/* * Copyright (c) 1994 by Xerox Corporation. All rights reserved. * Copyright (c) 1996 by Silicon Graphics. All rights reserved. * Copyright (c) 1998 by Fergus Henderson. All rights reserved. * Copyright (c) 2000-2008 by Hewlett-Packard Development 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(GC_WIN32_THREADS) #include #ifdef THREAD_LOCAL_ALLOC # include "private/thread_local_alloc.h" #endif /* THREAD_LOCAL_ALLOC */ /* Allocation lock declarations. */ #if !defined(USE_PTHREAD_LOCKS) # if defined(GC_DLL) __declspec(dllexport) CRITICAL_SECTION GC_allocate_ml; # else CRITICAL_SECTION GC_allocate_ml; # endif DWORD GC_lock_holder = NO_THREAD; /* Thread id for current holder of allocation lock */ #else pthread_mutex_t GC_allocate_ml = PTHREAD_MUTEX_INITIALIZER; unsigned long GC_lock_holder = NO_THREAD; #endif #ifdef GC_PTHREADS # include /* Cygwin-specific forward decls */ # undef pthread_create # undef pthread_sigmask # undef pthread_join # undef pthread_detach # undef dlopen # ifdef DEBUG_THREADS # ifdef CYGWIN32 # define DEBUG_CYGWIN_THREADS 1 # define DEBUG_WIN32_PTHREADS 0 # else # define DEBUG_WIN32_PTHREADS 1 # define DEBUG_CYGWIN_THREADS 0 # endif # else # define DEBUG_CYGWIN_THREADS 0 # define DEBUG_WIN32_PTHREADS 0 # endif STATIC void * GC_pthread_start(void * arg); STATIC void GC_thread_exit_proc(void *arg); # include #else # ifdef DEBUG_THREADS # define DEBUG_WIN32_THREADS 1 # else # define DEBUG_WIN32_THREADS 0 # endif # undef CreateThread # undef ExitThread # undef _beginthreadex # undef _endthreadex # undef _beginthread # ifdef DEBUG_THREADS # define DEBUG_WIN32_THREADS 1 # else # define DEBUG_WIN32_THREADS 0 # endif # ifndef MSWINCE # include /* For _beginthreadex, _endthreadex */ # endif #endif /* DllMain-based thread registration is currently incompatible */ /* with thread-local allocation, pthreads and WinCE. */ #if defined(GC_DLL) && !defined(MSWINCE) \ && !defined(THREAD_LOCAL_ALLOC) && !defined(GC_PTHREADS) static GC_bool GC_win32_dll_threads = FALSE; /* This code operates in two distinct modes, depending on */ /* the setting of GC_win32_dll_threads. If */ /* GC_win32_dll_threads is set, all threads in the process */ /* are implicitly registered with the GC by DllMain. */ /* No explicit registration is required, and attempts at */ /* explicit registration are ignored. This mode is */ /* very different from the Posix operation of the collector. */ /* In this mode access to the thread table is lock-free. */ /* Hence there is a static limit on the number of threads. */ /* If GC_win32_dll_threads is FALSE, or the collector is */ /* built without GC_DLL defined, things operate in a way */ /* that is very similar to Posix platforms, and new threads */ /* must be registered with the collector, e.g. by using */ /* preprocessor-based interception of the thread primitives. */ /* In this case, we use a real data structure for the thread */ /* table. Note that there is no equivalent of linker-based */ /* call interception, since we don't have ELF-like */ /* facilities. The Windows analog appears to be "API */ /* hooking", which really seems to be a standard way to */ /* do minor binary rewriting (?). I'd prefer not to have */ /* the basic collector rely on such facilities, but an */ /* optional package that intercepts thread calls this way */ /* would probably be nice. */ /* GC_win32_dll_threads must be set at initialization time, */ /* i.e. before any collector or thread calls. We make it a */ /* "dynamic" option only to avoid multiple library versions. */ #else # define GC_win32_dll_threads FALSE # undef MAX_THREADS # define MAX_THREADS 1 /* dll_thread_table[] is always empty. */ #endif /* We have two versions of the thread table. Which one */ /* we us depends on whether or not GC_win32_dll_threads */ /* is set. Note that before initialization, we don't */ /* add any entries to either table, even if DllMain is */ /* called. The main thread will be added on */ /* initialization. */ /* The type of the first argument to InterlockedExchange. */ /* Documented to be LONG volatile *, but at least gcc likes */ /* this better. */ typedef LONG * IE_t; GC_bool GC_thr_initialized = FALSE; GC_bool GC_need_to_lock = FALSE; static GC_bool parallel_initialized = FALSE; void GC_init_parallel(void); /* GC_use_DllMain() is currently incompatible with pthreads. */ /* It might be possible to get GC_DLL and DllMain-based thread registration */ /* to work with Cygwin, but if you try, you are on your own. */ #if defined(GC_DLL) && !defined(GC_PTHREADS) /* Turn on GC_win32_dll_threads */ GC_API void GC_CALL GC_use_DllMain(void) { # ifdef THREAD_LOCAL_ALLOC ABORT("Cannot use thread local allocation with DllMain-based " "thread registration."); /* Thread-local allocation really wants to lock at thread */ /* entry and exit. */ # else GC_ASSERT(!parallel_initialized); GC_win32_dll_threads = TRUE; GC_init_parallel(); # endif } #else GC_API void GC_CALL GC_use_DllMain(void) { ABORT("GC not configured as DLL"); } #endif STATIC DWORD GC_main_thread = 0; #define ADDR_LIMIT ((ptr_t)(word)-1) struct GC_Thread_Rep { union { AO_t tm_in_use; /* Updated without lock. */ /* We assert that unused */ /* entries have invalid ids of */ /* zero and zero stack fields. */ /* Used only with GC_win32_dll_threads. */ struct GC_Thread_Rep * tm_next; /* Hash table link without */ /* GC_win32_dll_threads. */ /* More recently allocated threads */ /* with a given pthread id come */ /* first. (All but the first are */ /* guaranteed to be dead, but we may */ /* not yet have registered the join.) */ } table_management; # define in_use table_management.tm_in_use # define next table_management.tm_next DWORD id; HANDLE handle; ptr_t stack_base; /* The cold end of the stack. */ /* 0 ==> entry not valid. */ /* !in_use ==> stack_base == 0 */ ptr_t last_stack_min; /* Last known minimum (hottest) address */ /* in stack or ADDR_LIMIT if unset */ # ifdef IA64 ptr_t backing_store_end; ptr_t backing_store_ptr; # endif GC_bool suspended; # ifdef GC_PTHREADS void *status; /* hold exit value until join in case it's a pointer */ pthread_t pthread_id; short flags; /* Protected by GC lock. */ # define FINISHED 1 /* Thread has exited. */ # define DETACHED 2 /* Thread is intended to be detached. */ # define KNOWN_FINISHED(t) (((t) -> flags) & FINISHED) # else # define KNOWN_FINISHED(t) 0 # endif # ifdef THREAD_LOCAL_ALLOC struct thread_local_freelists tlfs; # endif }; typedef struct GC_Thread_Rep * GC_thread; typedef volatile struct GC_Thread_Rep * GC_vthread; /* * We assumed that volatile ==> memory ordering, at least among * volatiles. This code should consistently use atomic_ops. */ volatile GC_bool GC_please_stop = FALSE; /* * We track thread attachments while the world is supposed to be stopped. * Unfortunately, we can't stop them from starting, since blocking in * DllMain seems to cause the world to deadlock. Thus we have to recover * If we notice this in the middle of marking. */ AO_t GC_attached_thread = FALSE; /* Return TRUE if an thread was attached since we last asked or */ /* since GC_attached_thread was explicitly reset. */ GC_bool GC_started_thread_while_stopped(void) { AO_t result; if (GC_win32_dll_threads) { AO_nop_full(); /* Prior heap reads need to complete earlier. */ result = AO_load(&GC_attached_thread); if (result) { AO_store(&GC_attached_thread, FALSE); } return ((GC_bool)result); } else { return FALSE; } } /* Thread table used if GC_win32_dll_threads is set. */ /* This is a fixed size array. */ /* Since we use runtime conditionals, both versions */ /* are always defined. */ # ifndef MAX_THREADS # define MAX_THREADS 512 # endif /* Things may get quite slow for large numbers of threads, */ /* since we look them up with sequential search. */ volatile struct GC_Thread_Rep dll_thread_table[MAX_THREADS]; volatile LONG GC_max_thread_index = 0; /* Largest index in dll_thread_table */ /* that was ever used. */ /* And now the version used if GC_win32_dll_threads is not set. */ /* This is a chained hash table, with much of the code borrowed */ /* From the Posix implementation. */ #ifndef THREAD_TABLE_SZ # define THREAD_TABLE_SZ 256 /* Must be power of 2 */ #endif STATIC GC_thread GC_threads[THREAD_TABLE_SZ]; /* It may not be safe to allocate when we register the first thread. */ /* Thus we allocated one statically. */ static struct GC_Thread_Rep first_thread; static GC_bool first_thread_used = FALSE; /* Add a thread to GC_threads. We assume it wasn't already there. */ /* Caller holds allocation lock. */ /* Unlike the pthreads version, the id field is set by the caller. */ STATIC GC_thread GC_new_thread(DWORD id) { word hv = ((word)id) % THREAD_TABLE_SZ; GC_thread result; GC_ASSERT(I_HOLD_LOCK()); if (!first_thread_used) { result = &first_thread; first_thread_used = TRUE; } else { GC_ASSERT(!GC_win32_dll_threads); result = (struct GC_Thread_Rep *) GC_INTERNAL_MALLOC(sizeof(struct GC_Thread_Rep), NORMAL); /* result can be NULL */ if (result == 0) return(0); } /* result -> id = id; Done by caller. */ result -> next = GC_threads[hv]; GC_threads[hv] = result; # ifdef GC_PTHREADS GC_ASSERT(result -> flags == 0 /* && result -> thread_blocked == 0 */); # endif return(result); } extern LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info); #if defined(GWW_VDB) && defined(MPROTECT_VDB) extern GC_bool GC_gww_dirty_init(void); /* Defined in os_dep.c. Returns TRUE if GetWriteWatch is available. */ /* may be called repeatedly. */ #endif GC_bool GC_in_thread_creation = FALSE; /* Protected by allocation lock. */ /* * This may be called from DllMain, and hence operates under unusual * constraints. In particular, it must be lock-free if GC_win32_dll_threads * is set. Always called from the thread being added. * If GC_win32_dll_threads is not set, we already hold the allocation lock, * except possibly during single-threaded start-up code. */ static GC_thread GC_register_my_thread_inner(struct GC_stack_base *sb, DWORD thread_id) { GC_vthread me; /* The following should be a no-op according to the win32 */ /* documentation. There is empirical evidence that it */ /* isn't. - HB */ # if defined(MPROTECT_VDB) # if defined(GWW_VDB) if (GC_incremental && !GC_gww_dirty_init()) SetUnhandledExceptionFilter(GC_write_fault_handler); # else if (GC_incremental) SetUnhandledExceptionFilter(GC_write_fault_handler); # endif # endif if (GC_win32_dll_threads) { int i; /* It appears to be unsafe to acquire a lock here, since this */ /* code is apparently not preemptible on some systems. */ /* (This is based on complaints, not on Microsoft's official */ /* documentation, which says this should perform "only simple */ /* initialization tasks".) */ /* Hence we make do with nonblocking synchronization. */ /* It has been claimed that DllMain is really only executed with */ /* a particular system lock held, and thus careful use of locking */ /* around code that doesn't call back into the system libraries */ /* might be OK. But this hasn't been tested across all win32 */ /* variants. */ /* cast away volatile qualifier */ for (i = 0; InterlockedExchange((void*)&dll_thread_table[i].in_use,1) != 0; i++) { /* Compare-and-swap would make this cleaner, but that's not */ /* supported before Windows 98 and NT 4.0. In Windows 2000, */ /* InterlockedExchange is supposed to be replaced by */ /* InterlockedExchangePointer, but that's not really what I */ /* want here. */ /* FIXME: We should eventually declare Win95 dead and use AO_ */ /* primitives here. */ if (i == MAX_THREADS - 1) ABORT("too many threads"); } /* Update GC_max_thread_index if necessary. The following is safe, */ /* and unlike CompareExchange-based solutions seems to work on all */ /* Windows95 and later platforms. */ /* Unfortunately, GC_max_thread_index may be temporarily out of */ /* bounds, so readers have to compensate. */ while (i > GC_max_thread_index) { InterlockedIncrement((IE_t)&GC_max_thread_index); } if (GC_max_thread_index >= MAX_THREADS) { /* We overshot due to simultaneous increments. */ /* Setting it to MAX_THREADS-1 is always safe. */ GC_max_thread_index = MAX_THREADS - 1; } me = dll_thread_table + i; } else /* Not using DllMain */ { GC_ASSERT(I_HOLD_LOCK()); GC_in_thread_creation = TRUE; /* OK to collect from unknown thread. */ me = GC_new_thread(thread_id); GC_in_thread_creation = FALSE; if (me == 0) ABORT("Failed to allocate memory for thread registering."); } # ifdef GC_PTHREADS /* me can be NULL -> segfault */ me -> pthread_id = pthread_self(); # endif if (!DuplicateHandle(GetCurrentProcess(), GetCurrentThread(), GetCurrentProcess(), (HANDLE*)&(me -> handle), 0, 0, DUPLICATE_SAME_ACCESS)) { GC_err_printf("Last error code: %d\n", (int)GetLastError()); ABORT("DuplicateHandle failed"); } me -> last_stack_min = ADDR_LIMIT; me -> stack_base = sb -> mem_base; # ifdef IA64 me -> backing_store_end = sb -> reg_base; # endif /* Up until this point, GC_push_all_stacks considers this thread */ /* invalid. */ /* Up until this point, this entry is viewed as reserved but invalid */ /* by GC_delete_thread. */ me -> id = thread_id; # if defined(THREAD_LOCAL_ALLOC) GC_init_thread_local((GC_tlfs)(&(me->tlfs))); # endif if (me -> stack_base == NULL) ABORT("Bad stack base in GC_register_my_thread_inner"); if (GC_win32_dll_threads) { if (GC_please_stop) { AO_store(&GC_attached_thread, TRUE); AO_nop_full(); /* Later updates must become visible after this. */ } /* We'd like to wait here, but can't, since waiting in DllMain */ /* provokes deadlocks. */ /* Thus we force marking to be restarted instead. */ } else { GC_ASSERT(!GC_please_stop); /* Otherwise both we and the thread stopping code would be */ /* holding the allocation lock. */ } return (GC_thread)(me); } /* * GC_max_thread_index may temporarily be larger than MAX_THREADS. * To avoid subscript errors, we check on access. */ #ifdef __GNUC__ __inline__ #endif STATIC LONG GC_get_max_thread_index(void) { LONG my_max = GC_max_thread_index; if (my_max >= MAX_THREADS) return MAX_THREADS-1; return my_max; } /* Return the GC_thread corresponding to a thread id. May be called */ /* without a lock, but should be called in contexts in which the */ /* requested thread cannot be asynchronously deleted, e.g. from the */ /* thread itself. */ /* This version assumes that either GC_win32_dll_threads is set, or */ /* we hold the allocator lock. */ /* Also used (for assertion checking only) from thread_local_alloc.c. */ GC_thread GC_lookup_thread_inner(DWORD thread_id) { if (GC_win32_dll_threads) { int i; LONG my_max = GC_get_max_thread_index(); for (i = 0; i <= my_max && (!AO_load_acquire(&(dll_thread_table[i].in_use)) || dll_thread_table[i].id != thread_id); /* Must still be in_use, since nobody else can store our thread_id. */ i++) {} if (i > my_max) { return 0; } else { return (GC_thread)(dll_thread_table + i); } } else { word hv = ((word)thread_id) % THREAD_TABLE_SZ; register GC_thread p = GC_threads[hv]; GC_ASSERT(I_HOLD_LOCK()); while (p != 0 && p -> id != thread_id) p = p -> next; return(p); } } /* Make sure thread descriptor t is not protected by the VDB */ /* implementation. */ /* Used to prevent write faults when the world is (partially) stopped, */ /* since it may have been stopped with a system lock held, and that */ /* lock may be required for fault handling. */ # if defined(MPROTECT_VDB) && !defined(MSWINCE) # define UNPROTECT(t) \ if (GC_dirty_maintained && !GC_win32_dll_threads && \ t != &first_thread) { \ GC_ASSERT(SMALL_OBJ(GC_size(t))); \ GC_remove_protection(HBLKPTR(t), 1, FALSE); \ } # else # define UNPROTECT(p) # endif /* If a thread has been joined, but we have not yet */ /* been notified, then there may be more than one thread */ /* in the table with the same win32 id. */ /* This is OK, but we need a way to delete a specific one. */ /* Assumes we hold the allocation lock unless */ /* GC_win32_dll_threads is set. */ /* If GC_win32_dll_threads is set it should be called from the */ /* thread being deleted. */ STATIC void GC_delete_gc_thread(GC_vthread gc_id) { CloseHandle(gc_id->handle); if (GC_win32_dll_threads) { /* This is intended to be lock-free. */ /* It is either called synchronously from the thread being deleted, */ /* or by the joining thread. */ /* In this branch asynchronous changes to *gc_id are possible. */ gc_id -> stack_base = 0; gc_id -> id = 0; # ifdef CYGWIN32 gc_id -> pthread_id = 0; # endif /* CYGWIN32 */ # ifdef GC_WIN32_PTHREADS gc_id -> pthread_id.p = NULL; # endif /* GC_WIN32_PTHREADS */ AO_store_release(&(gc_id->in_use), FALSE); } else { /* Cast away volatile qualifier, since we have lock. */ GC_thread gc_nvid = (GC_thread)gc_id; DWORD id = gc_nvid -> id; word hv = ((word)id) % THREAD_TABLE_SZ; register GC_thread p = GC_threads[hv]; register GC_thread prev = 0; GC_ASSERT(I_HOLD_LOCK()); while (p != gc_nvid) { prev = p; p = p -> next; } if (prev == 0) { GC_threads[hv] = p -> next; } else { prev -> next = p -> next; } GC_INTERNAL_FREE(p); } } /* Delete a thread from GC_threads. We assume it is there. */ /* (The code intentionally traps if it wasn't.) */ /* Assumes we hold the allocation lock unless */ /* GC_win32_dll_threads is set. */ /* If GC_win32_dll_threads is set it should be called from the */ /* thread being deleted. */ STATIC void GC_delete_thread(DWORD id) { if (GC_win32_dll_threads) { GC_thread t = GC_lookup_thread_inner(id); if (0 == t) { WARN("Removing nonexistent thread %ld\n", (long)id); } else { GC_delete_gc_thread(t); } } else { word hv = ((word)id) % THREAD_TABLE_SZ; register GC_thread p = GC_threads[hv]; register GC_thread prev = 0; GC_ASSERT(I_HOLD_LOCK()); while (p -> id != id) { prev = p; p = p -> next; } CloseHandle(p->handle); if (prev == 0) { GC_threads[hv] = p -> next; } else { prev -> next = p -> next; } GC_INTERNAL_FREE(p); } } GC_API int GC_CALL GC_register_my_thread(struct GC_stack_base *sb) { DWORD t = GetCurrentThreadId(); /* We lock here, since we want to wait for an ongoing GC. */ LOCK(); if (0 == GC_lookup_thread_inner(t)) { GC_register_my_thread_inner(sb, t); UNLOCK(); return GC_SUCCESS; } else { UNLOCK(); return GC_DUPLICATE; } } GC_API int GC_CALL GC_unregister_my_thread(void) { DWORD t = GetCurrentThreadId(); if (GC_win32_dll_threads) { # if defined(THREAD_LOCAL_ALLOC) /* Can't happen: see GC_use_DllMain(). */ GC_ASSERT(FALSE); # endif /* FIXME: Should we just ignore this? */ GC_delete_thread(t); } else { LOCK(); # if defined(THREAD_LOCAL_ALLOC) { GC_thread me = GC_lookup_thread_inner(t); GC_destroy_thread_local(&(me->tlfs)); } # endif GC_delete_thread(t); UNLOCK(); } return GC_SUCCESS; } #ifdef GC_PTHREADS /* A quick-and-dirty cache of the mapping between pthread_t */ /* and win32 thread id. */ #define PTHREAD_MAP_SIZE 512 DWORD GC_pthread_map_cache[PTHREAD_MAP_SIZE]; #define HASH(pthread_id) ((NUMERIC_THREAD_ID(pthread_id) >> 5) % PTHREAD_MAP_SIZE) /* It appears pthread_t is really a pointer type ... */ #define SET_PTHREAD_MAP_CACHE(pthread_id, win32_id) \ (GC_pthread_map_cache[HASH(pthread_id)] = (win32_id)) #define GET_PTHREAD_MAP_CACHE(pthread_id) \ GC_pthread_map_cache[HASH(pthread_id)] /* Return a GC_thread corresponding to a given pthread_t. */ /* Returns 0 if it's not there. */ /* We assume that this is only called for pthread ids that */ /* have not yet terminated or are still joinable, and */ /* cannot be concurrently terminated. */ /* Assumes we do NOT hold the allocation lock. */ static GC_thread GC_lookup_pthread(pthread_t id) { if (GC_win32_dll_threads) { int i; LONG my_max = GC_get_max_thread_index(); for (i = 0; i <= my_max && (!AO_load_acquire(&(dll_thread_table[i].in_use)) || THREAD_EQUAL(dll_thread_table[i].pthread_id, id)); /* Must still be in_use, since nobody else can store our thread_id. */ i++); if (i > my_max) return 0; return (GC_thread)(dll_thread_table + i); } else { /* We first try the cache. If that fails, we use a very slow */ /* approach. */ int hv_guess = GET_PTHREAD_MAP_CACHE(id) % THREAD_TABLE_SZ; int hv; GC_thread p; LOCK(); for (p = GC_threads[hv_guess]; 0 != p; p = p -> next) { if (THREAD_EQUAL(p -> pthread_id, id)) goto foundit; } for (hv = 0; hv < THREAD_TABLE_SZ; ++hv) { for (p = GC_threads[hv]; 0 != p; p = p -> next) { if (THREAD_EQUAL(p -> pthread_id, id)) goto foundit; } } p = 0; foundit: UNLOCK(); return p; } } #endif /* GC_PTHREADS */ void GC_push_thread_structures(void) { GC_ASSERT(I_HOLD_LOCK()); if (GC_win32_dll_threads) { /* Unlike the other threads implementations, the thread table here */ /* contains no pointers to the collectable heap. Thus we have */ /* no private structures we need to preserve. */ # ifdef GC_PTHREADS { int i; /* pthreads may keep a pointer in the thread exit value */ LONG my_max = GC_get_max_thread_index(); for (i = 0; i <= my_max; i++) if (dll_thread_table[i].in_use) GC_push_all((ptr_t)&(dll_thread_table[i].status), (ptr_t)(&(dll_thread_table[i].status)+1)); } # endif } else { GC_push_all((ptr_t)(GC_threads), (ptr_t)(GC_threads)+sizeof(GC_threads)); } # if defined(THREAD_LOCAL_ALLOC) GC_push_all((ptr_t)(&GC_thread_key), (ptr_t)(&GC_thread_key)+sizeof(&GC_thread_key)); /* Just in case we ever use our own TLS implementation. */ # endif } #if defined(MPROTECT_VDB) && !defined(MSWINCE) extern volatile AO_TS_t GC_fault_handler_lock; /* from os_dep.c */ #endif /* Suspend the given thread, if it's still active. */ STATIC void GC_suspend(GC_thread t) { # ifdef MSWINCE /* SuspendThread will fail if thread is running kernel code */ while (SuspendThread(t -> handle) == (DWORD)-1) Sleep(10); # else /* Apparently the Windows 95 GetOpenFileName call creates */ /* a thread that does not properly get cleaned up, and */ /* SuspendThread on its descriptor may provoke a crash. */ /* This reduces the probability of that event, though it still */ /* appears there's a race here. */ DWORD exitCode; UNPROTECT(t); if (GetExitCodeThread(t -> handle, &exitCode) && exitCode != STILL_ACTIVE) { # ifdef GC_PTHREADS t -> stack_base = 0; /* prevent stack from being pushed */ # else /* this breaks pthread_join on Cygwin, which is guaranteed to */ /* only see user pthreads */ GC_ASSERT(GC_win32_dll_threads); GC_delete_gc_thread(t); # endif return; } # if defined(MPROTECT_VDB) && !defined(MSWINCE) /* Acquire the spin lock we use to update dirty bits. */ /* Threads shouldn't get stopped holding it. But we may */ /* acquire and release it in the UNPROTECT call. */ while (AO_test_and_set_acquire(&GC_fault_handler_lock) == AO_TS_SET) {} # endif if (SuspendThread(t -> handle) == (DWORD)-1) ABORT("SuspendThread failed"); # endif t -> suspended = TRUE; # if defined(MPROTECT_VDB) && !defined(MSWINCE) AO_CLEAR(&GC_fault_handler_lock); # endif } /* Defined in misc.c */ #ifndef CYGWIN32 extern CRITICAL_SECTION GC_write_cs; #endif void GC_stop_world(void) { DWORD thread_id = GetCurrentThreadId(); int i; int my_max; if (!GC_thr_initialized) ABORT("GC_stop_world() called before GC_thr_init()"); GC_ASSERT(I_HOLD_LOCK()); /* This code is the same as in pthread_stop_world.c */ # ifdef PARALLEL_MARK if (GC_parallel) { GC_acquire_mark_lock(); GC_ASSERT(GC_fl_builder_count == 0); /* We should have previously waited for it to become zero. */ } # endif /* PARALLEL_MARK */ GC_please_stop = TRUE; # ifndef CYGWIN32 EnterCriticalSection(&GC_write_cs); # endif if (GC_win32_dll_threads) { /* Any threads being created during this loop will end up setting */ /* GC_attached_thread when they start. This will force marking to */ /* restart. */ /* This is not ideal, but hopefully correct. */ GC_attached_thread = FALSE; my_max = (int)GC_get_max_thread_index(); for (i = 0; i <= my_max; i++) { GC_vthread t = dll_thread_table + i; if (t -> stack_base != 0 && t -> id != thread_id) { GC_suspend((GC_thread)t); } } } else { GC_thread t; int i; for (i = 0; i < THREAD_TABLE_SZ; i++) { for (t = GC_threads[i]; t != 0; t = t -> next) { if (t -> stack_base != 0 && !KNOWN_FINISHED(t) && t -> id != thread_id) { GC_suspend(t); } } } } # ifndef CYGWIN32 LeaveCriticalSection(&GC_write_cs); # endif # ifdef PARALLEL_MARK if (GC_parallel) GC_release_mark_lock(); # endif } void GC_start_world(void) { DWORD thread_id = GetCurrentThreadId(); int i; GC_ASSERT(I_HOLD_LOCK()); if (GC_win32_dll_threads) { LONG my_max = GC_get_max_thread_index(); for (i = 0; i <= my_max; i++) { GC_thread t = (GC_thread)(dll_thread_table + i); if (t -> stack_base != 0 && t -> suspended && t -> id != thread_id) { if (ResumeThread(t -> handle) == (DWORD)-1) ABORT("ResumeThread failed"); t -> suspended = FALSE; } } } else { GC_thread t; int i; for (i = 0; i < THREAD_TABLE_SZ; i++) { for (t = GC_threads[i]; t != 0; t = t -> next) { if (t -> stack_base != 0 && t -> suspended && t -> id != thread_id) { if (ResumeThread(t -> handle) == (DWORD)-1) ABORT("ResumeThread failed"); UNPROTECT(t); t -> suspended = FALSE; } } } } GC_please_stop = FALSE; } # ifdef MSWINCE /* The VirtualQuery calls below won't work properly on WinCE, but */ /* since each stack is restricted to an aligned 64K region of */ /* virtual memory we can just take the next lowest multiple of 64K. */ # define GC_get_stack_min(s) \ ((ptr_t)(((DWORD)(s) - 1) & 0xFFFF0000)) # else /* A cache holding the results of the last VirtualQuery call. */ /* Protected by the allocation lock. */ static ptr_t last_address = 0; static MEMORY_BASIC_INFORMATION last_info; /* Probe stack memory region (starting at "s") to find out its */ /* lowest address (i.e. stack top). */ /* S must be a mapped address inside the region, NOT the first */ /* unmapped address. */ static ptr_t GC_get_stack_min(ptr_t s) { ptr_t bottom; GC_ASSERT(I_HOLD_LOCK()); if (s != last_address) { VirtualQuery(s, &last_info, sizeof(last_info)); last_address = s; } do { bottom = last_info.BaseAddress; VirtualQuery(bottom - 1, &last_info, sizeof(last_info)); last_address = bottom - 1; } while ((last_info.Protect & PAGE_READWRITE) && !(last_info.Protect & PAGE_GUARD)); return(bottom); } /* Return true if the page at s has protections appropriate */ /* for a stack page. */ static GC_bool GC_may_be_in_stack(ptr_t s) { GC_ASSERT(I_HOLD_LOCK()); if (s != last_address) { VirtualQuery(s, &last_info, sizeof(last_info)); last_address = s; } return (last_info.Protect & PAGE_READWRITE) && !(last_info.Protect & PAGE_GUARD); } # endif STATIC void GC_push_stack_for(GC_thread thread) { int dummy; ptr_t sp, stack_min; DWORD me = GetCurrentThreadId(); if (thread -> stack_base) { if (thread -> id == me) { sp = (ptr_t) &dummy; } else { CONTEXT context; context.ContextFlags = CONTEXT_INTEGER|CONTEXT_CONTROL; if (!GetThreadContext(thread -> handle, &context)) ABORT("GetThreadContext failed"); /* Push all registers that might point into the heap. Frame */ /* pointer registers are included in case client code was */ /* compiled with the 'omit frame pointer' optimisation. */ # define PUSH1(reg) GC_push_one((word)context.reg) # define PUSH2(r1,r2) PUSH1(r1), PUSH1(r2) # define PUSH4(r1,r2,r3,r4) PUSH2(r1,r2), PUSH2(r3,r4) # if defined(I386) PUSH4(Edi,Esi,Ebx,Edx), PUSH2(Ecx,Eax), PUSH1(Ebp); sp = (ptr_t)context.Esp; # elif defined(X86_64) PUSH4(Rax,Rcx,Rdx,Rbx); PUSH2(Rbp, Rsi); PUSH1(Rdi); PUSH4(R8, R9, R10, R11); PUSH4(R12, R13, R14, R15); sp = (ptr_t)context.Rsp; # elif defined(ARM32) PUSH4(R0,R1,R2,R3),PUSH4(R4,R5,R6,R7),PUSH4(R8,R9,R10,R11),PUSH1(R12); sp = (ptr_t)context.Sp; # elif defined(SHx) PUSH4(R0,R1,R2,R3), PUSH4(R4,R5,R6,R7), PUSH4(R8,R9,R10,R11); PUSH2(R12,R13), PUSH1(R14); sp = (ptr_t)context.R15; # elif defined(MIPS) PUSH4(IntAt,IntV0,IntV1,IntA0), PUSH4(IntA1,IntA2,IntA3,IntT0); PUSH4(IntT1,IntT2,IntT3,IntT4), PUSH4(IntT5,IntT6,IntT7,IntS0); PUSH4(IntS1,IntS2,IntS3,IntS4), PUSH4(IntS5,IntS6,IntS7,IntT8); PUSH4(IntT9,IntK0,IntK1,IntS8); sp = (ptr_t)context.IntSp; # elif defined(PPC) PUSH4(Gpr0, Gpr3, Gpr4, Gpr5), PUSH4(Gpr6, Gpr7, Gpr8, Gpr9); PUSH4(Gpr10,Gpr11,Gpr12,Gpr14), PUSH4(Gpr15,Gpr16,Gpr17,Gpr18); PUSH4(Gpr19,Gpr20,Gpr21,Gpr22), PUSH4(Gpr23,Gpr24,Gpr25,Gpr26); PUSH4(Gpr27,Gpr28,Gpr29,Gpr30), PUSH1(Gpr31); sp = (ptr_t)context.Gpr1; # elif defined(ALPHA) PUSH4(IntV0,IntT0,IntT1,IntT2), PUSH4(IntT3,IntT4,IntT5,IntT6); PUSH4(IntT7,IntS0,IntS1,IntS2), PUSH4(IntS3,IntS4,IntS5,IntFp); PUSH4(IntA0,IntA1,IntA2,IntA3), PUSH4(IntA4,IntA5,IntT8,IntT9); PUSH4(IntT10,IntT11,IntT12,IntAt); sp = (ptr_t)context.IntSp; # else # error "architecture is not supported" # endif } /* ! current thread */ /* Set stack_min to the lowest address in the thread stack, */ /* or to an address in the thread stack no larger than sp, */ /* taking advantage of the old value to avoid slow traversals */ /* of large stacks. */ if (thread -> last_stack_min == ADDR_LIMIT) { stack_min = GC_get_stack_min(thread -> stack_base); UNPROTECT(thread); thread -> last_stack_min = stack_min; } else { if (sp < thread -> stack_base && sp >= thread -> last_stack_min) { stack_min = sp; } else { # ifdef MSWINCE stack_min = GC_get_stack_min(thread -> stack_base); # else if (GC_may_be_in_stack(thread -> last_stack_min)) { stack_min = GC_get_stack_min(thread -> last_stack_min); } else { /* Stack shrunk? Is this possible? */ stack_min = GC_get_stack_min(thread -> stack_base); } # endif UNPROTECT(thread); thread -> last_stack_min = stack_min; } } GC_ASSERT(stack_min == GC_get_stack_min(thread -> stack_base) || (sp >= stack_min && stack_min < thread -> stack_base && stack_min > GC_get_stack_min(thread -> stack_base))); if (sp >= stack_min && sp < thread->stack_base) { # ifdef DEBUG_THREADS GC_printf("Pushing stack for 0x%x from sp %p to %p from 0x%x\n", (int)thread -> id, sp, thread -> stack_base, (int)me); # endif GC_push_all_stack(sp, thread->stack_base); } else { /* If not current thread then it is possible for sp to point to */ /* the guarded (untouched yet) page just below the current */ /* stack_min of the thread. */ if (thread -> id == me || sp >= thread->stack_base || sp + GC_page_size < stack_min) WARN("Thread stack pointer %p out of range, pushing everything\n", sp); # ifdef DEBUG_THREADS GC_printf("Pushing stack for 0x%x from (min) %p to %p from 0x%x\n", (int)thread -> id, stack_min, thread -> stack_base, (int)me); # endif GC_push_all_stack(stack_min, thread->stack_base); } } /* thread looks live */ } void GC_push_all_stacks(void) { DWORD me = GetCurrentThreadId(); GC_bool found_me = FALSE; # ifndef SMALL_CONFIG unsigned nthreads = 0; # endif if (GC_win32_dll_threads) { int i; LONG my_max = GC_get_max_thread_index(); for (i = 0; i <= my_max; i++) { GC_thread t = (GC_thread)(dll_thread_table + i); if (t -> in_use) { # ifndef SMALL_CONFIG ++nthreads; # endif GC_push_stack_for(t); if (t -> id == me) found_me = TRUE; } } } else { GC_thread t; int i; for (i = 0; i < THREAD_TABLE_SZ; i++) { for (t = GC_threads[i]; t != 0; t = t -> next) { # ifndef SMALL_CONFIG ++nthreads; # endif if (!KNOWN_FINISHED(t)) GC_push_stack_for(t); if (t -> id == me) found_me = TRUE; } } } # ifndef SMALL_CONFIG if (GC_print_stats == VERBOSE) { GC_log_printf("Pushed %d thread stacks%s\n", nthreads, GC_win32_dll_threads ? " based on DllMain thread tracking" : ""); } # endif if (!found_me && !GC_in_thread_creation) ABORT("Collecting from unknown thread."); } #ifdef PARALLEL_MARK # ifndef MAX_MARKERS # define MAX_MARKERS 16 # endif extern long GC_markers; /* Number of mark threads we would */ /* like to have. Includes the */ /* initiating thread. */ STATIC ptr_t marker_sp[MAX_MARKERS - 1]; /* The cold end of the stack */ /* for markers. */ # ifdef IA64 STATIC ptr_t marker_bsp[MAX_MARKERS - 1]; # endif STATIC ptr_t marker_last_stack_min[MAX_MARKERS - 1]; /* Last known minimum (hottest) address */ /* in stack (or ADDR_LIMIT if unset) */ /* for markers. */ #endif /* Find stack with the lowest address which overlaps the */ /* interval [start, limit). */ /* Return stack bounds in *lo and *hi. If no such stack */ /* is found, both *hi and *lo will be set to an address */ /* higher than limit. */ void GC_get_next_stack(char *start, char *limit, char **lo, char **hi) { int i; char * current_min = ADDR_LIMIT; /* Least in-range stack base */ ptr_t *plast_stack_min = NULL; /* Address of last_stack_min */ /* field for thread corresponding */ /* to current_min. */ GC_thread thread = NULL; /* Either NULL or points to the */ /* thread's hash table entry */ /* containing *plast_stack_min. */ /* First set current_min, ignoring limit. */ if (GC_win32_dll_threads) { LONG my_max = GC_get_max_thread_index(); for (i = 0; i <= my_max; i++) { ptr_t s = (ptr_t)(dll_thread_table[i].stack_base); if (s > start && s < current_min) { /* Update address of last_stack_min. */ plast_stack_min = (ptr_t * /* no volatile */) &dll_thread_table[i].last_stack_min; current_min = s; } } } else { for (i = 0; i < THREAD_TABLE_SZ; i++) { GC_thread t; for (t = GC_threads[i]; t != 0; t = t -> next) { ptr_t s = t -> stack_base; if (s > start && s < current_min) { /* Update address of last_stack_min. */ plast_stack_min = &t -> last_stack_min; thread = t; /* Remember current thread to unprotect. */ current_min = s; } } } # ifdef PARALLEL_MARK for (i = 0; i < GC_markers - 1; ++i) { ptr_t s = marker_sp[i]; # ifdef IA64 /* FIXME: not implemented */ # endif if (s > start && s < current_min) { GC_ASSERT(marker_last_stack_min[i] != NULL); plast_stack_min = &marker_last_stack_min[i]; current_min = s; thread = NULL; /* Not a thread's hash table entry. */ } } # endif } *hi = current_min; if (current_min == ADDR_LIMIT) { *lo = ADDR_LIMIT; return; } GC_ASSERT(current_min > start); # ifndef MSWINCE if (current_min > limit && !GC_may_be_in_stack(limit)) { /* Skip the rest since the memory region at limit address is */ /* not a stack (so the lowest address of the found stack would */ /* be above the limit value anyway). */ *lo = ADDR_LIMIT; return; } # endif /* Get the minimum address of the found stack by probing its memory */ /* region starting from the last known minimum (if set). */ if (*plast_stack_min == ADDR_LIMIT # ifndef MSWINCE || !GC_may_be_in_stack(*plast_stack_min) # endif ) { /* Unsafe to start from last value. */ *lo = GC_get_stack_min(current_min); } else { /* Use last value value to optimize search for min address */ *lo = GC_get_stack_min(*plast_stack_min); } /* Remember current stack_min value. */ if (thread != NULL) { UNPROTECT(thread); } *plast_stack_min = *lo; } #ifdef PARALLEL_MARK /* GC_mark_thread() is the same as in pthread_support.c */ #ifdef GC_PTHREADS STATIC void * GC_mark_thread(void * id) #else STATIC unsigned __stdcall GC_mark_thread(void * id) #endif { word my_mark_no = 0; marker_sp[(word)id] = GC_approx_sp(); # ifdef IA64 marker_bsp[(word)id] = GC_save_regs_in_stack(); # endif if ((word)id == (word)-1) return 0; /* to make compiler happy */ for (;; ++my_mark_no) { if (my_mark_no - GC_mark_no > (word)2) { /* resynchronize if we get far off, e.g. because GC_mark_no */ /* wrapped. */ my_mark_no = GC_mark_no; } # ifdef DEBUG_THREADS GC_printf("Starting mark helper for mark number %lu\n", (unsigned long)my_mark_no); # endif GC_help_marker(my_mark_no); } } #ifdef GC_ASSERTIONS unsigned long GC_mark_lock_holder = NO_THREAD; #endif /* GC_mark_threads[] is unused here unlike that in pthread_support.c */ #ifdef GC_PTHREADS /* start_mark_threads() is the same as in pthread_support.c except for: */ /* - GC_markers value is adjusted already; */ /* - thread stack is assumed to be large enough; and */ /* - statistics about the number of marker threads is already printed. */ STATIC void start_mark_threads(void) { unsigned i; pthread_attr_t attr; pthread_t new_thread; if (0 != pthread_attr_init(&attr)) ABORT("pthread_attr_init failed"); if (0 != pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED)) ABORT("pthread_attr_setdetachstate failed"); for (i = 0; i < GC_markers - 1; ++i) { marker_last_stack_min[i] = ADDR_LIMIT; if (0 != pthread_create(&new_thread, &attr, GC_mark_thread, (void *)(word)i)) { WARN("Marker thread creation failed, errno = %ld.\n", /* (word) */ errno); } } pthread_attr_destroy(&attr); } STATIC pthread_mutex_t mark_mutex = PTHREAD_MUTEX_INITIALIZER; STATIC pthread_cond_t builder_cv = PTHREAD_COND_INITIALIZER; /* GC_acquire/release_mark_lock(), GC_wait_builder/marker(), */ /* GC_wait_for_reclaim(), GC_notify_all_builder/marker() are the same */ /* as in pthread_support.c except that GC_generic_lock() is not used. */ #ifdef LOCK_STATS AO_t GC_block_count = 0; #endif void GC_acquire_mark_lock(void) { if (pthread_mutex_lock(&mark_mutex) != 0) { ABORT("pthread_mutex_lock failed"); } # ifdef LOCK_STATS (void)AO_fetch_and_add1(&GC_block_count); # endif /* GC_generic_lock(&mark_mutex); */ # ifdef GC_ASSERTIONS GC_mark_lock_holder = NUMERIC_THREAD_ID(pthread_self()); # endif } void GC_release_mark_lock(void) { GC_ASSERT(GC_mark_lock_holder == NUMERIC_THREAD_ID(pthread_self())); # ifdef GC_ASSERTIONS GC_mark_lock_holder = NO_THREAD; # endif if (pthread_mutex_unlock(&mark_mutex) != 0) { ABORT("pthread_mutex_unlock failed"); } } /* Collector must wait for a freelist builders for 2 reasons: */ /* 1) Mark bits may still be getting examined without lock. */ /* 2) Partial free lists referenced only by locals may not be scanned */ /* correctly, e.g. if they contain "pointer-free" objects, since the */ /* free-list link may be ignored. */ /* STATIC */ void GC_wait_builder(void) { GC_ASSERT(GC_mark_lock_holder == NUMERIC_THREAD_ID(pthread_self())); # ifdef GC_ASSERTIONS GC_mark_lock_holder = NO_THREAD; # endif if (pthread_cond_wait(&builder_cv, &mark_mutex) != 0) { ABORT("pthread_cond_wait failed"); } GC_ASSERT(GC_mark_lock_holder == NO_THREAD); # ifdef GC_ASSERTIONS GC_mark_lock_holder = NUMERIC_THREAD_ID(pthread_self()); # endif } void GC_wait_for_reclaim(void) { GC_acquire_mark_lock(); while (GC_fl_builder_count > 0) { GC_wait_builder(); } GC_release_mark_lock(); } void GC_notify_all_builder(void) { GC_ASSERT(GC_mark_lock_holder == NUMERIC_THREAD_ID(pthread_self())); if (pthread_cond_broadcast(&builder_cv) != 0) { ABORT("pthread_cond_broadcast failed"); } } STATIC pthread_cond_t mark_cv = PTHREAD_COND_INITIALIZER; void GC_wait_marker(void) { GC_ASSERT(GC_mark_lock_holder == NUMERIC_THREAD_ID(pthread_self())); # ifdef GC_ASSERTIONS GC_mark_lock_holder = NO_THREAD; # endif if (pthread_cond_wait(&mark_cv, &mark_mutex) != 0) { ABORT("pthread_cond_wait failed"); } GC_ASSERT(GC_mark_lock_holder == NO_THREAD); # ifdef GC_ASSERTIONS GC_mark_lock_holder = NUMERIC_THREAD_ID(pthread_self()); # endif } void GC_notify_all_marker(void) { if (pthread_cond_broadcast(&mark_cv) != 0) { ABORT("pthread_cond_broadcast failed"); } } #else /* ! GC_PTHREADS */ STATIC void start_mark_threads(void) { int i; GC_uintptr_t handle; unsigned thread_id; for (i = 0; i < GC_markers - 1; ++i) { marker_last_stack_min[i] = ADDR_LIMIT; handle = _beginthreadex(NULL /* security_attr */, 0 /* stack_size */, GC_mark_thread, (void *)(word)i, 0 /* flags */, &thread_id); if (!handle || handle == (GC_uintptr_t)-1L) WARN("Marker thread creation failed\n", 0); else { /* We may detach the thread (if handle is of HANDLE type) */ /* CloseHandle((HANDLE)handle); */ } } } STATIC HANDLE mark_mutex_event = (HANDLE)0; /* Event with auto-reset. */ volatile AO_t GC_mark_mutex_waitcnt = 0; /* Number of waiters + 1; */ /* 0 - unlocked. */ STATIC HANDLE builder_cv = (HANDLE)0; /* Event with manual reset */ /* mark_mutex_event, builder_cv, mark_cv are initialized in GC_thr_init(). */ /* #define LOCK_STATS */ #ifdef LOCK_STATS AO_t GC_block_count = 0; AO_t GC_unlocked_count = 0; #endif void GC_acquire_mark_lock(void) { if (AO_fetch_and_add1_acquire(&GC_mark_mutex_waitcnt) != 0) { # ifdef LOCK_STATS (void)AO_fetch_and_add1(&GC_block_count); # endif if (WaitForSingleObject(mark_mutex_event, INFINITE) == WAIT_FAILED) ABORT("WaitForSingleObject() failed"); } # ifdef LOCK_STATS else { (void)AO_fetch_and_add1(&GC_unlocked_count); } # endif GC_ASSERT(GC_mark_lock_holder == NO_THREAD); # ifdef GC_ASSERTIONS GC_mark_lock_holder = (unsigned long)GetCurrentThreadId(); # endif } void GC_release_mark_lock(void) { GC_ASSERT(GC_mark_lock_holder == (unsigned long)GetCurrentThreadId()); # ifdef GC_ASSERTIONS GC_mark_lock_holder = NO_THREAD; # endif GC_ASSERT(AO_load(&GC_mark_mutex_waitcnt) != 0); if (AO_fetch_and_sub1_release(&GC_mark_mutex_waitcnt) > 1 && SetEvent(mark_mutex_event) == FALSE) ABORT("SetEvent() failed"); } /* In GC_wait_for_reclaim/GC_notify_all_builder() we emulate POSIX */ /* cond_wait/cond_broadcast() primitives with WinAPI Event object */ /* (working in "manual reset" mode). This works here because */ /* GC_notify_all_builder() is always called holding lock on */ /* mark_mutex and the checked condition (GC_fl_builder_count == 0) */ /* is the only one for which broadcasting on builder_cv is performed. */ void GC_wait_for_reclaim(void) { GC_ASSERT(builder_cv != 0); for (;;) { GC_acquire_mark_lock(); if (GC_fl_builder_count == 0) break; if (ResetEvent(builder_cv) == FALSE) ABORT("ResetEvent() failed"); GC_release_mark_lock(); if (WaitForSingleObject(builder_cv, INFINITE) == WAIT_FAILED) ABORT("WaitForSingleObject() failed"); } GC_release_mark_lock(); } void GC_notify_all_builder(void) { GC_ASSERT(GC_mark_lock_holder == (unsigned long)GetCurrentThreadId()); GC_ASSERT(builder_cv != 0); GC_ASSERT(GC_fl_builder_count == 0); if (SetEvent(builder_cv) == FALSE) ABORT("SetEvent() failed"); } /* For GC_wait_marker/GC_notify_all_marker() the above technique does */ /* not work because they are used with different checked conditions in */ /* different places (and, in addition, notifying is done after leaving */ /* critical section) and this could result in a signal loosing between */ /* checking for a particular condition and calling WaitForSingleObject. */ /* So, we use PulseEvent() and NT SignalObjectAndWait() (which */ /* atomically sets mutex event to signaled state and starts waiting on */ /* condvar). A special case here is GC_mark_mutex_waitcnt == 1 (i.e. */ /* nobody waits for mark lock at this moment) - we don't change it */ /* (otherwise we may loose a signal sent between decrementing */ /* GC_mark_mutex_waitcnt and calling WaitForSingleObject()). */ STATIC HANDLE mark_cv = (HANDLE)0; /* Event with manual reset */ typedef DWORD (WINAPI * SignalObjectAndWait_type)( HANDLE, HANDLE, DWORD, BOOL); STATIC SignalObjectAndWait_type signalObjectAndWait_func = 0; void GC_wait_marker(void) { /* Here we assume that GC_wait_marker() is always called */ /* from a while(check_cond) loop. */ AO_t waitcnt; GC_ASSERT(mark_cv != 0); GC_ASSERT(signalObjectAndWait_func != 0); /* We inline GC_release_mark_lock() to have atomic */ /* unlock-and-wait action here. */ GC_ASSERT(GC_mark_lock_holder == (unsigned long)GetCurrentThreadId()); # ifdef GC_ASSERTIONS GC_mark_lock_holder = NO_THREAD; # endif if ((waitcnt = AO_load(&GC_mark_mutex_waitcnt)) > 1) { (void)AO_fetch_and_sub1_release(&GC_mark_mutex_waitcnt); } else { GC_ASSERT(AO_load(&GC_mark_mutex_waitcnt) != 0); } /* The state of mark_cv is non-signaled here. */ if ((*signalObjectAndWait_func)(mark_mutex_event /* hObjectToSignal */, mark_cv /* hObjectToWaitOn */, INFINITE /* timeout */, FALSE /* isAlertable */) == WAIT_FAILED) ABORT("SignalObjectAndWait() failed"); /* The state of mark_cv is non-signaled here again. */ if (waitcnt > 1) { GC_acquire_mark_lock(); } else { GC_ASSERT(GC_mark_mutex_waitcnt != 0); /* Acquire mark lock */ if (WaitForSingleObject(mark_mutex_event, INFINITE) == WAIT_FAILED) ABORT("WaitForSingleObject() failed"); GC_ASSERT(GC_mark_lock_holder == NO_THREAD); # ifdef GC_ASSERTIONS GC_mark_lock_holder = (unsigned long)GetCurrentThreadId(); # endif } } void GC_notify_all_marker(void) { GC_ASSERT(mark_cv != 0); if (PulseEvent(mark_cv) == FALSE) ABORT("PulseEvent() failed"); } /* Defined in os_dep.c */ extern GC_bool GC_wnt; #endif /* ! GC_PTHREADS */ #endif /* PARALLEL_MARK */ #ifndef GC_PTHREADS /* We have no DllMain to take care of new threads. Thus we */ /* must properly intercept thread creation. */ typedef struct { LPTHREAD_START_ROUTINE start; LPVOID param; } thread_args; STATIC void * GC_CALLBACK GC_win32_start_inner(struct GC_stack_base *sb, void *arg) { void * ret; thread_args *args = (thread_args *)arg; GC_register_my_thread(sb); /* This waits for an in-progress GC. */ # if DEBUG_WIN32_THREADS GC_printf("thread 0x%x starting...\n", (unsigned)GetCurrentThreadId()); # endif /* Clear the thread entry even if we exit with an exception. */ /* This is probably pointless, since an uncaught exception is */ /* supposed to result in the process being killed. */ #ifndef __GNUC__ __try { #endif /* __GNUC__ */ ret = (void *)(word)args->start (args->param); #ifndef __GNUC__ } __finally { #endif /* __GNUC__ */ GC_unregister_my_thread(); GC_free(args); #ifndef __GNUC__ } #endif /* __GNUC__ */ # if DEBUG_WIN32_THREADS GC_printf("thread 0x%x returned from start routine.\n", (unsigned)GetCurrentThreadId()); # endif return ret; } DWORD WINAPI GC_win32_start(LPVOID arg) { return (DWORD)(word)GC_call_with_stack_base(GC_win32_start_inner, arg); } GC_API HANDLE WINAPI GC_CreateThread( LPSECURITY_ATTRIBUTES lpThreadAttributes, DWORD dwStackSize, LPTHREAD_START_ROUTINE lpStartAddress, LPVOID lpParameter, DWORD dwCreationFlags, LPDWORD lpThreadId ) { HANDLE thread_h; thread_args *args; if (!parallel_initialized) GC_init_parallel(); /* make sure GC is initialized (i.e. main thread is attached, tls initialized) */ # if DEBUG_WIN32_THREADS GC_printf("About to create a thread from 0x%x\n", (unsigned)GetCurrentThreadId()); # endif if (GC_win32_dll_threads) { return CreateThread(lpThreadAttributes, dwStackSize, lpStartAddress, lpParameter, dwCreationFlags, lpThreadId); } else { args = GC_malloc_uncollectable(sizeof(thread_args)); /* Handed off to and deallocated by child thread. */ if (0 == args) { SetLastError(ERROR_NOT_ENOUGH_MEMORY); return NULL; } /* set up thread arguments */ args -> start = lpStartAddress; args -> param = lpParameter; GC_need_to_lock = TRUE; thread_h = CreateThread(lpThreadAttributes, dwStackSize, GC_win32_start, args, dwCreationFlags, lpThreadId); if( thread_h == 0 ) GC_free( args ); return thread_h; } } GC_API void WINAPI GC_ExitThread(DWORD dwExitCode) { GC_unregister_my_thread(); ExitThread(dwExitCode); } #ifndef MSWINCE GC_API GC_uintptr_t GC_CALL GC_beginthreadex( void *security, unsigned stack_size, unsigned ( __stdcall *start_address )( void * ), void *arglist, unsigned initflag, unsigned *thrdaddr) { GC_uintptr_t thread_h; thread_args *args; if (!parallel_initialized) GC_init_parallel(); /* make sure GC is initialized (i.e. main thread is attached, tls initialized) */ # if DEBUG_WIN32_THREADS GC_printf("About to create a thread from 0x%x\n", (unsigned)GetCurrentThreadId()); # endif if (GC_win32_dll_threads) { return _beginthreadex(security, stack_size, start_address, arglist, initflag, thrdaddr); } else { args = GC_malloc_uncollectable(sizeof(thread_args)); /* Handed off to and deallocated by child thread. */ if (0 == args) { SetLastError(ERROR_NOT_ENOUGH_MEMORY); return (GC_uintptr_t)(-1L); } /* set up thread arguments */ args -> start = (LPTHREAD_START_ROUTINE)start_address; args -> param = arglist; GC_need_to_lock = TRUE; thread_h = _beginthreadex(security, stack_size, (unsigned (__stdcall *) (void *))GC_win32_start, args, initflag, thrdaddr); if( thread_h == 0 ) GC_free( args ); return thread_h; } } GC_API void GC_CALL GC_endthreadex(unsigned retval) { GC_unregister_my_thread(); _endthreadex(retval); } #endif /* !MSWINCE */ #endif /* !GC_PTHREADS */ #ifdef MSWINCE typedef struct { HINSTANCE hInstance; HINSTANCE hPrevInstance; LPWSTR lpCmdLine; int nShowCmd; } main_thread_args; DWORD WINAPI main_thread_start(LPVOID arg); int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLine, int nShowCmd) { DWORD exit_code = 1; main_thread_args args = { hInstance, hPrevInstance, lpCmdLine, nShowCmd }; HANDLE thread_h; DWORD thread_id; /* initialize everything */ GC_init(); /* start the main thread */ thread_h = GC_CreateThread( NULL, 0, main_thread_start, &args, 0, &thread_id); if (thread_h != NULL) { WaitForSingleObject (thread_h, INFINITE); GetExitCodeThread (thread_h, &exit_code); CloseHandle (thread_h); } GC_deinit(); DeleteCriticalSection(&GC_allocate_ml); return (int) exit_code; } DWORD WINAPI main_thread_start(LPVOID arg) { main_thread_args * args = (main_thread_args *) arg; return (DWORD) GC_WinMain (args->hInstance, args->hPrevInstance, args->lpCmdLine, args->nShowCmd); } # else /* !MSWINCE */ /* Called by GC_init() - we hold the allocation lock. */ void GC_thr_init(void) { struct GC_stack_base sb; # ifdef GC_ASSERTIONS int sb_result; # endif GC_ASSERT(I_HOLD_LOCK()); if (GC_thr_initialized) return; GC_main_thread = GetCurrentThreadId(); GC_thr_initialized = TRUE; /* Add the initial thread, so we can stop it. */ # ifdef GC_ASSERTIONS sb_result = # endif GC_get_stack_base(&sb); GC_ASSERT(sb_result == GC_SUCCESS); # ifdef PARALLEL_MARK /* Set GC_markers. */ { char * markers_string = GETENV("GC_MARKERS"); if (markers_string != NULL) { GC_markers = atoi(markers_string); if (GC_markers > MAX_MARKERS) { WARN("Limiting number of mark threads\n", 0); GC_markers = MAX_MARKERS; } } else { # ifdef _WIN64 DWORD_PTR procMask = 0; DWORD_PTR sysMask; # else DWORD procMask = 0; DWORD sysMask; # endif int ncpu = 0; if (GetProcessAffinityMask(GetCurrentProcess(), (void *)&procMask, (void *)&sysMask) && procMask) { do { ncpu++; } while ((procMask &= procMask - 1) != 0); } GC_markers = ncpu; if (GC_markers >= MAX_MARKERS) GC_markers = MAX_MARKERS; /* silently limit GC_markers value */ } } /* Set GC_parallel. */ { # ifndef GC_PTHREADS HMODULE hK32; /* SignalObjectAndWait() API call works only under NT. */ # endif if (GC_markers <= 1 || GC_win32_dll_threads # ifndef GC_PTHREADS || GC_wnt == FALSE || (hK32 = GetModuleHandleA("kernel32.dll")) == (HMODULE)0 || (signalObjectAndWait_func = (SignalObjectAndWait_type) GetProcAddress(hK32, "SignalObjectAndWait")) == 0 # endif ) { /* Disable parallel marking. */ GC_parallel = FALSE; GC_markers = 1; } else { # ifndef GC_PTHREADS /* Initialize Win32 event objects for parallel marking. */ mark_mutex_event = CreateEventA(NULL /* attrs */, FALSE /* isManualReset */, FALSE /* initialState */, NULL /* name */); builder_cv = CreateEventA(NULL /* attrs */, TRUE /* isManualReset */, FALSE /* initialState */, NULL /* name */); mark_cv = CreateEventA(NULL /* attrs */, TRUE /* isManualReset */, FALSE /* initialState */, NULL /* name */); if (mark_mutex_event == (HANDLE)0 || builder_cv == (HANDLE)0 || mark_cv == (HANDLE)0) ABORT("CreateEvent() failed"); # endif GC_parallel = TRUE; /* Disable true incremental collection, but generational is OK. */ GC_time_limit = GC_TIME_UNLIMITED; } } if (GC_print_stats) { GC_log_printf("Number of marker threads = %ld\n", GC_markers); } # endif /* PARALLEL_MARK */ GC_ASSERT(0 == GC_lookup_thread_inner(GC_main_thread)); GC_register_my_thread_inner(&sb, GC_main_thread); # ifdef PARALLEL_MARK /* If we are using a parallel marker, actually start helper threads. */ if (GC_parallel) start_mark_threads(); # endif } #ifdef GC_PTHREADS struct start_info { void *(*start_routine)(void *); void *arg; GC_bool detached; }; int GC_pthread_join(pthread_t pthread_id, void **retval) { int result; GC_thread joinee; # if DEBUG_CYGWIN_THREADS GC_printf("thread 0x%x(0x%x) is joining thread 0x%x.\n", (int)pthread_self(), (int)GetCurrentThreadId(), (int)pthread_id); # endif # if DEBUG_WIN32_PTHREADS GC_printf("thread 0x%x(0x%x) is joining thread 0x%x.\n", (int)(pthread_self()).p, (int)GetCurrentThreadId(), pthread_id.p); # endif if (!parallel_initialized) GC_init_parallel(); /* Thread being joined might not have registered itself yet. */ /* After the join,thread id may have been recycled. */ /* FIXME: It would be better if this worked more like */ /* pthread_support.c. */ # ifndef GC_WIN32_PTHREADS while ((joinee = GC_lookup_pthread(pthread_id)) == 0) Sleep(10); # endif result = pthread_join(pthread_id, retval); # ifdef GC_WIN32_PTHREADS /* win32_pthreads id are unique */ joinee = GC_lookup_pthread(pthread_id); # endif if (!GC_win32_dll_threads) { LOCK(); GC_delete_gc_thread(joinee); UNLOCK(); } /* otherwise dllmain handles it. */ # if DEBUG_CYGWIN_THREADS GC_printf("thread 0x%x(0x%x) completed join with thread 0x%x.\n", (int)pthread_self(), (int)GetCurrentThreadId(), (int)pthread_id); # endif # if DEBUG_WIN32_PTHREADS GC_printf("thread 0x%x(0x%x) completed join with thread 0x%x.\n", (int)(pthread_self()).p, (int)GetCurrentThreadId(), pthread_id.p); # endif return result; } /* Cygwin-pthreads calls CreateThread internally, but it's not * easily interceptible by us.. * so intercept pthread_create instead */ int GC_pthread_create(pthread_t *new_thread, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg) { int result; struct start_info * si; if (!parallel_initialized) GC_init_parallel(); /* make sure GC is initialized (i.e. main thread is attached) */ if (GC_win32_dll_threads) { return pthread_create(new_thread, attr, start_routine, arg); } /* This is otherwise saved only in an area mmapped by the thread */ /* library, which isn't visible to the collector. */ si = GC_malloc_uncollectable(sizeof(struct start_info)); if (0 == si) return(EAGAIN); si -> start_routine = start_routine; si -> arg = arg; if (attr != 0 && pthread_attr_getdetachstate(attr, &si->detached) == PTHREAD_CREATE_DETACHED) { si->detached = TRUE; } # if DEBUG_CYGWIN_THREADS GC_printf("About to create a thread from 0x%x(0x%x)\n", (int)pthread_self(), (int)GetCurrentThreadId); # endif # if DEBUG_WIN32_PTHREADS GC_printf("About to create a thread from 0x%x(0x%x)\n", (int)(pthread_self()).p, (int)GetCurrentThreadId()); # endif GC_need_to_lock = TRUE; result = pthread_create(new_thread, attr, GC_pthread_start, si); if (result) { /* failure */ GC_free(si); } return(result); } STATIC void * GC_CALLBACK GC_pthread_start_inner(struct GC_stack_base *sb, void * arg) { struct start_info * si = arg; void * result; void *(*start)(void *); void *start_arg; DWORD thread_id = GetCurrentThreadId(); pthread_t pthread_id = pthread_self(); GC_thread me; # if DEBUG_CYGWIN_THREADS GC_printf("thread 0x%x(0x%x) starting...\n",(int)pthread_id, (int)thread_id); # endif # if DEBUG_WIN32_PTHREADS GC_printf("thread 0x%x(0x%x) starting...\n",(int) pthread_id.p, (int)thread_id); # endif GC_ASSERT(!GC_win32_dll_threads); /* If a GC occurs before the thread is registered, that GC will */ /* ignore this thread. That's fine, since it will block trying to */ /* acquire the allocation lock, and won't yet hold interesting */ /* pointers. */ LOCK(); /* We register the thread here instead of in the parent, so that */ /* we don't need to hold the allocation lock during pthread_create. */ me = GC_register_my_thread_inner(sb, thread_id); SET_PTHREAD_MAP_CACHE(pthread_id, thread_id); UNLOCK(); start = si -> start_routine; start_arg = si -> arg; if (si-> detached) me -> flags |= DETACHED; me -> pthread_id = pthread_id; GC_free(si); /* was allocated uncollectable */ pthread_cleanup_push(GC_thread_exit_proc, (void *)me); result = (*start)(start_arg); me -> status = result; pthread_cleanup_pop(1); # if DEBUG_CYGWIN_THREADS GC_printf("thread 0x%x(0x%x) returned from start routine.\n", (int)pthread_self(),(int)GetCurrentThreadId()); # endif # if DEBUG_WIN32_PTHREADS GC_printf("thread 0x%x(0x%x) returned from start routine.\n", (int)(pthread_self()).p, (int)GetCurrentThreadId()); # endif return(result); } STATIC void * GC_pthread_start(void * arg) { return GC_call_with_stack_base(GC_pthread_start_inner, arg); } STATIC void GC_thread_exit_proc(void *arg) { GC_thread me = (GC_thread)arg; GC_ASSERT(!GC_win32_dll_threads); # if DEBUG_CYGWIN_THREADS GC_printf("thread 0x%x(0x%x) called pthread_exit().\n", (int)pthread_self(),(int)GetCurrentThreadId()); # endif # if DEBUG_WIN32_PTHREADS GC_printf("thread 0x%x(0x%x) called pthread_exit().\n", (int)(pthread_self()).p,(int)GetCurrentThreadId()); # endif LOCK(); # if defined(THREAD_LOCAL_ALLOC) GC_destroy_thread_local(&(me->tlfs)); # endif if (me -> flags & DETACHED) { GC_delete_thread(GetCurrentThreadId()); } else { /* deallocate it as part of join */ me -> flags |= FINISHED; } UNLOCK(); } #ifndef GC_WIN32_PTHREADS /* win32 pthread does not support sigmask */ /* nothing required here... */ int GC_pthread_sigmask(int how, const sigset_t *set, sigset_t *oset) { if (!parallel_initialized) GC_init_parallel(); return pthread_sigmask(how, set, oset); } #endif int GC_pthread_detach(pthread_t thread) { int result; GC_thread thread_gc_id; if (!parallel_initialized) GC_init_parallel(); LOCK(); thread_gc_id = GC_lookup_pthread(thread); UNLOCK(); result = pthread_detach(thread); if (result == 0) { LOCK(); thread_gc_id -> flags |= DETACHED; /* Here the pthread thread id may have been recycled. */ if (thread_gc_id -> flags & FINISHED) { GC_delete_gc_thread(thread_gc_id); } UNLOCK(); } return result; } #else /* !GC_PTHREADS */ /* * We avoid acquiring locks here, since this doesn't seem to be preemptible. * This may run with an uninitialized collector, in which case we don't do much. * This implies that no threads other than the main one should be created * with an uninitialized collector. (The alternative of initializing * the collector here seems dangerous, since DllMain is limited in what it * can do.) */ #ifdef GC_DLL /*ARGSUSED*/ BOOL WINAPI DllMain(HINSTANCE inst, ULONG reason, LPVOID reserved) { struct GC_stack_base sb; DWORD thread_id; # ifdef GC_ASSERTIONS int sb_result; # endif static int entry_count = 0; if (parallel_initialized && !GC_win32_dll_threads) return TRUE; switch (reason) { case DLL_THREAD_ATTACH: # ifdef PARALLEL_MARK /* Don't register marker threads. */ if (GC_parallel) { /* We could reach here only if parallel_initialized == FALSE. */ break; } # endif GC_ASSERT(entry_count == 0 || parallel_initialized); ++entry_count; /* and fall through: */ case DLL_PROCESS_ATTACH: /* This may run with the collector uninitialized. */ thread_id = GetCurrentThreadId(); if (parallel_initialized && GC_main_thread != thread_id) { /* Don't lock here. */ # ifdef GC_ASSERTIONS sb_result = # endif GC_get_stack_base(&sb); GC_ASSERT(sb_result == GC_SUCCESS); # if defined(THREAD_LOCAL_ALLOC) || defined(PARALLEL_MARK) ABORT("Cannot initialize thread local cache from DllMain"); # endif GC_register_my_thread_inner(&sb, thread_id); } /* o.w. we already did it during GC_thr_init(), called by GC_init() */ break; case DLL_THREAD_DETACH: /* We are hopefully running in the context of the exiting thread. */ GC_ASSERT(parallel_initialized); if (!GC_win32_dll_threads) return TRUE; GC_delete_thread(GetCurrentThreadId()); break; case DLL_PROCESS_DETACH: { int i; int my_max; if (!GC_win32_dll_threads) return TRUE; my_max = (int)GC_get_max_thread_index(); for (i = 0; i <= my_max; ++i) { if (AO_load(&(dll_thread_table[i].in_use))) GC_delete_gc_thread(dll_thread_table + i); } GC_deinit(); DeleteCriticalSection(&GC_allocate_ml); } break; } return TRUE; } #endif /* GC_DLL */ #endif /* !GC_PTHREADS */ # endif /* !MSWINCE */ /* Perform all initializations, including those that */ /* may require allocation. */ /* Called without allocation lock. */ /* Must be called before a second thread is created. */ void GC_init_parallel(void) { if (parallel_initialized) return; parallel_initialized = TRUE; /* GC_init() calls us back, so set flag first. */ if (!GC_is_initialized) GC_init(); if (GC_win32_dll_threads) { GC_need_to_lock = TRUE; /* Cannot intercept thread creation. Hence we don't know if */ /* other threads exist. However, client is not allowed to */ /* create other threads before collector initialization. */ /* Thus it's OK not to lock before this. */ } /* Initialize thread local free lists if used. */ # if defined(THREAD_LOCAL_ALLOC) LOCK(); GC_init_thread_local(&GC_lookup_thread_inner(GetCurrentThreadId())->tlfs); UNLOCK(); # endif } #if defined(USE_PTHREAD_LOCKS) /* Support for pthread locking code. */ /* Pthread_mutex_try_lock may not win here, */ /* due to builtin support for spinning first? */ volatile GC_bool GC_collecting = 0; /* A hint that we're in the collector and */ /* holding the allocation lock for an */ /* extended period. */ void GC_lock(void) { pthread_mutex_lock(&GC_allocate_ml); } #endif /* USE_PTHREAD ... */ # if defined(THREAD_LOCAL_ALLOC) /* Add thread-local allocation support. Microsoft uses __declspec(thread) */ /* We must explicitly mark ptrfree and gcj free lists, since the free */ /* list links wouldn't otherwise be found. We also set them in the */ /* normal free lists, since that involves touching less memory than if */ /* we scanned them normally. */ void GC_mark_thread_local_free_lists(void) { int i; GC_thread p; for (i = 0; i < THREAD_TABLE_SZ; ++i) { for (p = GC_threads[i]; 0 != p; p = p -> next) { # ifdef DEBUG_THREADS GC_printf("Marking thread locals for 0x%x\n", p -> id); # endif GC_mark_thread_local_fls_for(&(p->tlfs)); } } } #if defined(GC_ASSERTIONS) void GC_check_tls_for(GC_tlfs p); # if defined(USE_CUSTOM_SPECIFIC) void GC_check_tsd_marks(tsd *key); # endif /* Check that all thread-local free-lists are completely marked. */ /* also check that thread-specific-data structures are marked. */ void GC_check_tls(void) { int i; GC_thread p; for (i = 0; i < THREAD_TABLE_SZ; ++i) { for (p = GC_threads[i]; 0 != p; p = p -> next) { GC_check_tls_for(&(p->tlfs)); } } # if defined(USE_CUSTOM_SPECIFIC) if (GC_thread_key != 0) GC_check_tsd_marks(GC_thread_key); # endif } #endif /* GC_ASSERTIONS */ #endif /* THREAD_LOCAL_ALLOC ... */ #endif /* GC_WIN32_THREADS */