From ca8810e29d31c7a37723d32fb93e18e2e765ff29 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aschulz@wikimedia.org>
Date: Mon, 19 Aug 2013 12:26:01 -0700
Subject: [PATCH] Added a few more trx sanity checks to DatabaseBase

* Also track the caller that added the callbacks

Change-Id: Idc4d9e4a89fcee28bd4b18ad6d8c6b09b9fe7e75
---
 includes/db/Database.php | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/includes/db/Database.php b/includes/db/Database.php
index 27e6dadb06..77002d6157 100644
--- a/includes/db/Database.php
+++ b/includes/db/Database.php
@@ -3069,7 +3069,7 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
 	 * @since 1.20
 	 */
 	final public function onTransactionIdle( $callback ) {
-		$this->mTrxIdleCallbacks[] = $callback;
+		$this->mTrxIdleCallbacks[] = array( $callback, wfGetCaller() );
 		if ( !$this->mTrxLevel ) {
 			$this->runOnTransactionIdleCallbacks();
 		}
@@ -3088,7 +3088,7 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
 	 */
 	final public function onTransactionPreCommitOrIdle( $callback ) {
 		if ( $this->mTrxLevel ) {
-			$this->mTrxPreCommitCallbacks[] = $callback;
+			$this->mTrxPreCommitCallbacks[] = array( $callback, wfGetCaller() );
 		} else {
 			$this->onTransactionIdle( $callback ); // this will trigger immediately
 		}
@@ -3108,8 +3108,9 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
 			$this->mTrxIdleCallbacks = array(); // recursion guard
 			foreach ( $callbacks as $callback ) {
 				try {
+					list( $phpCallback ) = $callback;
 					$this->clearFlag( DBO_TRX ); // make each query its own transaction
-					call_user_func( $callback );
+					call_user_func( $phpCallback );
 					$this->setFlag( $autoTrx ? DBO_TRX : 0 ); // restore automatic begin()
 				} catch ( Exception $e ) {}
 			}
@@ -3132,7 +3133,8 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
 			$this->mTrxPreCommitCallbacks = array(); // recursion guard
 			foreach ( $callbacks as $callback ) {
 				try {
-					call_user_func( $callback );
+					list( $phpCallback ) = $callback;
+					call_user_func( $phpCallback );
 				} catch ( Exception $e ) {}
 			}
 		} while ( count( $this->mTrxPreCommitCallbacks ) );
@@ -3232,6 +3234,7 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
 		if ( $this->mTrxDoneWrites ) {
 			Profiler::instance()->transactionWritingOut( $this->mServer, $this->mDBname );
 		}
+		$this->mTrxDoneWrites = false;
 		$this->runOnTransactionIdleCallbacks();
 	}
 
@@ -3266,6 +3269,7 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
 		if ( $this->mTrxDoneWrites ) {
 			Profiler::instance()->transactionWritingOut( $this->mServer, $this->mDBname );
 		}
+		$this->mTrxDoneWrites = false;
 	}
 
 	/**
@@ -3850,9 +3854,21 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
 		return (string)$this->mConn;
 	}
 
+	/**
+	 * Run a few simple sanity checks
+	 */
 	public function __destruct() {
+		if ( $this->mTrxLevel && $this->mTrxDoneWrites ) {
+			trigger_error( "Uncommitted DB writes (transaction from {$this->mTrxFname})." );
+		}
 		if ( count( $this->mTrxIdleCallbacks ) || count( $this->mTrxPreCommitCallbacks ) ) {
-			trigger_error( "Transaction idle or pre-commit callbacks still pending." ); // sanity
+			$callers = array();
+			foreach ( $this->mTrxIdleCallbacks as $callbackInfo ) {
+				$callers[] = $callbackInfo[0];
+
+			}
+			$callers = implode( ', ', $callers );
+			trigger_error( "DB transaction  callbacks still pending (from $callers)." );
 		}
 	}
 }
-- 
2.20.1