The following are examples of php_calldist.d.
This script traces the elapsed time of PHP functions and prints a report
containing distribution plots per subroutine. Here it traces the example program
Tracing... Hit Ctrl-C to end.
^C
Exclusive function elapsed times (us),
func_abc.php, func, func_a
value ------------- Distribution ------------- count
128 | 0
256 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1
512 | 0
func_abc.php, func, func_b
value ------------- Distribution ------------- count
128 | 0
256 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1
512 | 0
func_abc.php, func, func_c
value ------------- Distribution ------------- count
128 | 0
256 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1
512 | 0
func_abc.php, func, sleep
value ------------- Distribution ------------- count
262144 | 0
524288 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 3
1048576 | 0
Inclusive function elapsed times (us),
func_abc.php, func, func_c
value ------------- Distribution ------------- count
262144 | 0
524288 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1
1048576 | 0
func_abc.php, func, func_b
value ------------- Distribution ------------- count
524288 | 0
1048576 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1
2097152 | 0
func_abc.php, func, sleep
value ------------- Distribution ------------- count
262144 | 0
524288 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 3
1048576 | 0
func_abc.php, func, func_a
value ------------- Distribution ------------- count
1048576 | 0
2097152 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ 1
4194304 | 0
In total, 3 subroutines were called, one each of func_a(), func_b() and
func_c(), and sleep was called 3 times. You can see this reflected in the
"count" column on the right.
The exclusive subroutine elapsed times show that each subroutine spent
between 256 and 512 microseconds. This time excludes the time spent in
other subroutines.
The inclusive subroutine elapsed times show that func_c() took between 0.5
seconds and 1 second, func_b() took between 1 second and 2.1 seconds, and
func_a() took between 2.1 seconds and 4.2 seconds to execute. This time
includes the time spent in other subroutines called, and since func_a() called
func_b() which called func_c(), these times make sense.
These elapsed times are the absolute time from when the subroutine began to
when it completed - which includes off-CPU time due to other system events
such as I/O, scheduling, interrupts, etc.
Elapsed times are useful for identifying where latencies are.
See Notes/ALLelapsed_notes.txt for more details. Also see
detailed explanation of exclusive vs inclusive subroutine time.