1 /*
   2  * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "runtime/thread.inline.hpp"
  27 #include "runtime/threadCritical.hpp"
  28 
  29 // OS-includes here
  30 #include <thread.h>
  31 #include <synch.h>
  32 
  33 //
  34 // See threadCritical.hpp for details of this class.
  35 //
  36 // For some reason, we don't do locking until the
  37 // os::init() call completes. I'm not sure why this
  38 // is, and have left it that way for now. This should
  39 // be reviewed later.
  40 
  41 static  mutex_t  global_mut;
  42 static  thread_t global_mut_owner = -1;
  43 static  int      global_mut_count = 0;
  44 static  bool     initialized = false;
  45 
  46 ThreadCritical::ThreadCritical() {
  47   if (initialized) {
  48     thread_t owner = thr_self();
  49     if (global_mut_owner != owner) {
  50       if (os::Solaris::mutex_lock(&global_mut))
  51         fatal("ThreadCritical::ThreadCritical: mutex_lock failed (%s)",
  52               strerror(errno));
  53       assert(global_mut_count == 0, "must have clean count");
  54       assert(global_mut_owner == -1, "must have clean owner");
  55     }
  56     global_mut_owner = owner;
  57     ++global_mut_count;
  58   } else {
  59     assert (Threads::number_of_threads() == 0, "valid only during initialization");
  60   }
  61 }
  62 
  63 ThreadCritical::~ThreadCritical() {
  64   if (initialized) {
  65     assert(global_mut_owner == thr_self(), "must have correct owner");
  66     assert(global_mut_count > 0, "must have correct count");
  67     --global_mut_count;
  68     if (global_mut_count == 0) {
  69       global_mut_owner = -1;
  70       if (os::Solaris::mutex_unlock(&global_mut))
  71         fatal("ThreadCritical::~ThreadCritical: mutex_unlock failed "
  72               "(%s)", strerror(errno));
  73     }
  74   } else {
  75     assert (Threads::number_of_threads() == 0, "valid only during initialization");
  76   }
  77 }
  78 
  79 void ThreadCritical::initialize() {
  80   // This method is called at the end of os::init(). Until
  81   // then, we don't do real locking.
  82   initialized = true;
  83 }
  84 
  85 void ThreadCritical::release() {
  86 }