Re: Pointers For Newbies, Reminders For Oldies

Ford, Mike wrote: >> -----Original Message----- >> From: Rene Veerman [mailto:rene7705@gmail.com] >> Sent: 27 January 2010 22:46 >> >> And if your script needs to pass large (> 5Mb) arrays around to >> functions, be sure to use passing-by-reference; failing to do so can >> double your memory requirements, >> possibly hitting the ini_set('memory_lmit', ??) > > Have you benchmarked this? PHP's copy-on-change philosophy means there shouldn't be > much difference in memory terms -- so unless you actually expect to change the array's > contents, you should pass by value. > > As proof, I constructed this little test: > > function test($arg, $base_mem) > { > echo "Additional inside func = ", memory_get_usage()-$base_mem, "<br > />\n"; > } > try changing this to access the array in some way such as: function test($arg, $base_mem) { foreach( $arg as $index => $value ) { } echo "Additional= ", memory_get_usage()-$base_mem, "\n"; } After array creation = 52696 Additional = 101152 Final = 117200 vs: function test(&$arg, $base_mem) After array creation = 52696 Additional = 53104 Final = 101696 there's the double memory usage