jdk8-mips64-public/hotspot: src/os/solaris/vm/osThread_solaris.cpp@d2f8c38e543d (annotated)

src/os/solaris/vm/osThread_solaris.cpp@d2f8c38e543d (annotated)

src/os/solaris/vm/osThread_solaris.cpp

Fri, 07 Dec 2012 01:09:03 -0800

author: roland
date: Fri, 07 Dec 2012 01:09:03 -0800
changeset 4325: d2f8c38e543d
parent 4318: cd3d6a6b95d9
child 5237: f2110083203d
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code 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
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 // no precompiled headers
 #include "runtime/atomic.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "runtime/os.hpp"
 #include "runtime/osThread.hpp"
 #include "runtime/safepoint.hpp"
 #include "runtime/vmThread.hpp"
 #include <signal.h>
  // ***************************************************************
  // Platform dependent initialization and cleanup
  // ***************************************************************
 void OSThread::pd_initialize() {
   _thread_id                         = 0;
   sigemptyset(&_caller_sigmask);
   _current_callback                  = NULL;
   _current_callback_lock = VM_Version::supports_compare_and_exchange() ? NULL
                     : new Mutex(Mutex::suspend_resume, "Callback_lock", true);
   _saved_interrupt_thread_state      = _thread_new;
   _vm_created_thread                 = false;
 }
 void OSThread::pd_destroy() {
 }
 // Synchronous interrupt support
 //
 // _current_callback == NULL          no pending callback
 //                   == 1             callback_in_progress
 //                   == other value   pointer to the pending callback
 //
 // CAS on v8 is implemented by using a global atomic_memory_operation_lock,
 // which is shared by other atomic functions. It is OK for normal uses, but
 // dangerous if used after some thread is suspended or if used in signal
 // handlers. Instead here we use a special per-thread lock to synchronize
 // updating _current_callback if we are running on v8. Note in general trying
 // to grab locks after a thread is suspended is not safe, but it is safe for
 // updating _current_callback, because synchronous interrupt callbacks are
 // currently only used in:
 // 1. GetThreadPC_Callback - used by WatcherThread to profile VM thread
 // There is no overlap between the callbacks, which means we won't try to
 // grab a thread's sync lock after the thread has been suspended while holding
 // the same lock.
 // used after a thread is suspended
 static intptr_t compare_and_exchange_current_callback (
        intptr_t callback, intptr_t *addr, intptr_t compare_value, Mutex *sync) {
   if (VM_Version::supports_compare_and_exchange()) {
     return Atomic::cmpxchg_ptr(callback, addr, compare_value);
   } else {
     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
     if (*addr == compare_value) {
       *addr = callback;
       return compare_value;
     } else {
       return callback;
     }
   }
 }
 // used in signal handler
 static intptr_t exchange_current_callback(intptr_t callback, intptr_t *addr, Mutex *sync) {
   if (VM_Version::supports_compare_and_exchange()) {
     return Atomic::xchg_ptr(callback, addr);
   } else {
     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
     intptr_t cb = *addr;
     *addr = callback;
     return cb;
   }
 }
 // one interrupt at a time. spin if _current_callback != NULL
 int OSThread::set_interrupt_callback(Sync_Interrupt_Callback * cb) {
   int count = 0;
   while (compare_and_exchange_current_callback(
          (intptr_t)cb, (intptr_t *)&_current_callback, (intptr_t)NULL, _current_callback_lock) != NULL) {
     while (_current_callback != NULL) {
       count++;
 #ifdef ASSERT
       if ((WarnOnStalledSpinLock > 0) &&
           (count % WarnOnStalledSpinLock == 0)) {
           warning("_current_callback seems to be stalled: %p", _current_callback);
       }
 #endif
       os::yield_all(count);
     }
   }
   return 0;
 }
 // reset _current_callback, spin if _current_callback is callback_in_progress
 void OSThread::remove_interrupt_callback(Sync_Interrupt_Callback * cb) {
   int count = 0;
   while (compare_and_exchange_current_callback(
          (intptr_t)NULL, (intptr_t *)&_current_callback, (intptr_t)cb, _current_callback_lock) != (intptr_t)cb) {
 #ifdef ASSERT
     intptr_t p = (intptr_t)_current_callback;
     assert(p == (intptr_t)callback_in_progress ||
            p == (intptr_t)cb, "wrong _current_callback value");
 #endif
     while (_current_callback != cb) {
       count++;
 #ifdef ASSERT
       if ((WarnOnStalledSpinLock > 0) &&
           (count % WarnOnStalledSpinLock == 0)) {
           warning("_current_callback seems to be stalled: %p", _current_callback);
       }
 #endif
       os::yield_all(count);
     }
   }
 }
 void OSThread::do_interrupt_callbacks_at_interrupt(InterruptArguments *args) {
   Sync_Interrupt_Callback * cb;
   cb = (Sync_Interrupt_Callback *)exchange_current_callback(
         (intptr_t)callback_in_progress, (intptr_t *)&_current_callback, _current_callback_lock);
   if (cb == NULL) {
     // signal is delivered too late (thread is masking interrupt signal??).
     // there is nothing we need to do because requesting thread has given up.
   } else if ((intptr_t)cb == (intptr_t)callback_in_progress) {
     fatal("invalid _current_callback state");
   } else {
     assert(cb->target()->osthread() == this, "wrong target");
     cb->execute(args);
     cb->leave_callback();             // notify the requester
   }
   // restore original _current_callback value
   intptr_t p;
   p = exchange_current_callback((intptr_t)cb, (intptr_t *)&_current_callback, _current_callback_lock);
   assert(p == (intptr_t)callback_in_progress, "just checking");
 }
 // Called by the requesting thread to send a signal to target thread and
 // execute "this" callback from the signal handler.
 int OSThread::Sync_Interrupt_Callback::interrupt(Thread * target, int timeout) {
   // Let signals to the vm_thread go even if the Threads_lock is not acquired
   assert(Threads_lock->owned_by_self() || (target == VMThread::vm_thread()),
          "must have threads lock to call this");
   OSThread * osthread = target->osthread();
   // may block if target thread already has a pending callback
   osthread->set_interrupt_callback(this);
   _target = target;
   int rslt = thr_kill(osthread->thread_id(), os::Solaris::SIGasync());
   assert(rslt == 0, "thr_kill != 0");
   bool status = false;
   jlong t1 = os::javaTimeMillis();
   { // don't use safepoint check because we might be the watcher thread.
     MutexLockerEx ml(_sync, Mutex::_no_safepoint_check_flag);
     while (!is_done()) {
       status = _sync->wait(Mutex::_no_safepoint_check_flag, timeout);
       // status == true if timed out
       if (status) break;
       // update timeout
       jlong t2 = os::javaTimeMillis();
       timeout -= t2 - t1;
       t1 = t2;
     }
   }
   // reset current_callback
   osthread->remove_interrupt_callback(this);
   return status;
 }
 void OSThread::Sync_Interrupt_Callback::leave_callback() {
   if (!_sync->owned_by_self()) {
     // notify requesting thread
     MutexLockerEx ml(_sync, Mutex::_no_safepoint_check_flag);
     _is_done = true;
     _sync->notify_all();
   } else {
     // Current thread is interrupted while it is holding the _sync lock, trying
     // to grab it again will deadlock. The requester will timeout anyway,
     // so just return.
     _is_done = true;
   }
 }
 // copied from synchronizer.cpp
 void OSThread::handle_spinlock_contention(int tries) {
   if (NoYieldsInMicrolock) return;
   if (tries > 10) {
     os::yield_all(tries); // Yield to threads of any priority
   } else if (tries > 5) {
     os::yield();          // Yield to threads of same or higher priority
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/os/solaris/vm/osThread_solaris.cpp@d2f8c38e543d (annotated)

src/os/solaris/vm/osThread_solaris.cpp