Make the DatabaseTracker thread-safe.

WebCore/storage/DatabaseTracker.cpp

Index: WebCore/storage/DatabaseTracker.cpp
===================================================================
--- WebCore/storage/DatabaseTracker.cpp	(revision 55036)
+++ WebCore/storage/DatabaseTracker.cpp	(working copy)
@@ -51,13 +51,19 @@
 
 namespace WebCore {
 
-OriginQuotaManager& DatabaseTracker::originQuotaManager()
+OriginQuotaManager& DatabaseTracker::originQuotaManagerNoLock()
 {
-    populateOrigins();
     ASSERT(m_quotaManager);
     return *m_quotaManager;
 }
 
+OriginQuotaManager& DatabaseTracker::originQuotaManager()
+{
+    MutexLocker lockDatabase(m_databaseGuard);
+    populateOrigins();
+    return originQuotaManagerNoLock();
+}
+
 DatabaseTracker& DatabaseTracker::tracker()
 {
     DEFINE_STATIC_LOCAL(DatabaseTracker, tracker, ());
@@ -66,36 +72,29 @@
 
 DatabaseTracker::DatabaseTracker()
     : m_client(0)
-    , m_proposedDatabase(0)
-#ifndef NDEBUG
-    , m_thread(currentThread())
-#endif
 {
     SQLiteFileSystem::registerSQLiteVFS();
 }
 
 void DatabaseTracker::setDatabaseDirectoryPath(const String& path)
 {
-    ASSERT(currentThread() == m_thread);
     ASSERT(!m_database.isOpen());
     m_databaseDirectoryPath = path;
 }
 
-const String& DatabaseTracker::databaseDirectoryPath() const
+String DatabaseTracker::databaseDirectoryPath() const
 {
-    ASSERT(currentThread() == m_thread);
-    return m_databaseDirectoryPath;
+    return m_databaseDirectoryPath.threadsafeCopy();
 }
 
 String DatabaseTracker::trackerDatabasePath() const
 {
-    ASSERT(currentThread() == m_thread);
     return SQLiteFileSystem::appendDatabaseFileNameToPath(m_databaseDirectoryPath, "Databases.db");
 }
 
 void DatabaseTracker::openTrackerDatabase(bool createIfDoesNotExist)
 {
-    ASSERT(currentThread() == m_thread);
+    ASSERT(!m_databaseGuard.tryLock());
 
     if (m_database.isOpen())
         return;
@@ -106,67 +105,87 @@
 
     if (!m_database.open(databasePath)) {
         // FIXME: What do do here?
+        LOG_ERROR("Failed to open databasePath %s.", databasePath.ascii().data());
         return;
     }
+    m_database.setSharable(true);
     if (!m_database.tableExists("Origins")) {
         if (!m_database.executeCommand("CREATE TABLE Origins (origin TEXT UNIQUE ON CONFLICT REPLACE, quota INTEGER NOT NULL ON CONFLICT FAIL);")) {
             // FIXME: and here
+            LOG_ERROR("Failed to create Origins table");
         }
     }
     if (!m_database.tableExists("Databases")) {
         if (!m_database.executeCommand("CREATE TABLE Databases (guid INTEGER PRIMARY KEY AUTOINCREMENT, origin TEXT, name TEXT, displayName TEXT, estimatedSize INTEGER, path TEXT);")) {
             // FIXME: and here
+            LOG_ERROR("Failed to create Databases table");
         }
     }
 }
 
 bool DatabaseTracker::canEstablishDatabase(ScriptExecutionContext* context, const String& name, const String& displayName, unsigned long estimatedSize)
 {
-    ASSERT(currentThread() == m_thread);
+    SecurityOrigin* origin = context->securityOrigin();
+    ProposedDatabase details;
 
-    // Populate the origins before we establish a database; this guarantees that quotaForOrigin
-    // can run on the database thread later.
-    populateOrigins();
+    unsigned long long requirement;
+    unsigned long long tempUsage;
+    {
+        Locker<OriginQuotaManager> locker(originQuotaManager());
+        MutexLocker lockDatabase(m_databaseGuard);
 
-    SecurityOrigin* origin = context->securityOrigin();
+        populateOrigins();
 
-    // Since we're imminently opening a database within this context's origin, make sure this origin is being tracked by the QuotaTracker
-    // by fetching it's current usage now
-    unsigned long long usage = usageForOrigin(origin);
+        // Since we're imminently opening a database within this context's origin, make sure this origin is being tracked by the QuotaTracker
+        // by fetching its current usage now.
+        unsigned long long usage = usageForOriginNoLock(origin);
 
-    // If a database already exists, ignore the passed-in estimated size and say it's OK.
-    if (hasEntryForDatabase(origin, name))
-        return true;
+        // If a database already exists, ignore the passed-in estimated size and say it's OK.
+        if (hasEntryForDatabase(origin, name))
+            return true;
 
-    // If the database will fit, allow its creation.
-    unsigned long long requirement = usage + max(1UL, estimatedSize);
-    if (requirement < usage)
-        return false; // If the estimated size is so big it causes an overflow, don't allow creation.
-    if (requirement <= quotaForOrigin(origin))
-        return true;
+        // If the database will fit, allow its creation.
+        requirement = usage + max(1UL, estimatedSize);
+        tempUsage = usage;
+        if (requirement < usage)
+            return false; // If the estimated size is so big it causes an overflow, don't allow creation.
+        if (requirement <= quotaForOriginNoLock(origin))
+            return true;
 
-    // Give the chrome client a chance to increase the quota.
-    // Temporarily make the details of the proposed database available, so the client can get at them.
-    pair<SecurityOrigin*, DatabaseDetails> details(origin, DatabaseDetails(name, displayName, estimatedSize, 0));
-    m_proposedDatabase = &details;
+        // Give the chrome client a chance to increase the quota.
+        // Temporarily make the details of the proposed database available, so the client can get at them.
+        // FIXME: We should really just pass the details into this call, rather than using m_proposedDatabases.
+        details = ProposedDatabase(origin, DatabaseDetails(name, displayName, estimatedSize, 0));
+        m_proposedDatabases.add(&details);
+    }
+    // Drop all locks before calling out; we don't know what they'll do.
     context->databaseExceededQuota(name);
-    m_proposedDatabase = 0;
+    {
+        MutexLocker lockDatabase(m_databaseGuard);
+        m_proposedDatabases.remove(&details);
+    }
 
     // If the database will fit now, allow its creation.
     return requirement <= quotaForOrigin(origin);
 }
 
+bool DatabaseTracker::hasEntryForOriginNoLock(SecurityOrigin* origin)
+{
+    ASSERT(!m_databaseGuard.tryLock());
+    ASSERT(m_quotaMap);
+    return m_quotaMap->contains(origin);
+}
+
 bool DatabaseTracker::hasEntryForOrigin(SecurityOrigin* origin)
 {
-    ASSERT(currentThread() == m_thread);
+    MutexLocker lockDatabase(m_databaseGuard);
     populateOrigins();
-    MutexLocker lockQuotaMap(m_quotaMapGuard);
-    return m_quotaMap->contains(origin);
+    return hasEntryForOriginNoLock(origin);
 }
 
 bool DatabaseTracker::hasEntryForDatabase(SecurityOrigin* origin, const String& databaseIdentifier)
 {
-    ASSERT(currentThread() == m_thread);
+    ASSERT(!m_databaseGuard.tryLock());
     openTrackerDatabase(false);
     if (!m_database.isOpen())
         return false;
@@ -193,16 +212,17 @@
 
 String DatabaseTracker::originPath(SecurityOrigin* origin) const
 {
-    ASSERT(currentThread() == m_thread);
-    return SQLiteFileSystem::appendDatabaseFileNameToPath(m_databaseDirectoryPath, origin->databaseIdentifier());
+    return SQLiteFileSystem::appendDatabaseFileNameToPath(m_databaseDirectoryPath.threadsafeCopy(), origin->databaseIdentifier());
 }
 
-String DatabaseTracker::fullPathForDatabase(SecurityOrigin* origin, const String& name, bool createIfNotExists)
+String DatabaseTracker::fullPathForDatabaseNoLock(SecurityOrigin* origin, const String& name, bool createIfNotExists)
 {
-    ASSERT(currentThread() == m_thread);
+    ASSERT(!m_databaseGuard.tryLock());
+    ASSERT(!originQuotaManagerNoLock().tryLock());
 
-    if (m_proposedDatabase && m_proposedDatabase->first == origin && m_proposedDatabase->second.name() == name)
-        return String();
+    for (HashSet<ProposedDatabase*>::iterator iter = m_proposedDatabases.begin(); iter != m_proposedDatabases.end(); ++iter)
+        if ((*iter)->first == origin && (*iter)->second.name() == name)
+            return String();
 
     String originIdentifier = origin->databaseIdentifier();
     String originPath = this->originPath(origin);
@@ -212,7 +232,7 @@
         return String();
 
     // See if we have a path for this database yet
-    openTrackerDatabase(false);
+    // TODO: Why don't we try to open the database first?
     if (!m_database.isOpen())
         return String();
     SQLiteStatement statement(m_database, "SELECT path FROM Databases WHERE origin=? AND name=?;");
@@ -231,36 +251,42 @@
         return String();
 
     if (result != SQLResultDone) {
-        LOG_ERROR("Failed to retrieve filename from Database Tracker for origin %s, name %s", origin->databaseIdentifier().ascii().data(), name.ascii().data());
+        LOG_ERROR("Failed to retrieve filename from Database Tracker for origin %s, name %s", originIdentifier.ascii().data(), name.ascii().data());
         return String();
     }
     statement.finalize();
 
-    String fileName = SQLiteFileSystem::getFileNameForNewDatabase(originPath, name, origin->databaseIdentifier(), &m_database);
+    String fileName = SQLiteFileSystem::getFileNameForNewDatabase(originPath, name, originIdentifier, &m_database);
     if (!addDatabase(origin, name, fileName))
         return String();
 
     // If this origin's quota is being tracked (open handle to a database in this origin), add this new database
     // to the quota manager now
     String fullFilePath = SQLiteFileSystem::appendDatabaseFileNameToPath(originPath, fileName);
-    {
-        Locker<OriginQuotaManager> locker(originQuotaManager());
-        if (originQuotaManager().tracksOrigin(origin))
-            originQuotaManager().addDatabase(origin, name, fullFilePath);
-    }
+    if (originQuotaManagerNoLock().tracksOrigin(origin))
+        originQuotaManagerNoLock().addDatabase(origin, name, fullFilePath);
 
     return fullFilePath;
 }
 
+String DatabaseTracker::fullPathForDatabase(SecurityOrigin* origin, const String& name, bool createIfNotExists)
+{
+    Locker<OriginQuotaManager> locker(originQuotaManager());
+    MutexLocker lockDatabase(m_databaseGuard);
+    populateOrigins();
+
+    return fullPathForDatabaseNoLock(origin, name, createIfNotExists);
+}
+
 void DatabaseTracker::populateOrigins()
 {
+    ASSERT(!m_databaseGuard.tryLock());
     if (m_quotaMap)
         return;
 
-    ASSERT(currentThread() == m_thread);
-
     m_quotaMap.set(new QuotaMap);
-    m_quotaManager.set(new OriginQuotaManager);
+    if (!m_quotaManager)
+        m_quotaManager.set(new OriginQuotaManager);
 
     openTrackerDatabase(false);
     if (!m_database.isOpen())
@@ -268,8 +294,10 @@
 
     SQLiteStatement statement(m_database, "SELECT origin, quota FROM Origins");
 
-    if (statement.prepare() != SQLResultOk)
+    if (statement.prepare() != SQLResultOk) {
+        LOG_ERROR("Failed to prepare statement.");
         return;
+    }
 
     int result;
     while ((result = statement.step()) == SQLResultRow) {
@@ -278,20 +306,20 @@
     }
 
     if (result != SQLResultDone)
-        LOG_ERROR("Failed to read in all origins from the database");
+        LOG_ERROR("Failed to read in all origins from the database.");
 }
 
 void DatabaseTracker::origins(Vector<RefPtr<SecurityOrigin> >& result)
 {
-    ASSERT(currentThread() == m_thread);
+    MutexLocker lockDatabase(m_databaseGuard);
     populateOrigins();
-    MutexLocker lockQuotaMap(m_quotaMapGuard);
+    ASSERT(m_quotaMap);
     copyKeysToVector(*m_quotaMap, result);
 }
 
-bool DatabaseTracker::databaseNamesForOrigin(SecurityOrigin* origin, Vector<String>& resultVector)
+bool DatabaseTracker::databaseNamesForOriginNoLock(SecurityOrigin* origin, Vector<String>& resultVector)
 {
-    ASSERT(currentThread() == m_thread);
+    ASSERT(!m_databaseGuard.tryLock());
     openTrackerDatabase(false);
     if (!m_database.isOpen())
         return false;
@@ -315,44 +343,57 @@
     return true;
 }
 
+bool DatabaseTracker::databaseNamesForOrigin(SecurityOrigin* origin, Vector<String>& resultVector)
+{
+    MutexLocker lockDatabase(m_databaseGuard);
+    return databaseNamesForOriginNoLock(origin, resultVector);
+}
+
 DatabaseDetails DatabaseTracker::detailsForNameAndOrigin(const String& name, SecurityOrigin* origin)
 {
-    ASSERT(currentThread() == m_thread);
+    String originIdentifier = origin->databaseIdentifier();
+    String displayName;
+    int64_t expectedUsage;
 
-    if (m_proposedDatabase && m_proposedDatabase->first == origin && m_proposedDatabase->second.name() == name)
-        return m_proposedDatabase->second;
+    {
+        MutexLocker lockDatabase(m_databaseGuard);
 
-    String originIdentifier = origin->databaseIdentifier();
+        for (HashSet<ProposedDatabase*>::iterator iter = m_proposedDatabases.begin(); iter != m_proposedDatabases.end(); ++iter)
+            if ((*iter)->first == origin && (*iter)->second.name() == name)
+                return (*iter)->second;
 
-    openTrackerDatabase(false);
-    if (!m_database.isOpen())
-        return DatabaseDetails();
-    SQLiteStatement statement(m_database, "SELECT displayName, estimatedSize FROM Databases WHERE origin=? AND name=?");
-    if (statement.prepare() != SQLResultOk)
-        return DatabaseDetails();
+        openTrackerDatabase(false);
+        if (!m_database.isOpen())
+            return DatabaseDetails();
+        SQLiteStatement statement(m_database, "SELECT displayName, estimatedSize FROM Databases WHERE origin=? AND name=?");
+        if (statement.prepare() != SQLResultOk)
+            return DatabaseDetails();
 
-    statement.bindText(1, originIdentifier);
-    statement.bindText(2, name);
+        statement.bindText(1, originIdentifier);
+        statement.bindText(2, name);
 
-    int result = statement.step();
-    if (result == SQLResultDone)
-        return DatabaseDetails();
+        int result = statement.step();
+        if (result == SQLResultDone)
+            return DatabaseDetails();
 
-    if (result != SQLResultRow) {
-        LOG_ERROR("Error retrieving details for database %s in origin %s from tracker database", name.ascii().data(), originIdentifier.ascii().data());
-        return DatabaseDetails();
+        if (result != SQLResultRow) {
+            LOG_ERROR("Error retrieving details for database %s in origin %s from tracker database", name.ascii().data(), originIdentifier.ascii().data());
+            return DatabaseDetails();
+        }
+        displayName = statement.getColumnText(0);
+        expectedUsage = statement.getColumnInt64(1);
     }
 
-    return DatabaseDetails(name, statement.getColumnText(0), statement.getColumnInt64(1), usageForDatabase(name, origin));
+    return DatabaseDetails(name, displayName, expectedUsage, usageForDatabase(name, origin));
 }
 
 void DatabaseTracker::setDatabaseDetails(SecurityOrigin* origin, const String& name, const String& displayName, unsigned long estimatedSize)
 {
-    ASSERT(currentThread() == m_thread);
-
     String originIdentifier = origin->databaseIdentifier();
     int64_t guid = 0;
 
+    MutexLocker lockDatabase(m_databaseGuard);
+
     openTrackerDatabase(true);
     if (!m_database.isOpen())
         return;
@@ -400,7 +441,6 @@
 
 unsigned long long DatabaseTracker::usageForDatabase(const String& name, SecurityOrigin* origin)
 {
-    ASSERT(currentThread() == m_thread);
     String path = fullPathForDatabase(origin, name, false);
     if (path.isEmpty())
         return 0;
@@ -441,6 +481,7 @@
     if (!database)
         return;
 
+    Locker<OriginQuotaManager> quotaManagerLocker(originQuotaManager());
     MutexLocker openDatabaseMapLock(m_openDatabaseMapGuard);
 
     if (!m_openDatabaseMap) {
@@ -476,6 +517,10 @@
 
     m_openDatabaseMap->remove(database->securityOrigin());
     delete nameMap;
+    originQuotaManagerNoLock().removeOrigin(database->securityOrigin());
+
+    // Throw away m_quotaMap whenever we've cleared out an origin--otherwise we never get rid of stale entries.  The next call that needs it will populateOrigins().
+    m_quotaMap.clear();
 }
 
 void DatabaseTracker::getOpenDatabases(SecurityOrigin* origin, const String& name, HashSet<RefPtr<Database> >* databases)
@@ -496,92 +541,103 @@
         databases->add(*it);
 }
 
-unsigned long long DatabaseTracker::usageForOrigin(SecurityOrigin* origin)
+unsigned long long DatabaseTracker::usageForOriginNoLock(SecurityOrigin* origin)
 {
-    ASSERT(currentThread() == m_thread);
-    Locker<OriginQuotaManager> locker(originQuotaManager());
+    ASSERT(!originQuotaManagerNoLock().tryLock());
 
     // Use the OriginQuotaManager mechanism to calculate the usage
-    if (originQuotaManager().tracksOrigin(origin))
-        return originQuotaManager().diskUsage(origin);
+    if (originQuotaManagerNoLock().tracksOrigin(origin))
+        return originQuotaManagerNoLock().diskUsage(origin);
 
     // If the OriginQuotaManager doesn't track this origin already, prime it to do so
-    originQuotaManager().trackOrigin(origin);
+    originQuotaManagerNoLock().trackOrigin(origin);
 
     Vector<String> names;
-    databaseNamesForOrigin(origin, names);
+    databaseNamesForOriginNoLock(origin, names);
 
     for (unsigned i = 0; i < names.size(); ++i)
-        originQuotaManager().addDatabase(origin, names[i], fullPathForDatabase(origin, names[i], false));
+        originQuotaManagerNoLock().addDatabase(origin, names[i], fullPathForDatabaseNoLock(origin, names[i], false));
 
-    if (!originQuotaManager().tracksOrigin(origin))
+    if (!originQuotaManagerNoLock().tracksOrigin(origin))
         return 0;
-    return originQuotaManager().diskUsage(origin);
+    return originQuotaManagerNoLock().diskUsage(origin);
 }
 
+unsigned long long DatabaseTracker::usageForOrigin(SecurityOrigin* origin)
+{
+    Locker<OriginQuotaManager> locker(originQuotaManager());
+
+    return usageForOriginNoLock(origin);
+}
+
+unsigned long long DatabaseTracker::quotaForOriginNoLock(SecurityOrigin* origin)
+{
+    ASSERT(!m_databaseGuard.tryLock());
+    ASSERT(m_quotaMap);
+    return m_quotaMap->get(origin);
+}
+
 unsigned long long DatabaseTracker::quotaForOrigin(SecurityOrigin* origin)
 {
-    ASSERT(currentThread() == m_thread || m_quotaMap);
+    MutexLocker lockDatabase(m_databaseGuard);
     populateOrigins();
-    MutexLocker lockQuotaMap(m_quotaMapGuard);
-    return m_quotaMap->get(origin);
+    return quotaForOriginNoLock(origin);
 }
 
 void DatabaseTracker::setQuota(SecurityOrigin* origin, unsigned long long quota)
 {
-    ASSERT(currentThread() == m_thread);
-    if (quotaForOrigin(origin) == quota)
+    MutexLocker lockDatabase(m_databaseGuard);
+
+    populateOrigins();
+    if (quotaForOriginNoLock(origin) == quota)
         return;
 
     openTrackerDatabase(true);
     if (!m_database.isOpen())
         return;
 
-    {
-        MutexLocker lockQuotaMap(m_quotaMapGuard);
+    if (!m_quotaMap->contains(origin)) {
+        SQLiteStatement statement(m_database, "INSERT INTO Origins VALUES (?, ?)");
+        if (statement.prepare() != SQLResultOk) {
+            LOG_ERROR("Unable to establish origin %s in the tracker", origin->databaseIdentifier().ascii().data());
+        } else {
+            statement.bindText(1, origin->databaseIdentifier());
+            statement.bindInt64(2, quota);
 
-        if (!m_quotaMap->contains(origin)) {
-            SQLiteStatement statement(m_database, "INSERT INTO Origins VALUES (?, ?)");
-            if (statement.prepare() != SQLResultOk) {
+            if (statement.step() != SQLResultDone)
                 LOG_ERROR("Unable to establish origin %s in the tracker", origin->databaseIdentifier().ascii().data());
-            } else {
-                statement.bindText(1, origin->databaseIdentifier());
-                statement.bindInt64(2, quota);
+        }
+    } else {
+        SQLiteStatement statement(m_database, "UPDATE Origins SET quota=? WHERE origin=?");
+        bool error = statement.prepare() != SQLResultOk;
+        if (!error) {
+            statement.bindInt64(1, quota);
+            statement.bindText(2, origin->databaseIdentifier());
 
-                if (statement.step() != SQLResultDone)
-                    LOG_ERROR("Unable to establish origin %s in the tracker", origin->databaseIdentifier().ascii().data());
-            }
-        } else {
-            SQLiteStatement statement(m_database, "UPDATE Origins SET quota=? WHERE origin=?");
-            bool error = statement.prepare() != SQLResultOk;
-            if (!error) {
-                statement.bindInt64(1, quota);
-                statement.bindText(2, origin->databaseIdentifier());
-
-                error = !statement.executeCommand();
-            }
-
-            if (error)
-                LOG_ERROR("Failed to set quota %llu in tracker database for origin %s", quota, origin->databaseIdentifier().ascii().data());
+            error = !statement.executeCommand();
         }
 
-        // FIXME: Is it really OK to update the quota in memory if we failed to update it on disk?
-        m_quotaMap->set(origin, quota);
+        if (error)
+            LOG_ERROR("Failed to set quota %llu in tracker database for origin %s", quota, origin->databaseIdentifier().ascii().data());
     }
 
+    // FIXME: Is it really OK to update the quota in memory if we failed to update it on disk?
+    m_quotaMap->set(origin, quota);
+
     if (m_client)
         m_client->dispatchDidModifyOrigin(origin);
 }
 
 bool DatabaseTracker::addDatabase(SecurityOrigin* origin, const String& name, const String& path)
 {
-    ASSERT(currentThread() == m_thread);
+    ASSERT(!m_databaseGuard.tryLock());
+    ASSERT(m_quotaMap);
     openTrackerDatabase(true);
     if (!m_database.isOpen())
         return false;
 
     // New database should never be added until the origin has been established
-    ASSERT(hasEntryForOrigin(origin));
+    ASSERT(hasEntryForOriginNoLock(origin));
 
     SQLiteStatement statement(m_database, "INSERT INTO Databases (origin, name, path) VALUES (?, ?, ?);");
 
@@ -605,8 +661,6 @@
 
 void DatabaseTracker::deleteAllDatabases()
 {
-    ASSERT(currentThread() == m_thread);
-
     Vector<RefPtr<SecurityOrigin> > originsCopy;
     origins(originsCopy);
 
@@ -614,19 +668,24 @@
         deleteOrigin(originsCopy[i].get());
 }
 
+// It is the caller's responsibility to make sure that nobody is trying to create, delete, open, or close databases in this origin while the deletion is
+// taking place.
 void DatabaseTracker::deleteOrigin(SecurityOrigin* origin)
 {
-    ASSERT(currentThread() == m_thread);
-    openTrackerDatabase(false);
-    if (!m_database.isOpen())
-        return;
+    Vector<String> databaseNames;
+    {
+        MutexLocker lockDatabase(m_databaseGuard);
+        openTrackerDatabase(false);
+        if (!m_database.isOpen())
+            return;
 
-    Vector<String> databaseNames;
-    if (!databaseNamesForOrigin(origin, databaseNames)) {
-        LOG_ERROR("Unable to retrieve list of database names for origin %s", origin->databaseIdentifier().ascii().data());
-        return;
+        if (!databaseNamesForOriginNoLock(origin, databaseNames)) {
+            LOG_ERROR("Unable to retrieve list of database names for origin %s", origin->databaseIdentifier().ascii().data());
+            return;
+        }
     }
 
+    // We drop the lock here because holding locks during a call to deleteDatabaseFile will deadlock.
     for (unsigned i = 0; i < databaseNames.size(); ++i) {
         if (!deleteDatabaseFile(origin, databaseNames[i])) {
             // Even if the file can't be deleted, we want to try and delete the rest, don't return early here.
@@ -634,41 +693,42 @@
         }
     }
 
-    SQLiteStatement statement(m_database, "DELETE FROM Databases WHERE origin=?");
-    if (statement.prepare() != SQLResultOk) {
-        LOG_ERROR("Unable to prepare deletion of databases from origin %s from tracker", origin->databaseIdentifier().ascii().data());
-        return;
-    }
+    {
+        // To satisfy the lock hierarchy, we have to lock the originQuotaManager before m_databaseGuard if there's any chance we'll to lock both.
+        Locker<OriginQuotaManager> quotaManagerLocker(originQuotaManager());
+        MutexLocker lockDatabase(m_databaseGuard);
+        SQLiteStatement statement(m_database, "DELETE FROM Databases WHERE origin=?");
+        if (statement.prepare() != SQLResultOk) {
+            LOG_ERROR("Unable to prepare deletion of databases from origin %s from tracker", origin->databaseIdentifier().ascii().data());
+            return;
+        }
 
-    statement.bindText(1, origin->databaseIdentifier());
+        statement.bindText(1, origin->databaseIdentifier());
 
-    if (!statement.executeCommand()) {
-        LOG_ERROR("Unable to execute deletion of databases from origin %s from tracker", origin->databaseIdentifier().ascii().data());
-        return;
-    }
+        if (!statement.executeCommand()) {
+            LOG_ERROR("Unable to execute deletion of databases from origin %s from tracker", origin->databaseIdentifier().ascii().data());
+            return;
+        }
 
-    SQLiteStatement originStatement(m_database, "DELETE FROM Origins WHERE origin=?");
-    if (originStatement.prepare() != SQLResultOk) {
-        LOG_ERROR("Unable to prepare deletion of origin %s from tracker", origin->databaseIdentifier().ascii().data());
-        return;
-    }
+        SQLiteStatement originStatement(m_database, "DELETE FROM Origins WHERE origin=?");
+        if (originStatement.prepare() != SQLResultOk) {
+            LOG_ERROR("Unable to prepare deletion of origin %s from tracker", origin->databaseIdentifier().ascii().data());
+            return;
+        }
 
-    originStatement.bindText(1, origin->databaseIdentifier());
+        originStatement.bindText(1, origin->databaseIdentifier());
 
-    if (!originStatement.executeCommand()) {
-        LOG_ERROR("Unable to execute deletion of databases from origin %s from tracker", origin->databaseIdentifier().ascii().data());
-        return;
-    }
+        if (!originStatement.executeCommand()) {
+            LOG_ERROR("Unable to execute deletion of databases from origin %s from tracker", origin->databaseIdentifier().ascii().data());
+            return;
+        }
 
-    SQLiteFileSystem::deleteEmptyDatabaseDirectory(originPath(origin));
+        SQLiteFileSystem::deleteEmptyDatabaseDirectory(originPath(origin));
 
-    RefPtr<SecurityOrigin> originPossiblyLastReference = origin;
-    {
-        MutexLocker lockQuotaMap(m_quotaMapGuard);
+        RefPtr<SecurityOrigin> originPossiblyLastReference = origin;
         m_quotaMap->remove(origin);
 
-        Locker<OriginQuotaManager> quotaManagerLocker(originQuotaManager());
-        originQuotaManager().removeOrigin(origin);
+        originQuotaManagerNoLock().removeOrigin(origin);
 
         // If we removed the last origin, do some additional deletion.
         if (m_quotaMap->isEmpty()) {
@@ -677,27 +737,34 @@
            SQLiteFileSystem::deleteDatabaseFile(trackerDatabasePath());
            SQLiteFileSystem::deleteEmptyDatabaseDirectory(m_databaseDirectoryPath);
         }
-    }
 
-    if (m_client) {
-        m_client->dispatchDidModifyOrigin(origin);
-        for (unsigned i = 0; i < databaseNames.size(); ++i)
-            m_client->dispatchDidModifyDatabase(origin, databaseNames[i]);
+        if (m_client) {
+            m_client->dispatchDidModifyOrigin(origin);
+            for (unsigned i = 0; i < databaseNames.size(); ++i)
+                m_client->dispatchDidModifyDatabase(origin, databaseNames[i]);
+        }
     }
 }
 
 void DatabaseTracker::deleteDatabase(SecurityOrigin* origin, const String& name)
 {
-    ASSERT(currentThread() == m_thread);
-    openTrackerDatabase(false);
-    if (!m_database.isOpen())
-        return;
+    {
+        MutexLocker lockDatabase(m_databaseGuard);
+        openTrackerDatabase(false);
+        if (!m_database.isOpen())
+            return;
+    }
 
+    // We drop the lock here because holding locks during a call to deleteDatabaseFile will deadlock.
     if (!deleteDatabaseFile(origin, name)) {
         LOG_ERROR("Unable to delete file for database %s in origin %s", name.ascii().data(), origin->databaseIdentifier().ascii().data());
         return;
     }
 
+    // To satisfy the lock hierarchy, we have to lock the originQuotaManager before m_databaseGuard if there's any chance we'll to lock both.
+    Locker<OriginQuotaManager> quotaManagerLocker(originQuotaManager());
+    MutexLocker lockDatabase(m_databaseGuard);
+
     SQLiteStatement statement(m_database, "DELETE FROM Databases WHERE origin=? AND name=?");
     if (statement.prepare() != SQLResultOk) {
         LOG_ERROR("Unable to prepare deletion of database %s from origin %s from tracker", name.ascii().data(), origin->databaseIdentifier().ascii().data());
@@ -712,10 +779,7 @@
         return;
     }
 
-    {
-        Locker<OriginQuotaManager> quotaManagerLocker(originQuotaManager());
-        originQuotaManager().removeDatabase(origin, name);
-    }
+    originQuotaManagerNoLock().removeDatabase(origin, name);
 
     if (m_client) {
         m_client->dispatchDidModifyOrigin(origin);
@@ -723,26 +787,31 @@
     }
 }
 
+// deleteDatabaseFile has to release locks between looking up the list of databases to close and closing them.  While this is in progress, the caller
+// is responsible for making sure no new databases are opened in the file to be deleted.
 bool DatabaseTracker::deleteDatabaseFile(SecurityOrigin* origin, const String& name)
 {
-    ASSERT(currentThread() == m_thread);
+    LOG_ERROR("in deleteDatabaseFile(%s,%s)",
+      origin->databaseIdentifier().ascii().data(), name.ascii().data());
     String fullPath = fullPathForDatabase(origin, name, false);
-    if (fullPath.isEmpty())
+    if (fullPath.isEmpty()) {
+        LOG_ERROR("out [empty] deleteDatabaseFile(%s,%s)",
+          origin->databaseIdentifier().ascii().data(), name.ascii().data());
         return true;
+    }
 
     Vector<RefPtr<Database> > deletedDatabases;
 
-    // Make sure not to hold the m_openDatabaseMapGuard mutex when calling
+    // Make sure not to hold the any locks when calling
     // Database::markAsDeletedAndClose(), since that can cause a deadlock
     // during the synchronous DatabaseThread call it triggers.
-
     {
         MutexLocker openDatabaseMapLock(m_openDatabaseMapGuard);
         if (m_openDatabaseMap) {
             // There are some open databases, lets check if they are for this origin.
             DatabaseNameMap* nameMap = m_openDatabaseMap->get(origin);
             if (nameMap && nameMap->size()) {
-                // There are some open databases for this origin, lets check
+                // There are some open databases for this origin, let's check
                 // if they are this database by name.
                 DatabaseSet* databaseSet = nameMap->get(name);
                 if (databaseSet && databaseSet->size()) {
@@ -758,12 +827,13 @@
     for (unsigned i = 0; i < deletedDatabases.size(); ++i)
         deletedDatabases[i]->markAsDeletedAndClose();
 
+    LOG_ERROR("out [full] deleteDatabaseFile(%s,%s)",
+      origin->databaseIdentifier().ascii().data(), name.ascii().data());
     return SQLiteFileSystem::deleteDatabaseFile(fullPath);
 }
 
 void DatabaseTracker::setClient(DatabaseTrackerClient* client)
 {
-    ASSERT(currentThread() == m_thread);
     m_client = client;
 }