Question

What are the usages of the following API's/ Macros in contiki ?

1. PROCESS
2. uip_debug_ipaddr_print
3. AUTOSTART_PROCESSES
4. PROCESS_THREAD
5. PROCESS_WAIT_EVENT_UNTIL
6. PROCESS_END
7. simple_udp_register
8. simple_udp_sendto
9. uip_create_linklocal_allnodes_mcast
10. servreg_hack_register

Answer 1

What are the usage of the following API's/Macros in contiki?
a) PROCESS :-
A process in Contiki consists of a single protothread(Protothreads are a type of lightweight stackless threads designed for severly memory constrained systems such as deeply embedded systems or sensor network nodes).

Declare a process.
   This macro declares a process. The process has two names: the variable of the process structure, which is used by the C program, and a human readable string name, which is used when debugging. A configuration option allows removal of the readable name to save RAM.

e.i., #define PROCESS ( name, strname)
   name:   The variable name of the process structure.
   strname: The string representation of the process' name.

b) AUTOSTART_PROCESSES :-
   Contiki provides a mechanism where processes can be automatically started either when the system is booted, or when a module that contains the processes is loaded. Autostarted processes are kept on a list, that is used by the autostart module to start the processes. The processes are started in the order they appear on the list.

i.e., AUTOSTART_PROCESSES(&name1, &name2, ...)
   name1, name2, ... - The name of processes to be autostarted.

c) PROCESS_THREAD :-
   This macro is used to define the body (protothread) of a process. The process is called whenever an event occurs in the system, A process always start with the PROCESS_BEGIN() macro and end with the PROCESS_END() macro.

i.e.,#define PROCESS_THREAD( name, ev, data)
  
d) PROCESS_WAIT_EVENT_UNTIL :-
   Wait for an event to be posted to the process, with an extra condition. It blocks the currently running process until the process receives an event.

i.e., #define PROCESS_WAIT_EVENT_UNTIL(c)   
   c: The condition that must be true for the process to continue.