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SCIOPTA - Real-Time Kernel

User’s Manual Manual Version 4.1 5-13

SCIOPTA - Real-Time Kernel

5 Processes

5.13 Addressing Processes

5.13.1 Introduction

In a typical SCIOPTA design you need to address processes. For example you want to

• send SCIOPTA messages to a process,

• kill a process

• get a stored name of a process

• observe a process

• get or set the priority of a process

• start and stop processes

In SCIOPTA you are addressing processes by using their process ID (pid). There are two methods to get process

IDs depending if you have to do with static or dynamic processes.

5.13.2 Get Process IDs of Static Processes

Static processes are created by the kernel at start-up. They are designed with the SCIOPTA SCONF configuration

utility by defining the name and all other process parameters such as priority and process stack sizes.

You can address static process by appending the string

_pid

to the process name if the process resides in the system module. If the static process resides inside another module

than the system module, you need to precede the process name with the module name and an underscore in be

tween.

For instance if you have a static process defined in the system module with the name controller you can address

it by giving controller_pid. To send a message to that process you can use:

sc_msgTx (mymsg, controller_pid, myflags);

If you have a static process in the module tcs (which is not the system module) with the name display you can

address it by giving tcs_display_pid. To send a message to that process you can use:

sc_msgTx (mymsg, tcs_display_pid, myflags);

5.13.3 Get Process IDs of Dynamic Processes

Dynamic processes can be created and killed during run-time. Often dynamic processes are used to run multiple

instances of common code.

The process IDs of dynamic processes can be retrieved by using the system call sc_procIdGet.

The process creation system calls sc_procPrioCreate, sc_procIntCreate and sc_procTimCreate will also return

the process IDs which can be used for further addressing.

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