Mercurial > hg > truffle
annotate agent/src/os/win32/Buffer.cpp @ 3917:eca1193ca245
4965777: GC changes to support use of discovered field for pending references
Summary: If and when the reference handler thread is able to use the discovered field to link reference objects in its pending list, so will GC. In that case, GC will scan through this field once a reference object has been placed on the pending list, but not scan that field before that stage, as the field is used by the concurrent GC thread to link discovered objects. When ReferenceHandleR thread does not use the discovered field for the purpose of linking the elements in the pending list, as would be the case in older JDKs, the JVM will fall back to the old behaviour of using the next field for that purpose.
Reviewed-by: jcoomes, mchung, stefank
| author | ysr |
|---|---|
| date | Wed, 07 Sep 2011 13:55:42 -0700 |
| parents | c18cbe5936b8 |
| children |
| rev | line source |
|---|---|
| 0 | 1 /* |
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| 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 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 25 #include "Buffer.hpp" | |
| 26 | |
| 27 #include <string.h> | |
| 28 | |
| 29 Buffer::Buffer(int bufSize) { | |
| 30 buf = new char[bufSize]; | |
| 31 sz = bufSize; | |
| 32 fill = 0; | |
| 33 drain = 0; | |
| 34 } | |
| 35 | |
| 36 Buffer::~Buffer() { | |
| 37 delete[] buf; | |
| 38 } | |
| 39 | |
| 40 char* | |
| 41 Buffer::fillPos() { | |
| 42 return buf + fill; | |
| 43 } | |
| 44 | |
| 45 int | |
| 46 Buffer::remaining() { | |
| 47 return sz - fill; | |
| 48 } | |
| 49 | |
| 50 int | |
| 51 Buffer::size() { | |
| 52 return sz; | |
| 53 } | |
| 54 | |
| 55 bool | |
| 56 Buffer::incrFillPos(int amt) { | |
| 57 if (fill + amt >= sz) { | |
| 58 return false; | |
| 59 } | |
| 60 fill += amt; | |
| 61 return true; | |
| 62 } | |
| 63 | |
| 64 int | |
| 65 Buffer::readByte() { | |
| 66 if (drain < fill) { | |
| 67 return buf[drain++] & 0xFF; | |
| 68 } else { | |
| 69 return -1; | |
| 70 } | |
| 71 } | |
| 72 | |
| 73 int | |
| 74 Buffer::readBytes(char* data, int len) { | |
| 75 int numRead = 0; | |
| 76 while (numRead < len) { | |
| 77 int c = readByte(); | |
| 78 if (c < 0) break; | |
| 79 data[numRead++] = (char) c; | |
| 80 } | |
| 81 return numRead; | |
| 82 } | |
| 83 | |
| 84 char* | |
| 85 Buffer::drainPos() { | |
| 86 return buf + drain; | |
| 87 } | |
| 88 | |
| 89 int | |
| 90 Buffer::drainRemaining() { | |
| 91 return fill - drain; | |
| 92 } | |
| 93 | |
| 94 bool | |
| 95 Buffer::incrDrainPos(int amt) { | |
| 96 if (drainRemaining() < amt) { | |
| 97 return false; | |
| 98 } | |
| 99 drain += amt; | |
| 100 return true; | |
| 101 } | |
| 102 | |
| 103 void | |
| 104 Buffer::compact() { | |
| 105 // Copy down data | |
| 106 memmove(buf, buf + drain, fill - drain); | |
| 107 // Adjust positions | |
| 108 fill -= drain; | |
| 109 drain = 0; | |
| 110 } |