From: Ian Lance Taylor Date: Fri, 12 Feb 2010 03:23:26 +0000 (+0000) Subject: * gold-threads.h (class Once): Define. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=114dfbe13efea1a1405dbcf5d9254e59d309382f;p=binutils-gdb.git * 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. --- diff --git a/gold/ChangeLog b/gold/ChangeLog index 21d04a58787..346806f93dd 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,60 @@ +2010-02-11 Ian Lance Taylor + + * 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. + 2010-02-10 Ian Lance Taylor * dirsearch.cc (Dirsearch::initialize): Add all blockers before diff --git a/gold/archive.cc b/gold/archive.cc index 011c36ddd61..a8b0fc6c7d8 100644 --- a/gold/archive.cc +++ b/gold/archive.cc @@ -1,6 +1,6 @@ // archive.cc -- archive support for gold -// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -275,7 +275,8 @@ Archive::interpret_header(const Archive_header* hdr, off_t off, else if (hdr->ar_name[1] == ' ') { // This is the symbol table. - pname->clear(); + if (!pname->empty()) + pname->clear(); } else if (hdr->ar_name[1] == '/') { diff --git a/gold/fileread.cc b/gold/fileread.cc index ac30769216e..4e8157f7957 100644 --- a/gold/fileread.cc +++ b/gold/fileread.cc @@ -1,6 +1,6 @@ // fileread.cc -- read files for gold -// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -38,6 +38,7 @@ #include "target.h" #include "binary.h" #include "descriptors.h" +#include "gold-threads.h" #include "fileread.h" #ifndef HAVE_READV @@ -95,6 +96,10 @@ File_read::View::is_locked() // Class File_read. +// A lock for the File_read static variables. +static Lock* file_counts_lock = NULL; +static Initialize_lock file_counts_initialize_lock(&file_counts_lock); + // The File_read static variables. unsigned long long File_read::total_mapped_bytes; unsigned long long File_read::current_mapped_bytes; @@ -204,11 +209,17 @@ File_read::release() { gold_assert(this->is_locked()); - File_read::total_mapped_bytes += this->mapped_bytes_; - File_read::current_mapped_bytes += this->mapped_bytes_; + if (!parameters->options_valid() || parameters->options().stats()) + { + file_counts_initialize_lock.initialize(); + Hold_optional_lock hl(file_counts_lock); + File_read::total_mapped_bytes += this->mapped_bytes_; + File_read::current_mapped_bytes += this->mapped_bytes_; + if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes) + File_read::maximum_mapped_bytes = File_read::current_mapped_bytes; + } + this->mapped_bytes_ = 0; - if (File_read::current_mapped_bytes > File_read::maximum_mapped_bytes) - File_read::maximum_mapped_bytes = File_read::current_mapped_bytes; // Only clear views if there is only one attached object. Otherwise // we waste time trying to clear cached archive views. Similarly diff --git a/gold/fileread.h b/gold/fileread.h index 47c8e0ff27e..5aac7ad6274 100644 --- a/gold/fileread.h +++ b/gold/fileread.h @@ -1,6 +1,6 @@ // fileread.h -- read files for gold -*- C++ -*- -// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -218,16 +218,15 @@ class File_read File_read(const File_read&); File_read& operator=(const File_read&); - // Total bytes mapped into memory during the link. This variable - // may not be accurate when running multi-threaded. + // Total bytes mapped into memory during the link if --stats. static unsigned long long total_mapped_bytes; - // Current number of bytes mapped into memory during the link. This - // variable may not be accurate when running multi-threaded. + // Current number of bytes mapped into memory during the link if + // --stats. static unsigned long long current_mapped_bytes; - // High water mark of bytes mapped into memory during the link. - // This variable may not be accurate when running multi-threaded. + // High water mark of bytes mapped into memory during the link if + // --stats. static unsigned long long maximum_mapped_bytes; // A view into the file. diff --git a/gold/gold-threads.cc b/gold/gold-threads.cc index b99cf275847..f5347bfcb4a 100644 --- a/gold/gold-threads.cc +++ b/gold/gold-threads.cc @@ -1,6 +1,6 @@ // gold-threads.cc -- thread support for gold -// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -278,13 +278,13 @@ Condvar::~Condvar() #ifdef ENABLE_THREADS -// Class Initialize_lock_once. This exists to hold a pthread_once_t -// structure for Initialize_lock. +// Class Once_initialize. This exists to hold a pthread_once_t +// structure for Once. -class Initialize_lock_once +class Once_initialize { public: - Initialize_lock_once() + Once_initialize() : once_(PTHREAD_ONCE_INIT) { } @@ -297,107 +297,151 @@ class Initialize_lock_once pthread_once_t once_; }; -#endif // !defined(ENABLE_THREADS) +#endif // defined(ENABLE_THREADS) #ifdef ENABLE_THREADS -// A single lock which controls access to initialize_lock_pointer. -// This is used because we can't pass parameters to functions passed -// to pthread_once. +// A single lock which controls access to once_pointer. This is used +// because we can't pass parameters to functions passed to +// pthread_once. + +static pthread_mutex_t once_pointer_control = PTHREAD_MUTEX_INITIALIZER; -static pthread_mutex_t initialize_lock_control = PTHREAD_MUTEX_INITIALIZER; +// A pointer to Once structure we want to run. Access to this is +// controlled by once_pointer_control. -// A pointer to a pointer to the lock which we need to initialize -// once. Access to this is controlled by initialize_lock_control. +static Once* once_pointer; -static Lock** initialize_lock_pointer; +// The argument to pass to the Once structure. Access to this is +// controlled by once_pointer_control. -// A routine passed to pthread_once which initializes the lock which -// initialize_lock_pointer points to. +static void* once_arg; + +// A routine passed to pthread_once which runs the Once pointer. extern "C" { static void -initialize_lock_once() +c_run_once(void) { - *initialize_lock_pointer = new Lock(); + once_pointer->internal_run(once_arg); } } -#endif // !defined(ENABLE_THREADS) +#endif // defined(ENABLE_THREADS) -// Class Initialize_lock. +// Class Once. -Initialize_lock::Initialize_lock(Lock** pplock) - : pplock_(pplock) +Once::Once() + : was_run_(false), was_run_lock_(0) { #ifndef ENABLE_THREADS this->once_ = NULL; #else - this->once_ = new Initialize_lock_once(); + this->once_ = new Once_initialize(); #endif } -// Initialize the lock. +// Run the function once. -bool -Initialize_lock::initialize() +void +Once::run_once(void* arg) { - // If the lock has already been initialized, we don't need to do - // anything. Note that this assumes that the pointer value will be - // set completely or not at all. I hope this is always safe. We - // want to do this for efficiency. - if (*this->pplock_ != NULL) - return true; +#ifndef ENABLE_THREADS - // We can't initialize the lock until we have read the options. - if (!parameters->options_valid()) - return false; + // If there is no threads support, we don't need to use pthread_once. + if (!this->was_run_) + this->internal_run(arg); - // If the user did not use --threads, then we can initialize - // directly. - if (!parameters->options().threads()) +#else // defined(ENABLE_THREADS) + + if (parameters->options_valid() && !parameters->options().threads()) { - *this->pplock_ = new Lock(); - return true; + // If we are not using threads, we don't need to lock. + if (!this->was_run_) + this->internal_run(arg); + return; } -#ifndef ENABLE_THREADS - - // If there is no threads support, we don't need to use - // pthread_once. - *this->pplock_ = new Lock(); - -#else // !defined(ENABLE_THREADS) + // If we have the sync builtins, use them to skip the lock if the + // value has already been initialized. +#ifdef __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 + while (true) + { + if (__sync_bool_compare_and_swap(&this->was_run_lock_, 0, 1)) + break; + } + bool was_run = this->was_run_; + while (true) + { + if (__sync_bool_compare_and_swap(&this->was_run_lock_, 1, 0)) + break; + } + if (was_run) + return; +#endif // Since we can't pass parameters to routines called by - // pthread_once, we use a static variable: initialize_lock_pointer. - // That in turns means that we need to use a mutex to control access - // to initialize_lock_pointer. + // pthread_once, we use a static variable: once_pointer. This in + // turns means that we need to use a mutex to control access to + // once_pointer. - int err = pthread_mutex_lock(&initialize_lock_control); + int err = pthread_mutex_lock(&once_pointer_control); if (err != 0) gold_fatal(_("pthread_mutex_lock failed: %s"), strerror(err)); - initialize_lock_pointer = this->pplock_; + once_pointer = this; + once_arg = arg; - err = pthread_once(this->once_->once_control(), initialize_lock_once); + err = pthread_once(this->once_->once_control(), c_run_once); if (err != 0) gold_fatal(_("pthread_once failed: %s"), strerror(err)); - initialize_lock_pointer = NULL; + once_pointer = NULL; + once_arg = NULL; - err = pthread_mutex_unlock(&initialize_lock_control); + err = pthread_mutex_unlock(&once_pointer_control); if (err != 0) - gold_fatal(_("pthread_mutex_unlock failed: %s"), strerror(err)); + gold_fatal(_("pthread_mutex_unlock falied: %s"), strerror(err)); - gold_assert(*this->pplock_ != NULL); +#endif // defined(ENABLE_THREADS) +} + +// Actually run the function in the child class. This function will +// be run only once. + +void +Once::internal_run(void* arg) +{ + this->do_run_once(arg); + this->was_run_ = true; +} + +// Class Initialize_lock. + +// Initialize the lock. + +bool +Initialize_lock::initialize() +{ + // We can't initialize the lock until we have read the options. + if (!parameters->options_valid()) + return false; + else + { + this->run_once(NULL); + return true; + } +} -#endif // !defined(ENABLE_THREADS) +// Initialize the lock exactly once. - return true; +void +Initialize_lock::do_run_once(void*) +{ + *this->pplock_ = new Lock(); } } // End namespace gold. diff --git a/gold/gold-threads.h b/gold/gold-threads.h index 9c49b57d071..78a87b24d64 100644 --- a/gold/gold-threads.h +++ b/gold/gold-threads.h @@ -1,6 +1,6 @@ // gold-threads.h -- thread support for gold -*- C++ -*- -// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -35,6 +35,7 @@ namespace gold { class Condvar; +class Once_initialize; class Initialize_lock_once; // The interface for the implementation of a Lock. @@ -191,6 +192,39 @@ class Condvar Condvar_impl* condvar_; }; +// A class used to do something once. This is an abstract parent +// class; any actual use will involve a child of this. + +class Once +{ + public: + Once(); + + // Call this function to do whatever it is. We pass an argument + // even though you have to use a child class because in some uses + // setting the argument would itself require a Once class. + void + run_once(void* arg); + + // This is an internal function, which must be public because it is + // run by an extern "C" function called via pthread_once. + void + internal_run(void* arg); + + protected: + // This must be implemented by the child class. + virtual void + do_run_once(void* arg) = 0; + + private: + // True if we have already run the function. + bool was_run_; + // Internal compare-and-swap lock on was_run_; + uint32_t was_run_lock_; + // The lock to run the function only once. + Once_initialize* once_; +}; + // A class used to initialize a lock exactly once, after the options // have been read. This is needed because the implementation of locks // depends on whether we've seen the --threads option. Before the @@ -199,23 +233,27 @@ class Condvar // variable of the class which has a lock which needs to be // initialized. -class Initialize_lock +class Initialize_lock : public Once { public: // The class which uses this will have a pointer to a lock. This // must be constructed with a pointer to that pointer. - Initialize_lock(Lock** pplock); + Initialize_lock(Lock** pplock) + : pplock_(pplock) + { } // Initialize the lock. Return true if the lock is now initialized, // false if it is not (because the options have not yet been read). bool initialize(); + protected: + void + do_run_once(void*); + private: // A pointer to the lock pointer which must be initialized. Lock** const pplock_; - // If needed, a pointer to a pthread_once_t structure. - Initialize_lock_once* once_; }; } // End namespace gold. diff --git a/gold/parameters.cc b/gold/parameters.cc index 9cf78080fab..1d0f082e197 100644 --- a/gold/parameters.cc +++ b/gold/parameters.cc @@ -1,6 +1,6 @@ // parameters.cc -- general parameters for a link using gold -// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -30,6 +30,47 @@ namespace gold { +// Our local version of the variable, which is not const. + +static Parameters static_parameters; + +// The global variable. + +const Parameters* parameters = &static_parameters; + +// A helper class to set the target once. + +class Set_parameters_target_once : public Once +{ + public: + Set_parameters_target_once(Parameters* parameters) + : parameters_(parameters) + { } + + protected: + void + do_run_once(void* arg) + { this->parameters_->set_target_once(static_cast(arg)); } + + private: + Parameters* parameters_; +}; + +// We only need one Set_parameters_target_once. + +static +Set_parameters_target_once set_parameters_target_once(&static_parameters); + +// Class Parameters. + +Parameters::Parameters() + : errors_(NULL), options_(NULL), target_(NULL), + doing_static_link_valid_(false), doing_static_link_(false), + debug_(0), + set_parameters_target_once_(&set_parameters_target_once) + { + } + void Parameters::set_errors(Errors* errors) { @@ -61,10 +102,28 @@ Parameters::set_doing_static_link(bool doing_static_link) void Parameters::set_target(Target* target) { - if (!this->target_valid()) - this->target_ = target; - else - gold_assert(target == this->target_); + this->set_parameters_target_once_->run_once(static_cast(target)); + gold_assert(target == this->target_); +} + +// This is called at most once. + +void +Parameters::set_target_once(Target* target) +{ + gold_assert(this->target_ == NULL); + this->target_ = target; +} + +// Clear the target, for testing. + +void +Parameters::clear_target() +{ + this->target_ = NULL; + // We need a new Set_parameters_target_once so that we can set the + // target again. + this->set_parameters_target_once_ = new Set_parameters_target_once(this); } // Return whether TARGET is compatible with the target we are using. @@ -122,15 +181,6 @@ Parameters::size_and_endianness() const gold_unreachable(); } - -// Our local version of the variable, which is not const. - -static Parameters static_parameters; - -// The global variable. - -const Parameters* parameters = &static_parameters; - void set_parameters_errors(Errors* errors) { static_parameters.set_errors(errors); } diff --git a/gold/parameters.h b/gold/parameters.h index 88d8a870323..85b8ef6d67d 100644 --- a/gold/parameters.h +++ b/gold/parameters.h @@ -1,6 +1,6 @@ // parameters.h -- general parameters for a link using gold -*- C++ -*- -// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -31,6 +31,7 @@ class Errors; class Target; template class Sized_target; +class Set_parameters_target_once; // Here we define the Parameters class which simply holds simple // general parameters which apply to the entire link. We use a global @@ -49,11 +50,7 @@ class Sized_target; class Parameters { public: - Parameters() - : errors_(NULL), options_(NULL), target_(NULL), - doing_static_link_valid_(false), doing_static_link_(false), - debug_(0) - { } + Parameters(); // These should be called as soon as they are known. void @@ -112,8 +109,7 @@ class Parameters // Clear the target, for testing. void - clear_target() - { this->target_ = NULL; } + clear_target(); // Return true if TARGET is compatible with the current target. bool @@ -150,12 +146,18 @@ class Parameters private: + void + set_target_once(Target*); + + friend class Set_parameters_target_once; + Errors* errors_; const General_options* options_; Target* target_; bool doing_static_link_valid_; bool doing_static_link_; int debug_; + Set_parameters_target_once* set_parameters_target_once_; }; // This is a global variable. diff --git a/gold/readsyms.cc b/gold/readsyms.cc index 6cff8534bb9..cd8814c70f5 100644 --- a/gold/readsyms.cc +++ b/gold/readsyms.cc @@ -1,6 +1,6 @@ // readsyms.cc -- read input file symbols for gold -// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -360,6 +360,19 @@ Read_symbols::do_group(Workqueue* workqueue) const Input_file_group* group = this->input_argument_->group(); Task_token* this_blocker = this->this_blocker_; + Finish_group* finish_group = new Finish_group(this->input_objects_, + this->symtab_, + this->layout_, + this->mapfile_, + input_group, + this->next_blocker_); + + Task_token* next_blocker = new Task_token(true); + next_blocker->add_blocker(); + workqueue->queue_soon(new Start_group(this->symtab_, finish_group, + this_blocker, next_blocker)); + this_blocker = next_blocker; + for (Input_file_group::const_iterator p = group->begin(); p != group->end(); ++p) @@ -367,7 +380,7 @@ Read_symbols::do_group(Workqueue* workqueue) const Input_argument* arg = &*p; gold_assert(arg->is_file()); - Task_token* next_blocker = new Task_token(true); + next_blocker = new Task_token(true); next_blocker->add_blocker(); workqueue->queue_soon(new Read_symbols(this->input_objects_, this->symtab_, this->layout_, @@ -377,15 +390,9 @@ Read_symbols::do_group(Workqueue* workqueue) this_blocker = next_blocker; } - const int saw_undefined = this->symtab_->saw_undefined(); - workqueue->queue_soon(new Finish_group(this->input_objects_, - this->symtab_, - this->layout_, - this->mapfile_, - input_group, - saw_undefined, - this_blocker, - this->next_blocker_)); + finish_group->set_blocker(this_blocker); + + workqueue->queue_soon(finish_group); } // Return a debugging name for a Read_symbols task. @@ -476,6 +483,40 @@ Add_symbols::run(Workqueue*) this->sd_ = NULL; } +// Class Start_group. + +Start_group::~Start_group() +{ + if (this->this_blocker_ != NULL) + delete this->this_blocker_; + // next_blocker_ is deleted by the task associated with the first + // file in the group. +} + +// We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_. + +Task_token* +Start_group::is_runnable() +{ + if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked()) + return this->this_blocker_; + return NULL; +} + +void +Start_group::locks(Task_locker* tl) +{ + tl->add(this, this->next_blocker_); +} + +// Store the number of undefined symbols we see now. + +void +Start_group::run(Workqueue*) +{ + this->finish_group_->set_saw_undefined(this->symtab_->saw_undefined()); +} + // Class Finish_group. Finish_group::~Finish_group() @@ -507,7 +548,7 @@ Finish_group::locks(Task_locker* tl) void Finish_group::run(Workqueue*) { - int saw_undefined = this->saw_undefined_; + size_t saw_undefined = this->saw_undefined_; while (saw_undefined != this->symtab_->saw_undefined()) { saw_undefined = this->symtab_->saw_undefined(); diff --git a/gold/readsyms.h b/gold/readsyms.h index c054b57d7c6..626cb38ce21 100644 --- a/gold/readsyms.h +++ b/gold/readsyms.h @@ -1,6 +1,6 @@ // readsyms.h -- read input file symbols for gold -*- C++ -*- -// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -35,6 +35,7 @@ class Input_objects; class Symbol_table; class Input_group; class Archive; +class Finish_group; // This Task is responsible for reading the symbols from an input // file. This also includes reading the relocations so that we can @@ -200,6 +201,43 @@ class Input_group Archives archives_; }; +// This class starts the handling of a group. It exists only to pick +// up the number of undefined symbols at that point, so that we only +// run back through the group if we saw a new undefined symbol. + +class Start_group : public Task +{ + public: + Start_group(Symbol_table* symtab, Finish_group* finish_group, + Task_token* this_blocker, Task_token* next_blocker) + : symtab_(symtab), finish_group_(finish_group), + this_blocker_(this_blocker), next_blocker_(next_blocker) + { } + + ~Start_group(); + + // The standard Task methods. + + Task_token* + is_runnable(); + + void + locks(Task_locker*); + + void + run(Workqueue*); + + std::string + get_name() const + { return "Start_group"; } + + private: + Symbol_table* symtab_; + Finish_group* finish_group_; + Task_token* this_blocker_; + Task_token* next_blocker_; +}; + // This class is used to finish up handling a group. It is just a // closure. @@ -208,16 +246,28 @@ class Finish_group : public Task public: Finish_group(Input_objects* input_objects, Symbol_table* symtab, Layout* layout, Mapfile* mapfile, Input_group* input_group, - int saw_undefined, Task_token* this_blocker, Task_token* next_blocker) : input_objects_(input_objects), symtab_(symtab), layout_(layout), mapfile_(mapfile), input_group_(input_group), - saw_undefined_(saw_undefined), this_blocker_(this_blocker), - next_blocker_(next_blocker) + saw_undefined_(0), this_blocker_(NULL), next_blocker_(next_blocker) { } ~Finish_group(); + // Set the number of undefined symbols when we start processing the + // group. This is called by the Start_group task. + void + set_saw_undefined(size_t saw_undefined) + { this->saw_undefined_ = saw_undefined; } + + // Set the blocker to use for this task. + void + set_blocker(Task_token* this_blocker) + { + gold_assert(this->this_blocker_ == NULL); + this->this_blocker_ = this_blocker; + } + // The standard Task methods. Task_token* @@ -239,7 +289,7 @@ class Finish_group : public Task Layout* layout_; Mapfile* mapfile_; Input_group* input_group_; - int saw_undefined_; + size_t saw_undefined_; Task_token* this_blocker_; Task_token* next_blocker_; }; diff --git a/gold/symtab.h b/gold/symtab.h index c8aac26bd8e..1a81fd11ed8 100644 --- a/gold/symtab.h +++ b/gold/symtab.h @@ -1354,7 +1354,7 @@ class Symbol_table get_sized_symbol(const Symbol*) const; // Return the count of undefined symbols seen. - int + size_t saw_undefined() const { return this->saw_undefined_; } @@ -1709,7 +1709,7 @@ class Symbol_table // We increment this every time we see a new undefined symbol, for // use in archive groups. - int saw_undefined_; + size_t saw_undefined_; // The index of the first global symbol in the output file. unsigned int first_global_index_; // The file offset within the output symtab section where we should diff --git a/gold/target-select.cc b/gold/target-select.cc index dcd3017f07c..859bc3bd62c 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 . // 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* diff --git a/gold/target-select.h b/gold/target-select.h index d1cd44f229d..4e2ea922684 100644 --- a/gold/target-select.h +++ b/gold/target-select.h @@ -1,6 +1,6 @@ // target-select.h -- select a target for an object file -*- C++ -*- -// Copyright 2006, 2007, 2008 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -31,6 +31,24 @@ namespace gold { class Target; +class Target_selector; + +// Used to set the target only once. + +class Set_target_once : public Once +{ + public: + Set_target_once(Target_selector* target_selector) + : target_selector_(target_selector) + { } + + protected: + void + do_run_once(void*); + + private: + Target_selector* target_selector_; +}; // We want to avoid a master list of targets, which implies using a // global constructor. And we also want the program to start up as @@ -141,6 +159,12 @@ class Target_selector instantiate_target(); private: + // Set the target. + void + set_target(); + + friend class Set_target_once; + // ELF machine code. const int machine_; // Target size--32 or 64. @@ -154,11 +178,8 @@ class Target_selector // The singleton Target structure--this points to an instance of the // real implementation. Target* instantiated_target_; - // Lock to make sure that we don't instantiate the target more than - // once. - Lock* lock_; - // We only want to initialize the lock_ pointer once. - Initialize_lock initialize_lock_; + // Used to set the target only once. + Set_target_once set_target_once_; }; // Select the target for an ELF file.