1990/0403/gnot/lock.c (diff list | history)

1990/0312/sys/src/9/gnot/lock.c:4,9 – 1990/0403/sys/src/9/gnot/lock.c:4,18 (short | long | prev | next)
1990/03091		#include "dat.h" #include "fns.h"
1990/0403		#define PCOFF -2 /* * N.B. Ken's compiler generates a TAS instruction for the sequence: * * if(l->key >= 0){ * l->key |= 0x80; * ... */
1990/03091		void lock(Lock *l) {
1990/0312/sys/src/9/gnot/lock.c:12,35 – 1990/0403/sys/src/9/gnot/lock.c:21,49
1990/03091		/* * Try the fast grab first */ if(tas(l->key) == 0){ l->pc = ((ulong*)&l)[-1];
1990/0403		if(l->key >= 0){ l->key |= 0x80; l->pc = ((ulong*)&i)[PCOFF];
1990/03091		return; } for(i=0; i<10000000; i++) if(tas(l->key) == 0){ l->pc = ((ulong*)&l)[-1];
1990/0403		if(l->key >= 0){ l->key |= 0x80; l->pc = ((ulong*)&i)[PCOFF];
1990/03091		return; } l->key[0] = 0; panic("lock loop %lux pc %lux held by pc %lux\n", l, ((ulong*)&l)[-1], l->pc);
1990/0403		l->key = 0; panic("lock loop %lux pc %lux held by pc %lux\n", l, ((ulong*)&i)[PCOFF], l->pc);
1990/03091		} int canlock(Lock *l) { if(tas(l->key) == 0){ l->pc = ((ulong*)&l)[-1];
1990/0403		int i; if(l->key >= 0){ l->key |= 0x80; l->pc = ((ulong*)&i)[PCOFF];
1990/03091		return 1; } return 0;
1990/0312/sys/src/9/gnot/lock.c:39,45 – 1990/0403/sys/src/9/gnot/lock.c:53,59
1990/03091		unlock(Lock *l) { l->pc = 0; l->key[0] = 0;
1990/0403		l->key = 0;
1990/03091		} void