diff options
Diffstat (limited to 'include')
| -rwxr-xr-x | include/diaspora.php | 12 | ||||
| -rw-r--r-- | include/lock.php | 15 |
2 files changed, 18 insertions, 9 deletions
diff --git a/include/diaspora.php b/include/diaspora.php index 29846eedf..35cd66059 100755 --- a/include/diaspora.php +++ b/include/diaspora.php @@ -119,6 +119,9 @@ function find_diaspora_person_by_handle($handle) { $update = false; $got_lock = false; + $endlessloop = 0; + $maxloops = 10; + do { $r = q("select * from fcontact where network = '%s' and addr = '%s' limit 1", dbesc(NETWORK_DIASPORA), @@ -153,7 +156,12 @@ function find_diaspora_person_by_handle($handle) { // Lock the function to prevent race conditions if multiple items // come in at the same time from a person who doesn't exist in // fcontact - $got_lock = lock_function('find_diaspora_person_by_handle', false); + // + // Don't loop forever. On the last loop, try to create the contact + // whether the function is locked or not. Maybe the locking thread + // has died or something. At any rate, a duplicate in 'fcontact' + // is a much smaller problem than a deadlocked thread + $got_lock = (($endlessloop + 1) < $maxloops ? lock_function('find_diaspora_person_by_handle', false) : true ); if($got_lock) { logger('find_diaspora_person_by_handle: create or refresh', LOGGER_DEBUG); @@ -175,7 +183,7 @@ function find_diaspora_person_by_handle($handle) { block_on_function_lock('find_diaspora_person_by_handle'); } } - } while((! $person) && (! $got_lock)); + } while((! $person) && (! $got_lock) && (++$endlessloop < $maxloops)); // We need to try again if the person wasn't in 'fcontact' but the function was locked. // The fact that the function was locked may mean that another process was creating the // person's record. It could also mean another process was creating or updating an unrelated diff --git a/include/lock.php b/include/lock.php index 9bdb71125..5f1ca6323 100644 --- a/include/lock.php +++ b/include/lock.php @@ -3,11 +3,12 @@ // Provide some ability to lock a PHP function so that multiple processes // can't run the function concurrently if(! function_exists('lock_function')) { -function lock_function($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; + $start = time(); do { q("LOCK TABLE locks WRITE"); @@ -33,19 +34,21 @@ function lock_function($fn_name, $block = true, $wait_sec = 2) { if(($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, LOGGER_DEBUG); + logger('lock_function: function ' . $fn_name . ' with blocking = ' . $block . ' got_lock = ' . $got_lock . ' time = ' . (time() - $start), 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) @@ -54,7 +57,7 @@ function block_on_function_lock($fn_name, $wait_sec = 2) { if(count($r) && $r[0]['locked']) sleep($wait_sec); - } while(count($r) && $r[0]['locked']); + } while(count($r) && $r[0]['locked'] && ((time() - $start) < $timeout)); return; }} @@ -62,11 +65,9 @@ function block_on_function_lock($fn_name, $wait_sec = 2) { if(! function_exists('unlock_function')) { function unlock_function($fn_name) { - //$r = q("LOCK TABLE lock WRITE"); $r = q("UPDATE locks SET locked = 0 WHERE name = '%s' LIMIT 1", dbesc($fn_name) ); - //$r = q("UNLOCK TABLES"); logger('unlock_function: released lock for function ' . $fn_name, LOGGER_DEBUG); |