commit 3be5b1ecdf66f6eaaa0ba98f9b36cc2d93bf54d9
author ssid <ssid@chromium.org> Wed Jan 13 14:21:57 2016
committer Commit bot <commit-bot@chromium.org> Wed Jan 13 14:23:13 2016
tree 20326a0c236d72a2e28b007f1782116cf301b07c
parent 3a6f49f649c3c413ca10fc60ec85f39532ac9e45

[tracing] Add separate dump provider for sql connection

The sql connection memory dump is not thread safe since the connections
can get deleted while a dump is happening. To make this thread safe,
this CL introduces a dump provider class owned by the connection. This
class holds a lock when dumping and deleting the database. Also, to
workaround thread safe dump provider registration, it uses the
UnregisterAndDeleteDumpProviderAsync api added in crrev.com/1430073002.

BUG=466141

Review URL: https://codereview.chromium.org/1434993002

Cr-Commit-Position: refs/heads/master@{#369161}

sql/connection.h

diff --git a/sql/connection.h b/sql/connection.h
index e121b9fe..b35e2fa 100644
--- a/sql/connection.h
+++ b/sql/connection.h
@@ -20,7 +20,6 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
-#include "base/trace_event/memory_dump_provider.h"
 #include "sql/sql_export.h"
 
 struct sqlite3;
@@ -33,6 +32,7 @@
 
 namespace sql {
 
+class ConnectionMemoryDumpProvider;
 class Recovery;
 class Statement;
 
@@ -105,7 +105,7 @@
   DISALLOW_COPY_AND_ASSIGN(TimeSource);
 };
 
-class SQL_EXPORT Connection : public base::trace_event::MemoryDumpProvider {
+class SQL_EXPORT Connection {
  private:
   class StatementRef;  // Forward declaration, see real one below.
 
@@ -113,7 +113,7 @@
   // The database is opened by calling Open[InMemory](). Any uncommitted
   // transactions will be rolled back when this object is deleted.
   Connection();
-  ~Connection() override;
+  ~Connection();
 
   // Pre-init configuration ----------------------------------------------------
 
@@ -484,11 +484,6 @@
   // with the syntax of a SQL statement, or problems with the database schema.
   static bool ShouldIgnoreSqliteCompileError(int error);
 
-  // base::trace_event::MemoryDumpProvider implementation.
-  bool OnMemoryDump(
-      const base::trace_event::MemoryDumpArgs& args,
-      base::trace_event::ProcessMemoryDump* process_memory_dump) override;
-
   // Collect various diagnostic information and post a crash dump to aid
   // debugging.  Dump rate per database is limited to prevent overwhelming the
   // crash server.
@@ -511,6 +506,7 @@
 
   FRIEND_TEST_ALL_PREFIXES(SQLConnectionTest, CollectDiagnosticInfo);
   FRIEND_TEST_ALL_PREFIXES(SQLConnectionTest, GetAppropriateMmapSize);
+  FRIEND_TEST_ALL_PREFIXES(SQLConnectionTest, OnMemoryDump);
   FRIEND_TEST_ALL_PREFIXES(SQLConnectionTest, RegisterIntentToUpload);
 
   // Internal initialize function used by both Init and InitInMemory. The file
@@ -795,6 +791,9 @@
   // changes.
   scoped_ptr<TimeSource> clock_;
 
+  // Stores the dump provider object when db is open.
+  scoped_ptr<ConnectionMemoryDumpProvider> memory_dump_provider_;
+
   DISALLOW_COPY_AND_ASSIGN(Connection);
 };