ZBasic System Library
178
ZBasic Microcontrollers
Type
Subroutine
Invocation
LongJmp(jmpbuf, val)
Parameter
Method
Type
Description
jmpbuf
ByRef
Array of Byte
A buffer holding the return context, see description below.
val
ByVal
int16
The value to be returned to the original SetJmp() caller.
Discussion
This subroutine, in conjunction with SetJmp(), provides a way to circumvent the normal call-return
structure and return directly to a distant caller. It is the equivalent of a non-local Goto function and can be
used, among other purposes, to handle exceptions in your programs. The first parameter specifies a
Byte array that has been previously initialized by a call to SetJmp(). The second parameter specifies a
value that will be seen by the original SetJmp() caller as the return value. This value, which should be
non-zero, can indicate the nature of the condition that led to the LongJmp() call. See the section on
Exception Handling in the ZBasic Reference Manual for more details.
Caution
Passing a jump buffer that has not been prepared by a call to SetJmp(), one that has been modified
after the SetJmp()call, or one that was prepared by a subroutine/function that is no longer active will
have unpredictable and almost certainly undesirable effects.
Compatibility
This routine is not available in BasicX compatibility mode. Also, this routine should not be used in
applications that use ZBasic objects because it bypasses the execution of destructors that are necessary
for proper object management.
See Also
 |
 |
 |