Open System Services System Calls Reference Manual (G06.29+, H06.08+, J06.03+)

PUT_WRITEREADX(2) OSS System Calls Reference Manual
might be sharing the segment. The application must ensure that the buffer used in the call to the
PUT_WRITEREADX() function is not reused before the I/O completes with a call to
AWAITIOX.
For programming information about the WRITEREADX procedure, see the Enscribe
Programmer’s Guide and the Guardian Programmer’s Guide.
To use this function on systems running J06.10 or later RVUs or H06.21 or later RVUs, you must
perform all of the following tasks:
• Include the pthread.h header file in the application.
• Compile the application using the _PUT_MODEL_ feature test macro or equivalent
compiler command option.
• Link the application to the zputdll library.
On systems running H06.24 or later H-series RVUs or J06.13 or later J-series RVUs, you can use
this function with 32-bit or 64-bit applications.
To use this function in a 32-bit application on systems running H06.24 or later RVUs or J06.13 or
later RVUs, perform the same tasks (described above) used to enable the function on systems
running H06.21/J06.10 or later RVUs.
To use this function in a 64-bit application on systems running H06.24 or later RVUs or J06.13 or
later RVUs, you must perform all of the following tasks:
• Include the pthread.h header file in the application.
• Compile the application using the _PUT_MODEL_ feature test macro or equivalent
compiler command option.
• Compile the application using the -Wlp64 compiler command option.
• Link the application to the yputdll library (/G/system/zdllnnn/yputdll).
Considerations
Buffer use PUT_WRITEREADX( ) is intended for use with 32-bit extended addresses and
64-bit extended addresses. The data buffer for PUT_WRITEREADX( ) can be
either in the caller’s stack segment or any extended data segment.
Terminals A special hardware feature is incorporated in the asynchronous multiplexer con-
troller that ensures the system is ready to read from the terminal as soon as the
write is completed.
Interprocess communication
The PUT_WRITEREADX() function is used to originate a message to another
process that was previously opened, then waits for a reply from that process.
Waited I/O read operation
If a waited I/O PUT_WRITEREADX() call is executed, the count_read param-
eter indicates the number of bytes actually read.
Nowait I/O read operation
If a nowait I/O PUT_WRITEREADX( ) call is executed, count_read has no
meaning and can be omitted. The count of the number of bytes read is obtained
when the I/O operation completes through the count-transferred parameter of the
Guardian AWAITIOX procedure.
The PUT_WRITEREADX() function must complete with a corresponding call
to the Guardian AWAITIOX procedure when used with a file that is opened for
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