Import BSDDB 4.7.25 (as of svn r89086)

mutex/mut_failchk.c

@@ -0,0 +1,70 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 2005,2008 Oracle.  All rights reserved.
+ *
+ * $Id: mut_failchk.c 63573 2008-05-23 21:43:21Z trent.nelson $
+ */
+
+#include "db_config.h"
+
+#include "db_int.h"
+#include "dbinc/mutex_int.h"
+
+/*
+ * __mut_failchk --
+ *	Check for mutexes held by dead processes.
+ *
+ * PUBLIC: int __mut_failchk __P((ENV *));
+ */
+int
+__mut_failchk(env)
+	ENV *env;
+{
+	DB_ENV *dbenv;
+	DB_MUTEX *mutexp;
+	DB_MUTEXMGR *mtxmgr;
+	DB_MUTEXREGION *mtxregion;
+	db_mutex_t i;
+	int ret;
+	char buf[DB_THREADID_STRLEN];
+
+	dbenv = env->dbenv;
+	mtxmgr = env->mutex_handle;
+	mtxregion = mtxmgr->reginfo.primary;
+	ret = 0;
+
+	MUTEX_SYSTEM_LOCK(env);
+	for (i = 1; i <= mtxregion->stat.st_mutex_cnt; ++i, ++mutexp) {
+		mutexp = MUTEXP_SET(i);
+
+		/*
+		 * We're looking for per-process mutexes where the process
+		 * has died.
+		 */
+		if (!F_ISSET(mutexp, DB_MUTEX_ALLOCATED) ||
+		    !F_ISSET(mutexp, DB_MUTEX_PROCESS_ONLY))
+			continue;
+
+		/*
+		 * The thread that allocated the mutex may have exited, but
+		 * we cannot reclaim the mutex if the process is still alive.
+		 */
+		if (dbenv->is_alive(
+		    dbenv, mutexp->pid, 0, DB_MUTEX_PROCESS_ONLY))
+			continue;
+
+		__db_msg(env, "Freeing mutex for process: %s",
+		    dbenv->thread_id_string(dbenv, mutexp->pid, 0, buf));
+
+		/* Unlock and free the mutex. */
+		if (F_ISSET(mutexp, DB_MUTEX_LOCKED))
+			MUTEX_UNLOCK(env, i);
+
+		if ((ret = __mutex_free_int(env, 0, &i)) != 0)
+			break;
+	}
+	MUTEX_SYSTEM_UNLOCK(env);
+
+	return (ret);
+}