diff options
Diffstat (limited to 'include/spinlock/hclh.h')
| -rw-r--r-- | include/spinlock/hclh.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/include/spinlock/hclh.h b/include/spinlock/hclh.h index 296448b..ece56c6 100644 --- a/include/spinlock/hclh.h +++ b/include/spinlock/hclh.h @@ -81,6 +81,8 @@ ck_spinlock_hclh_lock(struct ck_spinlock_hclh **glob_queue, thread->wait = true; thread->splice = false; thread->cluster_id = (*local_queue)->cluster_id; + /* Make sure previous->previous doesn't appear to be NULL */ + thread->previous = *local_queue; /* Serialize with respect to update of local queue. */ ck_pr_fence_store_atomic(); @@ -91,13 +93,15 @@ ck_spinlock_hclh_lock(struct ck_spinlock_hclh **glob_queue, /* Wait until previous thread from the local queue is done with lock. */ ck_pr_fence_load(); - if (previous->previous != NULL && - previous->cluster_id == thread->cluster_id) { - while (ck_pr_load_uint(&previous->wait) == true) + if (previous->previous != NULL) { + while (ck_pr_load_uint(&previous->wait) == true && + ck_pr_load_int(&previous->cluster_id) == thread->cluster_id && + ck_pr_load_uint(&previous->splice) == false) ck_pr_stall(); /* We're head of the global queue, we're done */ - if (ck_pr_load_uint(&previous->splice) == false) + if (ck_pr_load_int(&previous->cluster_id) == thread->cluster_id && + ck_pr_load_uint(&previous->splice) == false) return; } |