2002/0406/port/taslock.c (diff list | history)

2002/0406/sys/src/9/port/taslock.c:1,192 – 2002/0413/sys/src/9/port/taslock.c:1,197 (short | long | prev | next)
1992/0222		#include "u.h"
1992/0321		#include "../port/lib.h"
1992/0222		#include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h"
2002/0403		struct {
1998/0606		ulong locks; ulong glare; ulong inglare; } lockstats;
2000/1106		static void dumplockmem(char *tag, Lock *l) { uchar *cp; int i; iprint("%s: ", tag); cp = (uchar*)l; for(i = 0; i < 64; i++) iprint("%2.2ux ", cp[i]); iprint("\n"); }
1992/0222		void
1995/1030		lockloop(Lock *l, ulong pc) {
1998/0606		Proc *p; p = l->p;
2001/0527		print("lock 0x%lux loop key 0x%lux pc 0x%lux held by pc 0x%lux proc %lud\n", l, l->key, pc, l->pc, p ? p->pid : 0);
1995/1030		dumpaproc(up);
1998/0606		if(p != nil) dumpaproc(p);
1996/0523
1998/0604		if(up && up->state == Running && islo())
1996/0523		sched();
1995/1030		}
2002/0403		int
1992/0222		lock(Lock *l) {
2002/0403		int i; ulong pc;
1995/1009
1999/0501		pc = getcallerpc(&l);
1995/1009
2002/0403		lockstats.locks++; if(up) up->nlocks++; /* prevent being scheded */
1996/0522		if(tas(&l->key) == 0){
2002/0404		if(up) up->lastlock = l;
1996/0522		l->pc = pc;
1998/0604		l->p = up; l->isilock = 0;
2002/0403		return 0;
1995/1009		}
2002/0403		if(up) up->nlocks--; /* didn't get the lock, allow scheding */
1995/0108
1999/0811		lockstats.glare++;
1996/0522		for(;;){
1999/0811		lockstats.inglare++;
1996/0522		i = 0;
1998/0604		while(l->key){
2002/0403		if(i++ > 100000000){ i = 0; lockloop(l, pc);
1996/0522		}
1998/0604		}
2002/0403		if(up) up->nlocks++;
1995/1009		if(tas(&l->key) == 0){
2002/0403		if(up) up->lastlock = l;
1995/1009		l->pc = pc;
1998/0604		l->p = up; l->isilock = 0;
2002/0403		return 1;
1995/1009		}
2002/0403		if(up) up->nlocks--;
1995/0108		}
2002/0404		return 0; /* For the compiler */
1995/0110		}
1995/0108
1995/0110		void ilock(Lock *l) { ulong x;
2002/0403		ulong pc;
1995/0110
1999/0501		pc = getcallerpc(&l);
1999/0811		lockstats.locks++;
1995/1009
1995/0110		x = splhi(); if(tas(&l->key) == 0){
2002/0403		if(up) up->lastlock = l;
1995/0110		l->sr = x;
1995/1009		l->pc = pc;
1998/0604		l->p = up; l->isilock = 1;
1993/1204		return;
1995/0110		}
1999/0811		lockstats.glare++;
2002/0402		if(conf.nmach < 2){ dumplockmem("ilock:", l);
2002/0114		panic("ilock: no way out: pc %luX\n", pc);
2002/0402		}
1998/0522
1993/0830		for(;;){
1999/0811		lockstats.inglare++;
1998/0228		splx(x);
1994/0808		while(l->key) ;
1998/0228		x = splhi();
1995/0110		if(tas(&l->key) == 0){
2002/0404		if(up) up->lastlock = l;
1995/0110		l->sr = x;
1995/1009		l->pc = pc;
1998/0604		l->p = up; l->isilock = 1;
1992/0222		return;
1995/0110		}
1992/0222		} }
1995/0109		int canlock(Lock *l)
1994/0322		{
2002/0403		if(up) up->nlocks++;
2002/0402		if(tas(&l->key)){
2002/0403		if(up) up->nlocks--;
1996/0511		return 0;
2002/0402		}
1996/0522
2002/0403		if(up) up->lastlock = l;
1999/0501		l->pc = getcallerpc(&l);
1998/0604		l->p = up; l->isilock = 0;
1992/0222		return 1; }
2002/0413		int buggeredsched;
1992/0222		void unlock(Lock *l) {
1998/0522		if(l->key == 0)
1999/0501		print("unlock: not locked: pc %luX\n", getcallerpc(&l));
1998/0604		if(l->isilock)
1999/0710		print("unlock of ilock: pc %lux, held by %lux\n", getcallerpc(&l), l->pc);
2002/0402		if(l->p != up) print("unlock: up changed: pc %lux, acquired at pc %lux, lock p 0x%p, unlock up 0x%p\n", getcallerpc(&l), l->pc, l->p, up);
1997/0327		l->key = 0;
2002/0406		coherence(); /* give up the processor if ... */ if(up && --up->nlocks == 0 /* we've closed the last nexted lock */
2002/0413		if(up && --up->nlocks == 0 /* we've closed the last nested lock */
2002/0406		&& up->delaysched /* we delayed scheduling because of the lock */ && up->state == Running){ /* we're in running state */
2002/0402		up->delaysched = 0; sched();
2002/0413		&& up->state == Running){ /* we're in running state */ if(!islo()) buggeredsched++; else{ up->delaysched = 0; sched(); }
2002/0402		}
1994/0322		} void iunlock(Lock *l) { ulong sr;
1998/0603		if(l->key == 0)
1999/0501		print("iunlock: not locked: pc %luX\n", getcallerpc(&l));
1998/0604		if(!l->isilock)
1999/0710		print("iunlock of lock: pc %lux, held by %lux\n", getcallerpc(&l), l->pc);
1998/0603
1994/0322		sr = l->sr;
1997/0327		l->key = 0;
2001/0314		coherence();
1998/0606
1999/0501		m->splpc = getcallerpc(&l);
1998/0606		splxpc(sr);
1992/0222		}