READV

The READV function reads data on a socket and stores it in a set of buffers. If a datagram packet is too long to fit in the supplied buffers, datagram sockets discard extra bytes.

The following requirements apply to this call:

Authorization:

Supervisor state or problem state, any PSW key.

Dispatchable unit mode:

Task.

Cross memory mode:

PASN = HASN.

Amode:

31-bit or 24-bit.

Note: See "Addressability mode (Amode) considerations" under CALL instruction API environmental restrictions and programming requirements.

ASC mode:

Primary address space control (ASC) mode.

Interrupt status:

Enabled for interrupts.

Locks:

Unlocked.

Control parameters:

All parameters must be addressable by the caller and in the primary address space.

Figure 1 shows an example of READV call instructions.

Figure 1. READV call instruction example

       WORKING-STORAGE SECTION.
       01  SOC-FUNCTION         PIC X(16) VALUE 'READV'.
       01  S                      PIC 9(4)  BINARY.
       01  IOVCNT                 PIC 9(8)  BINARY.
 
       01  IOV.
           03 BUFFER-ENTRY OCCURS N TIMES.
             05 BUFFER-POINTER    USAGE IS POINTER.
             05 RESERVED          PIC X(4).
             05 BUFFER_LENGTH     PIC 9(8) BINARY.
 
       01  ERRNO                  PIC 9(8) BINARY.
       01  RETCODE                PIC 9(8) BINARY.


       PROCEDURE DIVISION.
       SET BUFFER-POINTER(1) TO ADDRESS OF BUFFER1.
       SET BUFFER-LENGTH(1) TO LENGTH OF BUFFER1.
       SET BUFFER-POINTER(2) TO ADDRESS OF BUFFER2.
       SET BUFFER-LENGTH(2) TO LENGTH OF BUFFER2.
       "   "                "  "         "
       "   "                "  "         "
       SET BUFFER-POINTER(n) TO ADDRESS OF BUFFERn.
       SET BUFFER-LENGTH(n) TO LENGTH OF BUFFERn.
       Call 'EZASOCKET' USING SOC-FUNCTION S IOV IOVCNT ERRNO RETCODE.

For equivalent PL/I and assembler language declarations, see Converting parameter descriptions.