Module: xenomai-3
Branch: next
Commit: 383e8ed5659076771c393a0f1aabb6da8c6b959b
URL:
http://git.xenomai.org/?p=xenomai-3.git;a=commit;h=383e8ed5659076771c393a0f1aabb6da8c6b959b
Author: Philippe Gerum <r...@xenomai.org>
Date: Sun Mar 15 13:02:55 2015 +0100
copperplate: fix synchronization with shared clusters
The inter-process synchronization can only work if the syncobj is
shared between processes. Add a dictionary object type with an
embedded syncobj for implementing shared clusters.
---
include/copperplate/cluster.h | 9 ++++-
lib/copperplate/cluster.c | 87 ++++++++++++++++++++++++++---------------
2 files changed, 63 insertions(+), 33 deletions(-)
diff --git a/include/copperplate/cluster.h b/include/copperplate/cluster.h
index 0f75690..9c76cbc 100644
--- a/include/copperplate/cluster.h
+++ b/include/copperplate/cluster.h
@@ -39,9 +39,14 @@ struct cluster {
struct dictionary *d;
};
+struct syndictionary {
+ struct hash_table table;
+ struct syncobj sobj;
+ struct hashobj hobj;
+};
+
struct syncluster {
- struct cluster c;
- struct syncobj *sobj;
+ struct syndictionary *d;
};
struct pvclusterobj {
diff --git a/lib/copperplate/cluster.c b/lib/copperplate/cluster.c
index 0dda986..7353aa8 100644
--- a/lib/copperplate/cluster.c
+++ b/lib/copperplate/cluster.c
@@ -139,20 +139,18 @@ redo:
}
d = xnmalloc(sizeof(*d));
- if (d == NULL) {
- ret = -ENOMEM;
- goto out;
- }
+ if (d == NULL)
+ return __bt(-ENOMEM);
hash_init(&d->table);
ret = hash_enter(&main_catalog, name, strlen(name), &d->hobj,
&hash_operations);
+ /*
+ * If someone managed to slip in, creating the cluster between
+ * the table look up and indexing the new cluster, retry the
+ * whole process.
+ */
if (ret == -EEXIST) {
- /*
- * Someone seems to have slipped in, creating the
- * cluster right after we failed retrieving it: retry
- * the whole process.
- */
hash_destroy(&d->table);
xnfree(d);
goto redo;
@@ -249,17 +247,40 @@ int cluster_walk(struct cluster *c,
int syncluster_init(struct syncluster *sc, const char *name)
{
+ struct syndictionary *d;
+ struct hashobj *hobj;
int ret;
- ret = __bt(cluster_init(&sc->c, name));
- if (ret)
- return ret;
+redo:
+ hobj = hash_search(&main_catalog, name, strlen(name),
+ &hash_operations);
+ if (hobj) {
+ d = container_of(hobj, struct syndictionary, hobj);
+ ret = 0;
+ goto out;
+ }
- sc->sobj = xnmalloc(sizeof(*sc->sobj));
- if (sc->sobj == NULL)
+ d = xnmalloc(sizeof(*d));
+ if (d == NULL)
return -ENOMEM;
- return syncobj_init(sc->sobj, CLOCK_COPPERPLATE,
+ hash_init(&d->table);
+
+ ret = hash_enter(&main_catalog, name, strlen(name), &d->hobj,
+ &hash_operations);
+ /*
+ * Same as cluster_init(), redo if someone slipped in,
+ * creating the cluster.
+ */
+ if (ret == -EEXIST) {
+ hash_destroy(&d->table);
+ xnfree(d);
+ goto redo;
+ }
+out:
+ sc->d = d;
+
+ return syncobj_init(&d->sobj, CLOCK_COPPERPLATE,
SYNCOBJ_FIFO, fnref_null);
}
@@ -271,26 +292,29 @@ int syncluster_addobj(struct syncluster *sc, const char
*name,
struct syncstate syns;
int ret;
- if (syncobj_lock(sc->sobj, &syns))
+ if (syncobj_lock(&sc->d->sobj, &syns))
return __bt(-EINVAL);
- ret = cluster_addobj(&sc->c, name, cobj);
+ cobj->cnode = __node_id;
+
+ ret = hash_enter_probe(&sc->d->table, name, strlen(name),
+ &cobj->hobj, &hash_operations);
if (ret)
goto out;
- if (!syncobj_grant_wait_p(sc->sobj))
+ if (!syncobj_grant_wait_p(&sc->d->sobj))
goto out;
/*
* Wake up all threads waiting for this key to appear in the
* dictionary.
*/
- syncobj_for_each_grant_waiter_safe(sc->sobj, thobj, tmp) {
+ syncobj_for_each_grant_waiter_safe(&sc->d->sobj, thobj, tmp) {
wait = threadobj_get_wait(thobj);
if (*wait->name == *name && strcmp(wait->name, name) == 0)
- syncobj_grant_to(sc->sobj, thobj);
+ syncobj_grant_to(&sc->d->sobj, thobj);
}
out:
- syncobj_unlock(sc->sobj, &syns);
+ syncobj_unlock(&sc->d->sobj, &syns);
return ret;
}
@@ -301,12 +325,12 @@ int syncluster_delobj(struct syncluster *sc,
struct syncstate syns;
int ret;
- if (syncobj_lock(sc->sobj, &syns))
+ if (syncobj_lock(&sc->d->sobj, &syns))
return __bt(-EINVAL);
- ret = __bt(cluster_delobj(&sc->c, cobj));
+ ret = __bt(hash_remove(&sc->d->table, &cobj->hobj, &hash_operations));
- syncobj_unlock(sc->sobj, &syns);
+ syncobj_unlock(&sc->d->sobj, &syns);
return ret;
}
@@ -317,17 +341,18 @@ int syncluster_findobj(struct syncluster *sc,
struct clusterobj **cobjp)
{
struct syncluster_wait_struct *wait = NULL;
- struct clusterobj *cobj;
struct syncstate syns;
+ struct hashobj *hobj;
int ret = 0;
- if (syncobj_lock(sc->sobj, &syns))
+ if (syncobj_lock(&sc->d->sobj, &syns))
return -EINVAL;
for (;;) {
- cobj = cluster_findobj(&sc->c, name);
- if (cobj) {
- *cobjp = cobj;
+ hobj = hash_search_probe(&sc->d->table, name, strlen(name),
+ &hash_operations);
+ if (hobj) {
+ *cobjp = container_of(hobj, struct clusterobj, hobj);
break;
}
if (timeout &&
@@ -343,7 +368,7 @@ int syncluster_findobj(struct syncluster *sc,
wait = threadobj_prepare_wait(struct
syncluster_wait_struct);
wait->name = name;
}
- ret = syncobj_wait_grant(sc->sobj, timeout, &syns);
+ ret = syncobj_wait_grant(&sc->d->sobj, timeout, &syns);
if (ret) {
if (ret == -EIDRM)
goto out;
@@ -351,7 +376,7 @@ int syncluster_findobj(struct syncluster *sc,
}
}
- syncobj_unlock(sc->sobj, &syns);
+ syncobj_unlock(&sc->d->sobj, &syns);
out:
if (wait)
threadobj_finish_wait();
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