INtime® 3.1 Software - tenAsys

B
The iwin32 subsystem
This appendix describes the iwin32 subsystem, which provides a Win32 API for the
INtime kernel. It is provided as a parallel API to the INtime API, and is intended to
make porting of existing Win32 applications easier. A subset of the Win32 functions is
implemented, and some extensions are defined to handle INtime features such as
interrupt handling and shared memory. The functionality of the subset is broadly
similar to the Windows CE version of the Win32 API, since Windows CE and INtime
have similar goals. Some groups of functions have been omitted where INtime does not
require the functionality, such as with the GUI functions.
The elements covered by the iwin32 API include the following:
• Processes and threads
• Mutexes, critical sections, semaphores and events
• I/O handling
• Registry handling
• Miscellaneous
In addition a number of real-time extension (RTX) functions are provided where more
real-time functionality is required; this includes functions for:
• Interrupt handling
• Shared memory
• Timers
This appendix also describes the iwin32x API, which gives access to real-time iwin32
objects from a Windows application, much in the same way that the NTX API gives
access to INtime objects from a Windows application.
Handles
Each object is identified by a handle. In INtime an object is uniquely identified by a
single handle value (16 bits for INtime, 32 bits for NTX). This handle can be used in
any INtime process and in Windows processes (using NTX). When the object is deleted
with a type-specific deletion function such as DeleteRtSemaphore, the handle becomes
invalid.
Iwin32 has a different handle system: the Create and Open functions return a handle
and different callers may receive different handles for the same object. A handle is
stored in 32 bits; an iwin32 handle can be distinguished from an INtime handle
141