oracle - Does Synchronized method synchronized if a Java method is invokded from PLSQL -

oracle - Does Synchronized method synchronized if a Java method is invokded from PLSQL -

i wondered if method not invoked in java thread thread or language, plsql.

as far concerned, plsql not have thread ,but has session, if hope method beingness called plsql procedure can synchronized.

my question

1.does synchronized keyword still work fine

2 calling create java thread

3.does synchronized keyword or other java concurrency object like(semaphore,conditionobject) only working in java thread?

the calling pl sql , , the execute method static method.

language java name 'xxx.xxx.xxx.engine.execute( java.lang.integer, java.lang.string, java.sql.timestamp, java.sql.timestamp, java.lang.long, java.lang.long, java.lang.long, java.lang.long, java.lang.long, java.lang.long, java.lang.long, java.lang.long, java.lang.string, java.lang.long )';

java oracle plsql synchronization synchronized