Abstract
Persistent programming languages manage volatile memory as a cache for stable storage, imposing a read
barrier on operations that access the cache, and a write barrier on updates to the cache. The read barrier
checks the cache residency of the target object while the write barrier marks the target as dirty in the cache
to support a write-back policy that defers updates to stable storage until eviction or stabilization. These
barriers may also subsume additional functionality, such as negotiation of locks on shared objects to support
concurrency control. Compilers for persistent programming languages generate barrier code to protect all
accesses to possibly persistent objects. Orthogonal persistence imposes this cost on every object access, since
all objects are potentially persistent, at significant overhead to execution. We have designed a new suite of
compiler optimizations, focusing on partial redundancy elimination of pointer-based access expressions, that
significantly reduce this impact. These are implemented in an analysis and optimization framework for Java
bytecodes, in support of orthogonal persistence for Java. In experiments with the traversal portions of the OO7
benchmark suite our optimizations reduce the number of read and write barriers executed by an average of
83% and 25%, respectively.
barrier on operations that access the cache, and a write barrier on updates to the cache. The read barrier
checks the cache residency of the target object while the write barrier marks the target as dirty in the cache
to support a write-back policy that defers updates to stable storage until eviction or stabilization. These
barriers may also subsume additional functionality, such as negotiation of locks on shared objects to support
concurrency control. Compilers for persistent programming languages generate barrier code to protect all
accesses to possibly persistent objects. Orthogonal persistence imposes this cost on every object access, since
all objects are potentially persistent, at significant overhead to execution. We have designed a new suite of
compiler optimizations, focusing on partial redundancy elimination of pointer-based access expressions, that
significantly reduce this impact. These are implemented in an analysis and optimization framework for Java
bytecodes, in support of orthogonal persistence for Java. In experiments with the traversal portions of the OO7
benchmark suite our optimizations reduce the number of read and write barriers executed by an average of
83% and 25%, respectively.
| Original language | English |
|---|---|
| Title of host publication | Advances in Persistent Object Systems |
| Subtitle of host publication | POS-8 and PJAVA-3 |
| Editors | Ron Morrison, Mick Jordan, Malcolm Atkinson |
| Publisher | Morgan Kauffman Publishers |
| Pages | 149-159 |
| ISBN (Print) | 1-55860-585-1 |
| Publication status | Published - 1998 |
| Externally published | Yes |