diff options
Diffstat (limited to 'tools/build/src/engine/boehm_gc/thread_local_alloc.c')
| -rw-r--r-- | tools/build/src/engine/boehm_gc/thread_local_alloc.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/tools/build/src/engine/boehm_gc/thread_local_alloc.c b/tools/build/src/engine/boehm_gc/thread_local_alloc.c new file mode 100644 index 000000000..f747b3557 --- /dev/null +++ b/tools/build/src/engine/boehm_gc/thread_local_alloc.c @@ -0,0 +1,310 @@ +/* + * Copyright (c) 2000-2005 by Hewlett-Packard Company. All rights reserved. + * + * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED + * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. + * + * Permission is hereby granted to use or copy this program + * for any purpose, provided the above notices are retained on all copies. + * Permission to modify the code and to distribute modified code is granted, + * provided the above notices are retained, and a notice that the code was + * modified is included with the above copyright notice. + */ +#include "private/gc_priv.h" + +# if defined(THREAD_LOCAL_ALLOC) + +#include "private/thread_local_alloc.h" +#include "gc_inline.h" + +# include <stdlib.h> + +#if defined(USE_COMPILER_TLS) + __thread +#elif defined(USE_WIN32_COMPILER_TLS) + __declspec(thread) +#endif +GC_key_t GC_thread_key; + +static GC_bool keys_initialized; + +/* Return a single nonempty freelist fl to the global one pointed to */ +/* by gfl. */ + +static void return_single_freelist(void *fl, void **gfl) +{ + void *q, **qptr; + + if (*gfl == 0) { + *gfl = fl; + } else { + GC_ASSERT(GC_size(fl) == GC_size(*gfl)); + /* Concatenate: */ + for (qptr = &(obj_link(fl)), q = *qptr; + (word)q >= HBLKSIZE; qptr = &(obj_link(q)), q = *qptr); + GC_ASSERT(0 == q); + *qptr = *gfl; + *gfl = fl; + } +} + +/* Recover the contents of the freelist array fl into the global one gfl.*/ +/* We hold the allocator lock. */ +static void return_freelists(void **fl, void **gfl) +{ + int i; + + for (i = 1; i < TINY_FREELISTS; ++i) { + if ((word)(fl[i]) >= HBLKSIZE) { + return_single_freelist(fl[i], gfl+i); + } + /* Clear fl[i], since the thread structure may hang around. */ + /* Do it in a way that is likely to trap if we access it. */ + fl[i] = (ptr_t)HBLKSIZE; + } + /* The 0 granule freelist really contains 1 granule objects. */ +# ifdef GC_GCJ_SUPPORT + if (fl[0] == ERROR_FL) return; +# endif + if ((word)(fl[0]) >= HBLKSIZE) { + return_single_freelist(fl[0], gfl+1); + } +} + +/* Each thread structure must be initialized. */ +/* This call must be made from the new thread. */ +/* Caller holds allocation lock. */ +void GC_init_thread_local(GC_tlfs p) +{ + int i; + + if (!keys_initialized) { + if (0 != GC_key_create(&GC_thread_key, 0)) { + ABORT("Failed to create key for local allocator"); + } + keys_initialized = TRUE; + } + if (0 != GC_setspecific(GC_thread_key, p)) { + ABORT("Failed to set thread specific allocation pointers"); + } + for (i = 1; i < TINY_FREELISTS; ++i) { + p -> ptrfree_freelists[i] = (void *)1; + p -> normal_freelists[i] = (void *)1; +# ifdef GC_GCJ_SUPPORT + p -> gcj_freelists[i] = (void *)1; +# endif + } + /* Set up the size 0 free lists. */ + /* We now handle most of them like regular free lists, to ensure */ + /* That explicit deallocation works. However, allocation of a */ + /* size 0 "gcj" object is always an error. */ + p -> ptrfree_freelists[0] = (void *)1; + p -> normal_freelists[0] = (void *)1; +# ifdef GC_GCJ_SUPPORT + p -> gcj_freelists[0] = ERROR_FL; +# endif +} + +#ifdef GC_GCJ_SUPPORT + extern void ** GC_gcjobjfreelist; +#endif + +/* We hold the allocator lock. */ +void GC_destroy_thread_local(GC_tlfs p) +{ + /* We currently only do this from the thread itself or from */ + /* the fork handler for a child process. */ +# ifndef HANDLE_FORK + GC_ASSERT(GC_getspecific(GC_thread_key) == (void *)p); +# endif + return_freelists(p -> ptrfree_freelists, GC_aobjfreelist); + return_freelists(p -> normal_freelists, GC_objfreelist); +# ifdef GC_GCJ_SUPPORT + return_freelists(p -> gcj_freelists, GC_gcjobjfreelist); +# endif +} + +#if defined(GC_ASSERTIONS) && defined(GC_PTHREADS) && !defined(CYGWIN32) \ + && !defined(GC_WIN32_PTHREADS) +# include <pthread.h> + extern char * GC_lookup_thread(pthread_t id); +#endif + +#if defined(GC_ASSERTIONS) && defined(GC_WIN32_THREADS) + extern char * GC_lookup_thread(int id); +#endif + +void * GC_malloc(size_t bytes) +{ + size_t granules = ROUNDED_UP_GRANULES(bytes); + void *tsd; + void *result; + void **tiny_fl; + +# if defined(REDIRECT_MALLOC) && !defined(USE_PTHREAD_SPECIFIC) + GC_key_t k = GC_thread_key; + if (EXPECT(0 == k, 0)) { + /* We haven't yet run GC_init_parallel. That means */ + /* we also aren't locking, so this is fairly cheap. */ + return GC_core_malloc(bytes); + } + tsd = GC_getspecific(k); +# else + GC_ASSERT(GC_is_initialized); + tsd = GC_getspecific(GC_thread_key); +# endif +# if defined(REDIRECT_MALLOC) && defined(USE_PTHREAD_SPECIFIC) + if (EXPECT(NULL == tsd, 0)) { + return GC_core_malloc(bytes); + } +# endif +# ifdef GC_ASSERTIONS + /* We can't check tsd correctly, since we don't have access to */ + /* the right declarations. But we can check that it's close. */ + LOCK(); + { +# if defined(GC_WIN32_THREADS) + char * me = (char *)GC_lookup_thread_inner(GetCurrentThreadId()); +# else + char * me = GC_lookup_thread(pthread_self()); +# endif + GC_ASSERT((char *)tsd > me && (char *)tsd < me + 1000); + } + UNLOCK(); +# endif + tiny_fl = ((GC_tlfs)tsd) -> normal_freelists; + GC_FAST_MALLOC_GRANS(result, granules, tiny_fl, DIRECT_GRANULES, + NORMAL, GC_core_malloc(bytes), obj_link(result)=0); + return result; +} + +void * GC_malloc_atomic(size_t bytes) +{ + size_t granules = ROUNDED_UP_GRANULES(bytes); + void *result; + void **tiny_fl; + + GC_ASSERT(GC_is_initialized); + tiny_fl = ((GC_tlfs)GC_getspecific(GC_thread_key)) + -> ptrfree_freelists; + GC_FAST_MALLOC_GRANS(result, bytes, tiny_fl, DIRECT_GRANULES, + PTRFREE, GC_core_malloc_atomic(bytes), 0/* no init */); + return result; +} + +#ifdef GC_GCJ_SUPPORT + +#include "include/gc_gcj.h" + +#ifdef GC_ASSERTIONS + extern GC_bool GC_gcj_malloc_initialized; +#endif + +extern int GC_gcj_kind; + +/* Gcj-style allocation without locks is extremely tricky. The */ +/* fundamental issue is that we may end up marking a free list, which */ +/* has freelist links instead of "vtable" pointers. That is usually */ +/* OK, since the next object on the free list will be cleared, and */ +/* will thus be interpreted as containg a zero descriptor. That's fine */ +/* if the object has not yet been initialized. But there are */ +/* interesting potential races. */ +/* In the case of incremental collection, this seems hopeless, since */ +/* the marker may run asynchronously, and may pick up the pointer to */ +/* the next freelist entry (which it thinks is a vtable pointer), get */ +/* suspended for a while, and then see an allocated object instead */ +/* of the vtable. This made be avoidable with either a handshake with */ +/* the collector or, probably more easily, by moving the free list */ +/* links to the second word of each object. The latter isn't a */ +/* universal win, since on architecture like Itanium, nonzero offsets */ +/* are not necessarily free. And there may be cache fill order issues. */ +/* For now, we punt with incremental GC. This probably means that */ +/* incremental GC should be enabled before we fork a second thread. */ +void * GC_gcj_malloc(size_t bytes, + void * ptr_to_struct_containing_descr) +{ + if (GC_EXPECT(GC_incremental, 0)) { + return GC_core_gcj_malloc(bytes, ptr_to_struct_containing_descr); + } else { + size_t granules = ROUNDED_UP_GRANULES(bytes); + void *result; + void **tiny_fl = ((GC_tlfs)GC_getspecific(GC_thread_key)) + -> gcj_freelists; + GC_ASSERT(GC_gcj_malloc_initialized); + GC_FAST_MALLOC_GRANS(result, bytes, tiny_fl, DIRECT_GRANULES, + GC_gcj_kind, + GC_core_gcj_malloc(bytes, + ptr_to_struct_containing_descr), + {AO_compiler_barrier(); + *(void **)result = ptr_to_struct_containing_descr;}); + /* This forces the initialization of the "method ptr". */ + /* This is necessary to ensure some very subtle properties */ + /* required if a GC is run in the middle of such an allocation. */ + /* Here we implicitly also assume atomicity for the free list. */ + /* and method pointer assignments. */ + /* We must update the freelist before we store the pointer. */ + /* Otherwise a GC at this point would see a corrupted */ + /* free list. */ + /* A real memory barrier is not needed, since the */ + /* action of stopping this thread will cause prior writes */ + /* to complete. */ + /* We assert that any concurrent marker will stop us. */ + /* Thus it is impossible for a mark procedure to see the */ + /* allocation of the next object, but to see this object */ + /* still containing a free list pointer. Otherwise the */ + /* marker, by misinterpreting the freelist link as a vtable */ + /* pointer, might find a random "mark descriptor" in the next */ + /* object. */ + return result; + } +} + +#endif /* GC_GCJ_SUPPORT */ + +/* The thread support layer must arrange to mark thread-local */ +/* free lists explicitly, since the link field is often */ +/* invisible to the marker. It knows hoe to find all threads; */ +/* we take care of an individual thread freelist structure. */ +void GC_mark_thread_local_fls_for(GC_tlfs p) +{ + ptr_t q; + int j; + + for (j = 1; j < TINY_FREELISTS; ++j) { + q = p -> ptrfree_freelists[j]; + if ((word)q > HBLKSIZE) GC_set_fl_marks(q); + q = p -> normal_freelists[j]; + if ((word)q > HBLKSIZE) GC_set_fl_marks(q); +# ifdef GC_GCJ_SUPPORT + q = p -> gcj_freelists[j]; + if ((word)q > HBLKSIZE) GC_set_fl_marks(q); +# endif /* GC_GCJ_SUPPORT */ + } +} + +#if defined(GC_ASSERTIONS) + /* Check that all thread-local free-lists in p are completely marked. */ + void GC_check_tls_for(GC_tlfs p) + { + ptr_t q; + int j; + + for (j = 1; j < TINY_FREELISTS; ++j) { + q = p -> ptrfree_freelists[j]; + if ((word)q > HBLKSIZE) GC_check_fl_marks(q); + q = p -> normal_freelists[j]; + if ((word)q > HBLKSIZE) GC_check_fl_marks(q); +# ifdef GC_GCJ_SUPPORT + q = p -> gcj_freelists[j]; + if ((word)q > HBLKSIZE) GC_check_fl_marks(q); +# endif /* GC_GCJ_SUPPORT */ + } + } +#endif /* GC_ASSERTIONS */ + +# else /* !THREAD_LOCAL_ALLOC */ + +# define GC_destroy_thread_local(t) + +# endif /* !THREAD_LOCAL_ALLOC */ + |