[jdk13u-dev] RFR: 8252090: JFR: StreamWriterHost::write_unbuffered() stucks in an infinite loop OpenJDK (build 13.0.1+9)

[Ekaterina Vergizova]

I'd like to backport 8252090 to 13u for parity with 11u.
The patch doesn't apply cleanly due to multiple context differences in jfrChunkWriter.cpp, reapplied manually.
Additionally 13u doesn't have JfrChunkHeadWriter::write_magic() method (JDK-8226511 is not in 13u), the corresponding changes are applied to JfrChunkWriter::open().
Tested with tier1 and jdk/jfr.

-------------

Commit messages:
 - Backport 9924c45faebdba4084c9a5dd5b415dfe6c979024

Changes: https://git.openjdk.java.net/jdk13u-dev/pull/66/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk13u-dev&pr=66&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8252090
  Stats: 58 lines in 10 files changed: 22 ins; 4 del; 32 mod
  Patch: https://git.openjdk.java.net/jdk13u-dev/pull/66.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk13u-dev pull/66/head:pull/66

PR: https://git.openjdk.java.net/jdk13u-dev/pull/66