* gold-threads.h (class Once): Define.

	(class Initialize_lock): Rewrite as child of Once.
	* gold-threads.cc (class Once_initialize): Define.
	(once_pointer_control): New static variable.
	(once_pointer, once_arg): New static variables.
	(c_run_once): New static function.
	(Once::Once, Once::run_once, Once::internal_run): New functions.
	(class Initialize_lock_once): Remove.
	(initialize_lock_control): Remove.
	(initialize_lock_pointer): Remove.
	(initialize_lock_once): Remove.
	(Initialize_lock::Initialize_lock): Move to gold-threads.h.
	(Initialize_lock::initialize): Rewrite.
	(Initialize_lock::do_run_once): New function.
	* archive.cc (Archive::interpret_header): Only clear name if it is
	not already empty.
	* fileread.cc: Include "gold-threads.h"
	(file_counts_lock): New static variable.
	(file_counts_initialize_lock): Likewise.
	(File_read::release): Only increment counts when using --stats.
	Use a lock around the increment.
	* parameters.cc (class Set_parameters_target_once): Define.
	(set_parameters_target_once): New static variable.
	(Parameters::Parameters): Move here from parameters.h.
	(Parameters::set_target): Rewrite.
	(Parameters::set_target_once): New function.
	(Parameters::clear_target): Move here and rewrite.
	* parameters.h (class Parameters): Update declarations.  Add
	set_parameters_target_once_ field.
	(Parameters::Parameters): Move to parameters.cc.
	(Parameters::clear_target): Likewise.
	* readsyms.cc (Read_symbols::do_group): Create a Start_group
	task.
	(Start_group::~Start_group): New function.
	(Start_group::is_runnable): New function.
	(Start_group::locks, Start_group::run): New functions.
	(Finish_group::run): Change saw_undefined to size_t.
	* readsyms.h (class Start_group): Define.
	(class Finish_group): Change saw_undefined_ field to size_t.
	(Finish_group::Finish_group): Remove saw_undefined and
	this_blocker parameters.  Change all callers.
	(Finish_group::set_saw_undefined): New function.
	(Finish_group::set_blocker): New function.
	* symtab.h (class Symbol_table): Change saw_undefined to return
	size_t.  Change saw_undefined_ field to size_t.
	* target-select.cc (Set_target_once::do_run_once): New function.
	(Target_selector::Target_selector): Initialize set_target_once_
	field.  Don't initialize lock_ and initialize_lock_ fields.
	(Target_selector::instantiate_target): Rewrite.
	(Target_selector::set_target): New function.
	* target-select.h (class Set_target_once): Define.
	(class Target_selector): Update declarations.  Make
	Set_target_once a friend.  Remove lock_ and initialize_lock_
	fields.  Add set_target_once_ field.

1 files changed, 22 insertions, 15 deletions

diff --git a/gold/target-select.cc b/gold/target-select.cc
index dcd3017..859bc3b 100644
--- a/gold/target-select.cc
+++ b/gold/target-select.cc
@@ -1,6 +1,6 @@
 // target-select.cc -- select a target for an object file
 
-// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
 // Written by Ian Lance Taylor <iant@google.com>.
 
 // This file is part of gold.
@@ -39,6 +39,14 @@ gold::Target_selector* target_selectors;
 namespace gold
 {
 
+// Class Set_target_once.
+
+void
+Set_target_once::do_run_once(void*)
+{
+  this->target_selector_->set_target();
+}
+
 // Construct a Target_selector, which means adding it to the linked
 // list.  This runs at global constructor time, so we want it to be
 // fast.
@@ -46,32 +54,31 @@ namespace gold
 Target_selector::Target_selector(int machine, int size, bool is_big_endian,
 				 const char* bfd_name)
   : machine_(machine), size_(size), is_big_endian_(is_big_endian),
-    bfd_name_(bfd_name), instantiated_target_(NULL), lock_(NULL),
-    initialize_lock_(&this->lock_)
-    
+    bfd_name_(bfd_name), instantiated_target_(NULL), set_target_once_(this)
 {
   this->next_ = target_selectors;
   target_selectors = this;
 }
 
-// Instantiate the target and return it.  Use a lock to avoid
-// instantiating two instances of the same target.
+// Instantiate the target and return it.  Use SET_TARGET_ONCE_ to
+// avoid instantiating two instances of the same target.
 
 Target*
 Target_selector::instantiate_target()
 {
-  // We assume that the pointer will either be written entirely or not
-  // at all.
-  if (this->instantiated_target_ == NULL)
-    {
-      this->initialize_lock_.initialize();
-      Hold_optional_lock hl(this->lock_);
-      if (this->instantiated_target_ == NULL)
-	this->instantiated_target_ = this->do_instantiate_target();
-    }
+  this->set_target_once_.run_once(NULL);
   return this->instantiated_target_;
 }
 
+// Instantiate the target.  This is called at most once.
+
+void
+Target_selector::set_target()
+{
+  gold_assert(this->instantiated_target_ == NULL);
+  this->instantiated_target_ = this->do_instantiate_target();
+}
+
 // Find the target for an ELF file.
 
 Target*