Posted By:
baris_aksu
Posted On:
Wednesday, June 30, 2004 01:47 AM
Hi all, I want to know whether there is any difference between the following scenarios in a multi-threaded environment : Say we have a function aMethod() that can be executed by more than one thread at a time in a class whose pseudo-code is something like : code: ------------------------ public class Test { public static void main(String[] args) { aMethod(); } static void aMethod() { Connection con = get_A_Connection(); con.setAutoCommit(false); try { insert_into(table_A); delete_form(table_b); con.commit(); } catch(Exception ex) { con.rollback(); } } }
More>>
Hi all,
I want to know whether there is any difference between the following scenarios in a multi-threaded environment :
Say we have a function aMethod() that can be executed by more than one thread at a time in a class whose pseudo-code is something like :
code:
------------------------
public class Test {
public static void main(String[] args) {
aMethod();
}
static void aMethod() {
Connection con = get_A_Connection();
con.setAutoCommit(false);
try {
insert_into(table_A);
delete_form(table_b);
con.commit();
}
catch(Exception ex) {
con.rollback();
}
}
}
Now, AFAIK insert and delete operations in aMethod() requires obtaining exclusive locks on the respective tables, so no one thread can ever insert into table A before its lock is released by the owning thread with a commit or rollback; effectively there is always only one thread executing inside aMethod() ant the other threads are waiting for the locks to be released. Am i right?
Is this situation the same with the following scenario, where access to aMethod() is synchronized? Here, still no two threads can be in aMethod() simultaneously, right?
code:
-----------------------
public class Test {
static Object syncObj = new Object();
public static void main(String[] args) {
synchronized(syncObj) {
aMethod();
}
}
static void aMethod() {
Connection con = get_A_Connection();
con.setAutoCommit(true);
try {
insert_into(table_A);
delete_form(table_b);
}
catch(Exception ex) {}
}
}
-------------------------------
Thanks in advance...
<<Less
