wikimedia / mediawiki

		do { // callbacks may add callbacks :)

			$callbacks = $this->mTrxPreCommitCallbacks;

			$this->mTrxPreCommitCallbacks = []; // consumed (and recursion guard)

			foreach ( $callbacks as $callback ) {

				try {

					list( $phpCallback ) = $callback;

					call_user_func( $phpCallback );

				} catch ( Exception $ex ) {

					MWExceptionHandler::logException( $ex );

					$e = $e ?: $ex;

				}

			}

		} while ( count( $this->mTrxPreCommitCallbacks ) );

		if ( $e instanceof Exception ) {

		/** @var Exception $e */

		$e = null; // first exception

		foreach ( $this->mTrxRecurringCallbacks as $callback ) {

			try {

				list( $phpCallback ) = $callback;

				$phpCallback( $trigger, $this );

			} catch ( Exception $ex ) {

				MWExceptionHandler::logException( $ex );

				$e = $e ?: $ex;

			}

		}

		if ( $e instanceof Exception ) {

			throw $e; // re-throw any first exception