JDK-8186238 : The constant pool entry to empty string ("") should not be pre-resolved during CDS dump time
  • Type: Bug
  • Component: hotspot
  • Sub-Component: runtime
  • Affected Version: 10
  • Priority: P2
  • Status: Closed
  • Resolution: Fixed
  • OS: generic
  • CPU: generic
  • Submitted: 2017-08-15
  • Updated: 2020-09-01
  • Resolved: 2017-08-16
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JDK 10
10 b21Fixed
Related Reports
Relates :  
JDK-8179302 - Pre-resolve constant pool string entries and cache resolved_reference arrays in CDS archive
Description
The constant pool entry to empty string ("") should not be pre-resolved during CDS archiving. Empty string is not archived and eliminated from the shared string table.
Comments
I'm also good with going with the one line fix!
15-08-2017
Since this is a one-line fix, I think it's better to push the fix, instead of doing an anti-delta of JDK-8179302 which introduced the error. The fix is of the "do less harm" type (from the resolved constants array, remove an element which didn't exist before JDK-8179302, and whose existence caused the failure). So the fix should be fairly low risk and shouldn't cause new failures to happen.
15-08-2017
Jiangli's patch seems to fix the failures. It's a bug in the AppCDS code and unrelated to the compiler. Many errors were triggered by the -esa option (enable system assertions) which happen to be used together with the -Xcomp test runs in hotspot nightly. diff --git a/src/share/vm/oops/constantPool.cpp b/src/share/vm/oops/constantPool.cpp --- a/src/share/vm/oops/constantPool.cpp +++ b/src/share/vm/oops/constantPool.cpp @@ -264,7 +264,7 @@ oop p = rr->obj_at(i); if (p != NULL) { int index = object_to_cp_index(i); - if (tag_at(index).is_string()) { + if (tag_at(index).is_string() && java_lang_String::hash_code(p) != 0) { oop op = StringTable::create_archived_string(p, THREAD); // If the String object is not archived (possibly too large), // NULL is returned. Also set it in the array, so we won���t
15-08-2017