diff options
Diffstat (limited to 'sys/kern/kern_srp.c')
| -rw-r--r-- | sys/kern/kern_srp.c | 61 |
1 files changed, 42 insertions, 19 deletions
diff --git a/sys/kern/kern_srp.c b/sys/kern/kern_srp.c index dcd08742558..02e607945d3 100644 --- a/sys/kern/kern_srp.c +++ b/sys/kern/kern_srp.c @@ -1,4 +1,4 @@ -/* $OpenBSD: kern_srp.c,v 1.1 2015/07/02 01:34:00 dlg Exp $ */ +/* $OpenBSD: kern_srp.c,v 1.2 2015/09/01 03:47:58 dlg Exp $ */ /* * Copyright (c) 2014 Jonathan Matthew <jmatthew@openbsd.org> @@ -187,24 +187,12 @@ srp_finalize(struct srp_gc *srp_gc) } } -void * -srp_enter(struct srp *srp) +static inline void * +srp_v(struct srp_hazard *hzrd, struct srp *srp) { - struct cpu_info *ci = curcpu(); - struct srp_hazard *hzrd; void *v; - u_int i; - - for (i = 0; i < nitems(ci->ci_srp_hazards); i++) { - hzrd = &ci->ci_srp_hazards[i]; - if (hzrd->sh_p == NULL) - break; - } - if (__predict_false(i == nitems(ci->ci_srp_hazards))) - panic("%s: not enough srp hazard records", __func__); hzrd->sh_p = srp; - membar_producer(); /* * ensure we update this cpu's hazard pointer to a value that's still @@ -220,8 +208,8 @@ srp_enter(struct srp *srp) return (v); } -void -srp_leave(struct srp *srp, void *v) +void * +srp_enter(struct srp *srp) { struct cpu_info *ci = curcpu(); struct srp_hazard *hzrd; @@ -229,9 +217,44 @@ srp_leave(struct srp *srp, void *v) for (i = 0; i < nitems(ci->ci_srp_hazards); i++) { hzrd = &ci->ci_srp_hazards[i]; - if (hzrd->sh_p == srp) { + if (hzrd->sh_p == NULL) + return (srp_v(hzrd, srp)); + } + + panic("%s: not enough srp hazard records", __func__); + + /* NOTREACHED */ + return (NULL); +} + +void * +srp_follow(struct srp *srp, void *v, struct srp *next) +{ + struct cpu_info *ci = curcpu(); + struct srp_hazard *hzrd; + + hzrd = ci->ci_srp_hazards + nitems(ci->ci_srp_hazards); + while (hzrd-- != ci->ci_srp_hazards) { + if (hzrd->sh_p == srp && hzrd->sh_v == v) + return (srp_v(hzrd, next)); + } + + panic("%s: unexpected ref %p via %p", __func__, v, srp); + + /* NOTREACHED */ + return (NULL); +} + +void +srp_leave(struct srp *srp, void *v) +{ + struct cpu_info *ci = curcpu(); + struct srp_hazard *hzrd; + + hzrd = ci->ci_srp_hazards + nitems(ci->ci_srp_hazards); + while (hzrd-- != ci->ci_srp_hazards) { + if (hzrd->sh_p == srp && hzrd->sh_v == v) { hzrd->sh_p = NULL; - hzrd->sh_v = NULL; return; } } |