1 files changed, 83 insertions, 0 deletions
diff --git a/storage/bdb/mp/mp_trickle.c b/storage/bdb/mp/mp_trickle.c
new file mode 100644
index 00000000000..71077ab60cc
--- /dev/null
+++ b/storage/bdb/mp/mp_trickle.c
@@ -0,0 +1,83 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996-2002
+ *	Sleepycat Software.  All rights reserved.
+ */
+#include "db_config.h"
+
+#ifndef lint
+static const char revid[] = "$Id: mp_trickle.c,v 11.24 2002/08/06 06:13:53 bostic Exp $";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+
+#include <stdlib.h>
+#endif
+
+#include "db_int.h"
+#include "dbinc/db_shash.h"
+#include "dbinc/mp.h"
+
+/*
+ * __memp_trickle --
+ *	Keep a specified percentage of the buffers clean.
+ *
+ * PUBLIC: int __memp_trickle __P((DB_ENV *, int, int *));
+ */
+int
+__memp_trickle(dbenv, pct, nwrotep)
+	DB_ENV *dbenv;
+	int pct, *nwrotep;
+{
+	DB_MPOOL *dbmp;
+	MPOOL *c_mp, *mp;
+	u_int32_t clean, dirty, i, total, dtmp;
+	int ret, wrote;
+
+	PANIC_CHECK(dbenv);
+	ENV_REQUIRES_CONFIG(dbenv,
+	    dbenv->mp_handle, "memp_trickle", DB_INIT_MPOOL);
+
+	dbmp = dbenv->mp_handle;
+	mp = dbmp->reginfo[0].primary;
+
+	if (nwrotep != NULL)
+		*nwrotep = 0;
+
+	if (pct < 1 || pct > 100)
+		return (EINVAL);
+
+	/*
+	 * If there are sufficient clean buffers, no buffers or no dirty
+	 * buffers, we're done.
+	 *
+	 * XXX
+	 * Using hash_page_dirty is our only choice at the moment, but it's not
+	 * as correct as we might like in the presence of pools having more
+	 * than one page size, as a free 512B buffer isn't the same as a free
+	 * 8KB buffer.
+	 *
+	 * Loop through the caches counting total/dirty buffers.
+	 */
+	for (ret = 0, i = dirty = total = 0; i < mp->nreg; ++i) {
+		c_mp = dbmp->reginfo[i].primary;
+		total += c_mp->stat.st_pages;
+		__memp_stat_hash(&dbmp->reginfo[i], c_mp, &dtmp);
+		dirty += dtmp;
+	}
+
+	clean = total - dirty;
+	if (clean == total || (clean * 100) / total >= (u_long)pct)
+		return (0);
+
+	if (nwrotep == NULL)
+		nwrotep = &wrote;
+	ret = __memp_sync_int(dbenv, NULL,
+	    ((total * pct) / 100) - clean, DB_SYNC_TRICKLE, nwrotep);
+
+	mp->stat.st_page_trickle += *nwrotep;
+
+	return (ret);
+}