Mercurial > hg > truffle
annotate src/share/vm/utilities/defaultStream.hpp @ 1716:be3f9c242c9d
6948538: CMS: BOT walkers can fall into object allocation and initialization cracks
Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode.
Reviewed-by: chrisphi, johnc, poonam
| author | ysr |
|---|---|
| date | Mon, 16 Aug 2010 15:58:42 -0700 |
| parents | c18cbe5936b8 |
| children | f95d63e2154a |
| rev | line source |
|---|---|
| 0 | 1 /* |
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6941466: Oracle rebranding changes for Hotspot repositories
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2 * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved. |
| 0 | 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 * | |
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6941466: Oracle rebranding changes for Hotspot repositories
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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6941466: Oracle rebranding changes for Hotspot repositories
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20 * or visit www.oracle.com if you need additional information or have any |
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6941466: Oracle rebranding changes for Hotspot repositories
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 25 class defaultStream : public xmlTextStream { | |
| 26 friend void ostream_abort(); | |
| 27 public: | |
| 28 enum { NO_WRITER = -1 }; | |
| 29 private: | |
| 30 bool _inited; | |
| 31 fileStream* _log_file; // XML-formatted file shared by all threads | |
| 32 static int _output_fd; | |
| 33 static int _error_fd; | |
| 34 static FILE* _output_stream; | |
| 35 static FILE* _error_stream; | |
| 36 | |
| 37 void init(); | |
| 38 void init_log(); | |
| 39 void finish_log(); | |
| 40 void finish_log_on_error(char *buf, int buflen); | |
| 41 public: | |
| 42 // must defer time stamp due to the fact that os::init() hasn't | |
| 43 // yet been called and os::elapsed_counter() may not be valid | |
| 44 defaultStream() { | |
| 45 _log_file = NULL; | |
| 46 _inited = false; | |
| 47 _writer = -1; | |
| 48 _last_writer = -1; | |
| 49 } | |
| 50 | |
| 51 ~defaultStream() { | |
| 52 if (has_log_file()) finish_log(); | |
| 53 } | |
| 54 | |
| 55 static inline FILE* output_stream() { | |
| 56 return DisplayVMOutputToStderr ? _error_stream : _output_stream; | |
| 57 } | |
| 58 static inline FILE* error_stream() { | |
| 59 return DisplayVMOutputToStdout ? _output_stream : _error_stream; | |
| 60 } | |
| 61 static inline int output_fd() { | |
| 62 return DisplayVMOutputToStderr ? _error_fd : _output_fd; | |
| 63 } | |
| 64 static inline int error_fd() { | |
| 65 return DisplayVMOutputToStdout ? _output_fd : _error_fd; | |
| 66 } | |
| 67 | |
| 68 virtual void write(const char* s, size_t len); | |
| 69 | |
| 70 void flush() { | |
| 71 // once we can determine whether we are in a signal handler, we | |
| 72 // should add the following assert here: | |
| 73 // assert(xxxxxx, "can not flush buffer inside signal handler"); | |
| 74 xmlTextStream::flush(); | |
| 75 fflush(output_stream()); | |
| 76 if (has_log_file()) _log_file->flush(); | |
| 77 } | |
| 78 | |
| 79 // advisory lock/unlock of _writer field: | |
| 80 private: | |
| 81 intx _writer; // thread_id with current rights to output | |
| 82 intx _last_writer; | |
| 83 public: | |
| 84 intx hold(intx writer_id); | |
| 85 void release(intx holder); | |
| 86 intx writer() { return _writer; } | |
| 87 bool has_log_file(); | |
| 88 | |
| 89 static defaultStream* instance; // sole instance | |
| 90 }; |