Parameter
vmcj/jni_strategy
Short text
Define strategy for JNI methods
Parameter Description
This parameter specifies how kernel functions implemented within the SAP kernel in C or C++ are called in the VM container. It is important that the VM C/C++ runtime stacks required for each thread are configured as small as possible in order to save memory space. Depending on the function type, this may lead to problems (large fields on the stack, recursive functions). In the VM container there is a service stack that is configured larger, which can execute large functions without any problem. The disadvantage of this service stack is a relatively small loss in performance resulting from the need to switch stacks.
Since the switch to the service stack is only required by a few functions, all kernel functions were classified that
• can run directly on the VM stack.
• have to run on the service stack.
By default, the VM container uses this information to execute functions. If there are still problems, and if it is not possible to change the size of the stack because of the available memory, this behavior can be changed.
The following options are available:
USE_MARKUP Call based on classification
INVOKE_ON_SERVICE_STACK Always call on the service stack
INVOKE_DIRECT Always call directly
Application Area
VMC
Parameter Unit
Character string
Default Value
USE_MARKUP
Who is permitted to make changes?
SAP
Operating System Restrictions
None
Database System Restrictions
None
Are other parameters affected or dependent?
vmcj/option/ss
