Move the "container updated" message for Buildables that build Diffs outside of the transaction

Summary:
Ref T13216. See PHI970. Ref T13054. See some discussion in T13216.

When a Harbormaster Buildable object is first created for a Diff, it has no `containerPHID` since the revision has not yet been created.

We later (after creating a revision) send the Buildable a message telling it that we've added a container and it should re-link the container object.

Currently, we send this message in `applyExternalEffects()`, which runs inside the Differential transaction. If Harbormaster races quickly enough, it can read the `Diff` object before the transaction commits, and not see the container update.

Add a `didCommitTransaction()` callback after the transactions commit, then move the message code there instead.

Test Plan:
  - See T13216 for substantial evidence that this change is on the right track.
  - Before change: added `sleep(15)`, reproduced the issue reliably.
  - After change: unable to reproduce issue even with `sleep(15)` (the `containerPHID` always populates correctly).

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13216, T13054

Differential Revision: https://secure.phabricator.com/D19807

src/applications/differential/xaction/DifferentialRevisionUpdateTransaction.php

@@ -57,6 +57,12 @@ final class DifferentialRevisionUpdateTransaction
     // Harbormaster. See discussion in T8650.
     $diff->setRevisionID($object->getID());
     $diff->save();
+  }
+
+  public function didCommitTransaction($object, $value) {
+    $editor = $this->getEditor();
+    $diff = $editor->requireDiff($value);
+    $omnipotent = PhabricatorUser::getOmnipotentUser();
 
     // If there are any outstanding buildables for this diff, tell
     // Harbormaster that their containers need to be updated. This is
@@ -64,7 +70,7 @@ final class DifferentialRevisionUpdateTransaction
     // and unit results.
 
     $buildables = id(new HarbormasterBuildableQuery())
-      ->setViewer(PhabricatorUser::getOmnipotentUser())
+      ->setViewer($omnipotent)
       ->withManualBuildables(false)
       ->withBuildablePHIDs(array($diff->getPHID()))
       ->execute();

src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php

@@ -869,6 +869,24 @@ abstract class PhabricatorApplicationTransactionEditor
     return $xactions;
   }
 
+  final protected function didCommitTransactions(
+    PhabricatorLiskDAO $object,
+    array $xactions) {
+
+    foreach ($xactions as $xaction) {
+      $type = $xaction->getTransactionType();
+
+      $xtype = $this->getModularTransactionType($type);
+      if (!$xtype) {
+        continue;
+      }
+
+      $xtype = clone $xtype;
+      $xtype->setStorage($xaction);
+      $xtype->didCommitTransaction($object, $xaction->getNewValue());
+    }
+  }
+
   public function setContentSource(PhabricatorContentSource $content_source) {
     $this->contentSource = $content_source;
     return $this;
@@ -1106,6 +1124,9 @@ abstract class PhabricatorApplicationTransactionEditor
         $object->saveTransaction();
         $transaction_open = false;
       }
+
+      $this->didCommitTransactions($object, $xactions);
+
     } catch (Exception $ex) {
       if ($read_locking) {
         $object->endReadLocking();

src/applications/transactions/storage/PhabricatorModularTransactionType.php

@@ -35,6 +35,10 @@ abstract class PhabricatorModularTransactionType
     return;
   }
 
+  public function didCommitTransaction($object, $value) {
+    return;
+  }
+
   public function getTransactionHasEffect($object, $old, $new) {
     return ($old !== $new);
   }

src/infrastructure/daemon/workers/query/PhabricatorWorkerTaskQuery.php

@@ -103,26 +103,26 @@ abstract class PhabricatorWorkerTaskQuery
     return $this->formatWhereClause($conn, $where);
   }
 
-  protected function buildOrderClause(AphrontDatabaseConnection $conn_r) {
+  protected function buildOrderClause(AphrontDatabaseConnection $conn) {
     // NOTE: The garbage collector executes this query with a date constraint,
     // and the query is inefficient if we don't use the same key for ordering.
     // See T9808 for discussion.
 
     if ($this->dateCreatedBefore) {
-      return qsprintf($conn_r, 'ORDER BY dateCreated DESC, id DESC');
+      return qsprintf($conn, 'ORDER BY dateCreated DESC, id DESC');
     } else if ($this->dateModifiedSince) {
-      return qsprintf($conn_r, 'ORDER BY dateModified DESC, id DESC');
+      return qsprintf($conn, 'ORDER BY dateModified DESC, id DESC');
     } else {
-      return qsprintf($conn_r, 'ORDER BY id DESC');
+      return qsprintf($conn, 'ORDER BY id DESC');
     }
   }
 
-  protected function buildLimitClause(AphrontDatabaseConnection $conn_r) {
-    $clause =  '';
+  protected function buildLimitClause(AphrontDatabaseConnection $conn) {
     if ($this->limit) {
-      $clause = qsprintf($conn_r, 'LIMIT %d', $this->limit);
+      return qsprintf($conn, 'LIMIT %d', $this->limit);
+    } else {
+      return qsprintf($conn, '');
     }
-    return $clause;
   }
 
 }

src/infrastructure/daemon/workers/query/PhabricatorWorkerTriggerQuery.php

@@ -145,19 +145,23 @@ final class PhabricatorWorkerTriggerQuery
     return $triggers;
   }
 
-  protected function buildJoinClause(AphrontDatabaseConnection $conn_r) {
+  protected function buildJoinClause(AphrontDatabaseConnection $conn) {
     $joins = array();
 
     if (($this->nextEpochMin !== null) ||
         ($this->nextEpochMax !== null) ||
         ($this->order == self::ORDER_EXECUTION)) {
       $joins[] = qsprintf(
-        $conn_r,
+        $conn,
         'JOIN %T e ON e.triggerID = t.id',
         id(new PhabricatorWorkerTriggerEvent())->getTableName());
     }
 
-    return implode(' ', $joins);
+    if ($joins) {
+      return qsprintf($conn, '%LJ', $joins);
+    } else {
+      return qsprintf($conn, '');
+    }
   }
 
   protected function buildWhereClause(AphrontDatabaseConnection $conn) {