commit 7bc4fad41e8a5a2efaba6fc0d272e79357d3877f
Author: Torvald Riegel <triegel@redhat.com>
Date:   Mon Jul 18 23:18:13 2011 +0200

    Add information to dispatch about closed nesting and uninstrumented code.
    
            * dispatch.h (GTM::abi_dispatch): Add can_run_uninstrumented_code and
            closed_nesting flags, as well as a closed nesting alternative.
            * method-serial.cc: Same.

diff --git a/libitm/dispatch.h b/libitm/dispatch.h
index 3643503..38f1342 100644
--- a/libitm/dispatch.h
+++ b/libitm/dispatch.h
@@ -255,8 +255,17 @@ public:
   // a unique object and so we don't want to destroy it from common code.
   virtual void fini() = 0;
 
+  // Return an alternative method that is compatible with the current
+  // method but supports closed nesting. Return zero if there is none.
+  virtual abi_dispatch* closed_nesting_alternative() { return 0; }
+
   bool read_only () const { return m_read_only; }
   bool write_through() const { return m_write_through; }
+  bool can_run_uninstrumented_code() const
+  {
+    return m_can_run_uninstrumented_code;
+  }
+  bool closed_nesting() const { return m_closed_nesting; }
 
   static void *operator new(size_t s) { return xmalloc (s); }
   static void operator delete(void *p) { free (p); }
@@ -275,7 +284,13 @@ public:
 protected:
   const bool m_read_only;
   const bool m_write_through;
-  abi_dispatch(bool ro, bool wt) : m_read_only(ro), m_write_through(wt) { }
+  const bool m_can_run_uninstrumented_code;
+  const bool m_closed_nesting;
+  abi_dispatch(bool ro, bool wt, bool uninstrumented, bool closed_nesting) :
+    m_read_only(ro), m_write_through(wt),
+    m_can_run_uninstrumented_code(uninstrumented),
+    m_closed_nesting(closed_nesting)
+  { }
 };
 
 }
diff --git a/libitm/method-serial.cc b/libitm/method-serial.cc
index a6fbc7f..009d221 100644
--- a/libitm/method-serial.cc
+++ b/libitm/method-serial.cc
@@ -38,7 +38,7 @@ namespace {
 class serial_dispatch : public abi_dispatch
 {
  public:
-  serial_dispatch() : abi_dispatch(false, true) { }
+  serial_dispatch() : abi_dispatch(false, true, true, false) { }
 
  protected:
   // Transactional loads and stores simply access memory directly.
@@ -77,9 +77,16 @@ class serial_dispatch : public abi_dispatch
   virtual void rollback() { abort(); }
   virtual void reinit() { }
   virtual void fini() { }
+
+  virtual abi_dispatch* closed_nesting_alternative()
+  {
+    // For nested transactions with an instrumented code path, we can do
+    // undo logging.
+    return GTM::dispatch_serial();
+  }
 };
 
-class serial_dispatch_ul : public serial_dispatch
+class serial_dispatch_ul : public abi_dispatch
 {
 protected:
   static void log(const void *addr, size_t len)
@@ -119,12 +126,17 @@ public:
     ::memset(dst, c, size);
   }
 
+  virtual bool trycommit() { return true; }
   // Local undo will handle this.
   // trydropreference() need not be changed either.
   virtual void rollback() { }
+  virtual void reinit() { }
+  virtual void fini() { }
 
   CREATE_DISPATCH_METHODS(virtual, )
   CREATE_DISPATCH_METHODS_MEM()
+
+  serial_dispatch_ul() : abi_dispatch(false, true, false, true) { }
 };
 
 } // anon namespace