src/hotspot/share/runtime/safepointMechanism.inline.hpp
changeset 47881 0ce0ac68ace7
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47824:cf127be65014 47881:0ce0ac68ace7
       
     1 /*
       
     2  * Copyright (c) 2017, 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 #ifndef SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_INLINE_HPP
       
    26 #define SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_INLINE_HPP
       
    27 
       
    28 #include "runtime/safepointMechanism.hpp"
       
    29 #include "runtime/safepoint.hpp"
       
    30 #include "runtime/thread.inline.hpp"
       
    31 
       
    32 bool SafepointMechanism::local_poll_armed(JavaThread* thread) {
       
    33   const intptr_t poll_word = reinterpret_cast<intptr_t>(thread->get_polling_page());
       
    34   return mask_bits_are_true(poll_word, poll_bit());
       
    35 }
       
    36 
       
    37 bool SafepointMechanism::global_poll() {
       
    38   return SafepointSynchronize::do_call_back();
       
    39 }
       
    40 
       
    41 bool SafepointMechanism::local_poll(Thread* thread) {
       
    42   if (thread->is_Java_thread()) {
       
    43     return local_poll_armed((JavaThread*)thread);
       
    44   } else {
       
    45     // If the poll is on a non-java thread we can only check the global state.
       
    46     return global_poll();
       
    47   }
       
    48 }
       
    49 
       
    50 bool SafepointMechanism::poll(Thread* thread) {
       
    51   if (uses_thread_local_poll()) {
       
    52     return local_poll(thread);
       
    53   } else {
       
    54     return global_poll();
       
    55   }
       
    56 }
       
    57 
       
    58 void SafepointMechanism::block_if_requested_local_poll(JavaThread *thread) {
       
    59   bool armed = local_poll_armed(thread); // load acquire, polling page -> op / global state
       
    60   if(armed) {
       
    61     // We could be armed for either a handshake operation or a safepoint
       
    62     if (thread->has_handshake()) {
       
    63       thread->handshake_process_by_self();
       
    64     } else {
       
    65       if (global_poll()) {
       
    66         SafepointSynchronize::block(thread);
       
    67       }
       
    68     }
       
    69   }
       
    70 }
       
    71 
       
    72 void SafepointMechanism::block_if_requested(JavaThread *thread) {
       
    73   if (uses_thread_local_poll()) {
       
    74     block_if_requested_local_poll(thread);
       
    75   } else {
       
    76     // If we don't have per thread poll this could a handshake or a safepoint
       
    77     if (global_poll()) {
       
    78       SafepointSynchronize::block(thread);
       
    79     }
       
    80   }
       
    81 }
       
    82 
       
    83 void SafepointMechanism::arm_local_poll(JavaThread* thread) {
       
    84   thread->set_polling_page(poll_armed_value());
       
    85 }
       
    86 
       
    87 void SafepointMechanism::disarm_local_poll(JavaThread* thread) {
       
    88   thread->set_polling_page(poll_disarmed_value());
       
    89 }
       
    90 
       
    91 #endif // SHARE_VM_RUNTIME_SAFEPOINTMECHANISM_INLINE_HPP