libitm: Optimize undo log.

	libitm/
	* local.cc (GTM_LB): Use GTM::gtm_undolog.
	(GTM::gtm_thread::drop_references_undolog): Remove.
	(GTM::gtm_thread::commit_undolog,
	GTM::gtm_thread::rollback_undolog): Move to ...
	* libitm_i.h (GTM::gtm_undolog): ...here. New.
	(GTM::gtm_undolog_entry): Remove.
	(GTM::gtm_thread): Adapt.
	* beginend.cc (GTM::gtm_thread::rollback): Adapt.
	(GTM::gtm_thread::trycommit): Adapt.
	* method-serial.cc (serial_dispatch::log): Adapt.
	* method-gl.cc (gl_wt_dispatch::pre_write): Adapt.
	(gl_wt_dispatch::store): Fix likely/unlikely.
	* containers.h (GTM::vector::resize): Add additional_capacity
	parameter and handle it.
	(GTM::vector::resize_noinline): New/adapt.
	(GTM::vector::push): New.

From-SVN: r182992

1 files changed, 25 insertions, 10 deletions

diff --git a/libitm/libitm_i.h b/libitm/libitm_i.h
index b53792a..f922d22 100644
--- a/libitm/libitm_i.h
+++ b/libitm/libitm_i.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2008, 2009, 2011 Free Software Foundation, Inc.
+/* Copyright (C) 2008, 2009, 2011, 2012 Free Software Foundation, Inc.
    Contributed by Richard Henderson <rth@redhat.com>.
 
    This file is part of the GNU Transactional Memory Library (libitm).
@@ -93,9 +93,6 @@ struct gtm_alloc_action
   bool allocated;
 };
 
-// This type is private to local.c.
-struct gtm_undolog_entry;
-
 struct gtm_thread;
 
 // A transaction checkpoint: data that has to saved and restored when doing
@@ -121,6 +118,29 @@ struct gtm_transaction_cp
   void commit(gtm_thread* tx);
 };
 
+// An undo log for writes.
+struct gtm_undolog
+{
+  vector<gtm_word> undolog;
+
+  // Log the previous value at a certain address.
+  // The easiest way to inline this is to just define this here.
+  void log(const void *ptr, size_t len)
+  {
+    size_t words = (len + sizeof(gtm_word) - 1) / sizeof(gtm_word);
+    gtm_word *undo = undolog.push(words + 2);
+    memcpy(undo, ptr, len);
+    undo[words] = len;
+    undo[words + 1] = (gtm_word) ptr;
+  }
+
+  void commit () { undolog.clear(); }
+  size_t size() const { return undolog.size(); }
+
+  // In local.cc
+  void rollback (size_t until_size = 0);
+};
+
 // Contains all thread-specific data required by the entire library.
 // This includes all data relevant to a single transaction. Because most
 // thread-specific data is about the current transaction, we also refer to
@@ -148,7 +168,7 @@ struct gtm_thread
   gtm_jmpbuf jb;
 
   // Data used by local.c for the undo log for both local and shared memory.
-  vector<gtm_undolog_entry*> undolog;
+  gtm_undolog undolog;
 
   // Data used by alloc.c for the malloc/free undo log.
   aa_tree<uintptr_t, gtm_alloc_action> alloc_actions;
@@ -254,11 +274,6 @@ struct gtm_thread
   // In eh_cpp.cc
   void revert_cpp_exceptions (gtm_transaction_cp *cp = 0);
 
-  // In local.cc
-  void commit_undolog (void);
-  void rollback_undolog (size_t until_size = 0);
-  void drop_references_undolog (const void *, size_t);
-
   // In retry.cc
   // Must be called outside of transactions (i.e., after rollback).
   void decide_retry_strategy (gtm_restart_reason);