* gold-threads.h (Once): Conditionalize member was_run_lock_ on
[ENABLE_THREADS && __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4], matching
its only use.
* gold-threads.cc (Once::Once): Likewise conditionalize initializer.
* gold-threads.h (Once::~Once): Explicitly define virtual destructor.
* icf.cc (get_section_contents): Cast snprintf arguments to long long
types to avoid warnings due to different uint64_t implementations
on different hosts.
(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.
* descriptors.cc: New file.
* descriptors.h: New file.
* gold-threads.h (class Hold_optional_lock): New class.
* fileread.cc: Include "descriptors.h".
(File_read::~File_read): Release descriptor rather than closing
it.
(File_read::open) [file]: Call open_descriptor rather than open.
Set is_descriptor_opened_.
(File_read::open) [memory]: Assert that descriptor is not open.
(File_read::reopen_descriptor): New function.
(File_read::release): Release descriptor.
(File_read::do_read): Make non-const. Reopen descriptor.
(File_read::read): Make non-const.
(File_read::make_view): Reopen descriptor.
(File_read::do_readv): Likewise.
* fileread.h (class File_read): Add is_descriptor_opened_ field.
Update declarations.
* layout.cc: Include "descriptors.h".
(Layout::create_build_id): Use open_descriptor rather than open.
* output.cc: Include "descriptors.h".
(Output_file::open): Use open_descriptor rather than open.
* archive.cc (Archive::const_iterator): Change Archive to be
non-const.
(Archive::begin, Archive::end): Make non-const.
(Archive::count_members): Likewise.
* archive.h (class Archive): Update declarations.
* object.h (Object::read): Make non-const.
* Makefile.am (CCFILES): Add descriptors.cc.
(HFILES): Add descriptors.h.
* Makefile.in: Rebuild.
