(PECL xhprof >= 0.9.0)
xhprof_enable — Start xhprof profiler
$flags = 0
   [, array $options
  ]] )Start xhprof profiling.
flags
       Optional flags to add additional information to the profiling. See the
       XHprof constants for further
       information about these flags, e.g., XHPROF_FLAGS_MEMORY
       to enable memory profiling.
      
optionsAn array of optional options, namely, the 'ignored_functions' option to pass in functions to be ignored during profiling.
   NULL
  
| Version | Description | 
|---|---|
| 0.9.2 | The optional optionsparameter was added. | 
Example #1 xhprof_enable() examples
<?php
// 1. elapsed time + memory + CPU profiling; and ignore built-in (internal) functions
xhprof_enable(XHPROF_FLAGS_NO_BUILTINS | XHPROF_FLAGS_CPU | XHPROF_FLAGS_MEMORY);
// 2. elapsed time profiling; ignore call_user_func* during profiling
xhprof_enable(
    0,
    array('ignored_functions' =>  array('call_user_func',
                                        'call_user_func_array')));
                                       
// 3. elapsed time + memory profiling; ignore call_user_func* during profiling
xhprof_enable(
    XHPROF_FLAGS_MEMORY,
    array('ignored_functions' =>  array('call_user_func',
                                        'call_user_func_array')));
?>