Sweden-Number/dlls/ntdll/critsection.c

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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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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>
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#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);
inline static LONG interlocked_inc( PLONG dest )
{
return interlocked_xchg_add( (int *)dest, 1 ) + 1;
}
inline static LONG interlocked_dec( PLONG dest )
{
return interlocked_xchg_add( (int *)dest, -1 ) - 1;
}
inline static 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;
}
#else /* linux */
static inline int futex_wait( int *addr, int val, struct timespec *timeout ) { return -ENOSYS; }
static inline int futex_wake( int *addr, int val ) { return -ENOSYS; }
static inline int use_futexes(void) { return 0; }
#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 = (HANDLE)interlocked_cmpxchg_ptr( (PVOID *)&crit->LockSemaphore,
(PVOID)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 )
{
if (use_futexes() && crit->DebugInfo) /* debug info is cleared by MakeCriticalSectionGlobal */
{
int val;
struct timespec timespec;
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;
}
else
{
HANDLE sem = get_semaphore( crit );
LARGE_INTEGER time;
time.QuadPart = timeout * (LONGLONG)-10000000;
return NtWaitForSingleObject( sem, FALSE, &time );
}
}
/***********************************************************************
* RtlInitializeCriticalSection (NTDLL.@)
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*
* Initialises a new critical section.
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*
* PARAMS
* crit [O] Critical section to initialise
*
* RETURNS
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* STATUS_SUCCESS.
*
* SEE
* RtlInitializeCriticalSectionAndSpinCount(), RtlDeleteCriticalSection(),
* RtlEnterCriticalSection(), RtlLeaveCriticalSection(),
* RtlTryEnterCriticalSection(), RtlSetCriticalSectionSpinCount()
*/
NTSTATUS WINAPI RtlInitializeCriticalSection( RTL_CRITICAL_SECTION *crit )
{
return RtlInitializeCriticalSectionAndSpinCount( crit, 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
* RtlInitializeCriticalSection(), RtlDeleteCriticalSection(),
* RtlEnterCriticalSection(), RtlLeaveCriticalSection(),
* RtlTryEnterCriticalSection(), RtlSetCriticalSectionSpinCount()
*/
NTSTATUS WINAPI RtlInitializeCriticalSectionAndSpinCount( RTL_CRITICAL_SECTION *crit, ULONG spincount )
{
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;
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if (NtCurrentTeb()->Peb->NumberOfProcessors <= 1) spincount = 0;
crit->SpinCount = spincount & ~0x80000000;
return STATUS_SUCCESS;
}
/***********************************************************************
* RtlSetCriticalSectionSpinCount (NTDLL.@)
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*
* Sets the spin count of a critical section.
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*
* PARAMS
* crit [I/O] Critical section
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* spincount [I] Spin count for crit
*
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* RETURNS
* The previous spin count.
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*
* NOTES
* If the system is not SMP, spincount is ignored and set to 0.
*
* SEE
* 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.@)
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*
* Frees the resources used by a critical section.
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*
* PARAMS
* crit [I/O] Critical section to free
*
* RETURNS
* STATUS_SUCCESS.
*
* SEE
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlEnterCriticalSection(),
* RtlLeaveCriticalSection(), RtlTryEnterCriticalSection()
*/
NTSTATUS WINAPI RtlDeleteCriticalSection( RTL_CRITICAL_SECTION *crit )
{
crit->LockCount = -1;
crit->RecursionCount = 0;
crit->OwningThread = 0;
if (crit->LockSemaphore) NtClose( crit->LockSemaphore );
crit->LockSemaphore = 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;
}
}
return STATUS_SUCCESS;
}
/***********************************************************************
* RtlpWaitForCriticalSection (NTDLL.@)
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*
* Waits for a busy critical section to become free.
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*
* 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
* 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];
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if (!name) name = "?";
ERR( "section %p %s wait timed out in thread %04lx, blocked by %04lx, retrying (60 sec)\n",
crit, debugstr_a(name), GetCurrentThreadId(), (DWORD)crit->OwningThread );
status = wait_semaphore( crit, 60 );
if ( status == STATUS_TIMEOUT && TRACE_ON(relay) )
{
ERR( "section %p %s wait timed out in thread %04lx, blocked by %04lx, retrying (5 min)\n",
crit, debugstr_a(name), GetCurrentThreadId(), (DWORD) 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
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlEnterCriticalSection(),
* RtlLeaveCriticalSection(), RtlTryEnterCriticalSection()
*/
NTSTATUS WINAPI RtlpUnWaitCriticalSection( RTL_CRITICAL_SECTION *crit )
{
if (use_futexes() && crit->DebugInfo) /* debug info is cleared by MakeCriticalSectionGlobal */
{
*(int *)&crit->LockSemaphore = 1;
futex_wake( (int *)&crit->LockSemaphore, 1 );
return STATUS_SUCCESS;
}
else
{
HANDLE sem = get_semaphore( crit );
NTSTATUS res = NtReleaseSemaphore( sem, 1, NULL );
if (res) RtlRaiseStatus( res );
return res;
}
}
/***********************************************************************
* RtlEnterCriticalSection (NTDLL.@)
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*
* Enters a critical section, waiting for it to become available if necessary.
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*
* PARAMS
* crit [I/O] Critical section to enter
*
* RETURNS
* STATUS_SUCCESS. The critical section is held by the caller.
*
* SEE
* 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( (int *)&crit->LockCount, 0, -1 ) == -1) goto done;
}
small_pause();
}
}
if (interlocked_inc( &crit->LockCount ))
{
if (crit->OwningThread == (HANDLE)GetCurrentThreadId())
{
crit->RecursionCount++;
return STATUS_SUCCESS;
}
/* Now wait for it */
RtlpWaitForCriticalSection( crit );
}
done:
crit->OwningThread = (HANDLE)GetCurrentThreadId();
crit->RecursionCount = 1;
return STATUS_SUCCESS;
}
/***********************************************************************
* RtlTryEnterCriticalSection (NTDLL.@)
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*
* Tries to enter a critical section without waiting.
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*
* 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
* RtlInitializeCriticalSection(), RtlInitializeCriticalSectionAndSpinCount(),
* RtlDeleteCriticalSection(), RtlEnterCriticalSection(),
* RtlLeaveCriticalSection(), RtlSetCriticalSectionSpinCount()
*/
BOOL WINAPI RtlTryEnterCriticalSection( RTL_CRITICAL_SECTION *crit )
{
BOOL ret = FALSE;
if (interlocked_cmpxchg( (int *)&crit->LockCount, 0, -1 ) == -1)
{
crit->OwningThread = (HANDLE)GetCurrentThreadId();
crit->RecursionCount = 1;
ret = TRUE;
}
else if (crit->OwningThread == (HANDLE)GetCurrentThreadId())
{
interlocked_inc( &crit->LockCount );
crit->RecursionCount++;
ret = TRUE;
}
return ret;
}
/***********************************************************************
* RtlLeaveCriticalSection (NTDLL.@)
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*
* Leaves a critical section.
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*
* PARAMS
* crit [I/O] Critical section to leave.
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*
* RETURNS
* STATUS_SUCCESS.
*
* SEE
* 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;
}