RFR: 8374862: assert(false) failed: Attempting to acquire lock MDOExtraData_lock/nosafepoint-1 out of order with lock tty_lock/tty -- possible deadlock (running with -XX:+Verbose -XX:+WizardMode -XX:+PrintDeoptimizationDetails) [v8]

[Guanqiang Han]

> Please review this change. Thanks!
> 
> **Description:**
> 
> When -XX:+PrintDeoptimizationDetails is enabled, vframeArray.cpp prints interpreted frames under ttyLocker. 
> https://github.com/openjdk/jdk/blob/578204f8c49f06be8b9c4855359ca61c9e107678/src/hotspot/share/runtime/vframeArray.cpp#L493-L503
> In the WizardMode && Verbose branch it calls Method::print_codes() / print_codes_on(). The bytecode printing path may acquire MDOExtraData_lock (rank nosafepoint-1). 
> https://github.com/openjdk/jdk/blob/578204f8c49f06be8b9c4855359ca61c9e107678/src/hotspot/share/interpreter/bytecodeTracer.cpp#L597-L602
> Calling it while holding tty_lock violates the global lock ranking order and triggers a lock rank inversion assertion.
> 
> **Fix:**
> 
> Generate the bytecode dump before taking tty_lock, and print it afterwards under ttyLocker to keep the output coherent while preserving correct lock acquisition order. 
> To avoid double buffering when the target stream is already a thread-local stringStream, extend BytecodeTracer::print_method_codes with a buffered flag . The new call site uses buffered=false when dumping into the temporary stringStream.
> 
> **Test:** 
> 
> GHA

Guanqiang Han has updated the pull request incrementally with one additional commit since the last revision:

  remove unused code

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/29186/files
  - new: https://git.openjdk.org/jdk/pull/29186/files/35cb8b9f..601ff0da

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29186&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29186&range=06-07

  Stats: 4 lines in 1 file changed: 0 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/29186.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29186/head:pull/29186

PR: https://git.openjdk.org/jdk/pull/29186