001package com.pi4j.io.wdt.impl; 002 003/* 004 * #%L 005 * ********************************************************************** 006 * ORGANIZATION : Pi4J 007 * PROJECT : Pi4J :: Java Library (Core) 008 * FILENAME : WDTimerImpl.java 009 * 010 * This file is part of the Pi4J project. More information about 011 * this project can be found here: https://www.pi4j.com/ 012 * ********************************************************************** 013 * %% 014 * Copyright (C) 2012 - 2019 Pi4J 015 * %% 016 * This program is free software: you can redistribute it and/or modify 017 * it under the terms of the GNU Lesser General Public License as 018 * published by the Free Software Foundation, either version 3 of the 019 * License, or (at your option) any later version. 020 * 021 * This program is distributed in the hope that it will be useful, 022 * but WITHOUT ANY WARRANTY; without even the implied warranty of 023 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 024 * GNU General Lesser Public License for more details. 025 * 026 * You should have received a copy of the GNU General Lesser Public 027 * License along with this program. If not, see 028 * <http://www.gnu.org/licenses/lgpl-3.0.html>. 029 * #L% 030 */ 031 032import com.pi4j.io.wdt.WDTimer; 033import com.pi4j.jni.WDT; 034import java.io.IOException; 035 036/** 037 * 038 * @author zerog 039 */ 040public final class WDTimerImpl implements WDTimer { 041 042 private static final WDTimerImpl instance = new WDTimerImpl(); 043 044 /** File handle for watchdog */ 045 private int fd = -1; 046 047 /** File name of watchdog */ 048 private String filename; 049 050 /** 051 * Singleton. 052 * 053 * @return instance 054 */ 055 public static WDTimer getInstance() { 056 return instance; 057 } 058 059 /** 060 * Open Watchdog. 061 * 062 * @throws IOException 063 */ 064 @Override 065 public void open() throws IOException { 066 open("/dev/watchdog"); 067 } 068 069 070 /** 071 * Open custom Watchdog 072 * 073 * @param file 074 * @throws IOException 075 */ 076 public void open(String file) throws IOException { 077 filename = file; 078 if(fd>0) { 079 throw new IOException("File "+filename+" already open."); 080 } 081 fd = WDT.open(file); 082 if(fd<0) { 083 throw new IOException("Cannot open file handle for " + filename + " got " + fd + " back."); 084 } 085 } 086 087 /** 088 * Set new timeout 089 * 090 * @param timeout 091 * @throws IOException 092 */ 093 @Override 094 public void setTimeOut(int timeout) throws IOException { 095 isOpen(); 096 int ret = WDT.setTimeOut(fd, timeout); 097 if(ret<0) { 098 throw new IOException("Cannot set timeout for " + filename + " got " + ret + " back."); 099 } 100 } 101 102 /** 103 * Get timeout 104 * 105 * @return 106 * @throws IOException 107 */ 108 @Override 109 public int getTimeOut() throws IOException { 110 isOpen(); 111 int ret = WDT.getTimeOut(fd); 112 if(ret<0) { 113 throw new IOException("Cannot read timeout for " + filename + " got " + ret + " back."); 114 } 115 return ret; 116 } 117 118 /** 119 * Ping a watchdog. 120 * 121 * @throws IOException 122 */ 123 @Override 124 public void heartbeat() throws IOException { 125 isOpen(); 126 int ret = WDT.ping(fd); 127 if(ret<0) { 128 throw new IOException("Heartbeat error. File " + filename + " got " + ret + " back."); 129 } 130 } 131 132 /** 133 * Disable watchdog with "Magic Close". Now watchdog not working. 134 * Close watchdog without call disable causes RaspberryPi reboot! 135 * @throws IOException 136 */ 137 @Override 138 public void disable() throws IOException { 139 isOpen(); 140 int ret = WDT.disable(fd); 141 if(ret<0) { 142 throw new IOException("Cannot disable WatchDog. File " + filename + " got " + ret + " back."); 143 } 144 } 145 146 /** 147 * Close a watchdog (file). If close without {@link disable} Raspberry reboot after 148 * timeout expired. 149 * 150 * @throws IOException 151 */ 152 @Override 153 public void close() throws IOException { 154 isOpen(); 155 int ret = WDT.close(fd); 156 if(ret<0) { 157 throw new IOException("Close file " + filename + " got " + ret + " back."); 158 } 159 fd=-1; 160 } 161 162 /** 163 * Test if WDT is open 164 * @throws IOException if not 165 */ 166 private void isOpen() throws IOException { 167 if(fd<0) { 168 throw new IOException("Watchdog is not open yet"); 169 } 170 } 171}