Synchronization Services

Use the synchronization functions to synchronize virtual testers during script playback. You can insert synchronization points and wait periods, and you can manage variables shared among virtual testers.

Summary

The following table lists the synchronization functions.

Function	Description
TSSSharedVarAssign()	Performs a shared variable assignment operation.
TSSSharedVarEval()	Gets the value of a shared variable and operates on the value as specified.
TSSSharedVarWait()	Waits for the value of a shared variable to match a specified range.
TSSSyncPoint()	Puts a synchronization point in a script.

TSSSharedVarAssign()

Performs a shared variable assignment operation.

Syntax

s32 TSSSharedVarAssign(char *name, s32 value, ShVarOp op, s32 
*returnVal)

Element	Description
name	The name of the shared variable to operate on.
value	The right-side value of the assignment expression.
op	Assignment operator. Can be one of the following: SHVOP_assign SHVOP_add SHVOP_subtract SHVOP_multliply SHVOP_divide SHVOP_modulo SHVOP_and SHVOP_or SHVOP_xor SHVOP_shiftleft SHVOP_shiftright
returnVal	OUTPUT. If not specified as NULL, the resulting value of name after application of op value.

Return Value

On success, this function retrieves the value of the specified shared variable before and after it has been operated on. The function exits with one of the following results:

• TSS_OK. Success.

• TSS_NOSERVER. No previous successful call to TSSConnect().

• TSS_INVALID. The entered name is not a shared variable.

• TSS_ABORT. Pending abort resulting from a user request to stop a suite run.

Comments

The data type ShVarOp is defined as follows:

typedef enum ShVarOp ShVarOp;
enum ShVarOp {
	 SHVOP_assign,
	 SHVOP_add,
	 SHVOP_subtract,
	 SHVOP_multiply,
	 SHVOP_divide
	 SHVOP_modulo,
	 SHVOP_and,
	 SHVOP_or,
	 SHVOP_xor,
	 SHVOP_shiftleft
	 SHVOP_shiftright
	 SHVOP_END
}

TSSSharedVarAssign("myVar",5,SHVOP_add,NULL) is equivalent to myVar += 5.

Example

This example adds 5 to the value of the shared variable lineCounter and puts the new value of lineCounter in returnval.

s32 returnval = 5;
s32 retVal = TSSSharedVarAssign("lineCounter", val, SHVOP_add, 
returnVal);

See Also

TSSSharedVarEval(), TSSSharedVarWait()

TSSSharedVarEval()

Gets the value of a shared variable and operates on the value as specified.

Syntax

s32 TSSSharedVarEval(char *name, s32 *value, ShVarAdj op)

Element	Description
name	The name of the shared variable to operate on.
value	OUTPUT. A local container into which the value of name is retrieved.
op	Increment/decrement operator for the returned value: Can be one of the following: SHVADJ_none SHVADJ_pre_inc SHVADJ_post_inc SHVADJ_pre_dec SHVADJ_post_dec

Return Value

On success, this function returns the new value of the specified shared variable as described above. The function exits with one of the following results:

• TSS_OK.Success.

• TSS_NOSERVER. No previous successful call to TSSConnect().

• TSS_INVALID. The entered name is not a shared variable.

• TSS_ABORT. Pending abort resulting from a user request to stop a suite run.

Comments

The data type ShVarAdj is defined as follows:

typedef enum ShVarAdj ShVarAdj;
enum ShVarAdj {
	 SHVADJ_none,
	 SHVADJ_pre_inc,
	 SHVADJ_post_inc,
	 SHVADJ_pre_dec,
	 SHVADJ_post_dec
}

Example

This example post-decrements the value of shared variable lineCounter and stores the result in val.

s32 val;
s32 retVal = TSSSharedVarEval("lineCounter",val,SHVADJ_post_inc);

See Also

TSSSharedVarAssign(), TSSSharedVarWait()

TSSSharedVarWait()

Waits for the value of a shared variable to match a specified range.

Syntax

s32 TSSSharedVarWait(char *name, s32 min, s32 max, s32 adjust, 
s32 timeout, s32 *returnVal)

Element	Description
name	The name of the shared variable to operate on.
min	The low range for the value of name.
max	The high range for the value of name.
adjust	The value to increment/decrement the named shared variable by once it meets the min - max range.
timeout	The time-out preference (how long to wait for the condition to be met). Enter one of the following: A negative number for no time-out. 0 to return immediately with an exit value of 1 (condition met) or 0 (not met). The number of milliseconds to wait for the value of name to meet the criteria, before timing out with and returning an exit value of 1 (met) or 0 (not met).
returnVal	OUTPUT. The value of name at the time of the return, before any possible adjustment. If timeout expired before the return, the value is not adjusted. Otherwise, returnVal is incremented/decremented by adjust.

Return Value

On success, this function returns 1 (condition was met before time-out) or 0 (time-out expired before the condition was met). The function exits with one of the following results:

• TSS_NOSERVER. No previous successful call to TSSConnect().

• TSS_INVALID. The entered name is not a shared variable.

• TSS_ABORT. Pending abort resulting from a user request to stop a suite run.

Comments

This call provides a method of blocking a virtual tester until a user-defined global event occurs.

If virtual testers are blocked on an event using the same shared variable, TestManager guarantees that the virtual testers are unblocked in the same order in which they were blocked.

Although this alone does not ensure an exact multiuser timing order in which statements following a wait are executed, the additional proper use of the arguments min, max, and adjust allows control over the order in which multiuser operations occur. (UNIX or Windows NT determines the order of the scheduling algorithms. For example, if two virtual testers are unblocked from a wait in a given order, the tester that was unblocked last might be released before the tester that was unblocked first.)

If a shared variable's value is modified, any subsequent attempt to modify this value -- other than through TSSSharedVarWait() -- blocks execution until all virtual testers already blocked have had an opportunity to unblock. This ensures that events cannot appear and then quickly disappear before a blocked virtual tester is unblocked. For example, if two virtual testers were blocked waiting for name to equal or exceed N, and if another virtual tester assigned the value N to name, then TestManager guarantees both virtual testers the opportunity to unblock before any other virtual tester is allowed to modify name.

Offering the opportunity for all virtual testers to unblock does not guarantee that all virtual testers actually unblock, because if TSSSharedVarWait() is called with a nonzero value of adjust by one or more of the blocked virtual testers, the shared variable value changes during the unblocking script. In the previous example, if the first user to unblock had called TSSSharedVarWait() with a negative adjust value, the event waited on by the second user would no longer be true after the first user unblocked. With proper choice of adjust values, you can control the order of events.

Example

This example returns 1 if the shared variable inProgress reaches a value between 10 and 20 within 60000 milliseconds of the time of the call. Otherwise, it returns 0. svVal contains the value of inProgress at the time of the return, before it is adjusted. (In this case, the adjustment value is 0 so the value of the shared variable is not adjusted.)

s32 svVal = 0;
s32 retVal = TSSSharedVarWait("inProgress",10,20,0,60000,svVal);

See Also

TSSSharedVarAssign(), TSSSharedVarEval()

TSSSyncPoint()

Puts a synchronization point in a script.

Syntax

s32 TSSSyncPoint(char *label)

Element	Description
label	The name of the synchronization point.

Return Value

This function exits with one of the following results:

• TSS_OK.Success.

• TSS_NOOP. The TSS server is running proxy.

• TSS_NOSERVER. No previous successful call to TSSConnect().

• TSS_INVALID. The synchronization point label is invalid.

• TSS_ABORT. Pending abort resulting from a user request to stop a suite run.

Comments

A script pauses at a synchronization point until the release criteria specified by the suite have been met. If the criteria are met, the script delays a random time specified in the suite and then resumes execution.

Typically, it is better to insert a synchronization point into a suite from TestManager rather than use the TSSSyncPoint() call inside a script.

If you insert a synchronization point into a suite, synchronization occurs at the beginning of the script. If you insert a synchronization point into a script with TSSSyncPoint(), synchronization occurs at the point of insertion. You can insert the command anywhere in the script.

Example

This example creates a sync point named BlockUntilSaveComplete.

s32 retVal = TSSSyncPoint("BlockUntilSaveComplete");