pixelflut-rgb-matrix-server/include/thread.h

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2020-12-26 12:23:47 +00:00
// -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
// Copyright (C) 2013 Henner Zeller <h.zeller@acm.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 version 2.
//
// 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 <http://gnu.org/licenses/gpl-2.0.txt>
#ifndef RPI_THREAD_H
#define RPI_THREAD_H
#include <stdint.h>
#include <pthread.h>
namespace rgb_matrix {
// Simple thread abstraction.
class Thread {
public:
Thread();
// The destructor waits for Run() to return so make sure it does.
virtual ~Thread();
// Wait for the Run() method to return.
void WaitStopped();
// Start thread. If realtime_priority is > 0, then this will be a
// thread with SCHED_FIFO and the given priority.
// If cpu_affinity is set !=, chooses the given bitmask of CPUs
// this thread should have an affinity to.
// On a Raspberry Pi 1, this doesn't matter, as there is only one core,
// Raspberry Pi 2 can has 4 cores, so any combination of (1<<0) .. (1<<3) is
// valid.
virtual void Start(int realtime_priority = 0, uint32_t cpu_affinity_mask = 0);
// Override this to do the work.
//
// This will be called in a thread once Start() has been called. You typically
// will have an endless loop doing stuff.
//
// It is a good idea to provide a way to communicate to the thread that
// it should stop (see ThreadedCanvasManipulator for an example)
virtual void Run() = 0;
private:
static void *PthreadCallRun(void *tobject);
bool started_;
pthread_t thread_;
};
// Non-recursive Mutex.
class Mutex {
public:
Mutex() { pthread_mutex_init(&mutex_, NULL); }
~Mutex() { pthread_mutex_destroy(&mutex_); }
void Lock() { pthread_mutex_lock(&mutex_); }
void Unlock() { pthread_mutex_unlock(&mutex_); }
// Wait on condition. If "timeout_ms" is < 0, it waits forever, otherwise
// until timeout is reached.
// Returns 'true' if condition is met, 'false', if wait timed out.
bool WaitOn(pthread_cond_t *cond, long timeout_ms = -1);
private:
pthread_mutex_t mutex_;
};
// Useful RAII wrapper around mutex.
class MutexLock {
public:
MutexLock(Mutex *m) : mutex_(m) { mutex_->Lock(); }
~MutexLock() { mutex_->Unlock(); }
private:
Mutex *const mutex_;
};
} // end namespace rgb_matrix
#endif // RPI_THREAD_H