Stack Executive (Exec)
A-5
Internal Stack Functions
A.2 Stack Executive (Exec)
A.2.1 Synopsis
At the heart of the stack is the Executive API (Exec). The Executive acts as a
message dispatcher for the internal stack components. This action is mostly
hidden from the application, but there are some public functions.
A.2.2 API Functions
Prepare the System for Execution
ExecOpen
Syntax
void ExecOpen();
Description
Prepares the stack for execution by initializing the individual components. Until
ExecOpen() is called, the system can not actually do any work, but after calling
this function, objects like routes and bindings can be created.
Shutdown Stack and Cleanup
ExecClose
Syntax
void ExecClose();
Description
Completes stack execution. This function is called to perform final cleanup on
the system after all user objects (like devices and bindings) have been de-
stroyed.
Signal Low Resource Condition
ExecLowResource
Syntax
void ExecLowResource();
Description
Informs the stack that memory resources are getting dangerously low. As a re-
sult of this call, the stack will abandon certain operations that hold excessive
resources. (Pending ARP packets are thrown away, IP packet fragments
pending reassembly are abandoned, etc.)