1999/0501/port/taslock.c (diff list | history)

port/taslock.c on 1992/0222
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"
1998/0606		struct { ulong locks; ulong glare; ulong inglare; } lockstats;
1992/0222		void
1995/1030		lockloop(Lock *l, ulong pc) {
1998/0606		Proc *p; p = l->p;
1998/0825		print("lock loop key 0x%lux pc 0x%lux held by pc 0x%lux proc %lud\n",
1998/0606		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		} void
1992/0222		lock(Lock *l) {
1998/0606		int i, cansched; ulong pc, oldpri;
1995/1009
1999/0501		pc = getcallerpc(&l);
1995/1009
1998/0606		lockstats.locks++;
1996/0522		if(tas(&l->key) == 0){ l->pc = pc;
1998/0604		l->p = up; l->isilock = 0;
1995/0110		return;
1995/1009		}
1995/0108
1998/0606		lockstats.glare++; cansched = up != nil && up->state == Running; if(cansched){ oldpri = up->priority; up->lockwait = 1; up->priority = PriLock; } else oldpri = 0;
1996/0522		for(;;){
1998/0606		lockstats.inglare++;
1996/0522		i = 0;
1998/0604		while(l->key){
1998/0606		if(conf.nmach < 2 && cansched){
1998/0604		if(i++ > 1000){ i = 0; lockloop(l, pc); } sched(); } else { if(i++ > 100000000){ i = 0; lockloop(l, pc); }
1996/0522		}
1998/0604		}
1995/1009		if(tas(&l->key) == 0){ l->pc = pc;
1998/0604		l->p = up; l->isilock = 0;
1998/0606		if(cansched){ up->lockwait = 0; up->priority = oldpri;
1998/0604		}
1995/0108		return;
1995/1009		}
1995/0108		}
1995/0110		}
1995/0108
1995/0110		void ilock(Lock *l) { ulong x;
1998/0606		ulong pc, oldpri; int cansched;
1995/0110
1999/0501		pc = getcallerpc(&l);
1998/0606		lockstats.locks++;
1995/1009
1995/0110		x = splhi(); if(tas(&l->key) == 0){ l->sr = x;
1995/1009		l->pc = pc;
1998/0604		l->p = up; l->isilock = 1;
1993/1204		return;
1995/0110		}
1998/0606		lockstats.glare++; cansched = up != nil && up->state == Running; if(cansched){ oldpri = up->priority; up->lockwait = 1; up->priority = PriLock; } else oldpri = 0;
1998/0522		if(conf.nmach < 2)
1999/0402		panic("ilock: no way out: pc %uX\n", pc);
1998/0522
1993/0830		for(;;){
1998/0606		lockstats.inglare++;
1998/0228		splx(x);
1994/0808		while(l->key) ;
1998/0228		x = splhi();
1995/0110		if(tas(&l->key) == 0){ l->sr = x;
1995/1009		l->pc = pc;
1998/0604		l->p = up; l->isilock = 1;
1998/0606		if(cansched){ up->lockwait = 0; up->priority = oldpri; }
1992/0222		return;
1995/0110		}
1992/0222		} }
1995/0109		int canlock(Lock *l)
1994/0322		{
1996/0522		if(tas(&l->key))
1996/0511		return 0;
1996/0522
1999/0501		l->pc = getcallerpc(&l);
1998/0604		l->p = up; l->isilock = 0;
1992/0222		return 1; } void unlock(Lock *l) {
1998/0604
1998/0522		if(l->key == 0)
1999/0501		print("unlock: not locked: pc %luX\n", getcallerpc(&l));
1998/0604		if(l->isilock)
1999/0501		print("iunlock of lock: pc %lux, held by %lux\n", getcallerpc(&l), l->pc);
1996/0522		l->pc = 0;
1997/0327		l->key = 0;
1997/0220		coherence();
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)
1999/0501		print("unlock of ilock: pc %lux, held by %lux\n", getcallerpc(&l), l->pc);
1998/0603
1994/0322		sr = l->sr;
1995/1014		l->pc = 0;
1997/0327		l->key = 0;
1997/0220		coherence();
1998/0606
1999/0501		m->splpc = getcallerpc(&l);
1998/0606		splxpc(sr);
1992/0222		}