src/os/solaris/vm/osThread_solaris.cpp

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rev 4773 : 8005849: JEP 167: Event-Based JVM Tracing
Reviewed-by: acorn, coleenp, sla
Contributed-by: Karen Kinnear <karen.kinnear@oracle.com>, Bengt Rutisson <bengt.rutisson@oracle.com>, Calvin Cheung <calvin.cheung@oracle.com>, Erik Gahlin <erik.gahlin@oracle.com>, Erik Helin <erik.helin@oracle.com>, Jesper Wilhelmsson <jesper.wilhelmsson@oracle.com>, Keith McGuigan <keith.mcguigan@oracle.com>, Mattias Tobiasson <mattias.tobiasson@oracle.com>, Markus Gronlund <markus.gronlund@oracle.com>, Mikael Auno <mikael.auno@oracle.com>, Nils Eliasson <nils.eliasson@oracle.com>, Nils Loodin <nils.loodin@oracle.com>, Rickard Backman <rickard.backman@oracle.com>, Staffan Larsen <staffan.larsen@oracle.com>, Stefan Karlsson <stefan.karlsson@oracle.com>, Yekaterina Kantserova <yekaterina.kantserova@oracle.com>
   1 /*
   2  * Copyright (c) 1998, 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  *


  24 
  25 // no precompiled headers
  26 #include "runtime/atomic.hpp"
  27 #include "runtime/handles.inline.hpp"
  28 #include "runtime/mutexLocker.hpp"
  29 #include "runtime/os.hpp"
  30 #include "runtime/osThread.hpp"
  31 #include "runtime/safepoint.hpp"
  32 #include "runtime/vmThread.hpp"
  33 
  34 #include <signal.h>
  35 
  36  // ***************************************************************
  37  // Platform dependent initialization and cleanup
  38  // ***************************************************************
  39 
  40 void OSThread::pd_initialize() {
  41   _thread_id                         = 0;
  42   sigemptyset(&_caller_sigmask);
  43 
  44   _current_callback                  = NULL;
  45   _current_callback_lock = VM_Version::supports_compare_and_exchange() ? NULL
  46                     : new Mutex(Mutex::suspend_resume, "Callback_lock", true);
  47 
  48   _saved_interrupt_thread_state      = _thread_new;
  49   _vm_created_thread                 = false;
  50 }
  51 
  52 void OSThread::pd_destroy() {
  53 }
  54 
  55 // Synchronous interrupt support
  56 //
  57 // _current_callback == NULL          no pending callback
  58 //                   == 1             callback_in_progress
  59 //                   == other value   pointer to the pending callback
  60 //
  61 
  62 // CAS on v8 is implemented by using a global atomic_memory_operation_lock,
  63 // which is shared by other atomic functions. It is OK for normal uses, but
  64 // dangerous if used after some thread is suspended or if used in signal
  65 // handlers. Instead here we use a special per-thread lock to synchronize
  66 // updating _current_callback if we are running on v8. Note in general trying
  67 // to grab locks after a thread is suspended is not safe, but it is safe for
  68 // updating _current_callback, because synchronous interrupt callbacks are
  69 // currently only used in:
  70 // 1. GetThreadPC_Callback - used by WatcherThread to profile VM thread
  71 // There is no overlap between the callbacks, which means we won't try to
  72 // grab a thread's sync lock after the thread has been suspended while holding
  73 // the same lock.
  74 
  75 // used after a thread is suspended
  76 static intptr_t compare_and_exchange_current_callback (
  77        intptr_t callback, intptr_t *addr, intptr_t compare_value, Mutex *sync) {
  78   if (VM_Version::supports_compare_and_exchange()) {
  79     return Atomic::cmpxchg_ptr(callback, addr, compare_value);
  80   } else {
  81     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
  82     if (*addr == compare_value) {
  83       *addr = callback;
  84       return compare_value;
  85     } else {
  86       return callback;
  87     }
  88   }
  89 }
  90 
  91 // used in signal handler
  92 static intptr_t exchange_current_callback(intptr_t callback, intptr_t *addr, Mutex *sync) {
  93   if (VM_Version::supports_compare_and_exchange()) {
  94     return Atomic::xchg_ptr(callback, addr);
  95   } else {
  96     MutexLockerEx ml(sync, Mutex::_no_safepoint_check_flag);
  97     intptr_t cb = *addr;
  98     *addr = callback;
  99     return cb;
 100   }
 101 }
 102 
 103 // one interrupt at a time. spin if _current_callback != NULL
 104 int OSThread::set_interrupt_callback(Sync_Interrupt_Callback * cb) {
 105   int count = 0;
 106   while (compare_and_exchange_current_callback(
 107          (intptr_t)cb, (intptr_t *)&_current_callback, (intptr_t)NULL, _current_callback_lock) != NULL) {
 108     while (_current_callback != NULL) {
 109       count++;
 110 #ifdef ASSERT
 111       if ((WarnOnStalledSpinLock > 0) &&
 112           (count % WarnOnStalledSpinLock == 0)) {
 113           warning("_current_callback seems to be stalled: %p", _current_callback);
 114       }
 115 #endif
 116       os::yield_all(count);
 117     }
 118   }
 119   return 0;
 120 }
 121 
 122 // reset _current_callback, spin if _current_callback is callback_in_progress
 123 void OSThread::remove_interrupt_callback(Sync_Interrupt_Callback * cb) {
 124   int count = 0;
 125   while (compare_and_exchange_current_callback(
 126          (intptr_t)NULL, (intptr_t *)&_current_callback, (intptr_t)cb, _current_callback_lock) != (intptr_t)cb) {
 127 #ifdef ASSERT
 128     intptr_t p = (intptr_t)_current_callback;
 129     assert(p == (intptr_t)callback_in_progress ||
 130            p == (intptr_t)cb, "wrong _current_callback value");
 131 #endif
 132     while (_current_callback != cb) {
 133       count++;
 134 #ifdef ASSERT
 135       if ((WarnOnStalledSpinLock > 0) &&
 136           (count % WarnOnStalledSpinLock == 0)) {
 137           warning("_current_callback seems to be stalled: %p", _current_callback);
 138       }
 139 #endif
 140       os::yield_all(count);
 141     }
 142   }
 143 }
 144 
 145 void OSThread::do_interrupt_callbacks_at_interrupt(InterruptArguments *args) {
 146   Sync_Interrupt_Callback * cb;
 147   cb = (Sync_Interrupt_Callback *)exchange_current_callback(
 148         (intptr_t)callback_in_progress, (intptr_t *)&_current_callback, _current_callback_lock);
 149 
 150   if (cb == NULL) {
 151     // signal is delivered too late (thread is masking interrupt signal??).
 152     // there is nothing we need to do because requesting thread has given up.
 153   } else if ((intptr_t)cb == (intptr_t)callback_in_progress) {
 154     fatal("invalid _current_callback state");
 155   } else {
 156     assert(cb->target()->osthread() == this, "wrong target");
 157     cb->execute(args);
 158     cb->leave_callback();             // notify the requester
 159   }
 160 
 161   // restore original _current_callback value
 162   intptr_t p;
 163   p = exchange_current_callback((intptr_t)cb, (intptr_t *)&_current_callback, _current_callback_lock);
 164   assert(p == (intptr_t)callback_in_progress, "just checking");
 165 }
 166 
 167 // Called by the requesting thread to send a signal to target thread and
 168 // execute "this" callback from the signal handler.
 169 int OSThread::Sync_Interrupt_Callback::interrupt(Thread * target, int timeout) {
 170   // Let signals to the vm_thread go even if the Threads_lock is not acquired
 171   assert(Threads_lock->owned_by_self() || (target == VMThread::vm_thread()),
 172          "must have threads lock to call this");
 173 
 174   OSThread * osthread = target->osthread();
 175 
 176   // may block if target thread already has a pending callback
 177   osthread->set_interrupt_callback(this);
 178 
 179   _target = target;
 180 
 181   int rslt = thr_kill(osthread->thread_id(), os::Solaris::SIGasync());
 182   assert(rslt == 0, "thr_kill != 0");
 183 
 184   bool status = false;
 185   jlong t1 = os::javaTimeMillis();
 186   { // don't use safepoint check because we might be the watcher thread.
 187     MutexLockerEx ml(_sync, Mutex::_no_safepoint_check_flag);
 188     while (!is_done()) {
 189       status = _sync->wait(Mutex::_no_safepoint_check_flag, timeout);
 190 
 191       // status == true if timed out
 192       if (status) break;
 193 
 194       // update timeout
 195       jlong t2 = os::javaTimeMillis();
 196       timeout -= t2 - t1;
 197       t1 = t2;
 198     }
 199   }
 200 
 201   // reset current_callback
 202   osthread->remove_interrupt_callback(this);
 203 
 204   return status;
 205 }
 206 
 207 void OSThread::Sync_Interrupt_Callback::leave_callback() {
 208   if (!_sync->owned_by_self()) {
 209     // notify requesting thread
 210     MutexLockerEx ml(_sync, Mutex::_no_safepoint_check_flag);
 211     _is_done = true;
 212     _sync->notify_all();
 213   } else {
 214     // Current thread is interrupted while it is holding the _sync lock, trying
 215     // to grab it again will deadlock. The requester will timeout anyway,
 216     // so just return.
 217     _is_done = true;
 218   }
 219 }
 220 
 221 // copied from synchronizer.cpp
 222 
 223 void OSThread::handle_spinlock_contention(int tries) {
 224   if (NoYieldsInMicrolock) return;
 225 
 226   if (tries > 10) {
 227     os::yield_all(tries); // Yield to threads of any priority
 228   } else if (tries > 5) {
 229     os::yield();          // Yield to threads of same or higher priority
 230   }
 231 }




   1 /*
   2  * Copyright (c) 1998, 2013, 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  *


  24 
  25 // no precompiled headers
  26 #include "runtime/atomic.hpp"
  27 #include "runtime/handles.inline.hpp"
  28 #include "runtime/mutexLocker.hpp"
  29 #include "runtime/os.hpp"
  30 #include "runtime/osThread.hpp"
  31 #include "runtime/safepoint.hpp"
  32 #include "runtime/vmThread.hpp"
  33 
  34 #include <signal.h>
  35 
  36  // ***************************************************************
  37  // Platform dependent initialization and cleanup
  38  // ***************************************************************
  39 
  40 void OSThread::pd_initialize() {
  41   _thread_id                         = 0;
  42   sigemptyset(&_caller_sigmask);
  43 




  44   _saved_interrupt_thread_state      = _thread_new;
  45   _vm_created_thread                 = false;
  46 }
  47 
  48 void OSThread::pd_destroy() {
  49 }
  50 






































































































































































  51 // copied from synchronizer.cpp
  52 
  53 void OSThread::handle_spinlock_contention(int tries) {
  54   if (NoYieldsInMicrolock) return;
  55 
  56   if (tries > 10) {
  57     os::yield_all(tries); // Yield to threads of any priority
  58   } else if (tries > 5) {
  59     os::yield();          // Yield to threads of same or higher priority
  60   }
  61 }
  62 
  63 void OSThread::SR_handler(Thread* thread, ucontext_t* uc) {
  64   os::Solaris::SR_handler(thread, uc);
  65 }