Changeset 38729 in vbox

Timestamp:

Sep 13, 2011 9:50:58 AM (14 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

73997

Message:

Main/Medium+Machine: fix lock order issues when creating diff images, and eliminate a bit of redundant code.

Location:

trunk/src/VBox/Main/src-server

Files:

• MachineImpl.cpp (modified) (5 diffs)
• MediumImpl.cpp (modified) (2 diffs)

trunk/src/VBox/Main/src-server/MachineImpl.cpp

@@ -3419 +3419 @@
     // request the host lock first, since might be calling Host methods for getting host drives;
     // next, protect the media tree all the while we're in here, as well as our member variables
-    AutoMultiWriteLock2 alock(mParent->host()->lockHandle(),
-                              this->lockHandle() COMMA_LOCKVAL_SRC_POS);
+    AutoMultiWriteLock2 alock(mParent->host(), this COMMA_LOCKVAL_SRC_POS);
     AutoWriteLock treeLock(&mParent->getMediaTreeLockHandle() COMMA_LOCKVAL_SRC_POS);
 
@@ -9300 +9299 @@
     AssertComRCReturn(autoCaller.rc(), autoCaller.rc());
 
-    AutoWriteLock alock(this COMMA_LOCKVAL_SRC_POS);
+    AutoMultiWriteLock2 alock(this->lockHandle(),
+                              &mParent->getMediaTreeLockHandle() COMMA_LOCKVAL_SRC_POS);
 
     /* must be in a protective state because we leave the lock below */
@@ -9442 +9442 @@
             }
 
-            /* leave the lock before the potentially lengthy operation */
-            alock.leave();
+            /* leave the locks before the potentially lengthy operation */
+            alock.release();
             rc = pMedium->createDiffStorage(diff, MediumVariant_Standard,
                                             pMediumLockList,
@@ -9449 +9449 @@
                                             true /* aWait */,
                                             pllRegistriesThatNeedSaving);
-            alock.enter();
+            alock.acquire();
             if (FAILED(rc)) throw rc;
 
@@ -11481 +11481 @@
     /* Creating a Progress object requires the VirtualBox lock, and
      * thus locking it here is required by the lock order rules. */
-    AutoMultiWriteLock2 alock(mParent->lockHandle(), this->lockHandle() COMMA_LOCKVAL_SRC_POS);
+    AutoMultiWriteLock2 alock(mParent, this COMMA_LOCKVAL_SRC_POS);
 
     if (control == mData->mSession.mDirectControl)

trunk/src/VBox/Main/src-server/MediumImpl.cpp

@@ -2529 +2529 @@
 
     // locking: we need the tree lock first because we access parent pointers
-    AutoReadLock treeLock(m->pVirtualBox->getMediaTreeLockHandle() COMMA_LOCKVAL_SRC_POS);
-    AutoMultiWriteLock2 alock(this, diff COMMA_LOCKVAL_SRC_POS);
+    AutoMultiWriteLock3 alock(&m->pVirtualBox->getMediaTreeLockHandle(),
+                              this->lockHandle(), diff->lockHandle() COMMA_LOCKVAL_SRC_POS);
 
     if (m->type == MediumType_Writethrough)
@@ -2573 +2573 @@
     }
 
-    treeLock.release();
     alock.release();