Fatal Error Handler [Debugging]

Functions to help clean up when fatal error is encountered. More...

Collaboration diagram for Fatal Error Handler:

Functions
void	ns3::FatalImpl::RegisterStream (std::ostream *stream)
	Register a stream to be flushed on abnormal exit.
void	ns3::FatalImpl::UnregisterStream (std::ostream *stream)
	Unregister a stream for flushing on abnormal exit.
void	ns3::FatalImpl::FlushStreams (void)
	Flush all currently registered streams.

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Detailed Description

Functions to help clean up when fatal error is encountered.

The functions in this group are used to perform limited clean up, like flushing active streams, when fatal error are encountered (through assertion fail, calls to NS_ABORT_* and calls to NS_FATAL_ERROR.

Currently, other than flushing active ostreams, these functions does not interfere with outside memory. There is still a residual risk that may be invalid ostream pointers may be present, and may corrupt the memory on the attempt to execute the flush() function.

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Function Documentation

void ns3::FatalImpl::FlushStreams

(

void

)

Flush all currently registered streams.

This function iterates through each registered stream and unregister them. The default SIGSEGV handler is overridden when this function is being executed, and will be restored when this function returns.

If a SIGSEGV is encountered (most likely due to bad ostream* being registered, or a registered osteam* pointing to an ostream that had already been destroyed), this function will skip the bad ostream* and continue to flush the next stram. The function will then terminate raising SIGIOT (aka SIGABRT)

DO NOT call this function until the program is ready to crash.

void ns3::FatalImpl::RegisterStream

(

std::ostream *

stream

)

Register a stream to be flushed on abnormal exit.

Parameters:

stream

The stream to be flushed on abnormal exit.

If a std::terminate() call is encountered after the stream had been registered and before it had been unregistered, stream->flush() will be called. Users of this function is to ensure stream remains valid until it had been unregistered.

void ns3::FatalImpl::UnregisterStream

(

std::ostream *

stream

)

Unregister a stream for flushing on abnormal exit.

Parameters:

stream

The stream to be unregistered.

After a stream had been unregistered, stream->flush() will no longer be called should abnormal termination is encountered.

If stream is not registered, nothing will happen.