IOWAIT

For SNA IMF/V only. IOWAIT waits for the completion of a previous no-wait I/O request.

Syntax

                     IV      LA      I         L

IOWAIT           (filenum, target, tcount, cstation)

Parameters

filenum (input)

Integer identifier specifying the file number or SNA IMF terminalid for which an I/O request is pending. If you specify zero, IOWAIT checks to see if any no-wait I/O request in your program has completed. filenum is a required parameter.

target (input)

Logical array. The target parameter has no meaning for SNA IMF. If you omit this parameter, be sure to retain the comma.

tcount (output)

Integer. The tcount parameter has no meaning for SNA IMF. If you omit this parameter, be sure to retain the comma.

cstation (output)

Integer that can contain selected SNA IMF result codes. The codes returned in cstation could, with wait I/O, be returned through the result parameter of either the RECV3270 or the TRAN3270 intrinsic. Several other result codes may be returned through IOWAIT, instead of either RECV3270 or TRAN3270, if the condition causing them arises during I/O.

The following codes can be returned through the cstation parameter of the IOWAIT intrinsic:

0 = Successful completion.

23 = Keyboard enable timeout has occurred.

24 = Response timeout has occurred.

91 = LU.T1 bind received.

92 = Unbind received.

93 = LU.T3 bind received.

94 = HOLDPRINT timer has expired (10 minutes).

95 = Host application requests PA key entry.

301 = Illegal DB register.

303 = Invalid SNA catalog file.

305 = Parameter bounds violation.

307 = Session is active.

308 = Session is inactive.

315 = Internal Error.

319 = LU-SSCP message pending.

320 = RU buffer too small.

336 = Link shutdown occurred.

337 = Protocol shutdown requested.

338 = Quiesce shutdown requested.

340 = No stack space.

348 = Invalid data offset.

351 = Link Failure occurred.

352 = Transport Internal Error Shutdown.

353 = Hierarchical Shutdown.

Description

Use IOWAIT with no-wait MPE V I/O. IOWAIT suspends processing until an outstanding I/O request completes. IOWAIT is also an MPE V and MPE XL intrinsic. See the MPE V Intrinsics Reference Manual or the MPE XL Intrinsics Reference Manual for more information.

If you open an SNA IMF/V device, specifying no-wait I/O in your call to the OPEN3270 intrinsic, you must follow every RECV3270 and TRAN3270 request with a call to either IODONTWAIT or IOWAIT, before you can call any other intrinsic. You can delay the call to IODONTWAIT or IOWAIT as long as necessary to allow effective I/O and processing overlap.

The IOWAIT intrinsic acts the same as the IODONTWAIT intrinsic with one exception: if your program calls IOWAIT, and no I/O has completed, your program is suspended until some I/O completes; if your program calls IODONTWAIT, and no I/O has completed, control is returned to your program.

You can call IOWAIT from programs written in SPL, COBOL II, Pascal, or FORTRAN.

SPL Procedure Declaration

INTEGER PROCEDURE IOWAIT (FILENUM, TARGET, TCOUNT, CSTATION);

INTEGER FILENUM,TCOUNT;

LOGICAL CSTATION;

LOGICAL ARRAY TARGET;

OPTION VARIABLE;

IOWAIT has a functional return, as shown below in the calling sequence. The IOWAIT intrinsic returns an integer that represents the terminalid for which the I/O completion occurred. If no completion occurred, zero is returned in FNUM.

SPL Calling Sequence

FNUM:=IOWAIT (FILENUM, TARGET, TCOUNT, CSTATION);

Condition Codes

CCE: Request granted. If the functional return is non-zero, then I/O completion occurred with no errors. If the return is zero, then no I/O has completed.
CCG: An end of file was encountered.
CCL: Request denied. Normal I/O completion did not occur because there were no I/O requests pending, a parameter error occurred, or an abnormal I/O completion occurred.

IOWAIT

Technical documentation

» Table of Contents