Mercurial > hg > graal-compiler
comparison src/share/vm/memory/gcLocker.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | c0492d52d55b |
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-1:000000000000 | 0:a61af66fc99e |
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1 /* | |
2 * Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
21 * have any questions. | |
22 * | |
23 */ | |
24 | |
25 # include "incls/_precompiled.incl" | |
26 # include "incls/_gcLocker.cpp.incl" | |
27 | |
28 volatile jint GC_locker::_jni_lock_count = 0; | |
29 volatile jint GC_locker::_lock_count = 0; | |
30 volatile bool GC_locker::_needs_gc = false; | |
31 volatile bool GC_locker::_doing_gc = false; | |
32 | |
33 void GC_locker::stall_until_clear() { | |
34 assert(!JavaThread::current()->in_critical(), "Would deadlock"); | |
35 MutexLocker ml(JNICritical_lock); | |
36 // Wait for _needs_gc to be cleared | |
37 while (GC_locker::needs_gc()) { | |
38 JNICritical_lock->wait(); | |
39 } | |
40 } | |
41 | |
42 void GC_locker::jni_lock_slow() { | |
43 MutexLocker mu(JNICritical_lock); | |
44 // Block entering threads if we know at least one thread is in a | |
45 // JNI critical region and we need a GC. | |
46 // We check that at least one thread is in a critical region before | |
47 // blocking because blocked threads are woken up by a thread exiting | |
48 // a JNI critical region. | |
49 while ((is_jni_active() && needs_gc()) || _doing_gc) { | |
50 JNICritical_lock->wait(); | |
51 } | |
52 jni_lock(); | |
53 } | |
54 | |
55 void GC_locker::jni_unlock_slow() { | |
56 MutexLocker mu(JNICritical_lock); | |
57 jni_unlock(); | |
58 if (needs_gc() && !is_jni_active()) { | |
59 // We're the last thread out. Cause a GC to occur. | |
60 // GC will also check is_active, so this check is not | |
61 // strictly needed. It's added here to make it clear that | |
62 // the GC will NOT be performed if any other caller | |
63 // of GC_locker::lock() still needs GC locked. | |
64 if (!is_active()) { | |
65 _doing_gc = true; | |
66 { | |
67 // Must give up the lock while at a safepoint | |
68 MutexUnlocker munlock(JNICritical_lock); | |
69 Universe::heap()->collect(GCCause::_gc_locker); | |
70 } | |
71 _doing_gc = false; | |
72 } | |
73 clear_needs_gc(); | |
74 JNICritical_lock->notify_all(); | |
75 } | |
76 } | |
77 | |
78 // Implementation of No_GC_Verifier | |
79 | |
80 #ifdef ASSERT | |
81 | |
82 No_GC_Verifier::No_GC_Verifier(bool verifygc) { | |
83 _verifygc = verifygc; | |
84 if (_verifygc) { | |
85 CollectedHeap* h = Universe::heap(); | |
86 assert(!h->is_gc_active(), "GC active during No_GC_Verifier"); | |
87 _old_invocations = h->total_collections(); | |
88 } | |
89 } | |
90 | |
91 | |
92 No_GC_Verifier::~No_GC_Verifier() { | |
93 if (_verifygc) { | |
94 CollectedHeap* h = Universe::heap(); | |
95 assert(!h->is_gc_active(), "GC active during No_GC_Verifier"); | |
96 if (_old_invocations != h->total_collections()) { | |
97 fatal("collection in a No_GC_Verifier secured function"); | |
98 } | |
99 } | |
100 } | |
101 | |
102 Pause_No_GC_Verifier::Pause_No_GC_Verifier(No_GC_Verifier * ngcv) { | |
103 _ngcv = ngcv; | |
104 if (_ngcv->_verifygc) { | |
105 // if we were verifying, then make sure that nothing is | |
106 // wrong before we "pause" verification | |
107 CollectedHeap* h = Universe::heap(); | |
108 assert(!h->is_gc_active(), "GC active during No_GC_Verifier"); | |
109 if (_ngcv->_old_invocations != h->total_collections()) { | |
110 fatal("collection in a No_GC_Verifier secured function"); | |
111 } | |
112 } | |
113 } | |
114 | |
115 | |
116 Pause_No_GC_Verifier::~Pause_No_GC_Verifier() { | |
117 if (_ngcv->_verifygc) { | |
118 // if we were verifying before, then reenable verification | |
119 CollectedHeap* h = Universe::heap(); | |
120 assert(!h->is_gc_active(), "GC active during No_GC_Verifier"); | |
121 _ngcv->_old_invocations = h->total_collections(); | |
122 } | |
123 } | |
124 | |
125 | |
126 // JRT_LEAF rules: | |
127 // A JRT_LEAF method may not interfere with safepointing by | |
128 // 1) acquiring or blocking on a Mutex or JavaLock - checked | |
129 // 2) allocating heap memory - checked | |
130 // 3) executing a VM operation - checked | |
131 // 4) executing a system call (including malloc) that could block or grab a lock | |
132 // 5) invoking GC | |
133 // 6) reaching a safepoint | |
134 // 7) running too long | |
135 // Nor may any method it calls. | |
136 JRT_Leaf_Verifier::JRT_Leaf_Verifier() | |
137 : No_Safepoint_Verifier(true, JRT_Leaf_Verifier::should_verify_GC()) | |
138 { | |
139 } | |
140 | |
141 JRT_Leaf_Verifier::~JRT_Leaf_Verifier() | |
142 { | |
143 } | |
144 | |
145 bool JRT_Leaf_Verifier::should_verify_GC() { | |
146 switch (JavaThread::current()->thread_state()) { | |
147 case _thread_in_Java: | |
148 // is in a leaf routine, there must be no safepoint. | |
149 return true; | |
150 case _thread_in_native: | |
151 // A native thread is not subject to safepoints. | |
152 // Even while it is in a leaf routine, GC is ok | |
153 return false; | |
154 default: | |
155 // Leaf routines cannot be called from other contexts. | |
156 ShouldNotReachHere(); | |
157 return false; | |
158 } | |
159 } | |
160 #endif |