VM66394: REXX SOCKETS HANGS WHEN CONNECTIVITY TO TCP/IP STACK IS LOST

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• User REXX Sockets application ABENDs or hangs when the TCP/IP
  stack stops running.
                                                                 .
  The user application captures 'alert' messages using the WAKEUP
  utility. These messages are then sent to a consolidated monitor
  facility using RXSockets.  If the TCP/IP stack stops, the user
  application fails with either hangs or ABENDs. The skeleton code
  for the application follows:
                                                                 .
     Loop forever
       wait for a message
       receive the message and format it
  
       socket(initialize)
       socket(socket)
       socket(setsockopt)
  
       socket(connect)
       socket(send)
  socket(close)
  
  socket(terminate)
     Loop end
                                                                 .
  When the TCP/IP stack stops, the socket(initialize) call never
  returns.  When the TCP/IP stack is restarted, there no recovery
  occurs and the application must be restarted.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: Any user of REXX Sockets (RXSOCKET) is       *
  *                 affected by this change.                     *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  If the TCPIP stack shuts down while a Rexx sockets program is
  running, the program might hang, depending on exactly when the
  sever interrupt from the stack arrives.
  

Problem conclusion

• Changes are made to post an ECB and set ETCPIPSEVEREDPATH when
  an unsolicited sever from the TCP/IP stack is received. Changes
  are made to have a proper control block setup to handle posting
  ECB.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  306PC1Ÿ UM35685 UM35686

Modules/Macros

• DMSRXU   DMSRXV
  

Fix information

• Fixed component name

  VM CMS

• Fixed component ID

  568411201

Applicable component levels

• R640 PSY UM35685

     UP20/07/02 P 2001

• R710 PSY UM35686

     UP21/06/29 P 2101

Fix is available

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