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PerfMon.javaAPI DocJ2ME MIDP 2.012146Thu Nov 07 12:02:24 GMT 2002com.sun.midp.perfmon

PerfMon

public class PerfMon extends Object implements PerformanceMonitor
A class that implements the PerformanceMonitor interface. A performance monitor session consists of a start time [ start method ] and an end time [ end method ]. This class tracks a number of system resources that provides the ability to track a system resource for delta's between the start and end of a session.

Each performance monitor session must include a call to the start and end methods in order to measure system resource delta's. Once a proper session call sequence has been made the application can then access the appropriate methods to retrieve the desired system resource delta. Once a call has been made to start method a new session has been started.

In order to ensure data integrity the implemenation of the PerformanceMonitor interface requires the appl using the interface always uses the interface with the proper calling sequence. Below is an example of how an application would use the PerformanceMonitor interface (and/or implemenation) correctly:

This example of code shows how an application might want to use the PerformanceMonitor interface to measure read() I/O resources. 

start = perfmon.start("read()"); // start a perfmon session

for (int i = 0 ; i < len ; i++ ) {
if ((ch = input.read()) != -1){
if (ch <= ' ') ch = ' ';
b.append((char) ch);
}
}
end = perfmon.end(); // end a perfmon session

perfmon.report(System.err); // print standard report format

String results =
Long.toString(
perfmon.getStat((
PerfMon.INSTRUCTION_COUNTER))); // get it as string

System.err.println(
"Instruction Counter (string): ["+
results + "]"); // print the string

Fields Summary
String
m_classname
the class name of the object being tested - prints on report
String
m_testname
the testname of the application being tested - prints on report
boolean
m_first_time
first time logic flag
long
m_start_t
start time for calling application
long
m_end_t
end time for calling application
long
m_delta_t
total time for calling application
int[]
m_start_count
all measurement start counters
int[]
m_end_count
all measurement end counters
int[]
m_delta_count
all measurement delta counters
Constructors Summary
public PerfMon()
Construct a PerfMon object.


             
      
	
	this("");
public PerfMon(String classname)
Construct a PerfMon object.

param
classname the application or classname being tested

        
        m_classname = classname;
                
        m_start_count = new int[TOTAL_SYSTEM_PERFMON_COUNTERS];
        m_end_count = new int[TOTAL_SYSTEM_PERFMON_COUNTERS];
        m_delta_count = new int[TOTAL_SYSTEM_PERFMON_COUNTERS];
Methods Summary
public synchronized longend()
Ends the performance monitor timer and system measurements.

return
end time (long - return System.currentTimeMillis())

        
        for (int i = 0; i < TOTAL_SYSTEM_PERFMON_COUNTERS; i++) {
            m_end_count[i] = getStat(i);
        }
        
        m_end_t = System.currentTimeMillis();
        
        return (m_end_t);
public intgetDelta(int perfmon_id)
Gets the appropriate perfmon status delta measurement value between a specific start and end time.

param
perfmon_id the perfmon id type (e.g. INSTRUCTION_COUNTER)
return
perfmon stat value (between start and end)
exception
IllegalStateException if start or end equal 0
exception
IllegalArgumentException invalid measurement type

        
        if ((m_start_count[INSTRUCTION_COUNTER] == 0) ||
            (m_end_count[INSTRUCTION_COUNTER] == 0))
            {
                
                throw new 
                    IllegalStateException("Invalid start/end sequence.");
            }
        
        if (perfmon_id < INSTRUCTION_COUNTER || 
            perfmon_id > GARBAGE_COLLECTION_RESCANS) {
            
            throw new 
                IllegalArgumentException("Invalid PerfMon measurement type");
        }
        
        return (int) (m_delta_count[perfmon_id] =
                      m_end_count[perfmon_id] -
                      m_start_count[perfmon_id]);
public longgetElapsedTime()
Gets the current perfmon session elapsed time.

return
current perfmon elapsed time
exception
IllegalStateException if start or end equal 0


        if ((m_start_count[INSTRUCTION_COUNTER] == 0) ||
            (m_end_count[INSTRUCTION_COUNTER] == 0)) {
            
            throw new 
                IllegalStateException("Invalid start/end sequence.");
        }
        return ((m_delta_t = m_end_t - m_start_t));
public longgetEndTime()
Gets the current perfmon session end time.

return
current perfmon end time in milliseconds

        return (m_end_t);
public longgetStartTime()
Gets the current perfmon session start time.

return
current perfmon start time in milliseconds


        return (m_start_t);
public intgetStat(int perfmon_id)
Gets the appropriate and current perfmon stat value.

param
perfmon_id perfmon id (e.g. THREAD_SWITCH_COUNTER).
return
perfmon status current value
exception
IllegalArgumentException if an invalid perfmon id type

        
        if (perfmon_id < INSTRUCTION_COUNTER || 
            perfmon_id > GARBAGE_COLLECTION_RESCANS) {
            
            throw new 
                IllegalArgumentException("Invalid PerfMon measurement type");
        }

        return (int)(sysGetCounter(perfmon_id));
public synchronized voidinit()
Initializes the performance monitor timer.

        
        m_start_t                       = 0;
        m_end_t                         = -1;
	m_testname                      = null;
        
        for (int i = 0; i < TOTAL_SYSTEM_PERFMON_COUNTERS; i++) {	    
	    m_start_count[i] = 0;
	    m_end_count[i] = 0;
	    m_delta_count[i] = 0;
	}
public synchronized voidreport(java.io.PrintStream printstream)
Reports a standard perfmon output format to a PrintStream which includes delta measurements (e.g. elapsed time) between a specific start and end time.

param
printstream output stream to print to


        Calendar cal = Calendar.getInstance();
        
        TimeZone tz = TimeZone.getTimeZone("GMT");
        cal.setTimeZone(tz);
        
        m_delta_t = m_end_t - m_start_t;
        
        for (int i = 0; i < TOTAL_SYSTEM_PERFMON_COUNTERS; i++) {
            m_delta_count[i] = m_end_count[i] - m_start_count[i];
        }

        if (m_first_time) {
            printstream.println("\n=====================================" +
                                "=====================================" +
                                "=====");
            printstream.println("\t\t\tPerformance Monitor Tracing Report");
            printstream.println("Application Name: ["+m_classname+"]");
            printstream.println("Report Date: ["+toString(cal) + "]");
            printstream.println("=====================================" +
                                "=====================================" +
                                "=====\n");
            m_first_time = false;
        }

        printstream.println("-------------------------------------" +
                            "-------------------------------------" +
                            "-----");
        printstream.println("Performance Monitor - Snapshot Analysis - ");
        printstream.println("TimeStamp: \t\t["+toString(cal)+"]");
        printstream.println("Class Name: \t\t["+m_classname+"]");
        printstream.println("Test Name: \t\t["+m_testname+"]");
        printstream.println("Elapsed Time : \t\t["+m_delta_t+
                           "] (milli-seconds)");
        printstream.println("Classname: \t\t["+m_classname+"]");
        printstream.println("Instruction Count: \t["+
                           m_delta_count[INSTRUCTION_COUNTER]+"]");
        printstream.println("Thread Switch Count: \t["+ 
                           m_delta_count[THREAD_SWITCH_COUNTER]+"]");
        printstream.println("Dynamic Object Count: \t["+ 
                           m_delta_count[DYNAMIC_OBJECT_COUNTER]+"]");
        printstream.println("Dynamic Alloc Count: \t["+ 
                           m_delta_count[DYNAMIC_ALLOC_COUNTER]+"]");
        printstream.println("Dynamic Dealloc Count: \t["+ 
                           m_delta_count[DYNAMIC_DEALLOC_COUNTER]+"]");
        printstream.println("Garbage Collect Count: \t["+
                           m_delta_count[GARBAGE_COLLECTION_COUNTER]+"]");
        printstream.println("GC Deferrals: \t\t["+ 
                           m_delta_count[TOTAL_GC_DEFERRALS]+"]");
        printstream.println("Maximum GC Deferrals: \t["+ 
                           m_delta_count[MAX_GC_DEFERRALS]+"]");
        printstream.println("Garbage Collect Rescans:["+ 
                           m_delta_count[GARBAGE_COLLECTION_RESCANS]+"]");
        printstream.println("-------------------------------------" +
                            "-------------------------------------" +
                            "-----\n");
public synchronized longstart(java.lang.String testname)
Starts the performance monitor timer and system measurements.

param
testname current method name
return
start time (long - return System.currentTimeMillis())


        this.init();
        
        m_testname = testname;
        
        for (int i = 0; i < TOTAL_SYSTEM_PERFMON_COUNTERS; i++) {
	    m_start_count[i] = getStat(i);
        }
        
        m_start_t = System.currentTimeMillis();
        
        return (m_start_t);
static native intsysGetCounter(int count)
All native methods are defined here NOTE: functions defined in $(MIDP_WS)/src/share/native/perfmon.c

param
count performance monitor counter type
return
current system measurement for counter type
exception
IllegalStateException if start or end equal 0

static java.lang.StringtoString(java.util.Calendar cal)
Formats a Date for output display.
param
cal calendar object
return
formatted calendar string format

        int h = cal.get(Calendar.HOUR);
        String hour = h == 0? " (00" : (h < 10? (" (0"+h) : (" ("+h));
        int m = cal.get(Calendar.MINUTE);
        String min = m == 0? ":00" : (m < 10? (":0"+m) : (":"+m));
        int am_pm = cal.get(Calendar.AM_PM);
        return cal.toString()+hour+min+" " + 
            (am_pm == Calendar.PM? "pm)" : "am)");