X-Git-Url: https://oss.titaniummirror.com/gitweb?p=msp430-binutils.git;a=blobdiff_plain;f=gold%2Fgold-threads.h;fp=gold%2Fgold-threads.h;h=9c49b57d071697927f1a40618ccc1bf86fe3a628;hp=0000000000000000000000000000000000000000;hb=88750007d7869f178f0ba528f41efd3b74c424cf;hpb=6df9443a374e2b81278c61b8afc0a1eef7db280b

diff --git a/gold/gold-threads.h b/gold/gold-threads.h
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+// gold-threads.h -- thread support for gold  -*- C++ -*-
+
+// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+// gold can be configured to support threads.  If threads are
+// supported, the user can specify at runtime whether or not to
+// support them.  This provides an interface to manage locking
+// accordingly.
+
+// Lock
+//   A simple lock class.
+
+#ifndef GOLD_THREADS_H
+#define GOLD_THREADS_H
+
+namespace gold
+{
+
+class Condvar;
+class Initialize_lock_once;
+
+// The interface for the implementation of a Lock.
+
+class Lock_impl
+{
+ public:
+  Lock_impl()
+  { }
+
+  virtual
+  ~Lock_impl()
+  { }
+
+  virtual void
+  acquire() = 0;
+
+  virtual void
+  release() = 0;
+};
+
+// A simple lock class.
+
+class Lock
+{
+ public:
+  Lock();
+
+  ~Lock();
+
+  // Acquire the lock.
+  void
+  acquire()
+  { this->lock_->acquire(); }
+
+  // Release the lock.
+  void
+  release()
+  { this->lock_->release(); }
+
+ private:
+  // This class can not be copied.
+  Lock(const Lock&);
+  Lock& operator=(const Lock&);
+
+  friend class Condvar;
+  Lock_impl*
+  get_impl() const
+  { return this->lock_; }
+
+  Lock_impl* lock_;
+};
+
+// RAII for Lock.
+
+class Hold_lock
+{
+ public:
+  Hold_lock(Lock& lock)
+    : lock_(lock)
+  { this->lock_.acquire(); }
+
+  ~Hold_lock()
+  { this->lock_.release(); }
+
+ private:
+  // This class can not be copied.
+  Hold_lock(const Hold_lock&);
+  Hold_lock& operator=(const Hold_lock&);
+
+  Lock& lock_;
+};
+
+class Hold_optional_lock
+{
+ public:
+  Hold_optional_lock(Lock* lock)
+    : lock_(lock)
+  {
+    if (this->lock_ != NULL)
+      this->lock_->acquire();
+  }
+
+  ~Hold_optional_lock()
+  {
+    if (this->lock_ != NULL)
+      this->lock_->release();
+  }
+
+ private:
+  Hold_optional_lock(const Hold_optional_lock&);
+  Hold_optional_lock& operator=(const Hold_optional_lock&);
+
+  Lock* lock_;
+};
+
+// The interface for the implementation of a condition variable.
+
+class Condvar_impl
+{
+ public:
+  Condvar_impl()
+  { }
+
+  virtual
+  ~Condvar_impl()
+  { }
+
+  virtual void
+  wait(Lock_impl*) = 0;
+
+  virtual void
+  signal() = 0;
+
+  virtual void
+  broadcast() = 0;
+};
+
+// A simple condition variable class.  It is always associated with a
+// specific lock.
+
+class Condvar
+{
+ public:
+  Condvar(Lock& lock);
+  ~Condvar();
+
+  // Wait for the condition variable to be signalled.  This should
+  // only be called when the lock is held.
+  void
+  wait()
+  { this->condvar_->wait(this->lock_.get_impl()); }
+
+  // Signal the condition variable--wake up at least one thread
+  // waiting on the condition variable.  This should only be called
+  // when the lock is held.
+  void
+  signal()
+  { this->condvar_->signal(); }
+
+  // Broadcast the condition variable--wake up all threads waiting on
+  // the condition variable.  This should only be called when the lock
+  // is held.
+  void
+  broadcast()
+  { this->condvar_->broadcast(); }
+
+ private:
+  // This class can not be copied.
+  Condvar(const Condvar&);
+  Condvar& operator=(const Condvar&);
+
+  Lock& lock_;
+  Condvar_impl* condvar_;
+};
+
+// 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
+// options have been read, we know we are single-threaded, so we can
+// get by without using a lock.  This class should be an instance
+// variable of the class which has a lock which needs to be
+// initialized.
+
+class Initialize_lock
+{
+ 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 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();
+
+ 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.
+
+#endif // !defined(GOLD_THREADS_H)