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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997-2002
* Sleepycat Software. All rights reserved.
*
* $Id: TestLockVec.java,v 1.4 2002/08/16 19:35:55 dda Exp $
*/
/*
* test of DbEnv.lock_vec()
*/
package com.sleepycat.test;
import com.sleepycat.db.*;
import java.io.FileNotFoundException;
public class TestLockVec
{
public static int locker1;
public static int locker2;
public static void gdb_pause()
{
try {
System.err.println("attach gdb and type return...");
System.in.read(new byte[10]);
}
catch (java.io.IOException ie) {
}
}
public static void main(String[] args)
{
try {
DbEnv dbenv1 = new DbEnv(0);
DbEnv dbenv2 = new DbEnv(0);
dbenv1.open(".",
Db.DB_CREATE | Db.DB_INIT_LOCK | Db.DB_INIT_MPOOL, 0);
dbenv2.open(".",
Db.DB_CREATE | Db.DB_INIT_LOCK | Db.DB_INIT_MPOOL, 0);
locker1 = dbenv1.lock_id();
locker2 = dbenv1.lock_id();
Db db1 = new Db(dbenv1, 0);
db1.open(null, "my.db", null, Db.DB_BTREE, Db.DB_CREATE, 0);
Db db2 = new Db(dbenv2, 0);
db2.open(null, "my.db", null, Db.DB_BTREE, 0, 0);
// populate our database, just two elements.
Dbt Akey = new Dbt("A".getBytes());
Dbt Adata = new Dbt("Adata".getBytes());
Dbt Bkey = new Dbt("B".getBytes());
Dbt Bdata = new Dbt("Bdata".getBytes());
// We don't allow Dbts to be reused within the
// same method call, so we need some duplicates.
Dbt Akeyagain = new Dbt("A".getBytes());
Dbt Bkeyagain = new Dbt("B".getBytes());
db1.put(null, Akey, Adata, 0);
db1.put(null, Bkey, Bdata, 0);
Dbt notInDatabase = new Dbt("C".getBytes());
/* make sure our check mechanisms work */
int expectedErrs = 0;
lock_check_free(dbenv2, Akey);
try {
lock_check_held(dbenv2, Bkey, Db.DB_LOCK_READ);
}
catch (DbException dbe1) {
expectedErrs += 1;
}
DbLock tmplock = dbenv1.lock_get(locker1, Db.DB_LOCK_NOWAIT,
Akey, Db.DB_LOCK_READ);
lock_check_held(dbenv2, Akey, Db.DB_LOCK_READ);
try {
lock_check_free(dbenv2, Akey);
}
catch (DbException dbe2) {
expectedErrs += 2;
}
if (expectedErrs != 1+2) {
System.err.println("lock check mechanism is broken");
System.exit(1);
}
dbenv1.lock_put(tmplock);
/* Now on with the test, a series of lock_vec requests,
* with checks between each call.
*/
System.out.println("get a few");
/* Request: get A(W), B(R), B(R) */
DbLockRequest[] reqs = new DbLockRequest[3];
reqs[0] = new DbLockRequest(Db.DB_LOCK_GET, Db.DB_LOCK_WRITE,
Akey, null);
reqs[1] = new DbLockRequest(Db.DB_LOCK_GET, Db.DB_LOCK_READ,
Bkey, null);
reqs[2] = new DbLockRequest(Db.DB_LOCK_GET, Db.DB_LOCK_READ,
Bkeyagain, null);
dbenv1.lock_vec(locker1, Db.DB_LOCK_NOWAIT, reqs, 0, 3);
/* Locks held: A(W), B(R), B(R) */
lock_check_held(dbenv2, Bkey, Db.DB_LOCK_READ);
lock_check_held(dbenv2, Akey, Db.DB_LOCK_WRITE);
System.out.println("put a couple");
/* Request: put A, B(first) */
reqs[0].set_op(Db.DB_LOCK_PUT);
reqs[1].set_op(Db.DB_LOCK_PUT);
dbenv1.lock_vec(locker1, Db.DB_LOCK_NOWAIT, reqs, 0, 2);
/* Locks held: B(R) */
lock_check_free(dbenv2, Akey);
lock_check_held(dbenv2, Bkey, Db.DB_LOCK_READ);
System.out.println("put one more, test index offset");
/* Request: put B(second) */
reqs[2].set_op(Db.DB_LOCK_PUT);
dbenv1.lock_vec(locker1, Db.DB_LOCK_NOWAIT, reqs, 2, 1);
/* Locks held: <none> */
lock_check_free(dbenv2, Akey);
lock_check_free(dbenv2, Bkey);
System.out.println("get a few");
/* Request: get A(R), A(R), B(R) */
reqs[0] = new DbLockRequest(Db.DB_LOCK_GET, Db.DB_LOCK_READ,
Akey, null);
reqs[1] = new DbLockRequest(Db.DB_LOCK_GET, Db.DB_LOCK_READ,
Akeyagain, null);
reqs[2] = new DbLockRequest(Db.DB_LOCK_GET, Db.DB_LOCK_READ,
Bkey, null);
dbenv1.lock_vec(locker1, Db.DB_LOCK_NOWAIT, reqs, 0, 3);
/* Locks held: A(R), B(R), B(R) */
lock_check_held(dbenv2, Akey, Db.DB_LOCK_READ);
lock_check_held(dbenv2, Bkey, Db.DB_LOCK_READ);
System.out.println("try putobj");
/* Request: get B(R), putobj A */
reqs[1] = new DbLockRequest(Db.DB_LOCK_GET, Db.DB_LOCK_READ,
Bkey, null);
reqs[2] = new DbLockRequest(Db.DB_LOCK_PUT_OBJ, 0,
Akey, null);
dbenv1.lock_vec(locker1, Db.DB_LOCK_NOWAIT, reqs, 1, 2);
/* Locks held: B(R), B(R) */
lock_check_free(dbenv2, Akey);
lock_check_held(dbenv2, Bkey, Db.DB_LOCK_READ);
System.out.println("get one more");
/* Request: get A(W) */
reqs[0] = new DbLockRequest(Db.DB_LOCK_GET, Db.DB_LOCK_WRITE,
Akey, null);
dbenv1.lock_vec(locker1, Db.DB_LOCK_NOWAIT, reqs, 0, 1);
/* Locks held: A(W), B(R), B(R) */
lock_check_held(dbenv2, Akey, Db.DB_LOCK_WRITE);
lock_check_held(dbenv2, Bkey, Db.DB_LOCK_READ);
System.out.println("putall");
/* Request: putall */
reqs[0] = new DbLockRequest(Db.DB_LOCK_PUT_ALL, 0,
null, null);
dbenv1.lock_vec(locker1, Db.DB_LOCK_NOWAIT, reqs, 0, 1);
lock_check_free(dbenv2, Akey);
lock_check_free(dbenv2, Bkey);
db1.close(0);
dbenv1.close(0);
db2.close(0);
dbenv2.close(0);
System.out.println("done");
}
catch (DbLockNotGrantedException nge) {
System.err.println("Db Exception: " + nge);
}
catch (DbException dbe) {
System.err.println("Db Exception: " + dbe);
}
catch (FileNotFoundException fnfe) {
System.err.println("FileNotFoundException: " + fnfe);
}
}
/* Verify that the lock is free, throw an exception if not.
* We do this by trying to grab a write lock (no wait).
*/
static void lock_check_free(DbEnv dbenv, Dbt dbt)
throws DbException
{
DbLock tmplock = dbenv.lock_get(locker2, Db.DB_LOCK_NOWAIT,
dbt, Db.DB_LOCK_WRITE);
dbenv.lock_put(tmplock);
}
/* Verify that the lock is held with the mode, throw an exception if not.
* If we have a write lock, we should not be able to get the lock
* for reading. If we have a read lock, we should be able to get
* it for reading, but not writing.
*/
static void lock_check_held(DbEnv dbenv, Dbt dbt, int mode)
throws DbException
{
DbLock never = null;
try {
if (mode == Db.DB_LOCK_WRITE) {
never = dbenv.lock_get(locker2, Db.DB_LOCK_NOWAIT,
dbt, Db.DB_LOCK_READ);
}
else if (mode == Db.DB_LOCK_READ) {
DbLock rlock = dbenv.lock_get(locker2, Db.DB_LOCK_NOWAIT,
dbt, Db.DB_LOCK_READ);
dbenv.lock_put(rlock);
never = dbenv.lock_get(locker2, Db.DB_LOCK_NOWAIT,
dbt, Db.DB_LOCK_WRITE);
}
else {
throw new DbException("lock_check_held bad mode");
}
}
catch (DbLockNotGrantedException nge) {
/* We expect this on our last lock_get call */
}
/* make sure we failed */
if (never != null) {
try {
dbenv.lock_put(never);
}
catch (DbException dbe2) {
System.err.println("Got some real troubles now");
System.exit(1);
}
throw new DbException("lock_check_held: lock was not held");
}
}
}
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