# Simple Triggers

Contents

- Introduction
- Where Defined
- Reference

# Introduction

Triggers in the process group interface are used to asynchronously receive and process messages destined for distributed data structures. The trigger interface is relatively versatile, permitting one to attach any function object to handle requests. The `simple_trigger` function simplifies a common case for triggers: attaching a trigger that invokes a specific member function of the distributed data structure.

# Where Defined

Header `<boost/graph/parallel/simple_trigger.hpp>`

# Reference

>     template<typename ProcessGroup, typename Class, typename T>
>       void
>       simple_trigger(ProcessGroup& pg, int tag, Class* self,
>                      void (Class::*pmf)(int source, int tag, const T& data,
>                                         trigger_receive_context context))

>     template<typename ProcessGroup, typename Class, typename T, typename Result>
>       void
>       simple_trigger(ProcessGroup& pg, int tag, Class* self,
>                      Result (Class::*pmf)(int source, int tag, const T& data,
>                                           trigger_receive_context context))

The `simple_trigger` function registers a trigger that invokes the given member function (`pmf`) on the object `self` whenever a message is received. If the member function has a return value, then the trigger has a reply, and can only be used via out-of-band sends that expect a reply. Otherwise, the member function returns `void`, and the function is registered as a normal trigger.

Copyright (C) 2007 Douglas Gregor

Copyright (C) 2007 Matthias Troyer