1 /* 2 Copyright (c) 2003, 2021, Oracle and/or its affiliates. 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License, version 2.0, 6 as published by the Free Software Foundation. 7 8 This program is also distributed with certain software (including 9 but not limited to OpenSSL) that is licensed under separate terms, 10 as designated in a particular file or component or in included license 11 documentation. The authors of MySQL hereby grant you an additional 12 permission to link the program and your derivative works with the 13 separately licensed software that they have included with MySQL. 14 15 This program is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License, version 2.0, for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with this program; if not, write to the Free Software 22 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 23 */ 24 25 #ifndef TIMER_HPP 26 #define TIMER_HPP 27 28 /** 29 * @class Timer 30 * @brief A timer class that can't be fooled by NTP:ing the system clock to old time 31 * The 'time' used by this class is 'ticks' since some platform 32 * specific epoch start. Typically retrieved by NdbTick_getCurrentTicks() 33 */ 34 class Timer { 35 public: Timer()36 Timer() { 37 m_delay = 10; 38 }; 39 Timer(Uint64 delay_time)40 Timer(Uint64 delay_time) { 41 m_delay = delay_time; 42 } 43 44 /** 45 * Set/Get alarm time of timer 46 */ setDelay(Uint64 delay_time)47 inline void setDelay(Uint64 delay_time) { m_delay = delay_time; } getDelay() const48 inline Uint64 getDelay() const { return m_delay; } 49 50 /** 51 * Start timer 52 */ reset(NDB_TICKS now)53 inline void reset(NDB_TICKS now) { 54 m_start_time = now; 55 } 56 check(NDB_TICKS now)57 inline bool check(NDB_TICKS now) { 58 59 /** 60 * Protect against time moving backwards. 61 * In that case use 'backtick' as new start. 62 */ 63 if (NdbTick_Compare(m_start_time,now) > 0) 64 { 65 m_start_time = now; 66 return false; 67 } 68 69 /** 70 * Standard alarm check 71 */ 72 if (NdbTick_Elapsed(m_start_time,now).milliSec() > m_delay) 73 return true; 74 75 /** 76 * Time progressing, but it is not alarm time yet 77 */ 78 return false; 79 } 80 81 private: 82 NDB_TICKS m_start_time; 83 Uint64 m_delay; 84 }; 85 86 #endif 87