/usr/include/ola/util/Watchdog.h is in libola-dev 0.10.3.nojsmin-2+deb9u1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 | /*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Watchdog.h
* Copyright (C) 2015 Simon Newton
*/
#ifndef INCLUDE_OLA_UTIL_WATCHDOG_H_
#define INCLUDE_OLA_UTIL_WATCHDOG_H_
#include <ola/Callback.h>
#include <ola/thread/Mutex.h>
#include <memory>
namespace ola {
/**
* @brief Detects if an operation stalls.
*
* The Watchdog can be used to detect when a operation has stalled. When
* enabled, the Clock() method should be called at regular intervals. While the
* operation is making forward progress, it should kick the watchdog by
* calling Kick().
*
* If Kick() isn't called for the specified number of clock cycles, the reset
* callback will be triggered.
*
* Once a watchdog has fired, it must be Disabled() and Enabled() again to
* reset it.
*
* This class is thread safe.
* See also https://en.wikipedia.org/wiki/Watchdog_timer
*
* @examplepara
*
* One way (not recommended) of using this would be:
*
* ~~~~~~~~~~~~~~~~~~~~~
* // Call periodically
* void WatchdogThread() {
* while (true) {
* watchdog->Clock();
* sleep(1);
* }
* }
*
* void WorkerThread() {
* watchdog->Enable();
* // Start operation.
* while (true) {
* DoWorkSlice();
* watchdog->Kick();
* }
* watchdog->Disable();
* }
* ~~~~~~~~~~~~~~~~~~~~~
*/
class Watchdog {
public:
/**
* @brief Create a new Watchdog.
* @param cycle_limit The number of cycles allowed before the reset callback
* is run.
* @param reset_callback the callback to run when the cycle limit is reached.
*/
Watchdog(unsigned int cycle_limit, Callback0<void> *reset_callback);
/**
* @brief Enable the watchdog.
*/
void Enable();
/**
* @brief Disable the watchdog.
*/
void Disable();
/**
* @brief Kick the watchdog to avoid a reset.
*
* This should be called regularly while the watchdog is enabled.
*/
void Kick();
/**
* @brief Check if the process has stalled due to a lack of Kick() calls.
*
* This should be called regularly. If it's been more than the specified
* number of clock cycles since a kick, the callback is run.
*/
void Clock();
private:
const unsigned int m_limit;
std::auto_ptr<Callback0<void> > m_callback;
ola::thread::Mutex m_mu;
bool m_enabled; // GUARDED_BY(m_mu);
unsigned int m_count; // GUARDED_BY(m_mu);
bool m_fired; // GUARDED_BY(m_mu);
};
} // namespace ola
#endif // INCLUDE_OLA_UTIL_WATCHDOG_H_
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