Counter
[Tools]

These functions allow you to get the time spent in a part of a code. More...

Typedefs

typedef struct _Eina_Counter Eina_Counter
 Counter type.

Functions

Eina_Countereina_counter_new (const char *name)
 Return a counter.
void eina_counter_free (Eina_Counter *counter)
 Delete a counter.
void eina_counter_start (Eina_Counter *counter)
 Start the time count.
void eina_counter_stop (Eina_Counter *counter, int specimen)
 Stop the time count.
char * eina_counter_dump (Eina_Counter *counter)
 Dump the result of all clocks of a counter to a stream.

Detailed Description

These functions allow you to get the time spent in a part of a code.

Before using the counter system, Eina must be initialized with eina_init() and later shut down with eina_shutdown(). The create a counter, use eina_counter_new(). To free it, use eina_counter_free().

To time a part of a code, call eina_counter_start() just before it, and eina_counter_stop() just after it. Each time you start to time a code, a clock is added to a list. You can give a number of that clock with the second argument of eina_counter_stop(). To send all the registered clocks to a stream (like stdout, ofr a file), use eina_counter_dump().

Here is a straightforward example:

 #include <stdlib.h>
 #include <stdio.h>

 #include <eina_counter.h>

 void test_malloc(void)
 {
    int i;

    for (i = 0; i < 100000; ++i)
    {
       void *buf;

       buf = malloc(100);
       free(buf);
    }
 }

 int main(void)
 {
    Eina_Counter *counter;

    if (!eina_init())
    {
        printf("Error during the initialization of eina\n");
        return EXIT_FAILURE;
    }

    counter = eina_counter_new("malloc");

    eina_counter_start(counter);
    test_malloc();
    eina_counter_stop(counter, 1);

    char* result = eina_counter_dump(counter);
    printf("%s", result);
    free(result);

    eina_counter_free(counter);
    eina_shutdown();

    return EXIT_SUCCESS;
 }

Compile this code with the following commant:

 * gcc -Wall -o test_eina_counter test_eina.c `pkg-config --cflags --libs eina`
 * 

The result should be something like that:

 * \# specimen    experiment time    starting time    ending time
 * 1              9794125            783816           10577941
 * 

Note that the displayed time is in nanosecond.


Function Documentation

Eina_Counter * eina_counter_new ( const char *  name  ) 

Return a counter.

Parameters:
name The name of the counter.
Returns:
A newly allocated counter.

This function returns a new counter. It is characterized by name. If name is NULL, the function returns NULL immediately. If memory allocation fails, NULL is returned and the error is set to EINA_ERROR_OUT_OF_MEMORY.

Whe the new counter is not needed anymore, use eina_counter_free() to free the allocated memory.

void eina_counter_free ( Eina_Counter counter  ) 

Delete a counter.

Parameters:
counter The counter to delete.

This function remove the clock of counter from the used clocks (see eina_counter_start()) and frees the memory allocated for counter. If counter is NULL, the function returns immediately.

void eina_counter_start ( Eina_Counter counter  ) 

Start the time count.

Parameters:
counter The counter.

This function specifies that the part of the code beginning just after its call is being to be timed, using counter. If counter is NULL, this function returns immediately.

This function adds the clock associated to counter in a list. If the memory needed by that clock can not be allocated, the function returns and the error is set to EINA_ERROR_OUT_OF_MEMORY.

To stop the timing, eina_counter_stop() must be called with the same counter.

void eina_counter_stop ( Eina_Counter counter,
int  specimen 
)

Stop the time count.

Parameters:
counter The counter.
specimen The number of the test.

This function stop the timing that has been started with eina_counter_start(). counter must be the same than the one used with eina_counter_start(). specimen is the number of the test. If counter or its associated clock are NULL, or if the time can't be retrieved the function exits.

char * eina_counter_dump ( Eina_Counter counter  ) 

Dump the result of all clocks of a counter to a stream.

Returns:
A string with a summary of the test.
Parameters:
counter The counter.

This function returns an malloc'd string containing the dump of all the valid clocks of counter. If counter NULL, the functions exits immediately. Otherwise, the output is formattted like that:

 * \# specimen    experiment time    starting time    ending time
 * 1              208                120000           120208
 * 

The unit of time is the nanosecond.