define DBGEXEC (1 << 21)
-#define ioproc_arg(io, type) (va_arg((io)->arg, type))
-extern int _threadgetpid(void);
extern void _threadmemset(void*, int, int);
extern void _threaddebugmemset(void*, int, int);
extern int _threadprocs;
DIR diff --git a/src/libthread/ucontext.c b/src/libthread/ucontext.c
t@@ -6,17 +6,18 @@ _threadinitstack(Thread *t, void (*f)(void*), void *arg)
sigset_t zero;
/* do a reasonable initialization */
- memset(&t->sched.uc, 0, sizeof t->sched.uc);
+ memset(&t->context.uc, 0, sizeof t->context.uc);
sigemptyset(&zero);
- sigprocmask(SIG_BLOCK, &zero, &t->sched.uc.uc_sigmask);
+ sigprocmask(SIG_BLOCK, &zero, &t->context.uc.uc_sigmask);
/* call getcontext, because on Linux makecontext neglects floating point */
- getcontext(&t->sched.uc);
+ getcontext(&t->context.uc);
/* call makecontext to do the real work. */
- t->sched.uc.uc_stack.ss_sp = t->stk;
- t->sched.uc.uc_stack.ss_size = t->stksize;
- makecontext(&t->sched.uc, (void(*)())f, 1, arg);
+ /* leave a few words open on both ends */
+ t->context.uc.uc_stack.ss_sp = t->stk+8;
+ t->context.uc.uc_stack.ss_size = t->stksize-16;
+ makecontext(&t->context.uc, (void(*)())f, 1, arg);
}
void