gthread-win32: Remove WinXP compat code

This commit is contained in:
Christoph Reiter 2018-05-29 17:10:05 +02:00
parent 6054d11001
commit cce2957938

View File

@ -73,81 +73,36 @@ g_thread_abort (gint status,
* of these new types is that they can be statically initialised to * of these new types is that they can be statically initialised to
* zero. That means that they are completely ABI compatible with our * zero. That means that they are completely ABI compatible with our
* GMutex and GCond APIs. * GMutex and GCond APIs.
*
* Unfortunately, Windows XP lacks these facilities and GLib still
* needs to support Windows XP. Our approach here is as follows:
*
* - avoid depending on structure declarations at compile-time by
* declaring our own GMutex and GCond strutures to be
* ABI-compatible with SRWLock and CONDITION_VARIABLE and using
* those instead
*
* - avoid a hard dependency on the symbols used to manipulate these
* structures by doing a dynamic lookup of those symbols at
* runtime
*
* - if the symbols are not available, emulate them using other
* primatives
*
* Using this approach also allows us to easily build a GLib that lacks
* support for Windows XP or to remove this code entirely when XP is no
* longer supported (end of line is currently April 8, 2014).
*/ */
typedef struct
{
void (__stdcall * CallThisOnThreadExit) (void); /* fake */
void (__stdcall * InitializeSRWLock) (gpointer lock);
void (__stdcall * DeleteSRWLock) (gpointer lock); /* fake */
void (__stdcall * AcquireSRWLockExclusive) (gpointer lock);
BOOLEAN (__stdcall * TryAcquireSRWLockExclusive) (gpointer lock);
void (__stdcall * ReleaseSRWLockExclusive) (gpointer lock);
void (__stdcall * AcquireSRWLockShared) (gpointer lock);
BOOLEAN (__stdcall * TryAcquireSRWLockShared) (gpointer lock);
void (__stdcall * ReleaseSRWLockShared) (gpointer lock);
void (__stdcall * InitializeConditionVariable) (gpointer cond);
void (__stdcall * DeleteConditionVariable) (gpointer cond); /* fake */
BOOL (__stdcall * SleepConditionVariableSRW) (gpointer cond,
gpointer lock,
DWORD timeout,
ULONG flags);
void (__stdcall * WakeAllConditionVariable) (gpointer cond);
void (__stdcall * WakeConditionVariable) (gpointer cond);
} GThreadImplVtable;
static GThreadImplVtable g_thread_impl_vtable;
/* {{{1 GMutex */ /* {{{1 GMutex */
void void
g_mutex_init (GMutex *mutex) g_mutex_init (GMutex *mutex)
{ {
g_thread_impl_vtable.InitializeSRWLock (mutex); InitializeSRWLock ((gpointer) mutex);
} }
void void
g_mutex_clear (GMutex *mutex) g_mutex_clear (GMutex *mutex)
{ {
if (g_thread_impl_vtable.DeleteSRWLock != NULL)
g_thread_impl_vtable.DeleteSRWLock (mutex);
} }
void void
g_mutex_lock (GMutex *mutex) g_mutex_lock (GMutex *mutex)
{ {
g_thread_impl_vtable.AcquireSRWLockExclusive (mutex); AcquireSRWLockExclusive ((gpointer) mutex);
} }
gboolean gboolean
g_mutex_trylock (GMutex *mutex) g_mutex_trylock (GMutex *mutex)
{ {
return g_thread_impl_vtable.TryAcquireSRWLockExclusive (mutex); return TryAcquireSRWLockExclusive ((gpointer) mutex);
} }
void void
g_mutex_unlock (GMutex *mutex) g_mutex_unlock (GMutex *mutex)
{ {
g_thread_impl_vtable.ReleaseSRWLockExclusive (mutex); ReleaseSRWLockExclusive ((gpointer) mutex);
} }
/* {{{1 GRecMutex */ /* {{{1 GRecMutex */
@ -221,83 +176,79 @@ g_rec_mutex_trylock (GRecMutex *mutex)
void void
g_rw_lock_init (GRWLock *lock) g_rw_lock_init (GRWLock *lock)
{ {
g_thread_impl_vtable.InitializeSRWLock (lock); InitializeSRWLock ((gpointer) lock);
} }
void void
g_rw_lock_clear (GRWLock *lock) g_rw_lock_clear (GRWLock *lock)
{ {
if (g_thread_impl_vtable.DeleteSRWLock != NULL)
g_thread_impl_vtable.DeleteSRWLock (lock);
} }
void void
g_rw_lock_writer_lock (GRWLock *lock) g_rw_lock_writer_lock (GRWLock *lock)
{ {
g_thread_impl_vtable.AcquireSRWLockExclusive (lock); AcquireSRWLockExclusive ((gpointer) lock);
} }
gboolean gboolean
g_rw_lock_writer_trylock (GRWLock *lock) g_rw_lock_writer_trylock (GRWLock *lock)
{ {
return g_thread_impl_vtable.TryAcquireSRWLockExclusive (lock); return TryAcquireSRWLockExclusive ((gpointer) lock);
} }
void void
g_rw_lock_writer_unlock (GRWLock *lock) g_rw_lock_writer_unlock (GRWLock *lock)
{ {
g_thread_impl_vtable.ReleaseSRWLockExclusive (lock); ReleaseSRWLockExclusive ((gpointer) lock);
} }
void void
g_rw_lock_reader_lock (GRWLock *lock) g_rw_lock_reader_lock (GRWLock *lock)
{ {
g_thread_impl_vtable.AcquireSRWLockShared (lock); AcquireSRWLockShared ((gpointer) lock);
} }
gboolean gboolean
g_rw_lock_reader_trylock (GRWLock *lock) g_rw_lock_reader_trylock (GRWLock *lock)
{ {
return g_thread_impl_vtable.TryAcquireSRWLockShared (lock); return TryAcquireSRWLockShared ((gpointer) lock);
} }
void void
g_rw_lock_reader_unlock (GRWLock *lock) g_rw_lock_reader_unlock (GRWLock *lock)
{ {
g_thread_impl_vtable.ReleaseSRWLockShared (lock); ReleaseSRWLockShared ((gpointer) lock);
} }
/* {{{1 GCond */ /* {{{1 GCond */
void void
g_cond_init (GCond *cond) g_cond_init (GCond *cond)
{ {
g_thread_impl_vtable.InitializeConditionVariable (cond); InitializeConditionVariable ((gpointer) cond);
} }
void void
g_cond_clear (GCond *cond) g_cond_clear (GCond *cond)
{ {
if (g_thread_impl_vtable.DeleteConditionVariable)
g_thread_impl_vtable.DeleteConditionVariable (cond);
} }
void void
g_cond_signal (GCond *cond) g_cond_signal (GCond *cond)
{ {
g_thread_impl_vtable.WakeConditionVariable (cond); WakeConditionVariable ((gpointer) cond);
} }
void void
g_cond_broadcast (GCond *cond) g_cond_broadcast (GCond *cond)
{ {
g_thread_impl_vtable.WakeAllConditionVariable (cond); WakeAllConditionVariable ((gpointer) cond);
} }
void void
g_cond_wait (GCond *cond, g_cond_wait (GCond *cond,
GMutex *entered_mutex) GMutex *entered_mutex)
{ {
g_thread_impl_vtable.SleepConditionVariableSRW (cond, entered_mutex, INFINITE, 0); SleepConditionVariableSRW ((gpointer) cond, (gpointer) entered_mutex, INFINITE, 0);
} }
gboolean gboolean
@ -326,7 +277,7 @@ g_cond_wait_until (GCond *cond,
if (span_millis >= INFINITE) if (span_millis >= INFINITE)
span_millis = INFINITE - 1; span_millis = INFINITE - 1;
signalled = g_thread_impl_vtable.SleepConditionVariableSRW (cond, entered_mutex, span_millis, 0); signalled = SleepConditionVariableSRW ((gpointer) cond, (gpointer) entered_mutex, span_millis, 0);
if (signalled) if (signalled)
break; break;
@ -580,491 +531,11 @@ g_system_thread_set_name (const gchar *name)
SetThreadName ((DWORD) -1, name); SetThreadName ((DWORD) -1, name);
} }
/* {{{1 SRWLock and CONDITION_VARIABLE emulation (for Windows XP) */
static CRITICAL_SECTION g_thread_xp_lock;
static DWORD g_thread_xp_waiter_tls;
/* {{{2 GThreadWaiter utility class for CONDITION_VARIABLE emulation */
typedef struct _GThreadXpWaiter GThreadXpWaiter;
struct _GThreadXpWaiter
{
HANDLE event;
volatile GThreadXpWaiter *next;
volatile GThreadXpWaiter **my_owner;
};
static GThreadXpWaiter *
g_thread_xp_waiter_get (void)
{
GThreadXpWaiter *waiter;
waiter = TlsGetValue (g_thread_xp_waiter_tls);
if G_UNLIKELY (waiter == NULL)
{
waiter = malloc (sizeof (GThreadXpWaiter));
if (waiter == NULL)
g_thread_abort (GetLastError (), "malloc");
waiter->event = CreateEvent (0, FALSE, FALSE, NULL);
if (waiter->event == NULL)
g_thread_abort (GetLastError (), "CreateEvent");
waiter->my_owner = NULL;
TlsSetValue (g_thread_xp_waiter_tls, waiter);
}
return waiter;
}
static void __stdcall
g_thread_xp_CallThisOnThreadExit (void)
{
GThreadXpWaiter *waiter;
waiter = TlsGetValue (g_thread_xp_waiter_tls);
if (waiter != NULL)
{
TlsSetValue (g_thread_xp_waiter_tls, NULL);
CloseHandle (waiter->event);
free (waiter);
}
}
/* {{{2 SRWLock emulation */
typedef struct
{
CRITICAL_SECTION writer_lock;
gboolean ever_shared; /* protected by writer_lock */
gboolean writer_locked; /* protected by writer_lock */
/* below is only ever touched if ever_shared becomes true */
CRITICAL_SECTION atomicity;
GThreadXpWaiter *queued_writer; /* protected by atomicity lock */
gint num_readers; /* protected by atomicity lock */
} GThreadSRWLock;
static void __stdcall
g_thread_xp_InitializeSRWLock (gpointer mutex)
{
*(GThreadSRWLock * volatile *) mutex = NULL;
}
static void __stdcall
g_thread_xp_DeleteSRWLock (gpointer mutex)
{
GThreadSRWLock *lock = *(GThreadSRWLock * volatile *) mutex;
if (lock)
{
if (lock->ever_shared)
DeleteCriticalSection (&lock->atomicity);
DeleteCriticalSection (&lock->writer_lock);
free (lock);
}
}
static GThreadSRWLock * __stdcall
g_thread_xp_get_srwlock (GThreadSRWLock * volatile *lock)
{
GThreadSRWLock *result;
/* It looks like we're missing some barriers here, but this code only
* ever runs on Windows XP, which in turn only ever runs on hardware
* with a relatively rigid memory model. The 'volatile' will take
* care of the compiler.
*/
result = *lock;
if G_UNLIKELY (result == NULL)
{
EnterCriticalSection (&g_thread_xp_lock);
/* Check again */
result = *lock;
if (result == NULL)
{
result = malloc (sizeof (GThreadSRWLock));
if (result == NULL)
g_thread_abort (errno, "malloc");
InitializeCriticalSection (&result->writer_lock);
result->writer_locked = FALSE;
result->ever_shared = FALSE;
*lock = result;
}
LeaveCriticalSection (&g_thread_xp_lock);
}
return result;
}
static void __stdcall
g_thread_xp_AcquireSRWLockExclusive (gpointer mutex)
{
GThreadSRWLock *lock = g_thread_xp_get_srwlock (mutex);
EnterCriticalSection (&lock->writer_lock);
/* CRITICAL_SECTION is reentrant, but SRWLock is not.
* Detect the deadlock that would occur on later Windows version.
*/
g_assert (!lock->writer_locked);
lock->writer_locked = TRUE;
if (lock->ever_shared)
{
GThreadXpWaiter *waiter = NULL;
EnterCriticalSection (&lock->atomicity);
if (lock->num_readers > 0)
lock->queued_writer = waiter = g_thread_xp_waiter_get ();
LeaveCriticalSection (&lock->atomicity);
if (waiter != NULL)
WaitForSingleObject (waiter->event, INFINITE);
lock->queued_writer = NULL;
}
}
static BOOLEAN __stdcall
g_thread_xp_TryAcquireSRWLockExclusive (gpointer mutex)
{
GThreadSRWLock *lock = g_thread_xp_get_srwlock (mutex);
if (!TryEnterCriticalSection (&lock->writer_lock))
return FALSE;
/* CRITICAL_SECTION is reentrant, but SRWLock is not.
* Ensure that this properly returns FALSE (as SRWLock would).
*/
if G_UNLIKELY (lock->writer_locked)
{
LeaveCriticalSection (&lock->writer_lock);
return FALSE;
}
lock->writer_locked = TRUE;
if (lock->ever_shared)
{
gboolean available;
EnterCriticalSection (&lock->atomicity);
available = lock->num_readers == 0;
LeaveCriticalSection (&lock->atomicity);
if (!available)
{
LeaveCriticalSection (&lock->writer_lock);
return FALSE;
}
}
return TRUE;
}
static void __stdcall
g_thread_xp_ReleaseSRWLockExclusive (gpointer mutex)
{
GThreadSRWLock *lock = *(GThreadSRWLock * volatile *) mutex;
lock->writer_locked = FALSE;
/* We need this until we fix some weird parts of GLib that try to
* unlock freshly-allocated mutexes.
*/
if (lock != NULL)
LeaveCriticalSection (&lock->writer_lock);
}
static void
g_thread_xp_srwlock_become_reader (GThreadSRWLock *lock)
{
if G_UNLIKELY (!lock->ever_shared)
{
InitializeCriticalSection (&lock->atomicity);
lock->queued_writer = NULL;
lock->num_readers = 0;
lock->ever_shared = TRUE;
}
EnterCriticalSection (&lock->atomicity);
lock->num_readers++;
LeaveCriticalSection (&lock->atomicity);
}
static void __stdcall
g_thread_xp_AcquireSRWLockShared (gpointer mutex)
{
GThreadSRWLock *lock = g_thread_xp_get_srwlock (mutex);
EnterCriticalSection (&lock->writer_lock);
/* See g_thread_xp_AcquireSRWLockExclusive */
g_assert (!lock->writer_locked);
g_thread_xp_srwlock_become_reader (lock);
LeaveCriticalSection (&lock->writer_lock);
}
static BOOLEAN __stdcall
g_thread_xp_TryAcquireSRWLockShared (gpointer mutex)
{
GThreadSRWLock *lock = g_thread_xp_get_srwlock (mutex);
if (!TryEnterCriticalSection (&lock->writer_lock))
return FALSE;
/* See g_thread_xp_AcquireSRWLockExclusive */
if G_UNLIKELY (lock->writer_locked)
{
LeaveCriticalSection (&lock->writer_lock);
return FALSE;
}
g_thread_xp_srwlock_become_reader (lock);
LeaveCriticalSection (&lock->writer_lock);
return TRUE;
}
static void __stdcall
g_thread_xp_ReleaseSRWLockShared (gpointer mutex)
{
GThreadSRWLock *lock = g_thread_xp_get_srwlock (mutex);
EnterCriticalSection (&lock->atomicity);
lock->num_readers--;
if (lock->num_readers == 0 && lock->queued_writer)
SetEvent (lock->queued_writer->event);
LeaveCriticalSection (&lock->atomicity);
}
/* {{{2 CONDITION_VARIABLE emulation */
typedef struct
{
volatile GThreadXpWaiter *first;
volatile GThreadXpWaiter **last_ptr;
} GThreadXpCONDITION_VARIABLE;
static void __stdcall
g_thread_xp_InitializeConditionVariable (gpointer cond)
{
*(GThreadXpCONDITION_VARIABLE * volatile *) cond = NULL;
}
static void __stdcall
g_thread_xp_DeleteConditionVariable (gpointer cond)
{
GThreadXpCONDITION_VARIABLE *cv = *(GThreadXpCONDITION_VARIABLE * volatile *) cond;
if (cv)
free (cv);
}
static GThreadXpCONDITION_VARIABLE * __stdcall
g_thread_xp_get_condition_variable (GThreadXpCONDITION_VARIABLE * volatile *cond)
{
GThreadXpCONDITION_VARIABLE *result;
/* It looks like we're missing some barriers here, but this code only
* ever runs on Windows XP, which in turn only ever runs on hardware
* with a relatively rigid memory model. The 'volatile' will take
* care of the compiler.
*/
result = *cond;
if G_UNLIKELY (result == NULL)
{
result = malloc (sizeof (GThreadXpCONDITION_VARIABLE));
if (result == NULL)
g_thread_abort (errno, "malloc");
result->first = NULL;
result->last_ptr = &result->first;
if (InterlockedCompareExchangePointer (cond, result, NULL) != NULL)
{
free (result);
result = *cond;
}
}
return result;
}
static BOOL __stdcall
g_thread_xp_SleepConditionVariableSRW (gpointer cond,
gpointer mutex,
DWORD timeout,
ULONG flags)
{
GThreadXpCONDITION_VARIABLE *cv = g_thread_xp_get_condition_variable (cond);
GThreadXpWaiter *waiter = g_thread_xp_waiter_get ();
DWORD status;
waiter->next = NULL;
EnterCriticalSection (&g_thread_xp_lock);
waiter->my_owner = cv->last_ptr;
*cv->last_ptr = waiter;
cv->last_ptr = &waiter->next;
LeaveCriticalSection (&g_thread_xp_lock);
g_mutex_unlock (mutex);
status = WaitForSingleObject (waiter->event, timeout);
if (status != WAIT_TIMEOUT && status != WAIT_OBJECT_0)
g_thread_abort (GetLastError (), "WaitForSingleObject");
g_mutex_lock (mutex);
if (status == WAIT_TIMEOUT)
{
EnterCriticalSection (&g_thread_xp_lock);
if (waiter->my_owner)
{
if (waiter->next)
waiter->next->my_owner = waiter->my_owner;
else
cv->last_ptr = waiter->my_owner;
*waiter->my_owner = waiter->next;
waiter->my_owner = NULL;
}
LeaveCriticalSection (&g_thread_xp_lock);
}
return status == WAIT_OBJECT_0;
}
static void __stdcall
g_thread_xp_WakeConditionVariable (gpointer cond)
{
GThreadXpCONDITION_VARIABLE *cv = g_thread_xp_get_condition_variable (cond);
volatile GThreadXpWaiter *waiter;
EnterCriticalSection (&g_thread_xp_lock);
waiter = cv->first;
if (waiter != NULL)
{
waiter->my_owner = NULL;
cv->first = waiter->next;
if (cv->first != NULL)
cv->first->my_owner = &cv->first;
else
cv->last_ptr = &cv->first;
}
if (waiter != NULL)
SetEvent (waiter->event);
LeaveCriticalSection (&g_thread_xp_lock);
}
static void __stdcall
g_thread_xp_WakeAllConditionVariable (gpointer cond)
{
GThreadXpCONDITION_VARIABLE *cv = g_thread_xp_get_condition_variable (cond);
volatile GThreadXpWaiter *waiter;
EnterCriticalSection (&g_thread_xp_lock);
waiter = cv->first;
cv->first = NULL;
cv->last_ptr = &cv->first;
while (waiter != NULL)
{
volatile GThreadXpWaiter *next;
next = waiter->next;
SetEvent (waiter->event);
waiter->my_owner = NULL;
waiter = next;
}
LeaveCriticalSection (&g_thread_xp_lock);
}
/* {{{2 XP Setup */
static void
g_thread_xp_init (void)
{
static const GThreadImplVtable g_thread_xp_impl_vtable = {
g_thread_xp_CallThisOnThreadExit,
g_thread_xp_InitializeSRWLock,
g_thread_xp_DeleteSRWLock,
g_thread_xp_AcquireSRWLockExclusive,
g_thread_xp_TryAcquireSRWLockExclusive,
g_thread_xp_ReleaseSRWLockExclusive,
g_thread_xp_AcquireSRWLockShared,
g_thread_xp_TryAcquireSRWLockShared,
g_thread_xp_ReleaseSRWLockShared,
g_thread_xp_InitializeConditionVariable,
g_thread_xp_DeleteConditionVariable,
g_thread_xp_SleepConditionVariableSRW,
g_thread_xp_WakeAllConditionVariable,
g_thread_xp_WakeConditionVariable
};
InitializeCriticalSection (&g_thread_xp_lock);
g_thread_xp_waiter_tls = TlsAlloc ();
g_thread_impl_vtable = g_thread_xp_impl_vtable;
}
/* {{{1 Epilogue */ /* {{{1 Epilogue */
static gboolean
g_thread_lookup_native_funcs (void)
{
GThreadImplVtable native_vtable = { 0, };
HMODULE kernel32;
kernel32 = GetModuleHandle ("KERNEL32.DLL");
if (kernel32 == NULL)
return FALSE;
#define GET_FUNC(name) if ((native_vtable.name = (void *) GetProcAddress (kernel32, #name)) == NULL) return FALSE
GET_FUNC(InitializeSRWLock);
GET_FUNC(AcquireSRWLockExclusive);
GET_FUNC(TryAcquireSRWLockExclusive);
GET_FUNC(ReleaseSRWLockExclusive);
GET_FUNC(AcquireSRWLockShared);
GET_FUNC(TryAcquireSRWLockShared);
GET_FUNC(ReleaseSRWLockShared);
GET_FUNC(InitializeConditionVariable);
GET_FUNC(SleepConditionVariableSRW);
GET_FUNC(WakeAllConditionVariable);
GET_FUNC(WakeConditionVariable);
#undef GET_FUNC
g_thread_impl_vtable = native_vtable;
return TRUE;
}
void void
g_thread_win32_init (void) g_thread_win32_init (void)
{ {
if (!g_thread_lookup_native_funcs ())
g_thread_xp_init ();
InitializeCriticalSection (&g_private_lock); InitializeCriticalSection (&g_private_lock);
#ifndef _MSC_VER #ifndef _MSC_VER
@ -1109,9 +580,6 @@ g_thread_win32_thread_detach (void)
} }
} }
while (dtors_called); while (dtors_called);
if (g_thread_impl_vtable.CallThisOnThreadExit)
g_thread_impl_vtable.CallThisOnThreadExit ();
} }
void void