diff options
Diffstat (limited to 'include/gc.h')
| -rw-r--r-- | include/gc.h | 38 |
1 files changed, 19 insertions, 19 deletions
diff --git a/include/gc.h b/include/gc.h index 081ae33a..429f6637 100644 --- a/include/gc.h +++ b/include/gc.h @@ -87,23 +87,20 @@ GC_API GC_word GC_CALL GC_get_gc_no(void); /* avoid data races on multiprocessors. */ #ifdef GC_THREADS + /* GC is parallelized for performance on multiprocessors. Set to */ + /* a non-zero value when client calls GC_start_mark_threads() */ + /* directly or starts the first non-main thread, provided the */ + /* collector is built with PARALLEL_MARK defined, and either */ + /* GC_MARKERS (or GC_NPROCS) environment variable is set to a value */ + /* bigger than 1, or multiple cores (processors) are available. */ + /* If GC_parallel is on (non-zero), incremental collection is only */ + /* partially functional, and may not be desirable. Starting from */ + /* GC v7.3, after setting, GC_parallel value is equal to the number */ + /* of marker threads minus one (i.e. the number of existing parallel */ + /* marker threads excluding the initiating one). */ GC_API GC_ATTR_DEPRECATED int GC_parallel; - /* GC is parallelized for performance on */ - /* multiprocessors. Set to a non-zero value */ - /* only implicitly if collector is built with */ - /* PARALLEL_MARK defined, and if either */ - /* GC_MARKERS (or GC_NPROCS) environment */ - /* variable is set to > 1, or multiple cores */ - /* (processors) are available. */ - /* If GC_parallel is on (non-zero), incremental */ - /* collection is only partially functional, */ - /* and may not be desirable. The getter does */ - /* not use or need synchronization (i.e. */ - /* acquiring the GC lock). Starting from */ - /* GC v7.3, GC_parallel value is equal to the */ - /* number of marker threads minus one (i.e. */ - /* number of existing parallel marker threads */ - /* excluding the initiating one). */ + + /* Return value of GC_parallel. Does not acquire the GC lock. */ GC_API int GC_CALL GC_get_parallel(void); #endif @@ -1459,9 +1456,11 @@ GC_API void * GC_CALL GC_call_with_stack_base(GC_stack_base_func /* fn */, /* systems. Return -1 otherwise. */ GC_API int GC_CALL GC_get_thr_restart_signal(void); - /* Restart marker threads after POSIX fork in child. Meaningless in */ - /* other situations. Should not be called if fork followed by exec. */ - /* Acquires the GC lock to avoid a data race. */ + /* Start the parallel marker threads, if available. Useful, e.g., */ + /* after POSIX fork in a child process (provided not followed by */ + /* exec) or in single-threaded clients (provided it is OK for the */ + /* client to perform marking in parallel). Acquires the GC lock to */ + /* avoid a data race. */ GC_API void GC_CALL GC_start_mark_threads(void); /* Explicitly enable GC_register_my_thread() invocation. */ @@ -1471,6 +1470,7 @@ GC_API void * GC_CALL GC_call_with_stack_base(GC_stack_base_func /* fn */, /* must be called from the main (or any previously registered) thread */ /* between the collector initialization and the first explicit */ /* registering of a thread (it should be called as late as possible). */ + /* Includes a GC_start_mark_threads() call. */ GC_API void GC_CALL GC_allow_register_threads(void); /* Register the current thread, with the indicated stack base, as */ |