package org.jkiss.dbeaver.ext.test.tools;
import java.sql.*;
import java.util.Properties;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
public class LockGenerator {
public static final int MAX_SESSIONS=79;
public static final int MIN_CHAIN_SIZE = 2;
public static final int MAX_CHAIN_SIZE = 4;
public static final int MAX_LEVEL_ITEMS = 2;
private static int getPid(Connection conn) throws SQLException {
PreparedStatement stmt = null;
ResultSet res = null;
try {
stmt = conn.prepareStatement("SELECT pg_backend_pid()");
res = stmt.executeQuery();
res.next();
return res.getInt(1);
} finally {
if (res != null) res.close();
if (stmt != null) stmt.close();
}
}
public static void main(String[] args) {
final String url = "jdbc:postgresql://localhost/postgres";
final Properties props = new Properties();
props.setProperty("user","");
props.setProperty("password","");
Connection conn = null;
PreparedStatement stmt = null;
ResultSet res = null;
try {
conn = DriverManager.getConnection(url, props);
conn.setAutoCommit(false);
stmt = conn.prepareStatement("SELECT EXISTS (SELECT 1 FROM information_schema.tables WHERE table_schema = current_schema AND table_name = 'usr')");
res = stmt.executeQuery();
res.next();
if (!res.getBoolean(1)){
System.out.println("Table not found");
stmt = conn.prepareStatement("create table usr(field INTEGER,v INTEGER, s VARCHAR)");
stmt.execute();
stmt = conn.prepareStatement("insert into usr(field,s) SELECT b,(SELECT string_agg(x, '')FROM (SELECT chr(ascii('A') + (random() * 25)::integer) FROM generate_series(1, 1024 + b * 0)) AS y(x)) s FROM generate_series(1,10000) as a(b)");
stmt.execute();
stmt = conn.prepareStatement("alter table usr add primary key (field)");
stmt.execute();
conn.commit();
System.out.println("Table created");
}
ExecutorService service = Executors.newFixedThreadPool(MAX_SESSIONS);
int sessionCount=0;
int field = 1;
while(sessionCount < MAX_SESSIONS) {
final int fieldVal = field;
service.submit(new Runnable() {
@Override
public void run() {
Connection c = null;
PreparedStatement s = null;
ResultSet r = null;
try {
c = DriverManager.getConnection(url, props);
c.setAutoCommit(false);
String pid = String.valueOf(getPid(c));
System.out.println("["+pid+"] Submited root session for "+String.valueOf(fieldVal));
s = c.prepareStatement("/*ROOT "+String.valueOf(fieldVal)+" */ update usr set v = 100500 where field = ?");
s.setInt(1, fieldVal);
s.executeUpdate();
while(true){
try {
Thread.sleep(600 * 1000);
} catch (InterruptedException e) {
e.printStackTrace();
break;
}
}
c.close();
} catch (SQLException e) {
e.printStackTrace();
return;
}
}
});
sessionCount++;
if ((MAX_SESSIONS - sessionCount) > MIN_CHAIN_SIZE) {
int chainCount = ThreadLocalRandom.current().nextInt(MIN_CHAIN_SIZE ,MAX_CHAIN_SIZE + 1);
if ((MAX_SESSIONS - sessionCount) >= chainCount) {
for(int i =0; i < chainCount;i++){
final int level = i;
int levelCount = ThreadLocalRandom.current().nextInt(1 ,MAX_LEVEL_ITEMS + 1);
for(int j = 0; j < levelCount;j++) {
final int levelNo = j;
service.submit(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(5000);
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
Connection c = null;
PreparedStatement s = null;
ResultSet r = null;
try {
c = DriverManager.getConnection(url, props);
c.setAutoCommit(false);
int pid = getPid(c);
String prefix;
if (levelNo > 0) {
int sublock = MAX_SESSIONS + (level * MAX_CHAIN_SIZE);
prefix = String.format("[%d] Sublock %d for %d -> %d (%d) ",pid,sublock,fieldVal,level,levelNo);
s = c.prepareStatement("/*"+prefix + "*/ update usr set v = 100500 where field = ?");
System.out.println("Sublock for "+prefix);
s.setInt(1, sublock);
s.executeUpdate();
}
prefix = String.format("[%d] %d->%d (%d) ",pid, fieldVal,level,levelNo);
s = c.prepareStatement("/*"+prefix + "*/ update usr set v = 100500 where field = ?");
s.setInt(1, fieldVal);
System.out.println("Wait session for "+prefix);
s.executeUpdate();
c.close();
} catch (SQLException e) {
e.printStackTrace();
return;
}
}
});
sessionCount++;
if (sessionCount >= MAX_SESSIONS) {
break;
}
}
if (sessionCount >= MAX_SESSIONS) {
break;
}
}
}
}
field++;
}
System.out.println("Sbmited "+sessionCount);
service.shutdown();
service.awaitTermination(1, TimeUnit.HOURS);
} catch (Exception e) {
e.printStackTrace();
}
}
}