cz.ues.platform.commons.pcb.internal

Interface PCB

public interface PCB

PCB (process controll block) is a process context. Each PCB is associated to concrete process using PID (process ID).

Since:

UES6-00

Method Summary

Methods

Modifier and Type	Method and Description
PID	getClientPID() Returns client process ID.
long	getExecutionTime() Returns duration of this process (in milliseconds).
PID	getParentPID() Returns parent process ID.
PID	getPID() Returns ID of process to which is this PCB associated.
java.lang.Object	getProperty(java.lang.String aKey) Reads property from process environment.
java.util.List<java.lang.Object>	getPropertyChain(java.lang.String aKey) Reads hierarchy of properties from process environment.
PID	getSessionPID() Returns session process ID.
long	getStartTime() Returns start time of process (time is returned as currentTimeMillis).
boolean	isInheritedProperty(java.lang.String aKey) Checks if property was initially set to actual process environment (is owned by actual process environment), or was inherited from parent process environment.
void	setProperty(java.lang.String aKey, java.lang.Object aValue) Sets property to process environment.
void	setRetainedProperty(java.lang.String aKey, java.lang.Object aValue) Sets retained property to process environment.

Method Detail

getPID

PID getPID()

Returns ID of process to which is this PCB associated.

Returns:

Process ID

Since:

UES6-00

getParentPID

PID getParentPID()

Returns parent process ID.

Returns:

Parent process ID

Since:

UES6-00

getClientPID

PID getClientPID()

Returns client process ID. Client process is special type of parent process which is set in case we are continuing some suspended (and typically serialized) process. Client PID allows us to track back execution across multiple application servers.

Returns:

Client process ID

Since:

UES6-00

getSessionPID

PID getSessionPID()

Returns session process ID. Session PID is ID of process, which started user session (typically by login). Session PID allows us to group processes so we can track back everything executed in this session.

Returns:

Session process ID

Since:

UES6-00

setProperty

void setProperty(java.lang.String aKey,
java.lang.Object aValue)

Sets property to process environment.

Parameters:

aKey - Unique property identifier

aValue - Property to be stored

Since:

UES6-00

setRetainedProperty

void setRetainedProperty(java.lang.String aKey,
java.lang.Object aValue)

Sets retained property to process environment.

Parameters:

aKey - Unique property identifier

aValue - Property to be stored

Since:

UES6-00

getProperty

java.lang.Object getProperty(java.lang.String aKey)

Reads property from process environment.

Parameters:

aKey - Property identifier

Returns:

Stored property, null if property does not exist in process environment

Since:

UES6-00

getPropertyChain

java.util.List<java.lang.Object> getPropertyChain(java.lang.String aKey)

Reads hierarchy of properties from process environment. Size of returned list corresponds to nested level of active PCB starting with zero position representing root PCB. Only own properties are present in list. In case some property is inherited on concrete level, null is added as value at corresponding position in list.

Parameters:

aKey - Property identifier

Returns:

Stored Property chain, List of nulls if property does not exist

Since:

UES6-06

isInheritedProperty

boolean isInheritedProperty(java.lang.String aKey)

Checks if property was initially set to actual process environment (is owned by actual process environment), or was inherited from parent process environment. (value of own properties can be directly modified while properties inherited from parent PCB must be first cloned before modification)

Parameters:

aKey - Property identifier

Returns:

True if property is inherited

Since:

UES6-00

getStartTime

long getStartTime()

Returns start time of process (time is returned as currentTimeMillis).

Returns:

Start time of process

Since:

UES6-00

getExecutionTime

long getExecutionTime()

Returns duration of this process (in milliseconds).

Returns:

Duration of process in milliseconds

Since:

UES6-00