JDK-8208390 : G1 should always use ticks as internal time base instead of double
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 11,12
  • Priority: P4
  • Status: Open
  • Resolution: Unresolved
  • Submitted: 2018-07-27
  • Updated: 2020-08-17
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Other
tbdUnresolved
Related Reports
Blocks :  
JDK-8243975 - Improve G1 naming of identifiers after JDK-8208390
Duplicate :  
JDK-8165576 - Time base of G1 collector should not be seconds stored in doubles
Relates :  
JDK-8243977 - Undo workaround for Solaris/SPARC in WorkerDataArray::print_summary_on
Relates :  
JDK-8243974 - Move G1CollectedHeap::millis_since_last_gc support from G1Policy
Description
Currently G1 uses normal doubles to hold time spans and points in time.

This has several disadvantages:
- there is no compiler help in detecting errors (matching units) when using them in calculations.
- since the time unit is not stored anywhere the code it is encoded in the variable and method names. This clutters the code and does not help with unit safety.

The suggestion here is to have G1 the Ticks/Tickspan type to store time and time spans instead.