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ExampleFinalizeNettlerThread Class Reference

Thread of example plugin. More...

#include <plugins/examples/basics/finalize_nettler_thread.h>

Inheritance diagram for ExampleFinalizeNettlerThread:

List of all members.

Public Member Functions

 ExampleFinalizeNettlerThread (const char *name)
 Constructor.
virtual ~ExampleFinalizeNettlerThread ()
 Destructor.
virtual void init ()
 Initialize the thread.
virtual void loop ()
 Thread loop.
virtual bool prepare_finalize_user ()
 Prepare finalization user implementation.
virtual void finalize ()
 Finalize the thread.

Protected Member Functions

virtual void run ()
 Stub to see name in backtrace for easier debugging.

Detailed Description

Thread of example plugin.

This thread does nothing but nagging once on finalize. On the first call to prepare finalize it returns false that it cannot be finalized, on the second time it allows finalization.

Author:
Tim Niemueller

Definition at line 30 of file finalize_nettler_thread.h.


Constructor & Destructor Documentation

ExampleFinalizeNettlerThread::ExampleFinalizeNettlerThread ( const char *  name)

Constructor.

Parameters:
namethread name

Definition at line 40 of file finalize_nettler_thread.cpp.

ExampleFinalizeNettlerThread::~ExampleFinalizeNettlerThread ( ) [virtual]

Destructor.

Definition at line 48 of file finalize_nettler_thread.cpp.


Member Function Documentation

void ExampleFinalizeNettlerThread::finalize ( ) [virtual]

Finalize the thread.

This method is executed just before the thread is canceled and destroyed. It is always preceeded by a call to prepare_finalize(). If this is not the case this is a failure. The condition can be checked with the boolean variable finalize_prepared.

This method is meant to be used in conjunction with aspects and to cover thread inter-dependencies. This routine MUST bring the thread into a safe state such that it may be canceled and destroyed afterwards. If there is any reason that this cannot happen make your prepare_finalize() reports so.

This method is called by the thread manager just before the thread is being cancelled. Here you can do whatever steps are necessary just before the thread is cancelled. Note that you thread is still running and might be in the middle of a loop, so it is not a good place to give up on all resources used. Mind segmentation faults that could happen. Protect the area with a mutex that you lock at the beginning of your loop and free in the end, and that you lock at the beginning of finalize and then never unlock. Also not that the finalization may be canceled afterwards. The next thing that happens is that either the thread is canceled and destroyed or that the finalization is canceled and the thread has to run again.

Finalize is called on a thread just before it is deleted. It is guaranteed to be called on a fully initialized thread (if no exception is thrown in init()) (this guarantee holds in the Fawkes framework).

The default implementation does nothing besides throwing an exception if prepare_finalize() has not been called.

Exceptions:
Exceptionthrown if prepare_finalize() has not been called.
See also:
prepare_finalize()
cancel_finalize()

Reimplemented from fawkes::Thread.

Definition at line 70 of file finalize_nettler_thread.cpp.

References fawkes::Logger::log_info(), and fawkes::LoggingAspect::logger.

void ExampleFinalizeNettlerThread::init ( ) [virtual]

Initialize the thread.

This method is meant to be used in conjunction with aspects. Some parts of the initialization may only happen after some aspect of the thread has been initialized. Implement the init method with these actions. It is guaranteed to be called just after all aspects have been initialized and only once in the lifetime of the thread. Throw an exception if any problem occurs and the thread should not run.

Just because your init() routine suceeds and everything looks fine for this thread does not automatically imply that it will run. If it belongs to a group of threads in a ThreadList and any of the other threads fail to initialize then no thread from this group is run and thus this thread will never run. In that situation finalize() is called for this very instance, prepare_finalize() however is not called.

See also:
Fawkes Thread Aspects

Reimplemented from fawkes::Thread.

Definition at line 63 of file finalize_nettler_thread.cpp.

References fawkes::Logger::log_info(), and fawkes::LoggingAspect::logger.

void ExampleFinalizeNettlerThread::loop ( ) [virtual]

Thread loop.

If num iterations module modc is 0 print out messaege, otherwise do nothing.

Reimplemented from fawkes::Thread.

Definition at line 57 of file finalize_nettler_thread.cpp.

bool ExampleFinalizeNettlerThread::prepare_finalize_user ( ) [virtual]

Prepare finalization user implementation.

This method is called by prepare_finalize(). If there can ever be a situation where it is not safe to turn of a thread at some point in time then implement this method to determine these unsafe states.

An example that comes to my mind is our Katana arm. If you turn it off it looses all power and collapses back upon itself. This may damage the arm if it is not in a safe position. In this situation this method would return false to indicate this problem.

It is up to the user to decide if this should be taken for an implied signal to get in such a safe state, if this is possible at all.

This feature should be used rarely as it can have tremendous implications on the performance and experience of the whole software. In any case your implementation should somehow inform the user of the problem that caused the finalization to fail. If you are using aspect use the LoggerAspect and log the reason.

The default implementation always allows finalization.

Returns:
true, if the thread can be finalized, false otherwise.

Reimplemented from fawkes::Thread.

Definition at line 77 of file finalize_nettler_thread.cpp.

References fawkes::Logger::log_warn(), and fawkes::LoggingAspect::logger.

virtual void ExampleFinalizeNettlerThread::run ( ) [inline, protected, virtual]

Stub to see name in backtrace for easier debugging.

See also:
Thread::run()

Reimplemented from fawkes::Thread.

Definition at line 46 of file finalize_nettler_thread.h.


The documentation for this class was generated from the following files:
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