Scippy

SCIP

Solving Constraint Integer Programs

interrupt.c
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1/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2/* */
3/* This file is part of the program and library */
4/* SCIP --- Solving Constraint Integer Programs */
5/* */
6/* Copyright (c) 2002-2024 Zuse Institute Berlin (ZIB) */
7/* */
8/* Licensed under the Apache License, Version 2.0 (the "License"); */
9/* you may not use this file except in compliance with the License. */
10/* You may obtain a copy of the License at */
11/* */
12/* http://www.apache.org/licenses/LICENSE-2.0 */
13/* */
14/* Unless required by applicable law or agreed to in writing, software */
15/* distributed under the License is distributed on an "AS IS" BASIS, */
16/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
17/* See the License for the specific language governing permissions and */
18/* limitations under the License. */
19/* */
20/* You should have received a copy of the Apache-2.0 license */
21/* along with SCIP; see the file LICENSE. If not visit scipopt.org. */
22/* */
23/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24
25/**@file interrupt.c
26 * @ingroup OTHER_CFILES
27 * @brief methods and datastructures for catching the user CTRL-C interrupt
28 * @author Tobias Achterberg
29 */
30
31/*---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
32
33#include <assert.h>
34#include <sys/types.h>
35#include <stdlib.h>
36#include <signal.h>
37
38#include "scip/def.h"
39#include "scip/pub_message.h"
41#include "scip/interrupt.h"
42
43
44static volatile
45int ninterrupts = 0; /**< static variable counting the number of CTRL-C interrupts */
46static volatile
47int nterms = 0; /**< static variable counting the number of times that the process received a SIGTERM signal */
48
49
50#ifdef SCIP_NO_SIGACTION
51typedef void (*SigHdlr)(int);
52
53/** CTRL-C interrupt data */
54struct SCIP_Interrupt
55{
56 SigHdlr oldsighdlr; /**< old CTRL-C interrupt handler */
57 int nuses; /**< number of times, the interrupt is captured */
58};
59
60#else
61
62/** CTRL-C interrupt data */
64{
65 struct sigaction oldsigaction; /**< old CTRL-C interrupt handler */
66 int nuses; /**< number of times, the interrupt is captured */
67};
68#endif
69
70/** interrupt handler for CTRL-C interrupts */
71static
73 int signum /**< interrupt signal number */
74 )
75{
77
79 if( ninterrupts >= 5 )
80 {
81 printf("pressed CTRL-C %d times. forcing termination.\n", ninterrupts);
82 exit(1);
83 }
84 else
85 {
86 printf("pressed CTRL-C %d times (5 times for forcing termination)\n", ninterrupts);
87 }
88}
89
90/** creates a CTRL-C interrupt data */
92 SCIP_INTERRUPT** interrupt /**< pointer to store the CTRL-C interrupt data */
93 )
94{
95 assert(interrupt != NULL);
96
97 SCIP_ALLOC( BMSallocMemory(interrupt) );
98 (*interrupt)->nuses = 0;
99
100 return SCIP_OKAY;
101}
102
103/** frees a CTRL-C interrupt data */
105 SCIP_INTERRUPT** interrupt /**< pointer to the CTRL-C interrupt data */
106 )
107{
108 assert(interrupt != NULL);
109
110 BMSfreeMemory(interrupt);
111}
112
113/** captures the CTRL-C interrupt to call the SCIP's own interrupt handler */
115 SCIP_INTERRUPT* interrupt /**< CTRL-C interrupt data */
116 )
117{
118 assert(interrupt != NULL);
119 assert(interrupt->nuses >= 0);
120
121 if( interrupt->nuses == 0 )
122 {
123#ifdef SCIP_NO_SIGACTION
124 interrupt->oldsighdlr = signal(SIGINT, interruptHandler);
125#else
126 struct sigaction newaction;
127
128 /* initialize new signal action */
129 newaction.sa_handler = interruptHandler;
130 newaction.sa_flags = 0;
131 (void)sigemptyset(&newaction.sa_mask);
132
133 /* set new signal action, and remember old one */
134 (void)sigaction(SIGINT, &newaction, &interrupt->oldsigaction);
135#endif
136
137 ninterrupts = 0;
138 nterms = 0;
139 }
140 interrupt->nuses++;
141}
142
143/** releases the CTRL-C interrupt and restores the old interrupt handler */
145 SCIP_INTERRUPT* interrupt /**< CTRL-C interrupt data */
146 )
147{
148 assert(interrupt != NULL);
149 assert(interrupt->nuses >= 1);
150
151 interrupt->nuses--;
152 if( interrupt->nuses == 0 )
153 {
154#ifdef SCIP_NO_SIGACTION
155 (void)signal(SIGINT, interrupt->oldsighdlr);
156#else
157 (void)sigaction(SIGINT, &interrupt->oldsigaction, NULL);
158#endif
159 }
160}
161
162/** returns whether the user interrupted by pressing CTRL-C */
164 void
165 )
166{
167 return (ninterrupts > 0);
168}
169
170/** returns whether a process termination signal was received */
172 void
173 )
174{
175 return (nterms > 0);
176}
177
178/** sends a termination signal to all SCIP processes so that they try to terminate as soon as possible
179 *
180 * @note For terminating a specific SCIP process use SCIPinterruptSolve().
181 */
183 void
184 )
185{
186 nterms++;
187}
188
189/** resets the number of interrupts to 0 */
191 void
192 )
193{
194 ninterrupts = 0;
195 nterms = 0;
196}
197
common defines and data types used in all packages of SCIP
#define NULL
Definition: def.h:267
#define SCIP_UNUSED(x)
Definition: def.h:428
#define SCIP_Bool
Definition: def.h:91
#define SCIP_ALLOC(x)
Definition: def.h:385
SCIP_RETCODE SCIPinterruptCreate(SCIP_INTERRUPT **interrupt)
Definition: interrupt.c:91
void SCIPinterruptRelease(SCIP_INTERRUPT *interrupt)
Definition: interrupt.c:144
static volatile int nterms
Definition: interrupt.c:47
void SCIPresetInterrupted(void)
Definition: interrupt.c:190
static volatile int ninterrupts
Definition: interrupt.c:45
void SCIPinterruptCapture(SCIP_INTERRUPT *interrupt)
Definition: interrupt.c:114
void SCIPinterruptFree(SCIP_INTERRUPT **interrupt)
Definition: interrupt.c:104
static void interruptHandler(int signum)
Definition: interrupt.c:72
void SCIPtryTerminate(void)
Definition: interrupt.c:182
SCIP_Bool SCIPterminated(void)
Definition: interrupt.c:171
SCIP_Bool SCIPinterrupted(void)
Definition: interrupt.c:163
methods for catching the user CTRL-C interrupt
memory allocation routines
#define BMSfreeMemory(ptr)
Definition: memory.h:145
#define BMSallocMemory(ptr)
Definition: memory.h:118
public methods for message output
struct sigaction oldsigaction
Definition: interrupt.c:65
@ SCIP_OKAY
Definition: type_retcode.h:42
enum SCIP_Retcode SCIP_RETCODE
Definition: type_retcode.h:63