IpplMemoryUsage.h

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// -*- C++ -*-
/***************************************************************************
 *
 * The IPPL Framework
 * 
 *
 * Visit http://people.web.psi.ch/adelmann/ for more details
 *
 ***************************************************************************/

#ifndef IPPL_MEMPRYUSAGE_H
#define IPPL_MEMPRYUSAGE_H

/*************************************************************************
 * IpplMemoryUsage - a simple singleton class which lets the user watch the
 * memory consumption of a program.
 * 
 * ATTENTION: We use following memory convention
 * 
 *            8 bit = 1 byte = 1e-3 kB = 1e-6 MB
 *                           = 1e-3 / 1.024 KiB (KibiByte)
 *                           = 1e-3 / 1.024 / 1.024 MiB (MebiByte)
 * 
 *           instead of the usually taken but wrong relation 1024 kB = 1 MB.
 *
 * General usage
 *  1) create the instance using IpplMemoryUsage::getInstance(unit, reset).
 *     The reset boolean indicates wether the memory at creation should be
 *     subtracted from the measurements later on.
 *     The class is based on t getrusage() that returns the memory
 *     consumption in kB (KiloByte). You can specify the return value of
 *     IpplMemoryUsage by the first argument.
 *     Although one can use those input parameters they are only applied
 *     at the first call. Additional calls with different input do NOT
 *     modify the instance.
 *  2) At any point in the program you can call IpplMemoryUsage::sample()
 *     to collect the data.
 *************************************************************************/

// include files
#include "Ippl.h"
#include <memory>

#include <sys/resource.h>
#include <sys/time.h> // not required but increases portability


class IpplMemoryUsage {

public:
    
    typedef IpplMemoryUsage*                    IpplMemory_p;
    typedef std::unique_ptr<IpplMemoryUsage>    IpplMemory_t;
    
    enum Unit {
        BIT,    
        B,      
        KB,     
        KiB,    
        MB,     
        MiB,    
        GB,     
        GiB     
    };
    
public:
    static IpplMemory_p getInstance(Unit unit=Unit::GB, bool reset = true);
    
    double getMemoryUsage(int core) const;
    
    void sample();
    
    const std::string& getUnit() const;
    
private:
    IpplMemoryUsage();
    
    IpplMemoryUsage(Unit unit = Unit::GB, bool reset = true);
    
    void sample_m();
    
private:
    static IpplMemory_t instance_mp;                
    std::unique_ptr<double[]> globalMemPerCore_m;   
    std::string unit_m;                             
    double initial_memory_m;                        
    double max_rss_m;                               
    double conversion_factor_m;                     
    double who_m;                                   
};

#endif