1 /*
   2  * Copyright (c) 2001, 2016, 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/os.hpp"
  27 #include "runtime/thread.inline.hpp"
  28 #include "runtime/threadCritical.hpp"
  29 
  30 // OS-includes here
  31 #include <thread.h>
  32 #include <synch.h>
  33 
  34 //
  35 // See threadCritical.hpp for details of this class.
  36 //
  37 // For some reason, we don't do locking until the
  38 // os::init() call completes. I'm not sure why this
  39 // is, and have left it that way for now. This should
  40 // be reviewed later.
  41 
  42 static  mutex_t  global_mut;
  43 static  thread_t global_mut_owner = -1;
  44 static  int      global_mut_count = 0;
  45 static  bool     initialized = false;
  46 
  47 ThreadCritical::ThreadCritical() {
  48   if (initialized) {
  49     thread_t owner = thr_self();
  50     if (global_mut_owner != owner) {
  51       if (os::Solaris::mutex_lock(&global_mut))
  52         fatal("ThreadCritical::ThreadCritical: mutex_lock failed (%s)",
  53               os::strerror(errno));
  54       assert(global_mut_count == 0, "must have clean count");
  55       assert(global_mut_owner == -1, "must have clean owner");
  56     }
  57     global_mut_owner = owner;
  58     ++global_mut_count;
  59   } else {
  60     assert (Threads::number_of_threads() == 0, "valid only during initialization");
  61   }
  62 }
  63 
  64 ThreadCritical::~ThreadCritical() {
  65   if (initialized) {
  66     assert(global_mut_owner == thr_self(), "must have correct owner");
  67     assert(global_mut_count > 0, "must have correct count");
  68     --global_mut_count;
  69     if (global_mut_count == 0) {
  70       global_mut_owner = -1;
  71       if (os::Solaris::mutex_unlock(&global_mut))
  72         fatal("ThreadCritical::~ThreadCritical: mutex_unlock failed (%s)", os::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 }