reactos/ntoskrnl/include/internal/spinlock.h

   1 /*
   2 * PROJECT:         ReactOS Kernel
   3 * LICENSE:         GPL - See COPYING in the top level directory
   4 * FILE:            ntoskrnl/include/spinlock.h
   5 * PURPOSE:         Internal Inlined Functions for spinlocks, shared with HAL
   6 * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
   7 */
   8
   9 VOID
  10 NTAPI
  11 Kii386SpinOnSpinLock(PKSPIN_LOCK SpinLock, ULONG Flags);
  12
  13 #ifndef CONFIG_SMP
  14
  15 //
  16 // Spinlock Acquire at IRQL >= DISPATCH_LEVEL
  17 //
  18 FORCEINLINE
  19 VOID
  20 KxAcquireSpinLock(IN PKSPIN_LOCK SpinLock)
  21 {
  22     /* On UP builds, spinlocks don't exist at IRQL >= DISPATCH */
  23     UNREFERENCED_PARAMETER(SpinLock);
  24 }
  25
  26 //
  27 // Spinlock Release at IRQL >= DISPATCH_LEVEL
  28 //
  29 FORCEINLINE
  30 VOID
  31 KxReleaseSpinLock(IN PKSPIN_LOCK SpinLock)
  32 {
  33     /* On UP builds, spinlocks don't exist at IRQL >= DISPATCH */
  34     UNREFERENCED_PARAMETER(SpinLock);
  35 }
  36
  37 #else
  38
  39 //
  40 // Spinlock Acquisition at IRQL >= DISPATCH_LEVEL
  41 //
  42 FORCEINLINE
  43 VOID
  44 KxAcquireSpinLock(IN PKSPIN_LOCK SpinLock)
  45 {
  46 #ifdef DBG
  47     /* Make sure that we don't own the lock already */
  48     if (((KSPIN_LOCK)KeGetCurrentThread() | 1) == *SpinLock)
  49     {
  50         /* We do, bugcheck! */
  51         KeBugCheckEx(SPIN_LOCK_ALREADY_OWNED, (ULONG_PTR)SpinLock, 0, 0, 0);
  52     }
  53 #endif
  54
  55     /* Try to acquire the lock */
  56     while (InterlockedBitTestAndSet((PLONG)SpinLock, 0))
  57     {
  58 #if defined(_M_IX86) && defined(DBG)
  59         /* On x86 debug builds, we use a much slower but useful routine */
  60         Kii386SpinOnSpinLock(SpinLock, 5);
  61 #else
  62         /* It's locked... spin until it's unlocked */
  63         while (*(volatile KSPIN_LOCK *)SpinLock & 1)
  64         {
  65                 /* Yield and keep looping */
  66                 YieldProcessor();
  67         }
  68 #endif
  69     }
  70 #ifdef DBG
  71     /* On debug builds, we OR in the KTHREAD */
  72     *SpinLock = (KSPIN_LOCK)KeGetCurrentThread() | 1;
  73 #endif
  74 }
  75
  76 //
  77 // Spinlock Release at IRQL >= DISPATCH_LEVEL
  78 //
  79 FORCEINLINE
  80 VOID
  81 KxReleaseSpinLock(IN PKSPIN_LOCK SpinLock)
  82 {
  83 #if DBG
  84     /* Make sure that the threads match */
  85     if (((KSPIN_LOCK)KeGetCurrentThread() | 1) != *SpinLock)
  86     {
  87         /* They don't, bugcheck */
  88         KeBugCheckEx(SPIN_LOCK_NOT_OWNED, (ULONG_PTR)SpinLock, 0, 0, 0);
  89     }
  90 #endif
  91     /* Clear the lock */
  92     InterlockedAnd((PLONG)SpinLock, 0);
  93 }
  94
  95 #endif