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/*
* Win32 critical sections
*
* Copyright 1998 Alexandre Julliard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include "config.h"
#include "wine/port.h"
#include <assert.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/types.h>
#include <time.h>
#include "ntstatus.h"
#define WIN32_NO_STATUS
#include "windef.h"
#include "winternl.h"
#include "wine/debug.h"
#include "ntdll_misc.h"
WINE_DEFAULT_DEBUG_CHANNEL(ntdll);
WINE_DECLARE_DEBUG_CHANNEL(relay);
static inline LONG interlocked_inc( PLONG dest )
{
return interlocked_xchg_add( dest, 1 ) + 1;
}
static inline LONG interlocked_dec( PLONG dest )
{
return interlocked_xchg_add( dest, -1 ) - 1;
}
static inline void small_pause(void)
{
#ifdef __i386__
__asm__ __volatile__( "rep;nop" : : : "memory" );
#else
__asm__ __volatile__( "" : : : "memory" );
#endif
}
#if defined(linux) && defined(__i386__)
static inline int futex_wait( int *addr, int val, struct timespec *timeout )
{
int res;
__asm__ __volatile__( "xchgl %2,%%ebx\n\t"
"int $0x80\n\t"
"xchgl %2,%%ebx"
: "=a" (res)
: "0" (240) /* SYS_futex */, "D" (addr),
"c" (0) /* FUTEX_WAIT */, "d" (val), "S" (timeout) );
return res;
}
static inline int futex_wake( int *addr, int val )
{
int res;
__asm__ __volatile__( "xchgl %2,%%ebx\n\t"
"int $0x80\n\t"
"xchgl %2,%%ebx"
: "=a" (res)
: "0" (240) /* SYS_futex */, "D" (addr),
"c" (1) /* FUTEX_WAKE */, "d" (val) );
return res;
}
static inline int use_futexes(void)
{
static int supported = -1;
if (supported == -1) supported = (futex_wait( &supported, 10, NULL ) != -ENOSYS);
return supported;
}
static inline NTSTATUS fast_wait( RTL_CRITICAL_SECTION *crit, int timeout )
{
int val;
struct timespec timespec;
if (!use_futexes()) return STATUS_NOT_IMPLEMENTED;
timespec.tv_sec = timeout;
timespec.tv_nsec = 0;
while ((val = interlocked_cmpxchg( (int *)&crit->LockSemaphore, 0, 1 )) != 1)
{
/* note: this may wait longer than specified in case of signals or */
/* multiple wake-ups, but that shouldn't be a problem */
if (futex_wait( (int *)&crit->LockSemaphore, val, &timespec ) == -ETIMEDOUT)
return STATUS_TIMEOUT;
}
return STATUS_WAIT_0;
}
static inline NTSTATUS fast_wake( RTL_CRITICAL_SECTION *crit )
{
if (!use_futexes()) return STATUS_NOT_IMPLEMENTED;
*(int *)&crit->LockSemaphore = 1;
futex_wake( (int *)&crit->LockSemaphore, 1 );
return STATUS_SUCCESS;
}
static inline void close_semaphore( RTL_CRITICAL_SECTION *crit )
{
if (!use_futexes()) NtClose( crit->LockSemaphore );
}
#elif defined(__APPLE__)
#include <mach/mach.h>
#include <mach/task.h>
#include <mach/semaphore.h>
static inline semaphore_t get_mach_semaphore( RTL_CRITICAL_SECTION *crit )
{
semaphore_t ret = *(int *)&crit->LockSemaphore;
if (!ret)
{
semaphore_t sem;
if (semaphore_create( mach_task_self(), &sem, SYNC_POLICY_FIFO, 0 )) return 0;
if (!(ret = interlocked_cmpxchg( (int *)&crit->LockSemaphore, sem, 0 )))
ret = sem;
else
semaphore_destroy( mach_task_self(), sem ); /* somebody beat us to it */
}
return ret;
}
static inline NTSTATUS fast_wait( RTL_CRITICAL_SECTION *crit, int timeout )
{
mach_timespec_t timespec;
semaphore_t sem = get_mach_semaphore( crit );
timespec.tv_sec = timeout;
timespec.tv_nsec = 0;
for (;;)
{
switch( semaphore_timedwait( sem, timespec ))
{
case KERN_SUCCESS:
return STATUS_WAIT_0;
case KERN_ABORTED:
continue; /* got a signal, restart */
case KERN_OPERATION_TIMED_OUT:
return STATUS_TIMEOUT;
default:
return STATUS_INVALID_HANDLE;
}
}
}
static inline NTSTATUS fast_wake( RTL_CRITICAL_SECTION *crit )
{
semaphore_t sem = get_mach_semaphore( crit );
semaphore_signal( sem );
return STATUS_SUCCESS;
}
static inline void close_semaphore( RTL_CRITICAL_SECTION *crit )
{
semaphore_destroy( mach_task_self(), *(int *)&crit->LockSemaphore );
}
#else /* __APPLE__ */
static inline NTSTATUS fast_wait( RTL_CRITICAL_SECTION *crit, int timeout )
{
return STATUS_NOT_IMPLEMENTED;
}
static inline NTSTATUS fast_wake( RTL_CRITICAL_SECTION *crit )
{
return STATUS_NOT_IMPLEMENTED;
}
static inline void close_semaphore( RTL_CRITICAL_SECTION *crit )
{
NtClose( crit->LockSemaphore );
}
#endif
/***********************************************************************
* get_semaphore
*/
static inline HANDLE get_semaphore( RTL_CRITICAL_SECTION *crit )
{
HANDLE ret = crit->LockSemaphore;
if (!ret)
{
HANDLE sem;
if (NtCreateSemaphore( &sem, SEMAPHORE_ALL_ACCESS, NULL, 0, 1 )) return 0;
if (!(ret = interlocked_cmpxchg_ptr( &crit->LockSemaphore, sem, 0 )))
ret = sem;
else
NtClose(sem); /* somebody beat us to it */
}
return ret;
}
/***********************************************************************
* wait_semaphore
*/
static inline NTSTATUS wait_semaphore( RTL_CRITICAL_SECTION *crit, int timeout )
{
NTSTATUS ret;
/* debug info is cleared by MakeCriticalSectionGlobal */
if (!crit->DebugInfo || ((ret = fast_wait( crit, timeout )) == STATUS_NOT_IMPLEMENTED))
{
HANDLE sem = get_semaphore( crit );
LARGE_INTEGER time;
time.QuadPart = timeout * (LONGLONG)-10000000;
ret = NTDLL_wait_for_multiple_objects( 1, &sem, 0, &time, 0 );
}
return ret;
}
/***********************************************************************
* RtlInitializeCriticalSection (NTDLL.@)
*
* Initialises a new critical section.
*
* PARAMS
* crit [O] Critical section to initialise
*
* RETURNS
* STATUS_SUCCESS.
*
* SEE
* RtlInitializeCriticalSectionEx(),
* RtlInitializeCriticalSectionAndSpinCount(), RtlDeleteCriticalSection(),
* RtlEnterCriticalSection(), RtlLeaveCriticalSection(),
* RtlTryEnterCriticalSection(), RtlSetCriticalSectionSpinCount()
*/
NTSTATUS WINAPI RtlInitializeCriticalSection( RTL_CRITICAL_SECTION *crit )
{
return RtlInitializeCriticalSectionEx( crit, 0, 0 );
}
/***********************************************************************
* RtlInitializeCriticalSectionAndSpinCount (NTDLL.@)
*
* Initialises a new critical section with a given spin count.
*
* PARAMS
* crit [O] Critical section to initialise
* spincount [I] Spin count for crit
*
* RETURNS
* STATUS_SUCCESS.
*
* NOTES
* Available on NT4 SP3 or later.
*
* SEE
* RtlInitializeCriticalSectionEx(),
* RtlInitializeCriticalSection(), RtlDeleteCriticalSection(),
* RtlEnterCriticalSection(), RtlLeaveCriticalSection(),
* RtlTryEnterCriticalSection(), RtlSetCriticalSectionSpinCount()
*/
NTSTATUS WINAPI RtlInitializeCriticalSectionAndSpinCount( RTL_CRITICAL_SECTION *crit, ULONG spincount )
{
return RtlInitializeCriticalSectionEx( crit, spincount, 0 );
}
/***********************************************************************
* RtlInitializeCriticalSectionEx (NTDLL.@)
*
* Initialises a new critical section with a given spin count and flags.
*
* PARAMS
* crit [O] Critical section to initialise.
* spincount [I] Number of times to spin upon contention.
* flags [I] RTL_CRITICAL_SECTION_FLAG_ flags from winnt.h.
*
* RETURNS
* STATUS_SUCCESS.
*
* NOTES
* Available on Vista or later.
*
* SEE
* RtlInitializeCriticalSection(), RtlDeleteCriticalSection(),
* RtlEnterCriticalSection(), RtlLeaveCriticalSection(),
* RtlTryEnterCriticalSection(), RtlSetCriticalSectionSpinCount()
*/
NTSTATUS WINAPI RtlInitializeCriticalSectionEx( RTL_CRITICAL_SECTION *crit, ULONG spincount, ULONG flags )
{
if (flags & (RTL_CRITICAL_SECTION_FLAG_DYNAMIC_SPIN|RTL_CRITICAL_SECTION_FLAG_STATIC_INIT))
FIXME("(%p,%u,0x%08x) semi-stub\n", crit, spincount, flags);
/* FIXME: if RTL_CRITICAL_SECTION_FLAG_STATIC_INIT is given, we should use
* memory from a static pool to hold the debug info. Then heap.c could pass
* this flag rather than initialising the process heap CS by hand. If this
* is done, then debug info should be managed through Rtlp[Allocate|Free]DebugInfo
* so (e.g.) MakeCriticalSectionGlobal() doesn't free it using HeapFree().
*/
if (flags & RTL_CRITICAL_SECTION_FLAG_NO_DEBUG_INFO)
crit->DebugInfo = NULL;
else
crit->DebugInfo = RtlAllocateHeap(GetProcessHeap(), 0, sizeof(RTL_CRITICAL_SECTION_DEBUG));
if (crit->DebugInfo)
{
crit->DebugInfo->Type = 0;
crit->DebugInfo->CreatorBackTraceIndex = 0;
crit->DebugInfo->CriticalSection = crit;
crit->DebugInfo->ProcessLocksList.Blink = &(crit->DebugInfo->ProcessLocksList);
crit->DebugInfo->ProcessLocksList.Flink = &(crit->DebugInfo->ProcessLocksList);
crit->DebugInfo->EntryCount = 0;
crit->DebugInfo->ContentionCount = 0;
memset( crit->DebugInfo->Spare, 0, sizeof(crit->DebugInfo->Spare) );
}
crit->LockCount = -1;
crit->RecursionCount = 0;
crit->OwningThread = 0;
crit->LockSemaphore = 0;
if (NtCurrentTeb()->Peb->NumberOfProcessors <= 1) spincount = 0;
crit->SpinCount = spincount & ~0x80000000;
return STATUS_SUCCESS;
}
/***********************************************************************
* RtlSetCriticalSectionSpinCount (NTDLL.@)
*
* Sets the spin count of a critical section.
*
* PARAMS
* crit [I/O] Critical section
* spincount [I] Spin count for crit
*
* RETURNS
* The previous spin count.
*
* NOTES
* If the system is not SMP, spincount is ignored and set to 0.
*
* SEE
* RtlInitializeCriticalSectionEx(),
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlEnterCriticalSection(),
* RtlLeaveCriticalSection(), RtlTryEnterCriticalSection()
*/
ULONG WINAPI RtlSetCriticalSectionSpinCount( RTL_CRITICAL_SECTION *crit, ULONG spincount )
{
ULONG oldspincount = crit->SpinCount;
if (NtCurrentTeb()->Peb->NumberOfProcessors <= 1) spincount = 0;
crit->SpinCount = spincount;
return oldspincount;
}
/***********************************************************************
* RtlDeleteCriticalSection (NTDLL.@)
*
* Frees the resources used by a critical section.
*
* PARAMS
* crit [I/O] Critical section to free
*
* RETURNS
* STATUS_SUCCESS.
*
* SEE
* RtlInitializeCriticalSectionEx(),
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlEnterCriticalSection(),
* RtlLeaveCriticalSection(), RtlTryEnterCriticalSection()
*/
NTSTATUS WINAPI RtlDeleteCriticalSection( RTL_CRITICAL_SECTION *crit )
{
crit->LockCount = -1;
crit->RecursionCount = 0;
crit->OwningThread = 0;
if (crit->DebugInfo)
{
/* only free the ones we made in here */
if (!crit->DebugInfo->Spare[0])
{
RtlFreeHeap( GetProcessHeap(), 0, crit->DebugInfo );
crit->DebugInfo = NULL;
}
close_semaphore( crit );
}
else NtClose( crit->LockSemaphore );
crit->LockSemaphore = 0;
return STATUS_SUCCESS;
}
/***********************************************************************
* RtlpWaitForCriticalSection (NTDLL.@)
*
* Waits for a busy critical section to become free.
*
* PARAMS
* crit [I/O] Critical section to wait for
*
* RETURNS
* STATUS_SUCCESS.
*
* NOTES
* Use RtlEnterCriticalSection() instead of this function as it is often much
* faster.
*
* SEE
* RtlInitializeCriticalSectionEx(),
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlEnterCriticalSection(),
* RtlLeaveCriticalSection(), RtlTryEnterCriticalSection()
*/
NTSTATUS WINAPI RtlpWaitForCriticalSection( RTL_CRITICAL_SECTION *crit )
{
for (;;)
{
EXCEPTION_RECORD rec;
NTSTATUS status = wait_semaphore( crit, 5 );
if ( status == STATUS_TIMEOUT )
{
const char *name = NULL;
if (crit->DebugInfo) name = (char *)crit->DebugInfo->Spare[0];
if (!name) name = "?";
ERR( "section %p %s wait timed out in thread %04x, blocked by %04x, retrying (60 sec)\n",
crit, debugstr_a(name), GetCurrentThreadId(), HandleToULong(crit->OwningThread) );
status = wait_semaphore( crit, 60 );
if ( status == STATUS_TIMEOUT && TRACE_ON(relay) )
{
ERR( "section %p %s wait timed out in thread %04x, blocked by %04x, retrying (5 min)\n",
crit, debugstr_a(name), GetCurrentThreadId(), HandleToULong(crit->OwningThread) );
status = wait_semaphore( crit, 300 );
}
}
if (status == STATUS_WAIT_0) break;
/* Throw exception only for Wine internal locks */
if ((!crit->DebugInfo) || (!crit->DebugInfo->Spare[0])) continue;
rec.ExceptionCode = STATUS_POSSIBLE_DEADLOCK;
rec.ExceptionFlags = 0;
rec.ExceptionRecord = NULL;
rec.ExceptionAddress = RtlRaiseException; /* sic */
rec.NumberParameters = 1;
rec.ExceptionInformation[0] = (ULONG_PTR)crit;
RtlRaiseException( &rec );
}
if (crit->DebugInfo) crit->DebugInfo->ContentionCount++;
return STATUS_SUCCESS;
}
/***********************************************************************
* RtlpUnWaitCriticalSection (NTDLL.@)
*
* Notifies other threads waiting on the busy critical section that it has
* become free.
*
* PARAMS
* crit [I/O] Critical section
*
* RETURNS
* Success: STATUS_SUCCESS.
* Failure: Any error returned by NtReleaseSemaphore()
*
* NOTES
* Use RtlLeaveCriticalSection() instead of this function as it is often much
* faster.
*
* SEE
* RtlInitializeCriticalSectionEx(),
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlEnterCriticalSection(),
* RtlLeaveCriticalSection(), RtlTryEnterCriticalSection()
*/
NTSTATUS WINAPI RtlpUnWaitCriticalSection( RTL_CRITICAL_SECTION *crit )
{
NTSTATUS ret;
/* debug info is cleared by MakeCriticalSectionGlobal */
if (!crit->DebugInfo || ((ret = fast_wake( crit )) == STATUS_NOT_IMPLEMENTED))
{
HANDLE sem = get_semaphore( crit );
ret = NtReleaseSemaphore( sem, 1, NULL );
}
if (ret) RtlRaiseStatus( ret );
return ret;
}
/***********************************************************************
* RtlEnterCriticalSection (NTDLL.@)
*
* Enters a critical section, waiting for it to become available if necessary.
*
* PARAMS
* crit [I/O] Critical section to enter
*
* RETURNS
* STATUS_SUCCESS. The critical section is held by the caller.
*
* SEE
* RtlInitializeCriticalSectionEx(),
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlSetCriticalSectionSpinCount(),
* RtlLeaveCriticalSection(), RtlTryEnterCriticalSection()
*/
NTSTATUS WINAPI RtlEnterCriticalSection( RTL_CRITICAL_SECTION *crit )
{
if (crit->SpinCount)
{
ULONG count;
if (RtlTryEnterCriticalSection( crit )) return STATUS_SUCCESS;
for (count = crit->SpinCount; count > 0; count--)
{
if (crit->LockCount > 0) break; /* more than one waiter, don't bother spinning */
if (crit->LockCount == -1) /* try again */
{
if (interlocked_cmpxchg( &crit->LockCount, 0, -1 ) == -1) goto done;
}
small_pause();
}
}
if (interlocked_inc( &crit->LockCount ))
{
if (crit->OwningThread == ULongToHandle(GetCurrentThreadId()))
{
crit->RecursionCount++;
return STATUS_SUCCESS;
}
/* Now wait for it */
RtlpWaitForCriticalSection( crit );
}
done:
crit->OwningThread = ULongToHandle(GetCurrentThreadId());
crit->RecursionCount = 1;
return STATUS_SUCCESS;
}
/***********************************************************************
* RtlTryEnterCriticalSection (NTDLL.@)
*
* Tries to enter a critical section without waiting.
*
* PARAMS
* crit [I/O] Critical section to enter
*
* RETURNS
* Success: TRUE. The critical section is held by the caller.
* Failure: FALSE. The critical section is currently held by another thread.
*
* SEE
* RtlInitializeCriticalSectionEx(),
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlEnterCriticalSection(),
* RtlLeaveCriticalSection(), RtlSetCriticalSectionSpinCount()
*/
BOOL WINAPI RtlTryEnterCriticalSection( RTL_CRITICAL_SECTION *crit )
{
BOOL ret = FALSE;
if (interlocked_cmpxchg( &crit->LockCount, 0, -1 ) == -1)
{
crit->OwningThread = ULongToHandle(GetCurrentThreadId());
crit->RecursionCount = 1;
ret = TRUE;
}
else if (crit->OwningThread == ULongToHandle(GetCurrentThreadId()))
{
interlocked_inc( &crit->LockCount );
crit->RecursionCount++;
ret = TRUE;
}
return ret;
}
/***********************************************************************
* RtlLeaveCriticalSection (NTDLL.@)
*
* Leaves a critical section.
*
* PARAMS
* crit [I/O] Critical section to leave.
*
* RETURNS
* STATUS_SUCCESS.
*
* SEE
* RtlInitializeCriticalSectionEx(),
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlEnterCriticalSection(),
* RtlSetCriticalSectionSpinCount(), RtlTryEnterCriticalSection()
*/
NTSTATUS WINAPI RtlLeaveCriticalSection( RTL_CRITICAL_SECTION *crit )
{
if (--crit->RecursionCount) interlocked_dec( &crit->LockCount );
else
{
crit->OwningThread = 0;
if (interlocked_dec( &crit->LockCount ) >= 0)
{
/* someone is waiting */
RtlpUnWaitCriticalSection( crit );
}
}
return STATUS_SUCCESS;
}