SY10InitializeCriticalSection

SY = System function

The SY10InitializeCriticalSection function Initializes a critical section pooling information.

SY10InitializeCriticalSection(pool)

Parameters:

Description:

Every critical section bases its inner workings on a proprietary data structure called pool informations.
Every critical section will have its own pool that must be initialized before it can be used.
The pool consists of an array of bytes where the number of items depends on the number of task unit that will use more two-byte fixed header.

Inglese Italiano If for example a given critical section is used in only two drives task you create an application pool of 4 byte making sure that a unit must use the ID 1 while the second the ID 2.

The ID are progressive starting from 1 and identify the location of the information in the pool, then pass an ID with index not available in the pool means invalidating the call and how it works.

NB: To avoid problems it is advisable to size the pool information with sufficient size to address all drives task.

In the following example initializes an information pool used then to a critical section.

configuration unit:

; critical section consts
CONST
	CS_POOL_HEADER		2		; fixed header in critical section pool info
	CS_POOL_SIZE		10		; critical section pool info size
 
ARRGBL
	LockPool		B		CS_POOL_HEADER + CS_POOL_SIZE

Unit initialization:

;===
;	Initialize system
;
GLOBAL
	Initialized		F	OUT
 
; main entry point
BEGIN
	CALL TASK_INIT
	WHILE TRUE
		CALL TASK_EXECUTE
		WAIT A_LOOP
	ENDWHILE
END
 
;===
;	Task initialization
;
SUB TASK_INIT
	SY10InitializeCriticalSection(LockPool)
	Initialized = TRUE
ENDSUB
 
;===
;	Task execution
;
SUB TASK_EXECUTE
	SUSPEND
ENDSUB

• The function must be performed only once during application initialization.
• The SY10EnterCriticalSection and SY10LeaveCriticalSection functions, should not be called before you have initialized the critical section with SY10InitializeCriticalSection.