> The manual test Cipher/DES/PerformanceTest.java fails with > ArithmeticException due to potential division by zero. The issue arises when > calculating the elapsed time using end - start, which could result in zero > milliseconds if start and end are identical due to the high speed of > execution. This leads to a division error in the following code snippet: > > > start = System.currentTimeMillis(); > end = System.currentTimeMillis(); > int speed = (int)((data.length * count)/(end - start)); > > This issue is easily reproducible on platforms where > System.currentTimeMillis() has low granularity, such as many versions of > Windows, end and start can be equal when obtaining System.currentTimeMillis() > if the test runs very quickly. > > The fix is to use System.nanoTime() instead, which is designed to measure > elapsed time with very high precision. This value is then converted to > microseconds so the tests can properly calculate the throughput (bytes > processed per microsecond) for the report. Example output: > > > Algorithm DataSize Rounds Bytes/microsec > DES/ECB/NoPadding 1024 100 66 > DES/ECB/NoPadding 1024 1000 50 > DES/ECB/NoPadding 8192 100 70 > DES/ECB/NoPadding 8192 1000 70 > Average: 64
Fernando Guallini has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains eight additional commits since the last revision: - converted to automated test - Merge branch 'master' into 8336240 - adding back the validation to avoid dividing by zero - byter per microsec - use microseconds as time unit - remove unused imports - tiny refactor - avoid dividing by zero ------------- Changes: - all: https://git.openjdk.org/jdk/pull/20135/files - new: https://git.openjdk.org/jdk/pull/20135/files/22ca20b9..98a91557 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=20135&range=04 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20135&range=03-04 Stats: 11760 lines in 507 files changed: 7377 ins; 2411 del; 1972 mod Patch: https://git.openjdk.org/jdk/pull/20135.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/20135/head:pull/20135 PR: https://git.openjdk.org/jdk/pull/20135
