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#include "private/gc_priv.h"
#if defined(GC_WIN32_THREADS)
#include <windows.h>
#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 <errno.h>
/* GC_DLL should not normally be defined, especially since we often do turn */
/* on THREAD_LOCAL_ALLOC, which is currently incompatible. */
/* 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. */
#ifdef GC_DLL
# error GC_DLL untested with Cygwin
#endif
/* 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
void * GC_pthread_start(void * arg);
void GC_thread_exit_proc(void *arg);
# include <pthread.h>
#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
# include <process.h> /* For _beginthreadex, _endthreadex */
#endif
#if defined(GC_DLL) && !defined(MSWINCE)
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
#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);
#ifdef GC_DLL
/* Turn on GC_win32_dll_threads */
GC_API void 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. */
# endif
GC_ASSERT(!parallel_initialized);
GC_win32_dll_threads = TRUE;
GC_init_parallel();
}
#else
GC_API void GC_use_DllMain(void)
{
ABORT("GC not configured as DLL");
}
#endif
DWORD GC_main_thread = 0;
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 */
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. */
# define THREAD_TABLE_SZ 256 /* Must be power of 2 */
GC_thread GC_threads[THREAD_TABLE_SZ];
/* 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. */
GC_thread GC_new_thread(DWORD id)
{
word hv = ((word)id) % THREAD_TABLE_SZ;
GC_thread result;
/* It may not be safe to allocate when we register the first thread. */
static struct GC_Thread_Rep first_thread;
static GC_bool first_thread_used = FALSE;
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);
# ifdef GC_PTHREADS
/* result can be NULL -> segfault */
GC_ASSERT(result -> flags == 0);
# endif
}
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 noop 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 preeemptible 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((IE_t)&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;
}
# 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)) {
DWORD last_error = GetLastError();
GC_err_printf("Last error code: %d\n", last_error);
ABORT("DuplicateHandle failed");
}
me -> stack_base = sb -> mem_base;
/* 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
LONG GC_get_max_thread_index()
{
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);
}
}
/* A version of the above that acquires the lock if necessary. Note */
/* that the identically named function for pthreads is different, and */
/* just assumes we hold the lock. */
/* Also used (for assertion checking only) from thread_local_alloc.c. */
static GC_thread GC_lookup_thread(DWORD thread_id)
{
if (GC_win32_dll_threads) {
return GC_lookup_thread_inner(thread_id);
} else {
GC_thread result;
LOCK();
result = GC_lookup_thread_inner(thread_id);
UNLOCK();
return result;
}
}
/* 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. */
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 asynchronosu 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. */
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", (GC_word)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_register_my_thread(struct GC_stack_base *sb) {
DWORD t = GetCurrentThreadId();
if (0 == GC_lookup_thread(t)) {
/* We lock here, since we want to wait for an ongoing GC. */
LOCK();
GC_register_my_thread_inner(sb, t);
UNLOCK();
return GC_SUCCESS;
} else {
return GC_DUPLICATE;
}
}
GC_API int GC_unregister_my_thread(void)
{
DWORD t = GetCurrentThreadId();
# if defined(THREAD_LOCAL_ALLOC)
LOCK();
{
GC_thread me = GC_lookup_thread_inner(t);
GC_destroy_thread_local(&(me->tlfs));
}
UNLOCK();
# endif
if (GC_win32_dll_threads) {
/* Should we just ignore this? */
GC_delete_thread(t);
} else {
LOCK();
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
}
/* Suspend the given thread, if it's still active. */
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;
if (GetExitCodeThread(t -> handle, &exitCode) &&
exitCode != STILL_ACTIVE) {
t -> stack_base = 0; /* prevent stack from being pushed */
# ifndef GC_PTHREADS
/* 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 (SuspendThread(t -> handle) == (DWORD)-1)
ABORT("SuspendThread failed");
# endif
t -> suspended = TRUE;
}
/* Defined in misc.c */
#ifndef CYGWIN32
extern CRITICAL_SECTION GC_write_cs;
#endif
void GC_stop_world(void)
{
DWORD thread_id = GetCurrentThreadId();
int i;
if (!GC_thr_initialized) ABORT("GC_stop_world() called before GC_thr_init()");
GC_ASSERT(I_HOLD_LOCK());
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;
for (i = 0; i <= GC_get_max_thread_index(); 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
}
void GC_start_world(void)
{
DWORD thread_id = GetCurrentThreadId();
int i;
LONG my_max = GC_get_max_thread_index();
GC_ASSERT(I_HOLD_LOCK());
if (GC_win32_dll_threads) {
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");
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
static ptr_t GC_get_stack_min(ptr_t s)
{
ptr_t bottom;
MEMORY_BASIC_INFORMATION info;
VirtualQuery(s, &info, sizeof(info));
do {
bottom = info.BaseAddress;
VirtualQuery(bottom - 1, &info, sizeof(info));
} while ((info.Protect & PAGE_READWRITE)
&& !(info.Protect & PAGE_GUARD));
return(bottom);
}
# endif
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 */
stack_min = GC_get_stack_min(thread->stack_base);
if (sp >= stack_min && sp < thread->stack_base) {
# if DEBUG_WIN32_PTHREADS || DEBUG_WIN32_THREADS \
|| DEBUG_CYGWIN_THREADS
GC_printf("Pushing thread from %p to %p for 0x%x from 0x%x\n",
sp, thread -> stack_base, thread -> id, me);
# endif
GC_push_all_stack(sp, thread->stack_base);
} else {
WARN("Thread stack pointer 0x%lx out of range, pushing everything\n",
(unsigned long)(size_t)sp);
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;
size_t nthreads = 0;
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) {
++nthreads;
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) {
++nthreads;
if (!KNOWN_FINISHED(t)) GC_push_stack_for(t);
if (t -> id == me) found_me = TRUE;
}
}
}
if (GC_print_stats == VERBOSE) {
GC_log_printf("Pushed %d thread stacks ", nthreads);
if (GC_win32_dll_threads) {
GC_log_printf("based on DllMain thread tracking\n");
} else {
GC_log_printf("\n");
}
}
if (!found_me && !GC_in_thread_creation)
ABORT("Collecting from unknown thread.");
}
void GC_get_next_stack(char *start, char **lo, char **hi)
{
int i;
# define ADDR_LIMIT (char *)(-1L)
char * current_min = ADDR_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 (0 != s && s > start && s < current_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 = (ptr_t)(t -> stack_base);
if (0 != s && s > start && s < current_min) {
current_min = s;
}
}
}
}
*hi = current_min;
if (current_min == ADDR_LIMIT) {
*lo = ADDR_LIMIT;
return;
}
*lo = GC_get_stack_min(current_min);
if (*lo < start) *lo = start;
}
#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 DWORD WINAPI thread_start(LPVOID arg);
void * GC_win32_start_inner(struct GC_stack_base *sb, LPVOID arg)
{
void * ret;
thread_args *args = (thread_args *)arg;
# if DEBUG_WIN32_THREADS
GC_printf("thread 0x%x starting...\n", GetCurrentThreadId());
# endif
GC_register_my_thread(sb); /* This waits for an in-progress GC. */
/* 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 *)(size_t)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",
GetCurrentThreadId());
# endif
return ret;
}
DWORD WINAPI GC_win32_start(LPVOID arg)
{
return (DWORD)(size_t)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 = NULL;
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", 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;
}
}
void WINAPI GC_ExitThread(DWORD dwExitCode)
{
GC_unregister_my_thread();
ExitThread(dwExitCode);
}
uintptr_t GC_beginthreadex(
void *security, unsigned stack_size,
unsigned ( __stdcall *start_address )( void * ),
void *arglist, unsigned initflag, unsigned *thrdaddr)
{
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", 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 (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;
}
}
void GC_endthreadex(unsigned retval)
{
GC_unregister_my_thread();
_endthreadex(retval);
}
#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_all_interior_pointers = 0; /* JJGR */
GC_no_dls = 1; /* JJGR */
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;
int sb_result;
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. */
sb_result = GC_get_stack_base(&sb);
GC_ASSERT(sb_result == GC_SUCCESS);
GC_register_my_thread(&sb);
}
#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;
int i;
GC_thread joinee;
# if DEBUG_CYGWIN_THREADS
GC_printf("thread 0x%x(0x%x) is joining thread 0x%x.\n",
(int)pthread_self(), 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, 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(), 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, 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(), GetCurrentThreadId);
# endif
# if DEBUG_WIN32_PTHREADS
GC_printf("About to create a thread from 0x%x(0x%x)\n",
(int)(pthread_self()).p, 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);
}
void * 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;
GC_bool detached;
int i;
# if DEBUG_CYGWIN_THREADS
GC_printf("thread 0x%x(0x%x) starting...\n",(int)pthread_id,
thread_id);
# endif
# if DEBUG_WIN32_PTHREADS
GC_printf("thread 0x%x(0x%x) starting...\n",(int) pthread_id.p,
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(),GetCurrentThreadId());
# endif
# if DEBUG_WIN32_PTHREADS
GC_printf("thread 0x%x(0x%x) returned from start routine.\n",
(int)(pthread_self()).p, GetCurrentThreadId());
# endif
return(result);
}
void * GC_pthread_start(void * arg)
{
return GC_call_with_stack_base(GC_pthread_start_inner, arg);
}
void GC_thread_exit_proc(void *arg)
{
GC_thread me = (GC_thread)arg;
int i;
GC_ASSERT(!GC_win32_dll_threads);
# if DEBUG_CYGWIN_THREADS
GC_printf("thread 0x%x(0x%x) called pthread_exit().\n",
(int)pthread_self(),GetCurrentThreadId());
# endif
# if DEBUG_WIN32_PTHREADS
GC_printf("thread 0x%x(0x%x) called pthread_exit().\n",
(int)(pthread_self()).p,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 preemptable.
* 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
GC_API BOOL WINAPI DllMain(HINSTANCE inst, ULONG reason, LPVOID reserved)
{
struct GC_stack_base sb;
DWORD thread_id;
int sb_result;
static int entry_count = 0;
if (parallel_initialized && !GC_win32_dll_threads) return TRUE;
switch (reason) {
case DLL_THREAD_ATTACH:
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. */
sb_result = GC_get_stack_base(&sb);
GC_ASSERT(sb_result == GC_SUCCESS);
# ifdef THREAD_LOCAL_ALLOC
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;
if (!GC_win32_dll_threads) return TRUE;
for (i = 0; i <= GC_get_max_thread_index(); ++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(GetCurrentThreadId())->tlfs));
UNLOCK();
# endif
}
#if defined(USE_PTHREAD_LOCKS)
/* Support for pthread locking code. */
/* Pthread_mutex_try_lock may not win here, */
/* due to builtinsupport 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) {
GC_mark_thread_local_fls_for(&(p->tlfs));
}
}
}
#if defined(GC_ASSERTIONS)
/* 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 */