Parameter values set by the application

SOC-FUNCTION

A 16-byte character field containing SELECT. The field is left-justified and padded on the right with blanks.

MAXSOC

A fullword binary field that specifies the largest socket descriptor value that is being checked. The SELECTEX call tests only bits that are in the range 0 through the MAXSOC value minus 1. For example, if you set the MAXSOC value to 50, the range is 0 – 49.

TIMEOUT

If TIMEOUT is a positive value, it specifies a maximum interval to wait for the selection to complete. If TIMEOUT-SECONDS is a negative value, the SELECTEX call blocks until a socket becomes ready or an ECB or ECB in a list is posted. To poll the sockets and return immediately, set TIMEOUT to be zeros.

TIMEOUT is specified in the two-word TIMEOUT as follows:

TIMEOUT-SECONDS, word one of the TIMEOUT field, is the seconds component of the timeout value.
TIMEOUT-MICROSEC, word two of the TIMEOUT field, is the microseconds component of the timeout value (0—999999).

For example, if you want SELECTEX to time out after 3.5 seconds, set TIMEOUT-SECONDS to 3 and TIMEOUT-MICROSEC to 500000.

RSNDMSK

The bit-mask array to control checking for read interrupts. If this parameter is not specified or the specified bit-mask is zeros, the SELECT will not check for read interrupts. The length of this bit-mask array is dependent on the value in MAXSOC.

WSNDMSK

The bit-mask array to control checking for write interrupts. If this parameter is not specified or the specified bit-mask is zeros, the SELECT will not check for write interrupts. The length of this bit-mask array is dependent on the value in MAXSOC.

ESNDMSK

The bit-mask array to control checking for exception interrupts. If this parameter is not specified or the specified bit-mask is zeros, the SELECT will not check for exception interrupts. The length of this bit-mask array is dependent on the value in MAXSOC.

SELECB

An ECB which, if posted, causes completion of the SELECTEX.

ECBLIST-PTR

A pointer to an ECB list. The application must set the high order bit in the ECB list address and pass that address using the BY VALUE option. The remaining parameters must be set back to the default by specifying BY REFERENCE before ERRNO.