RFR: 8304745: Lazily initialize byte[] in java.io.BufferedInputStream [v8]

[Sergey Tsypanov]

On Fri, 24 Mar 2023 19:30:22 GMT, Sergey Tsypanov <stsypanov at openjdk.org> wrote:

>> By default `BufferedInputStream` is constructed with internal buffer with capacity 8192. In some cases this buffer is never used, e.g. when we call `IS.readNBytes()` or `IS.readAllBytes()` (relying on `BIS.read1()`) or when `BufferedInputStream` is cascaded.
>
> Sergey Tsypanov has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Merge remote-tracking branch 'origin/8304745' into 8304745
>    
>    # Conflicts:
>    #	test/micro/org/openjdk/bench/java/io/BufferedInputStreamBenchmark.java
>  - 8304745: Fix line breaks

Comments added to benchmark.

make test TEST="micro:io.BufferedInputStreamBenchmark" MICRO="OPTIONS=-prof gc"

master

Benchmark                                                             (size)  Mode  Cnt      Score     Error   Units
BufferedInputStreamBenchmark.readAllBytes                               1024  avgt   20      7.278 ±   0.286   us/op
BufferedInputStreamBenchmark.readAllBytes:·gc.alloc.rate                1024  avgt   20   3377.138 ± 131.745  MB/sec
BufferedInputStreamBenchmark.readAllBytes:·gc.alloc.rate.norm           1024  avgt   20  25752.011 ±   0.001    B/op
BufferedInputStreamBenchmark.readAllBytes:·gc.count                     1024  avgt   20    123.000            counts
BufferedInputStreamBenchmark.readAllBytes:·gc.time                      1024  avgt   20   1085.000                ms
BufferedInputStreamBenchmark.readAllBytes                              16384  avgt   20     13.538 ±   0.759   us/op
BufferedInputStreamBenchmark.readAllBytes:·gc.alloc.rate               16384  avgt   20   2901.305 ± 167.849  MB/sec
BufferedInputStreamBenchmark.readAllBytes:·gc.alloc.rate.norm          16384  avgt   20  41112.228 ±   0.013    B/op
BufferedInputStreamBenchmark.readAllBytes:·gc.count                    16384  avgt   20    107.000            counts
BufferedInputStreamBenchmark.readAllBytes:·gc.time                     16384  avgt   20   1012.000                ms
BufferedInputStreamBenchmark.readAllBytesCascade                        1024  avgt   20     13.273 ±   0.729   us/op
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.alloc.rate         1024  avgt   20   2452.198 ± 136.123  MB/sec
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.alloc.rate.norm    1024  avgt   20  34064.020 ±   0.001    B/op
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.count              1024  avgt   20     93.000            counts
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.time               1024  avgt   20   1081.000                ms
BufferedInputStreamBenchmark.readAllBytesCascade                       16384  avgt   20     24.633 ±   3.127   us/op
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.alloc.rate        16384  avgt   20   1943.798 ± 229.336  MB/sec
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.alloc.rate.norm   16384  avgt   20  49424.413 ±   0.052    B/op
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.count             16384  avgt   20     72.000            counts
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.time              16384  avgt   20    993.000                ms

8304745

Benchmark                                                             (size)  Mode  Cnt      Score      Error   Units
BufferedInputStreamBenchmark.readAllBytes                               1024  avgt   20      2.212 ±    0.038   us/op
BufferedInputStreamBenchmark.readAllBytes:·gc.alloc.rate                1024  avgt   20   7563.662 ±  135.402  MB/sec
BufferedInputStreamBenchmark.readAllBytes:·gc.alloc.rate.norm           1024  avgt   20  17552.003 ±    0.001    B/op
BufferedInputStreamBenchmark.readAllBytes:·gc.count                     1024  avgt   20    339.000             counts
BufferedInputStreamBenchmark.readAllBytes:·gc.time                      1024  avgt   20    691.000                 ms
BufferedInputStreamBenchmark.readAllBytes                              16384  avgt   20      3.127 ±    0.071   us/op
BufferedInputStreamBenchmark.readAllBytes:·gc.alloc.rate               16384  avgt   20  10034.809 ±  222.058  MB/sec
BufferedInputStreamBenchmark.readAllBytes:·gc.alloc.rate.norm          16384  avgt   20  32912.053 ±    0.001    B/op
BufferedInputStreamBenchmark.readAllBytes:·gc.count                    16384  avgt   20    388.000             counts
BufferedInputStreamBenchmark.readAllBytes:·gc.time                     16384  avgt   20    953.000                 ms
BufferedInputStreamBenchmark.readAllBytesCascade                        1024  avgt   20      2.521 ±    0.048   us/op
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.alloc.rate         1024  avgt   20   6678.812 ±  126.007  MB/sec
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.alloc.rate.norm    1024  avgt   20  17664.004 ±    0.001    B/op
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.count              1024  avgt   20    176.000             counts
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.time               1024  avgt   20   1049.000                 ms
BufferedInputStreamBenchmark.readAllBytesCascade                       16384  avgt   20      4.728 ±    0.905   us/op
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.alloc.rate        16384  avgt   20   6911.193 ± 1061.227  MB/sec
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.alloc.rate.norm   16384  avgt   20  33024.080 ±    0.015    B/op
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.count             16384  avgt   20    191.000             counts
BufferedInputStreamBenchmark.readAllBytesCascade:·gc.time              16384  avgt   20   1157.000                 ms

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PR Comment: https://git.openjdk.org/jdk/pull/13150#issuecomment-1485425304
PR Comment: https://git.openjdk.org/jdk/pull/13150#issuecomment-1485427789