ScriptInterface::ParallelExceptionHandler Class Reference

Handle exceptions thrown in MPI parallel code. More...

#include <ParallelExceptionHandler.hpp>

Public Member Functions
	ParallelExceptionHandler (boost::mpi::communicator comm)
template<typename T >
void	parallel_try_catch (std::function< void()> const &callback) const
	Handle exceptions in synchronous code.

Detailed Description

Handle exceptions thrown in MPI parallel code.

Instantiate this class inside the catch block and after the catch block, like so:

boost::mpi::communicator world;
auto handler = ScriptInterface::ParallelExceptionHandler{world};
std::shared_ptr<MyClass> obj;
context()->parallel_try_catch([&obj]() {
  obj = std::make_shared<MyClass>(2., true);
});

Exceptions are handled as follows:

• the main rank throws: re-throw on main rank and throw Exception on all other ranks
• one or more of the worker nodes throw: collect error messages from worker nodes and throw them on the main rank as a std::runtime_error, throw Exception on all other ranks

Throwing a Exception guarantees that the partially initialized script interface object won't be registered in the GlobalContext dictionary; this is the only side-effect on worker nodes, since the exception itself is otherwise silently ignored. On the main rank, the thrown exception is converted to a Python exception.

Definition at line 58 of file ParallelExceptionHandler.hpp.

Constructor & Destructor Documentation

ParallelExceptionHandler()

ScriptInterface::ParallelExceptionHandler::ParallelExceptionHandler ( boost::mpi::communicator  comm )

inline

Definition at line 60 of file ParallelExceptionHandler.hpp.

Member Function Documentation

parallel_try_catch()

template<typename T >

void ScriptInterface::ParallelExceptionHandler::parallel_try_catch ( std::function< void()> const &  callback ) const

inline

Handle exceptions in synchronous code.

Error messages queued in the runtime error collector are flushed to standard error if the code throws on any rank.

Precondition

Must be called on all ranks.

The callback cannot invoke remote functions from the Communication::MpiCallbacks framework due to blocking communication (risk of MPI deadlock on worker nodes).

Parameters

[in]

callback

Callback to execute synchronously on all ranks.

Definition at line 74 of file ParallelExceptionHandler.hpp.

Referenced by ScriptInterface::GlobalContext::parallel_try_catch(), and ScriptInterface::LocalContext::parallel_try_catch().

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

• ParallelExceptionHandler.hpp
• ParallelExceptionHandler.cpp