\set ECHO all
/* Register alerts */
SELECT dbms_alert.register('a1');
 register 
----------
 
(1 row)

SELECT dbms_alert.register('a2');
 register 
----------
 
(1 row)

SELECT dbms_alert.register('tds');
 register 
----------
 
(1 row)

/* Test: multisession waitone */
SELECT dbms_alert.waitone('a1',20);
      waitone      
-------------------
 ("Msg1 for a1",0)
(1 row)

/* Test: multisession waitany */
SELECT dbms_alert.waitany(10);
       waitany        
----------------------
 (a2,"Msg1 for a2",0)
(1 row)

/* Test defered_signal */
/* This indicated that the transaction has begun */
SELECT dbms_alert.waitone('tds',10);
             waitone             
---------------------------------
 ("Begin defered_signal test",0)
(1 row)

/* The signal will not be received because the transaction is running */
SELECT dbms_alert.waitone('tds',2);
 waitone 
---------
 (,1)
(1 row)

SELECT dbms_alert.signal('b1','Transaction still running');
 signal 
--------
 
(1 row)

SELECT dbms_alert.signal('b1','Transaction committed');
 signal 
--------
 
(1 row)

/* Since the transaction has commited, the signal will be received */
SELECT dbms_alert.waitone('tds',10);
           waitone            
------------------------------
 ("Testing defered_signal",0)
(1 row)

/* Signal session A to send msg1 for a3 */
SELECT dbms_alert.signal('b2','to check unregistered alert wait');
 signal 
--------
 
(1 row)

/* Test: wait for unregistered alert which is signaled*/
SELECT dbms_alert.waitone('a3',2);
 waitone 
---------
 (,1)
(1 row)

/* Test: Register after alert is signaled and wait */
SELECT dbms_alert.register('a4');
 register 
----------
 
(1 row)

SELECT dbms_alert.waitone('a4',2);
 waitone 
---------
 (,1)
(1 row)

/* Test: remove one */
SELECT dbms_alert.remove('a1');
 remove 
--------
 
(1 row)

/* Signal session A to send msg2 for a1 */
SELECT dbms_alert.signal('b3','remove(a1) called');
 signal 
--------
 
(1 row)

/* Test: wait for removed alert */
SELECT dbms_alert.waitone('a1',2);
 waitone 
---------
 (,1)
(1 row)

/* Signal session A to send msg1 for a4 */
SELECT dbms_alert.signal('b4','to check unremoved alert');
 signal 
--------
 
(1 row)

/* Test: Check if unremoved alert is received */
SELECT dbms_alert.waitone('a4',10);
      waitone      
-------------------
 ("Msg1 for a4",0)
(1 row)

/* Test removeall */
SELECT dbms_alert.removeall();
 removeall 
-----------
 
(1 row)

/* Signal session A to send msg2 for a2 */
SELECT dbms_alert.signal('b5','removeall called');
 signal 
--------
 
(1 row)

/* Test: Use waitany to see if any alert is received */
SELECT dbms_alert.waitany(2);
 waitany 
---------
 (,,1)
(1 row)