org.javagroups.protocols
Class PERF
java.lang.Object
|
+--org.javagroups.stack.Protocol
|
+--org.javagroups.protocols.PERF
- public class PERF
- extends Protocol
Measures time taken by each protocol to process a message. PERF has to be the top protocol in a stack. It
adds a special header to the message which travels with the message. Upon initialization,
PERF creates a ProtocolObserver for each protocol layer in the stack. That observer notes the time taken for a
message to travel through the layer it observes, and records the start time, end time and total time
in the message itself (in the header created by PERF). When a message is received by PERF, the statistics
for the message are appended to a file (or displayed in a GUI (not yet done)).
For example, to write all performance data to a file, do the following:
- Set tracing to on, e.g.
trace=true
in javagroups.properties
- Add a trace statement for PERF.up():
trace0=PERF.up DEBUG /tmp/trace.perf
. This will write
all trace output to the given file.
- Version:
- $Revision: 1.4 $
- Author:
- Bela Ban Oct 2001
Fields inherited from class org.javagroups.stack.Protocol |
down_handler, down_prot, down_queue, down_thread, observer, props, stack, up_handler, up_prot, up_queue, up_thread |
Constructor Summary |
PERF()
|
Method Summary |
void |
down(Event evt)
An event is to be sent down the stack. |
java.lang.String |
getName()
All protocol names have to be unique ! |
boolean |
setProperties(java.util.Properties props)
Configures the protocol initially. |
void |
up(Event evt)
An event was received from the layer below. |
Methods inherited from class org.javagroups.stack.Protocol |
getDownProtocol, getDownQueue, getProperties, getUpProtocol, getUpQueue, init, passDown, passUp, providedDownServices, providedUpServices, receiveDownEvent, receiveUpEvent, requiredDownServices, requiredUpServices, setDownProtocol, setObserver, setPropertiesInternal, setProtocolStack, setUpProtocol, startDownHandler, startUpHandler, stopInternal |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
PERF
public PERF()
getName
public java.lang.String getName()
- All protocol names have to be unique !
- Overrides:
getName
in class Protocol
setProperties
public boolean setProperties(java.util.Properties props)
- Description copied from class:
Protocol
- Configures the protocol initially. A configuration string consists of name=value
items, separated by a ';' (semicolon), e.g.:
"loopback=false;unicast_inport=4444"
- Overrides:
setProperties
in class Protocol
up
public void up(Event evt)
- Description copied from class:
Protocol
- An event was received from the layer below. Usually the current layer will want to examine
the event type and - depending on its type - perform some computation
(e.g. removing headers from a MSG event type, or updating the internal membership list
when receiving a VIEW_CHANGE event).
Finally the event is either a) discarded, or b) an event is sent down
the stack using
passDown()
or c) the event (or another event) is sent up
the stack using passUp()
.
- Overrides:
up
in class Protocol
down
public void down(Event evt)
- Description copied from class:
Protocol
- An event is to be sent down the stack. The layer may want to examine its type and perform
some action on it, depending on the event's type. If the event is a message MSG, then
the layer may need to add a header to it (or do nothing at all) before sending it down
the stack using
passDown()
. In case of a GET_ADDRESS event (which tries to
retrieve the stack's address from one of the bottom layers), the layer may need to send
a new response event back up the stack using passUp()
.
- Overrides:
down
in class Protocol
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