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Diffstat (limited to 'gc/doc/README.environment')
| -rw-r--r-- | gc/doc/README.environment | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/gc/doc/README.environment b/gc/doc/README.environment index 5760342..f540692 100644 --- a/gc/doc/README.environment +++ b/gc/doc/README.environment @@ -1,5 +1,5 @@ The garbage collector looks at a number of environment variables which are -the used to affect its operation. These are examined only on Un*x-like +then used to affect its operation. These are examined only on Un*x-like platforms. GC_INITIAL_HEAP_SIZE=<bytes> - Initial heap size in bytes. May speed up @@ -32,6 +32,27 @@ GC_NPROCS=<n> - Linux w/threads only. Explicitly sets the number of processors GC_NO_BLACKLIST_WARNING - Prevents the collector from issuing "Needed to allocate blacklisted block at ..." warnings. +GC_IGNORE_GCJ_INFO - Ignore the type descriptors implicitly supplied by + GC_gcj_malloc and friends. This is useful for debugging + descriptor generation problems, and possibly for + temporarily working around such problems. It forces a + fully conservative scan of all heap objects except + those known to be pointerfree, and may thus have other + adverse effects. + +GC_PRINT_BACK_HEIGHT - Print max length of chain through unreachable objects + ending in a reachable one. If this number remains + bounded, then the program is "GC robust". This ensures + that a fixed number of misidentified pointers can only + result in a bounded space leak. This currently only + works if debugging allocation is used throughout. + It increases GC space and time requirements appreciably. + This feature is still somewhat experimental, and requires + that the collector have been built with MAKE_BACK_GRAPH + defined. For details, see Boehm, "Bounding Space Usage + of Conservative Garbage Collectors", POPL 2001, or + http://lib.hpl.hp.com/techpubs/2001/HPL-2001-251.html . + The following turn on runtime flags that are also program settable. Checked only during initialization. We expect that they will usually be set through other means, but this may help with debugging and testing: |