1996/0523/port/taslock.c (diff list | history)

1996/0522/sys/src/9/port/taslock.c:11,69 – 1996/0523/sys/src/9/port/taslock.c:11,51 (short | long | prev | next)
1995/1030		print("lock loop key 0x%lux pc 0x%lux held by pc 0x%lux proc %d\n", l->key, pc, l->pc, l->pid); dumpaproc(up);
1996/0523		/* lower priority till we get the lock */ if(up && up->state == Running && (getstatus()&IE)){ up->lockpri = 1; sched(); }
1995/1030		}
1996/0522		#define LOCKLOOP 100000000 /* to detect a lock loop */ #define SPINLOOP 10000000 /* to keep tas's off the bus */
1995/1030		void
1992/0222		lock(Lock *l) {
1996/0522		int i, pri, spins;
1996/0523		int i;
1996/0522		ulong pc, pid;
1995/1009		pc = getcallerpc(l);
1996/0522		if(up){ pid = up->pid; pri = up->priority; } else { pid = 0; pri = 0; }
1996/0523		pid = up ? up->pid : 0;
1995/1009
1996/0522		/* quick try, it might work */ if(tas(&l->key) == 0){ l->pc = pc; l->pid = pid; l->pri = pri;
1995/0110		return;
1995/1009		}
1995/0108
1996/0522		spins = 0; for(;;){ i = 0; while(l->key) if(i++ > SPINLOOP){ /* look for lock loops */ if(spins++ > LOCKLOOP/SPINLOOP){ spins = 0; lockloop(l, pc); }
1996/0511
1996/0522		/* possible priority inversion, try switching priority */ if(up && up->state == Running) if(getstatus()&IE) { print("priority inversion\n"); up->lockpri = l->pri; sched(); }
1996/0523		if(i++ > 100000000){ i = 0; lockloop(l, pc);
1996/0522		}
1995/1009		if(tas(&l->key) == 0){ l->pc = pc;
1996/0522		l->pid = pid; l->pri = pri; up->lockpri = 0;
1996/0523		if(up) up->lockpri = 0;
1995/0108		return;
1995/1009		}
1995/0108		}
1996/0522/sys/src/9/port/taslock.c:83,89 – 1996/0523/sys/src/9/port/taslock.c:65,70
1995/0110		l->sr = x;
1995/1009		l->pc = pc;
1995/1030		l->pid = pid;
1996/0522		l->pri = 0;
1993/1204		return;
1995/0110		}
1996/0522/sys/src/9/port/taslock.c:94,100 – 1996/0523/sys/src/9/port/taslock.c:75,80
1995/0110		l->sr = x;
1995/1009		l->pc = pc;
1995/1030		l->pid = pid;
1996/0522		l->pri = 0;
1992/0222		return;
1995/0110		}
1992/0222		}
1996/0522/sys/src/9/port/taslock.c:107,119 – 1996/0523/sys/src/9/port/taslock.c:87,93
1996/0511		return 0;
1996/0522		l->pc = getcallerpc(l); if(up){ l->pid = up->pid; l->pri = up->priority; } else { l->pid = 0; l->pri = 0;
1996/0511		}
1996/0523		l->pid = up ? up->pid : 0;
1992/0222		return 1; }
1996/0522/sys/src/9/port/taslock.c:122,128 – 1996/0523/sys/src/9/port/taslock.c:96,101
1992/0222		{
1996/0511		l->key = 0;
1996/0522		l->pc = 0;
1996/0516		l->pri = 0;
1994/0322		} void
1996/0522/sys/src/9/port/taslock.c:133,138 – 1996/0523/sys/src/9/port/taslock.c:106,110
1994/0322		sr = l->sr;
1995/0110		l->key = 0;
1995/1014		l->pc = 0;
1996/0522		l->pri = 0;
1994/0322		splx(sr);
1992/0222		}