READV call

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:

Requirement	Description
Authorization:	Supervisor state or problem state, any PSW key
Dispatchable unit mode:	Task
Cross memory mode:	PASN = HASN
Amode:	31-bit or 24-bit
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  SOKET-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 'EZASOKET' USING SOC-FUNCTION S IOV IOVCNT ERRNO RETCODE.