then used to affect its operation. These are examined only on Un*x-like
platforms and win32.
-GC_INITIAL_HEAP_SIZE=<bytes> - Initial heap size in bytes. May speed up
- process start-up.
+GC_INITIAL_HEAP_SIZE=<bytes> - Initial heap size in bytes. May speed up
+ process start-up.
GC_MAXIMUM_HEAP_SIZE=<bytes> - Maximum collected heap size.
GC_LOOP_ON_ABORT - Causes the collector abort routine to enter a tight loop.
- This may make it easier to debug, such a process, especially
- for multithreaded platforms that don't produce usable core
- files, or if a core file would be too large. On some
- platforms, this also causes SIGSEGV to be caught and
- result in an infinite loop in a handler, allowing
- similar debugging techniques.
+ This may make it easier to debug, such a process, especially
+ for multithreaded platforms that don't produce usable core
+ files, or if a core file would be too large. On some
+ platforms, this also causes SIGSEGV to be caught and
+ result in an infinite loop in a handler, allowing
+ similar debugging techniques.
-GC_PRINT_STATS - Turn on GC logging. Not functional with -DSMALL_CONFIG.
+GC_PRINT_STATS - Turn on GC logging. Not functional with SMALL_CONFIG.
GC_LOG_FILE - The name of the log file. Stderr by default.
GC_PRINT_VERBOSE_STATS - Turn on even more logging.
GC_DUMP_REGULARLY - Generate a GC debugging dump GC_dump() on startup
- and during every collection. Very verbose. Useful
- if you have a bug to report, but please include only the
- last complete dump.
+ and during every collection. Very verbose. Useful
+ if you have a bug to report, but please include only the
+ last complete dump.
GC_BACKTRACES=<n> - Generate n random backtraces (for heap profiling) after
- each GC. Collector must have been built with
- KEEP_BACK_PTRS. This won't generate useful output unless
- most objects in the heap were allocated through debug
- allocators. This is intended to be only a statistical
- sample; individual traces may be erroneous due to
- concurrent heap mutation.
+ each GC. Collector must have been built with
+ KEEP_BACK_PTRS. This won't generate useful output unless
+ most objects in the heap were allocated through debug
+ allocators. This is intended to be only a statistical
+ sample; individual traces may be erroneous due to
+ concurrent heap mutation.
GC_PRINT_ADDRESS_MAP - Linux only. Dump /proc/self/maps, i.e. various address
- maps for the process, to stderr on every GC. Useful for
- mapping root addresses to source for deciphering leak
- reports.
+ maps for the process, to stderr on every GC. Useful for
+ mapping root addresses to source for deciphering leak
+ reports.
GC_NPROCS=<n> - Linux w/threads only. Explicitly sets the number of processors
- that the GC should expect to use. Note that setting this to 1
- when multiple processors are available will preserve
- correctness, but may lead to really horrible performance,
- since the lock implementation will immediately yield without
- first spinning.
+ that the GC should expect to use. Note that setting this to 1
+ when multiple processors are available will preserve
+ correctness, but may lead to really horrible performance,
+ since the lock implementation will immediately yield without
+ first spinning.
GC_MARKERS=<n> - Only if compiled with PARALLEL_MARK. Set the number
- of marker threads. This is normally set to the number of
- processors. It is safer to adjust GC_MARKERS than GC_NPROCS,
- since GC_MARKERS has no impact on the lock implementation.
+ of marker threads. This is normally set to the number of
+ processors. It is safer to adjust GC_MARKERS than GC_NPROCS,
+ since GC_MARKERS has no impact on the lock implementation.
GC_NO_BLACKLIST_WARNING - Prevents the collector from issuing
- warnings about allocations of very large blocks.
- Deprecated. Use GC_LARGE_ALLOC_WARN_INTERVAL instead.
+ warnings about allocations of very large blocks.
+ Deprecated. Use GC_LARGE_ALLOC_WARN_INTERVAL instead.
GC_LARGE_ALLOC_WARN_INTERVAL=<n> - Print every nth warning about very large
- block allocations, starting with the nth one. Small values
- of n are generally benign, in that a bounded number of
- such warnings generally indicate at most a bounded leak.
- For best results it should be set at 1 during testing.
- Default is 5. Very large numbers effectively disable the
- warning.
+ block allocations, starting with the nth one. Small values
+ of n are generally benign, in that a bounded number of
+ such warnings generally indicate at most a bounded leak.
+ For best results it should be set at 1 during testing.
+ Default is 5. Very large numbers effectively disable the
+ warning.
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_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 .
+ 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 .
GC_RETRY_SIGNALS, GC_NO_RETRY_SIGNALS - Try to compensate for lost
- thread suspend signals in linux_threads.c. On by
- default for GC_OSF1_THREADS, off otherwise. Note
- that this does not work around a possible loss of
- thread restart signals. This seems to be necessary for
- some versions of Tru64. Since we've previously seen
- similar issues on some other operating systems, it
- was turned into a runtime flag to enable last-minute
- work-arounds.
+ thread suspend signals in linux_threads.c. On by
+ default for GC_OSF1_THREADS, off otherwise. Note
+ that this does not work around a possible loss of
+ thread restart signals. This seems to be necessary for
+ some versions of Tru64. Since we've previously seen
+ similar issues on some other operating systems, it
+ was turned into a runtime flag to enable last-minute
+ work-arounds.
GC_USE_GETWRITEWATCH=<n> - Only if MPROTECT_VDB and GWW_VDB are both defined
- (Win32 only). Explicitly specify which strategy of
- keeping track of dirtied pages should be used.
- If n=0 then GetWriteWatch() is not used (falling back to
- protecting pages and catching memory faults strategy)
- else the collector tries to use GetWriteWatch-based
- strategy (GWW_VDB) first if available.
+ (Win32 only). Explicitly specify which strategy of
+ keeping track of dirtied pages should be used.
+ If n=0 then GetWriteWatch() is not used (falling back to
+ protecting pages and catching memory faults strategy)
+ else the collector tries to use GetWriteWatch-based
+ strategy (GWW_VDB) first if available.
GC_DISABLE_INCREMENTAL - Ignore runtime requests to enable incremental GC.
- Useful for debugging.
+ Useful for debugging.
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:
GC_ENABLE_INCREMENTAL - Turn on incremental collection at startup. Note that,
- depending on platform and collector configuration, this
- may involve write protecting pieces of the heap to
- track modifications. These pieces may include pointerfree
- objects or not. Although this is intended to be
- transparent, it may cause unintended system call failures.
- Use with caution.
+ depending on platform and collector configuration, this
+ may involve write protecting pieces of the heap to
+ track modifications. These pieces may include pointerfree
+ objects or not. Although this is intended to be
+ transparent, it may cause unintended system call failures.
+ Use with caution.
GC_PAUSE_TIME_TARGET - Set the desired garbage collector pause time in msecs.
- This only has an effect if incremental collection is
- enabled. If a collection requires appreciably more time
- than this, the client will be restarted, and the collector
- will need to do additional work to compensate. The
- special value "999999" indicates that pause time is
- unlimited, and the incremental collector will behave
- completely like a simple generational collector. If
- the collector is configured for parallel marking, and
- run on a multiprocessor, incremental collection should
- only be used with unlimited pause time.
+ This only has an effect if incremental collection is
+ enabled. If a collection requires appreciably more time
+ than this, the client will be restarted, and the collector
+ will need to do additional work to compensate. The
+ special value "999999" indicates that pause time is
+ unlimited, and the incremental collector will behave
+ completely like a simple generational collector. If
+ the collector is configured for parallel marking, and
+ run on a multiprocessor, incremental collection should
+ only be used with unlimited pause time.
GC_FULL_FREQUENCY - Set the desired number of partial collections between full
- collections. Matters only if GC_incremental is set.
+ collections. Matters only if GC_incremental is set.
GC_FREE_SPACE_DIVISOR - Set GC_free_space_divisor to the indicated value.
Setting it to larger values decreases space consumption
- and increases GC frequency.
+ and increases GC frequency.
+
+GC_UNMAP_THRESHOLD - Set the desired memory blocks unmapping threshold (the
+ number of sequential garbage collections for which
+ a candidate block for unmapping should remain free). The
+ special value "0" completely disables unmapping.
+
+GC_FORCE_UNMAP_ON_GCOLLECT - Turn "unmap as much as possible on explicit GC"
+ mode on (overrides the default value). Has no effect on
+ implicitly-initiated garbage collections. Has no effect if
+ memory unmapping is disabled (or not compiled in) or if the
+ unmapping threshold is 1.
GC_FIND_LEAK - Turns on GC_find_leak and thus leak detection. Forces a
- collection at program termination to detect leaks that would
- otherwise occur after the last GC.
+ collection at program termination to detect leaks that would
+ otherwise occur after the last GC.
GC_ALL_INTERIOR_POINTERS - Turns on GC_all_interior_pointers and thus interior
- pointer recognition.
+ pointer recognition.
GC_DONT_GC - Turns off garbage collection. Use cautiously.
GC_TRACE=addr - Intended for collector debugging. Requires that the collector
- have been built with ENABLE_TRACE defined. Causes the debugger
- to log information about the tracing of address ranges
- containing addr. Typically addr is the address that contains
- a pointer to an object that mysteriously failed to get marked.
- Addr must be specified as a hexadecimal integer.
+ have been built with ENABLE_TRACE defined. Causes the debugger
+ to log information about the tracing of address ranges
+ containing addr. Typically addr is the address that contains
+ a pointer to an object that mysteriously failed to get marked.
+ Addr must be specified as a hexadecimal integer.
projects / cacao.git / blobdiff