Performance Profiling

To perform performance measurements or found applications bottlenecks you can use RhoMobile Profiler tool.

RhoMobile Profiler use performance counters to calculate execution time of specific function/code. There are 2 types of counters: global and local:

• Global counters created once and can be stopped/started many times. When Global counter destroyed, it log accumulative time of all start/stop intervals.
• Local counters can be stopped/started only once. While stopped, counter will log time interval between start and stop.

• Profiler log.
• Enable Profiler.
• Built-in performance counters.
• RhoProfiler Ruby API Examples
• RhoProfiler C/C++ API.

Profiler log.

When Counter stopped (Local counters) or destroyed(Global counters) information from counter will be logged in the following format:

(log prefix) PRFILER| (counter name)( (counter time Minutes:Seconds:Milliseconds) ): START/STOP

For example:

I 06/18/2012 23:27:20:311 00002ffc PROFILER| BROWSER_PAGE (0:03:104) : STOP

Enable Profiler.

Profiler is configurable at build time in build.yml file(Turned Off by default):

profiler: 1

Will turn on Profiler

After Profiler ON/OFF - full rebuild is required.

Built-in performance counters.

These counters start working after you turn on Profiler in build.yml:

• ERB_RENDER - ERB-file render (Ruby)
• CTRL_ACTION - Controller action (Ruby)
• INDEX_ACTION - Index page render
• ERB_RENDER - ERB-file render (Ruby)
• BROWSER_PAGE - Browser page loading time (Native)

• SyncEngine components has several native counters:

  ‘Sync’ - Full sync time

  ‘DB’ - Time spend for database insert/update/delete while sync

  ‘Net’ - Time spend for network communication while sync

These counters works only if you create them in application. You can create counter in controller action and destroy it after some operations:

• Sqlite database (Native)

  ‘SQLITE’ - counter for whole time processing SQL query including data conversion , sqlite3_step and prepare statement

  ‘SQLITE_EXEC’ - sqlite3_step time only.

To Enable Ruby Garbage collector logging modify rhoconfig.txt(set log level to Trace):

MinSeverity = 0

There are two Profiler API available: Ruby and Native(C/C++).

RhoProfiler Ruby API Examples

The RhoProfiler Ruby API contains the following static methods.

• create_counter creates a Global counter.
• destroy_counter destroys a Global counter.
• start_counter starts a Local or Global counter. If a Global counter with this name exists, this global counter will be started. If no global counter exists, a local counter will be created and started.
• stop_counter stops a Global or local counter.
• flush_counter logs information from a counter (Local or Global). Counter does not stop or start.
• start_created_counter - The counter will start only if it is already created previously (Global counter).

Example of custom counter:

def index
    RhoProfiler.create_counter('Counter1')

    RhoProfiler.start_counter('Counter1')
    function1()
    RhoProfiler.stop_counter('Counter1')

    #do something

    RhoProfiler.start_counter('Counter1')
    function2()
    RhoProfiler.stop_counter('Counter1')

    RhoProfiler.destroy_counter('Counter1') #Will log summary of function1 and function2 execution time
end

Example using ‘SQLITE’ built-in counter:

def some_method

 RhoProfiler.create_counter('SQLITE')

 #do something: create/update objects for example

 RhoProfiler.destroy_counter('SQLITE')

end

RhoProfiler C/C++ API.

RhoProfiler C/C++ API contains several defines to manipulate Performance Counters. Here is the list of defines:

//Global accumulative counters
#define PROF_CREATE_COUNTER(name)     // Create Global counter
#define PROF_DESTROY_COUNTER(name)    // Destroy Global counter
#define PROF_START(name) //Start Local or Global counter. If Global counter with this name exist , this global counter will started. If no global counter exists, local counter will be created and started.

#define PROF_STOP(name) // Stop Global or local counter. 
#define PROF_FLUSH_COUNTER(name,msg) //Log information from counter(Local or Global). Counter does not stopped or started. 
#define PROF_START_CREATED(name) //Counter will start only if it is already created previously(Global counter)

Example:

#include "statistic/RhoProfiler.h"
void testFunction()
{
    PROF_CREATE_COUNTER("Counter1");

    PROF_START("Counter1");
    function1();
    PROF_STOP("Counter1");

    //do something

    PROF_START("Counter1")
    function2();
    PROF_STOP("Counter1")

    PROF_DESTROY_COUNTER("Counter1") #Will log summary of function1 and function2 execution time
}