Use the new mutex in the replay cache structure

Rather coarse at the moment: While one thread is blocking waiting for data to
be flushed to disk, another thread is unnecessarily prevented from scanning the
in-memory data.

* rc_base.c (krb5_rc_resolve_type): Initialize the mutex in the replay cache
structure.
(krb5_rc_default, krb5_rc_resolve_full): Destroy it if creation of the replay
cache fails.
* rc_dfl.c (krb5_rc_dfl_get_span, krb5_rc_dfl_init): Lock the mutex while
operating on the replay cache object.
(krb5_rc_dfl_expunge_locked): Renamed from krb5_rc_dfl_expunge and made static.
Call krb5_rc_dfl_recover_locked.
(krb5_rc_dfl_expunge): New wrapper function, locks the mutex.
(krb5_rc_dfl_recover_locked): Renamed from krb5_rc_dfl_recover and made static.
Call krb5_rc_dfl_expunge_locked.
(krb5_rc_dfl_recover): New wrapper function, locks the mutex.
(krb5_rc_dfl_store): Lock the mutex.  Call _expunge_locked.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@16295 dc483132-0cff-0310-8789-dd5450dbe970

3 files changed, 103 insertions, 17 deletions

diff --git a/src/lib/krb5/rcache/ChangeLog b/src/lib/krb5/rcache/ChangeLog
index 870054477..86629857e 100644
--- a/src/lib/krb5/rcache/ChangeLog
+++ b/src/lib/krb5/rcache/ChangeLog
@@ -1,3 +1,19 @@
+2004-04-30  Ken Raeburn  <raeburn@mit.edu>
+
+	* rc_base.c (krb5_rc_resolve_type): Initialize the mutex in the
+	replay cache structure.
+	(krb5_rc_default, krb5_rc_resolve_full): Destroy it if creation of
+	the replay cache fails.
+	* rc_dfl.c (krb5_rc_dfl_get_span, krb5_rc_dfl_init): Lock the
+	mutex while operating on the replay cache object.
+	(krb5_rc_dfl_expunge_locked): Renamed from krb5_rc_dfl_expunge and
+	made static.  Call krb5_rc_dfl_recover_locked.
+	(krb5_rc_dfl_expunge): New wrapper function, locks the mutex.
+	(krb5_rc_dfl_recover_locked): Renamed from krb5_rc_dfl_recover and
+	made static.  Call krb5_rc_dfl_expunge_locked.
+	(krb5_rc_dfl_recover): New wrapper function, locks the mutex.
+	(krb5_rc_dfl_store): Lock the mutex.  Call _expunge_locked.
+
 2004-04-24  Ken Raeburn  <raeburn@mit.edu>
 
 	* rc_base.c (rc_typelist_lock): Use new partial initializer.
diff --git a/src/lib/krb5/rcache/rc_base.c b/src/lib/krb5/rcache/rc_base.c
index f26b359a9..bde942a5d 100644
--- a/src/lib/krb5/rcache/rc_base.c
+++ b/src/lib/krb5/rcache/rc_base.c
@@ -81,7 +81,7 @@ krb5_error_code krb5_rc_resolve_type(krb5_context context, krb5_rcache *id,
     /* allocate *id? nah */
     (*id)->ops = t->ops;
     k5_mutex_unlock(&rc_typelist_lock);
-    return 0;
+    return k5_mutex_init(&(*id)->lock);
 }
 
 char * krb5_rc_get_type(krb5_context context, krb5_rcache id)
@@ -117,12 +117,16 @@ krb5_rc_default(krb5_context context, krb5_rcache *id)
 
     if ((retval = krb5_rc_resolve_type(context, id, 
 				       krb5_rc_default_type(context)))) {
+	k5_mutex_destroy(&(*id)->lock);
 	FREE(*id);
 	return retval;
     }
     if ((retval = krb5_rc_resolve(context, *id, 
-				  krb5_rc_default_name(context))))
+				  krb5_rc_default_name(context)))) {
+	k5_mutex_destroy(&(*id)->lock);
 	FREE(*id);
+	return retval;
+    }
     (*id)->magic = KV5M_RCACHE;
     return retval;
 }
@@ -151,12 +155,16 @@ krb5_error_code krb5_rc_resolve_full(krb5_context context, krb5_rcache *id, char
 
     if ((retval = krb5_rc_resolve_type(context, id,type))) {
 	FREE(type);
+	k5_mutex_destroy(&(*id)->lock);
 	FREE(*id);
 	return retval;
     }
     FREE(type);
-    if ((retval = krb5_rc_resolve(context, *id,residual + 1)))
+    if ((retval = krb5_rc_resolve(context, *id,residual + 1))) {
+	k5_mutex_destroy(&(*id)->lock);
 	FREE(*id);
+	return retval;
+    }
     (*id)->magic = KV5M_RCACHE;
     return retval;
 }
diff --git a/src/lib/krb5/rcache/rc_dfl.c b/src/lib/krb5/rcache/rc_dfl.c
index a1899b3c9..c4473664c 100644
--- a/src/lib/krb5/rcache/rc_dfl.c
+++ b/src/lib/krb5/rcache/rc_dfl.c
@@ -178,7 +178,15 @@ krb5_error_code KRB5_CALLCONV
 krb5_rc_dfl_get_span(krb5_context context, krb5_rcache id,
 		     krb5_deltat *lifespan)
 {
-    *lifespan = ((struct dfl_data *) (id->data))->lifespan;
+    krb5_error_code err;
+    struct dfl_data *t;
+
+    t = (struct dfl_data *) id->data;
+    err = k5_mutex_lock(&id->lock);
+    if (err)
+	return err;
+    *lifespan = t->lifespan;
+    k5_mutex_unlock(&id->lock);
     return 0;
 }
 
@@ -188,19 +196,28 @@ krb5_rc_dfl_init(krb5_context context, krb5_rcache id, krb5_deltat lifespan)
     struct dfl_data *t = (struct dfl_data *)id->data;
     krb5_error_code retval;
 
+    retval = k5_mutex_lock(&id->lock);
+    if (retval)
+	return retval;
     t->lifespan = lifespan ? lifespan : context->clockskew;
     /* default to clockskew from the context */
 #ifndef NOIOSTUFF
-    if ((retval = krb5_rc_io_creat(context, &t->d, &t->name)))
+    if ((retval = krb5_rc_io_creat(context, &t->d, &t->name))) {
+	k5_mutex_unlock(&id->lock);
 	return retval;
+    }
     if ((krb5_rc_io_write(context, &t->d,
 			  (krb5_pointer) &t->lifespan, sizeof(t->lifespan))
-	 || krb5_rc_io_sync(context, &t->d)))
+	 || krb5_rc_io_sync(context, &t->d))) {
+	k5_mutex_unlock(&id->lock);
 	return KRB5_RC_IO;
+    }
 #endif
+    k5_mutex_unlock(&id->lock);
     return 0;
 }
 
+/* Called with the mutex already locked.  */
 krb5_error_code
 krb5_rc_dfl_close_no_free(krb5_context context, krb5_rcache id)
 {
@@ -227,7 +244,13 @@ krb5_rc_dfl_close_no_free(krb5_context context, krb5_rcache id)
 krb5_error_code KRB5_CALLCONV
 krb5_rc_dfl_close(krb5_context context, krb5_rcache id)
 {
+    krb5_error_code retval;
+    retval = k5_mutex_lock(&id->lock);
+    if (retval)
+	return retval;
     krb5_rc_dfl_close_no_free(context, id);
+    k5_mutex_unlock(&id->lock);
+    k5_mutex_destroy(&id->lock);
     free(id);
     return 0;
 }
@@ -377,9 +400,8 @@ errout:
 }
 
 
-
-krb5_error_code KRB5_CALLCONV
-krb5_rc_dfl_recover(krb5_context context, krb5_rcache id)
+static krb5_error_code
+krb5_rc_dfl_recover_locked(krb5_context context, krb5_rcache id)
 {
 #ifdef NOIOSTUFF
     return KRB5_RC_NOIO;
@@ -392,8 +414,9 @@ krb5_rc_dfl_recover(krb5_context context, krb5_rcache id)
     int expired_entries = 0;
     krb5_int32 now;
 
-    if ((retval = krb5_rc_io_open(context, &t->d, t->name)))
+    if ((retval = krb5_rc_io_open(context, &t->d, t->name))) {
 	return retval;
+    }
 
     t->recovering = 1;
 
@@ -457,13 +480,25 @@ io_fail:
     if (retval)
 	krb5_rc_io_close(context, &t->d);
     else if (expired_entries > EXCESSREPS)
-	retval = krb5_rc_dfl_expunge(context, id);
+	retval = krb5_rc_dfl_expunge_locked(context, id);
     t->recovering = 0;
     return retval;
 
 #endif
 }
 
+krb5_error_code KRB5_CALLCONV
+krb5_rc_dfl_recover(krb5_context context, krb5_rcache id)
+{
+    krb5_error_code ret;
+    ret = k5_mutex_lock(&id->lock);
+    if (ret)
+	return ret;
+    ret = krb5_rc_dfl_recover_locked(context, id);
+    k5_mutex_unlock(&id->lock);
+    return ret;
+}
+
 static krb5_error_code
 krb5_rc_io_store(krb5_context context, struct dfl_data *t,
 		 krb5_donot_replay *rep)
@@ -492,6 +527,8 @@ krb5_rc_io_store(krb5_context context, struct dfl_data *t,
     return ret;
 }
 
+static krb5_error_code krb5_rc_dfl_expunge_locked(krb5_context, krb5_rcache);
+
 krb5_error_code KRB5_CALLCONV
 krb5_rc_dfl_store(krb5_context context, krb5_rcache id, krb5_donot_replay *rep)
 {
@@ -503,36 +540,49 @@ krb5_rc_dfl_store(krb5_context context, krb5_rcache id, krb5_donot_replay *rep)
     if (ret)
 	return ret;
 
+    ret = k5_mutex_lock(&id->lock);
+    if (ret)
+	return ret;
+
     switch(rc_store(context, id, rep, now)) {
     case CMP_MALLOC:
+	k5_mutex_unlock(&id->lock);
 	return KRB5_RC_MALLOC;
     case CMP_REPLAY:
+	k5_mutex_unlock(&id->lock);
 	return KRB5KRB_AP_ERR_REPEAT;
     case 0: break;
     default: /* wtf? */ ;
     }
 #ifndef NOIOSTUFF
     ret = krb5_rc_io_store(context, t, rep);
-    if (ret)
+    if (ret) {
+	k5_mutex_unlock(&id->lock);
 	return ret;
+    }
 #endif
     /* Shall we automatically expunge? */
     if (t->nummisses > t->numhits + EXCESSREPS)
     {
-	return krb5_rc_dfl_expunge(context, id);
+	ret = krb5_rc_dfl_expunge_locked(context, id);
+	k5_mutex_unlock(&id->lock);
+	return ret;
     }
 #ifndef NOIOSTUFF
     else
     {
-	if (krb5_rc_io_sync(context, &t->d))
+	if (krb5_rc_io_sync(context, &t->d)) {
+	    k5_mutex_unlock(&id->lock);
 	    return KRB5_RC_IO;
+	}
     }
 #endif
+    k5_mutex_unlock(&id->lock);
     return 0;
 }
 
-krb5_error_code KRB5_CALLCONV
-krb5_rc_dfl_expunge(krb5_context context, krb5_rcache id)
+static krb5_error_code
+krb5_rc_dfl_expunge_locked(krb5_context context, krb5_rcache id)
 {
     struct dfl_data *t = (struct dfl_data *)id->data;
 #ifdef NOIOSTUFF
@@ -579,7 +629,7 @@ krb5_rc_dfl_expunge(krb5_context context, krb5_rcache id)
 	free(name);
 	if (retval)
 	    return retval;
-	retval = krb5_rc_dfl_recover(context, id);
+	retval = krb5_rc_dfl_recover_locked(context, id);
 	if (retval)
 	    return retval;
 	t = (struct dfl_data *)id->data; /* point to recovered cache */
@@ -619,3 +669,15 @@ krb5_rc_dfl_expunge(krb5_context context, krb5_rcache id)
     return retval;
 #endif
 }
+
+krb5_error_code KRB5_CALLCONV
+krb5_rc_dfl_expunge(krb5_context context, krb5_rcache id)
+{
+    krb5_error_code ret;
+    ret = k5_mutex_lock(&id->lock);
+    if (ret)
+	return ret;
+    ret = krb5_rc_dfl_expunge_locked(context, id);
+    k5_mutex_unlock(&id->lock);
+    return ret;
+}