pause_computation.cpp

#include <shogun/base/init.h>
#include <shogun/base/some.h>
#include <shogun/labels/BinaryLabels.h>
#include <shogun/lib/SGVector.h>
#include <shogun/lib/Signal.h>
#include <shogun/machine/Machine.h>
#include <iostream>
#include <thread>

using namespace shogun;
using namespace std;

// Mock Algorithm which implements a fake train_machine method
// (it's a stupid method than a fake one actually)
class MockAlg : public CMachine {

	public:
	MockAlg() : CMachine() {}
	~MockAlg() {}

protected:
	virtual bool train_machine(CFeatures * feat) {
		cout << "Training machine..." << endl;
		
		#pragma omp parallel for		
		for(int i=0; i<10000; i++)
		{
			if (cancel_computation())
				continue;
			pause_computation();
			
			cout << i << endl;
			// We set up a delay to simulate long computation
			this_thread::sleep_for(chrono::milliseconds(1000));
		}			
	}

	virtual void on_pause()
	{
		m_pause_computation_flag = true;	
		cout << "PAUSED" << endl;
		/* Here you will implement your custom actions */
		this_thread::sleep_for(chrono::milliseconds(5000));
		resume_computation();
	}

};

int main() {

	init_shogun_with_defaults();

	// Set up binary labels
	int * labs = new int[2];
	labs[0] = -1;
	labs[1] = 1;
    	SGVector<int32_t> labs_v {labs, 2};
	auto train_labs = some<CBinaryLabels>(labs_v);

	// We enable the signal handler. This way when pressing
	// CTRL+C, it will be Shogun handler to catch the SIGINT.
	get_global_signal()->enable_handler();

	MockAlg a, b;
	
	a.set_labels(train_labs);
	a.train();

	b.set_labels(train_labs);
	b.train();

	return 0;
}