Abdelrahman Said
124 lines
4.6 KiB
C
124 lines
4.6 KiB
C
/*
|
|
igraph library.
|
|
Copyright (C) 2003-2025 The igraph development team <igraph@igraph.org>
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#ifndef IGRAPH_INTERRUPT_H
|
|
#define IGRAPH_INTERRUPT_H
|
|
|
|
#include "igraph_decls.h"
|
|
#include "igraph_types.h"
|
|
|
|
IGRAPH_BEGIN_C_DECLS
|
|
|
|
/* This file contains the igraph interruption handling. */
|
|
|
|
/**
|
|
* \section interrupthandlers Interruption handlers
|
|
*
|
|
* <para>
|
|
* \a igraph is designed to be embeddable into several higher level
|
|
* languages (R and Python interfaces are included in the original
|
|
* package). Since most higher level languages consider internal \a igraph
|
|
* calls as atomic, interruption requests (like Ctrl-C in Python) must
|
|
* be handled differently depending on the environment \a igraph embeds
|
|
* into.</para>
|
|
* <para>
|
|
* An \emb interruption handler \eme is a function which is called regularly
|
|
* by \a igraph during long calculations. A typical usage of the interruption
|
|
* handler is to check whether the user tried to interrupt the calculation
|
|
* and return an appropriate value to signal this condition. For example,
|
|
* in R, one must call an internal R function regularly to check for
|
|
* interruption requests, and the \a igraph interruption handler is the
|
|
* perfect place to do that.</para>
|
|
* <para>
|
|
* If you are using the plain C interface of \a igraph or if you are
|
|
* allowed to replace the operating system's interruption handler (like
|
|
* SIGINT in Un*x systems), these calls are not of much use to you.</para>
|
|
* <para>
|
|
* The default interruption handler is empty.
|
|
* The \ref igraph_set_interruption_handler() function can be used to set a
|
|
* new interruption handler function of type
|
|
* \ref igraph_interruption_handler_t, see the
|
|
* documentation of this type for details.
|
|
* </para>
|
|
*/
|
|
|
|
/**
|
|
* \section writing_interruption_handlers Writing interruption handlers
|
|
*
|
|
* <para>
|
|
* You can write and install interruption handlers simply by defining a
|
|
* function of type \ref igraph_interruption_handler_t and calling
|
|
* \ref igraph_set_interruption_handler(). This feature is useful for
|
|
* interface writers, because usually this is the only way to allow handling
|
|
* of Ctrl-C and similar keypresses properly.
|
|
* </para>
|
|
* <para>
|
|
* Your interruption handler will be called regularly during long operations
|
|
* (so it is not guaranteed to be called during operations which tend to be
|
|
* short, like adding single edges). An interruption handler accepts no
|
|
* parameters and must return \c IGRAPH_SUCCESS if the calculation should go on. All
|
|
* other return values are considered to be a request for interruption,
|
|
* and the caller function would return a special error code, \c IGRAPH_INTERRUPTED.
|
|
* It is up to your error handler function to handle this error properly.
|
|
* </para>
|
|
*/
|
|
|
|
/**
|
|
* \section writing_functions_interruption_handling Writing \a igraph functions with
|
|
* proper interruption handling
|
|
*
|
|
* <para>
|
|
* There is practically a simple rule that should be obeyed when writing
|
|
* \a igraph functions. If the calculation is expected to take a long time
|
|
* in large graphs (a simple rule of thumb is to assume this for every
|
|
* function with a time complexity of at least O(n^2)), call
|
|
* \ref IGRAPH_ALLOW_INTERRUPTION in regular intervals like every 10th
|
|
* iteration or so.
|
|
* </para>
|
|
*/
|
|
|
|
/**
|
|
* \typedef igraph_interruption_handler_t
|
|
*
|
|
* This is the type of the interruption handler functions.
|
|
*
|
|
* \return false if the calculation should go on, true if the calculation
|
|
* should be interrupted.
|
|
*/
|
|
|
|
typedef igraph_bool_t igraph_interruption_handler_t(void);
|
|
|
|
/**
|
|
* \function igraph_allow_interruption
|
|
*
|
|
* This is the function which is called (usually via the
|
|
* \ref IGRAPH_ALLOW_INTERRUPTION macro) if \a igraph is checking for interruption
|
|
* requests.
|
|
*
|
|
* \return false if the calculation should go on, true if the calculation
|
|
* should be interrupted.
|
|
*/
|
|
|
|
IGRAPH_EXPORT igraph_bool_t igraph_allow_interruption(void);
|
|
|
|
IGRAPH_EXPORT igraph_interruption_handler_t * igraph_set_interruption_handler (igraph_interruption_handler_t * new_handler);
|
|
|
|
IGRAPH_END_C_DECLS
|
|
|
|
#endif
|