diff options
Diffstat (limited to 'src/lock/lock_alloc.incl')
| -rw-r--r-- | src/lock/lock_alloc.incl | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/lock/lock_alloc.incl b/src/lock/lock_alloc.incl new file mode 100644 index 00000000..edea07d2 --- /dev/null +++ b/src/lock/lock_alloc.incl @@ -0,0 +1,138 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 2011, 2012 Oracle and/or its affiliates. All rights reserved. + * + * $Id$ + */ + +/* + * This is a template for allocation in the lock region. The following + * macros must be defined: + * + * FREE_LIST_HEAD -- the name of the head of the free list. + * STRUCT_NAME -- the name of the structure in the free list. + * CURRENT_COUNT -- structure element for count of current objects. + * MAX_COUNT -- structure element for max of current objects. + * STEAL_NAME -- name of stat to track steals. + * STEAL_EVENT -- name of event to track steals. + */ +#define __lock_alloc() /* for ctags */ +{ + struct STRUCT_NAME *sh_thing; + DB_LOCKPART *end_p, *cur_p, *orig_p; + DB_LOCKREGION *region; + int begin, locked; + u_int32_t i, nobjs; + + region = lt->reginfo.primary; + + orig_p = <->part_array[part_id]; + if (region->part_t_size == 1) + goto alloc; +retry: MUTEX_UNLOCK(lt->env, orig_p->mtx_part); + locked = 0; + sh_thing = NULL; + end_p = <->part_array[region->part_t_size]; + /* + * Start looking at the next partition and wrap around. If + * we get back to our partition then raise an error. + */ + begin = 0; + nobjs = 0; + cur_p = orig_p + 1; +again: for (; sh_thing == NULL && cur_p < end_p; cur_p++) { + MUTEX_LOCK(lt->env, cur_p->mtx_part); + if ((sh_thing = SH_TAILQ_FIRST( + &cur_p->FREE_LIST_HEAD, STRUCT_NAME)) != NULL) + SH_TAILQ_REMOVE(&cur_p->FREE_LIST_HEAD, + sh_thing, links, STRUCT_NAME); + MUTEX_UNLOCK(lt->env, cur_p->mtx_part); + } + if (sh_thing != NULL) { + MUTEX_LOCK(lt->env, orig_p->mtx_part); + SH_TAILQ_INSERT_HEAD(&orig_p->FREE_LIST_HEAD, + sh_thing, links, STRUCT_NAME); + STAT_INC_VERB(env, + lock, STEAL_EVENT, orig_p->part_stat.STEAL_NAME, + cur_p - lt->part_array, part_id); + return (0); + } + if (!begin) { + begin = 1; + cur_p = lt->part_array; + end_p = orig_p; + goto again; + } + /* + * Try to get some more space in the region. + */ + LOCK_REGION_LOCK(lt->env); + MUTEX_LOCK(lt->env, orig_p->mtx_part); + locked = 1; + nobjs = 0; + /* check to see if we raced with someone. */ + if ((region->stat.MAX_COUNT == 0 || + region->stat.CURRENT_COUNT < region->stat.MAX_COUNT) && + SH_TAILQ_FIRST(&orig_p->FREE_LIST_HEAD, STRUCT_NAME) == NULL) { + MUTEX_UNLOCK(lt->env, orig_p->mtx_part); +alloc: locked = 0; + sh_thing = NULL; + cur_p = orig_p; + end_p = <->part_array[region->part_t_size]; + nobjs = region->stat.CURRENT_COUNT >> 2; + /* Just in case. */ + if (nobjs == 0) + nobjs = 1; + if (region->stat.MAX_COUNT != 0 && + region->stat.MAX_COUNT < + region->stat.CURRENT_COUNT + nobjs) + nobjs = region->stat.MAX_COUNT - + region->stat.CURRENT_COUNT; + /* + * If the max memory is not sized for max objects, + * allocate as much as possible. + */ + F_SET(<->reginfo, REGION_TRACKED); + while (__env_alloc(<->reginfo, + nobjs * sizeof(struct STRUCT_NAME), &sh_thing) != 0) + if ((nobjs >>= 1) == 0) + break; + F_CLR(<->reginfo, REGION_TRACKED); + region->stat.CURRENT_COUNT += nobjs; + if (region->part_t_size != 1) + LOCK_REGION_UNLOCK(lt->env); + + if (nobjs == 0) + goto err; + + for (i = 0; i < nobjs; i++) { + memset(sh_thing, 0, sizeof (struct STRUCT_NAME)); + if (&cur_p->free_locks == + (struct __flock *)&cur_p->FREE_LIST_HEAD) + ((struct __db_lock *) + sh_thing)->status = DB_LSTAT_FREE; + MUTEX_LOCK(lt->env, cur_p->mtx_part); + SH_TAILQ_INSERT_HEAD(&cur_p->FREE_LIST_HEAD, + sh_thing, links, STRUCT_NAME); + MUTEX_UNLOCK(lt->env, cur_p->mtx_part); + if (region->part_t_size != 1 && ++cur_p == end_p) + cur_p = lt->part_array; + sh_thing++; + } + if (region->part_t_size != 1) + MUTEX_LOCK(lt->env, orig_p->mtx_part); + locked = 1; + } else + LOCK_REGION_UNLOCK(lt->env); + + if (SH_TAILQ_FIRST(&orig_p->FREE_LIST_HEAD, STRUCT_NAME) != NULL) + return (0); + /* Somone stole all the locks! */ + if (nobjs > 0) + goto retry; + +err: if (region->part_t_size != 1 && locked == 0) + MUTEX_LOCK(lt->env, orig_p->mtx_part); + return (__lock_nomem(lt->env, "lock entries")); +} |