SQL> select * from v$version;


BANNER
----------------------------------------------------------------------------------------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
PL/SQL Release 11.2.0.4.0 - Production
CORE    11.2.0.4.0      Production
TNS for Linux: Version 11.2.0.4.0 - Production
NLSRTL Version 11.2.0.4.0 - Production



create or replace procedure proc 
is
begin
null;
end;
/


begin
   proc;
   execute immediate 'alter procedure proc compile';
end;
/




SQL> select sid from v$mystat where rownum=1;


       SID
----------
       134


SQL> create or replace procedure proc 
  2  is
  3  begin
  4     null;
  5  end;
  6  /


Procedure created.


SQL> begin
  2     proc;
  3     execute immediate 'alter procedure proc compile';
  4  end;
  5  /


-------------hang----------






SQL> select sid,event,blocking_session from v$session where sid=134;


       SID EVENT                          BLOCKING_SESSION
---------- ------------------------------ ----------------
       134 library cache pin                           134






SQL> SELECT s.sid, kglpnmod "HOLD Mode", kglpnreq "Req Mode"
  2  FROM v$session_wait w, x$kglpn p, v$session s ,v$process o
  3  WHERE p.kglpnuse=s.saddr
  4  AND kglpnhdl=w.p1raw
  5  and w.event like '%library cache pin%'
  6  and s.paddr=o.addr;


       SID  HOLD Mode   Req Mode
---------- ---------- ----------
       134          2          0
       134          0          3