// Provide some ability to lock a PHP function so that multiple processes
// can't run the function concurrently
if(! function_exists('lock_function')) {
-function lock_function($fn_name, $block = true, $wait_sec = 2) {
+function lock_function($fn_name, $block = true, $wait_sec = 2, $timeout = 30) {
if( $wait_sec == 0 )
$wait_sec = 2; // don't let the user pick a value that's likely to crash the system
$got_lock = false;
+ $start = time();
do {
- q("LOCK TABLE locks WRITE");
- $r = q("SELECT locked FROM locks WHERE name = '%s' LIMIT 1",
+ q("LOCK TABLE `locks` WRITE");
+ $r = q("SELECT `locked`, `created` FROM `locks` WHERE `name` = '%s' LIMIT 1",
dbesc($fn_name)
);
- if((count($r)) && (! $r[0]['locked'])) {
- q("UPDATE locks SET locked = 1 WHERE name = '%s' LIMIT 1",
+ if((count($r)) AND (!$r[0]['locked'] OR (strtotime($r[0]['created']) < time() - 3600))) {
+ q("UPDATE `locks` SET `locked` = 1, `created` = '%s' WHERE `name` = '%s'",
+ dbesc(datetime_convert()),
dbesc($fn_name)
);
$got_lock = true;
}
elseif(! $r) { // the Boolean value for count($r) should be equivalent to the Boolean value of $r
- q("INSERT INTO locks ( name, locked ) VALUES ( '%s', 1 )",
- dbesc($fn_name)
+ q("INSERT INTO `locks` (`name`, `created`, `locked`) VALUES ('%s', '%s', 1)",
+ dbesc($fn_name),
+ dbesc(datetime_convert())
);
$got_lock = true;
}
if(($block) && (! $got_lock))
sleep($wait_sec);
- } while(($block) && (! $got_lock));
+ } while(($block) && (! $got_lock) && ((time() - $start) < $timeout));
+
+ logger('lock_function: function ' . $fn_name . ' with blocking = ' . $block . ' got_lock = ' . $got_lock . ' time = ' . (time() - $start), LOGGER_DEBUG);
- logger('lock_function: function ' . $fn_name . ' with blocking = ' . $block . ' got_lock = ' . $got_lock, LOGGER_DEBUG);
-
return $got_lock;
}}
if(! function_exists('block_on_function_lock')) {
-function block_on_function_lock($fn_name, $wait_sec = 2) {
+function block_on_function_lock($fn_name, $wait_sec = 2, $timeout = 30) {
if( $wait_sec == 0 )
$wait_sec = 2; // don't let the user pick a value that's likely to crash the system
+ $start = time();
+
do {
$r = q("SELECT locked FROM locks WHERE name = '%s' LIMIT 1",
dbesc($fn_name)
if(count($r) && $r[0]['locked'])
sleep($wait_sec);
- } while(count($r) && $r[0]['locked']);
+ } while(count($r) && $r[0]['locked'] && ((time() - $start) < $timeout));
return;
}}
if(! function_exists('unlock_function')) {
function unlock_function($fn_name) {
- //$r = q("LOCK TABLE lock WRITE");
- $r = q("UPDATE locks SET locked = 0 WHERE name = '%s' LIMIT 1",
+ $r = q("UPDATE `locks` SET `locked` = 0, `created` = '0000-00-00 00:00:00' WHERE `name` = '%s'",
dbesc($fn_name)
);
- //$r = q("UNLOCK TABLES");
logger('unlock_function: released lock for function ' . $fn_name, LOGGER_DEBUG);
return;
}}
-
-?>