hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsLockVerifier.hpp
author ysr
Thu, 21 Oct 2010 17:29:24 -0700
changeset 6984 c6718f921eb6
parent 5547 f4b087cbb361
child 7397 5b173b4ca846
permissions -rw-r--r--
6992998: CMSWaitDuration=0 causes hangs with +ExplicitGCInvokesConcurrent Summary: Closed a timing hole during which concurrent full gc requests can be missed. The hole can increase the latency of the response to a full gc request by up to the value of CMSWaitDuration. If CMSWaitDuration=0 is, as currently, interpreted as an unbounded wait, suitable in certain tuning scenarios, the application can potentially hang. Made two obscure tunables, including CMSWaitDuration, manageable. Reviewed-by: jcoomes, tonyp
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
     1
/*
5547
f4b087cbb361 6941466: Oracle rebranding changes for Hotspot repositories
trims
parents: 4574
diff changeset
     2
 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved.
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
     3
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
489c9b5090e2 Initial load
duke
parents:
diff changeset
     4
 *
489c9b5090e2 Initial load
duke
parents:
diff changeset
     5
 * This code is free software; you can redistribute it and/or modify it
489c9b5090e2 Initial load
duke
parents:
diff changeset
     6
 * under the terms of the GNU General Public License version 2 only, as
489c9b5090e2 Initial load
duke
parents:
diff changeset
     7
 * published by the Free Software Foundation.
489c9b5090e2 Initial load
duke
parents:
diff changeset
     8
 *
489c9b5090e2 Initial load
duke
parents:
diff changeset
     9
 * This code is distributed in the hope that it will be useful, but WITHOUT
489c9b5090e2 Initial load
duke
parents:
diff changeset
    10
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
489c9b5090e2 Initial load
duke
parents:
diff changeset
    11
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
489c9b5090e2 Initial load
duke
parents:
diff changeset
    12
 * version 2 for more details (a copy is included in the LICENSE file that
489c9b5090e2 Initial load
duke
parents:
diff changeset
    13
 * accompanied this code).
489c9b5090e2 Initial load
duke
parents:
diff changeset
    14
 *
489c9b5090e2 Initial load
duke
parents:
diff changeset
    15
 * You should have received a copy of the GNU General Public License version
489c9b5090e2 Initial load
duke
parents:
diff changeset
    16
 * 2 along with this work; if not, write to the Free Software Foundation,
489c9b5090e2 Initial load
duke
parents:
diff changeset
    17
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
489c9b5090e2 Initial load
duke
parents:
diff changeset
    18
 *
5547
f4b087cbb361 6941466: Oracle rebranding changes for Hotspot repositories
trims
parents: 4574
diff changeset
    19
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
f4b087cbb361 6941466: Oracle rebranding changes for Hotspot repositories
trims
parents: 4574
diff changeset
    20
 * or visit www.oracle.com if you need additional information or have any
f4b087cbb361 6941466: Oracle rebranding changes for Hotspot repositories
trims
parents: 4574
diff changeset
    21
 * questions.
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
    22
 *
489c9b5090e2 Initial load
duke
parents:
diff changeset
    23
 */
489c9b5090e2 Initial load
duke
parents:
diff changeset
    24
489c9b5090e2 Initial load
duke
parents:
diff changeset
    25
///////////// Locking verification specific to CMS //////////////
489c9b5090e2 Initial load
duke
parents:
diff changeset
    26
// Much like "assert_lock_strong()", except
489c9b5090e2 Initial load
duke
parents:
diff changeset
    27
// that it relaxes the assertion somewhat for the parallel GC case, where
489c9b5090e2 Initial load
duke
parents:
diff changeset
    28
// main GC thread or the CMS thread might hold the lock on behalf of
489c9b5090e2 Initial load
duke
parents:
diff changeset
    29
// the parallel threads.
489c9b5090e2 Initial load
duke
parents:
diff changeset
    30
class CMSLockVerifier: AllStatic {
489c9b5090e2 Initial load
duke
parents:
diff changeset
    31
 public:
4574
b2d5b0975515 6631166: CMS: better heuristics when combatting fragmentation
ysr
parents: 1
diff changeset
    32
  static void assert_locked(const Mutex* lock, const Mutex* p_lock1, const Mutex* p_lock2)
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
    33
    PRODUCT_RETURN;
4574
b2d5b0975515 6631166: CMS: better heuristics when combatting fragmentation
ysr
parents: 1
diff changeset
    34
  static void assert_locked(const Mutex* lock, const Mutex* p_lock) {
b2d5b0975515 6631166: CMS: better heuristics when combatting fragmentation
ysr
parents: 1
diff changeset
    35
    assert_locked(lock, p_lock, NULL);
b2d5b0975515 6631166: CMS: better heuristics when combatting fragmentation
ysr
parents: 1
diff changeset
    36
  }
1
489c9b5090e2 Initial load
duke
parents:
diff changeset
    37
  static void assert_locked(const Mutex* lock) {
489c9b5090e2 Initial load
duke
parents:
diff changeset
    38
    assert_locked(lock, NULL);
489c9b5090e2 Initial load
duke
parents:
diff changeset
    39
  }
489c9b5090e2 Initial load
duke
parents:
diff changeset
    40
};