dlls/ntdll/critsection.c

   1 /*
   2  * Win32 critical sections
   3  *
   4  * Copyright 1998 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <errno.h>
  26 #include <stdio.h>
  27 #include <sys/types.h>
  28 #include "winerror.h"
  29 #include "ntddk.h"
  30 #include "wine/debug.h"
  31
  32 WINE_DEFAULT_DEBUG_CHANNEL(ntdll);
  33 WINE_DECLARE_DEBUG_CHANNEL(relay);
  34
  35 inline static LONG interlocked_inc( PLONG dest )
  36 {
  37     return interlocked_xchg_add( dest, 1 ) + 1;
  38 }
  39
  40 inline static LONG interlocked_dec( PLONG dest )
  41 {
  42     return interlocked_xchg_add( dest, -1 ) - 1;
  43 }
  44
  45 /***********************************************************************
  46  *           get_semaphore
  47  */
  48 static inline HANDLE get_semaphore( RTL_CRITICAL_SECTION *crit )
  49 {
  50     HANDLE ret = crit->LockSemaphore;
  51     if (!ret)
  52     {
  53         HANDLE sem;
  54         if (NtCreateSemaphore( &sem, SEMAPHORE_ALL_ACCESS, NULL, 0, 1 )) return 0;
  55         if (!(ret = (HANDLE)interlocked_cmpxchg_ptr( (PVOID *)&crit->LockSemaphore,
  56                                                      (PVOID)sem, 0 )))
  57             ret = sem;
  58         else
  59             NtClose(sem);  /* somebody beat us to it */
  60     }
  61     return ret;
  62 }
  63
  64 /***********************************************************************
  65  *           RtlInitializeCriticalSection   (NTDLL.@)
  66  */
  67 NTSTATUS WINAPI RtlInitializeCriticalSection( RTL_CRITICAL_SECTION *crit )
  68 {
  69     crit->DebugInfo      = NULL;
  70     crit->LockCount      = -1;
  71     crit->RecursionCount = 0;
  72     crit->OwningThread   = 0;
  73     crit->LockSemaphore  = 0;
  74     return STATUS_SUCCESS;
  75 }
  76
  77 /***********************************************************************
  78  *           RtlInitializeCriticalSectionAndSpinCount   (NTDLL.@)
  79  * The InitializeCriticalSectionAndSpinCount (KERNEL32) function is
  80  * available on NT4SP3 or later, and Win98 or later.
  81  * I am assuming that this is the correct definition given the MSDN
  82  * docs for the kernel32 functions.
  83  */
  84 NTSTATUS WINAPI RtlInitializeCriticalSectionAndSpinCount( RTL_CRITICAL_SECTION *crit, DWORD spincount )
  85 {
  86     if(spincount) TRACE("critsection=%p: spincount=%ld not supported\n", crit, spincount);
  87     crit->SpinCount = spincount;
  88     return RtlInitializeCriticalSection( crit );
  89 }
  90
  91
  92 /***********************************************************************
  93  *           RtlDeleteCriticalSection   (NTDLL.@)
  94  */
  95 NTSTATUS WINAPI RtlDeleteCriticalSection( RTL_CRITICAL_SECTION *crit )
  96 {
  97     crit->LockCount      = -1;
  98     crit->RecursionCount = 0;
  99     crit->OwningThread   = 0;
 100     if (crit->LockSemaphore) NtClose( crit->LockSemaphore );
 101     crit->LockSemaphore  = 0;
 102     return STATUS_SUCCESS;
 103 }
 104
 105
 106 /***********************************************************************
 107  *           RtlpWaitForCriticalSection   (NTDLL.@)
 108  */
 109 NTSTATUS WINAPI RtlpWaitForCriticalSection( RTL_CRITICAL_SECTION *crit )
 110 {
 111     for (;;)
 112     {
 113         EXCEPTION_RECORD rec;
 114         HANDLE sem = get_semaphore( crit );
 115
 116         DWORD res = WaitForSingleObject( sem, 5000L );
 117         if ( res == WAIT_TIMEOUT )
 118         {
 119             const char *name = (char *)crit->DebugInfo;
 120             if (!name || IsBadStringPtrA(name,80)) name = "?";
 121             ERR( "section %p %s wait timed out, retrying (60 sec) tid=%08lx\n",
 122                  crit, debugstr_a(name), GetCurrentThreadId() );
 123             res = WaitForSingleObject( sem, 60000L );
 124             if ( res == WAIT_TIMEOUT && TRACE_ON(relay) )
 125             {
 126                 ERR( "section %p %s wait timed out, retrying (5 min) tid=%08lx\n",
 127                      crit, debugstr_a(name), GetCurrentThreadId() );
 128                 res = WaitForSingleObject( sem, 300000L );
 129             }
 130         }
 131         if (res == STATUS_WAIT_0) return STATUS_SUCCESS;
 132
 133         rec.ExceptionCode    = EXCEPTION_CRITICAL_SECTION_WAIT;
 134         rec.ExceptionFlags   = 0;
 135         rec.ExceptionRecord  = NULL;
 136         rec.ExceptionAddress = RtlRaiseException;  /* sic */
 137         rec.NumberParameters = 1;
 138         rec.ExceptionInformation[0] = (DWORD)crit;
 139         RtlRaiseException( &rec );
 140     }
 141 }
 142
 143
 144 /***********************************************************************
 145  *           RtlpUnWaitCriticalSection   (NTDLL.@)
 146  */
 147 NTSTATUS WINAPI RtlpUnWaitCriticalSection( RTL_CRITICAL_SECTION *crit )
 148 {
 149     HANDLE sem = get_semaphore( crit );
 150     NTSTATUS res = NtReleaseSemaphore( sem, 1, NULL );
 151     if (res) RtlRaiseStatus( res );
 152     return res;
 153 }
 154
 155
 156 /***********************************************************************
 157  *           RtlEnterCriticalSection   (NTDLL.@)
 158  */
 159 NTSTATUS WINAPI RtlEnterCriticalSection( RTL_CRITICAL_SECTION *crit )
 160 {
 161     if (interlocked_inc( &crit->LockCount ))
 162     {
 163         if (crit->OwningThread == GetCurrentThreadId())
 164         {
 165             crit->RecursionCount++;
 166             return STATUS_SUCCESS;
 167         }
 168
 169         /* Now wait for it */
 170         RtlpWaitForCriticalSection( crit );
 171     }
 172     crit->OwningThread   = GetCurrentThreadId();
 173     crit->RecursionCount = 1;
 174     return STATUS_SUCCESS;
 175 }
 176
 177
 178 /***********************************************************************
 179  *           RtlTryEnterCriticalSection   (NTDLL.@)
 180  */
 181 BOOL WINAPI RtlTryEnterCriticalSection( RTL_CRITICAL_SECTION *crit )
 182 {
 183     BOOL ret = FALSE;
 184     if (interlocked_cmpxchg( &crit->LockCount, 0L, -1 ) == -1)
 185     {
 186         crit->OwningThread   = GetCurrentThreadId();
 187         crit->RecursionCount = 1;
 188         ret = TRUE;
 189     }
 190     else if (crit->OwningThread == GetCurrentThreadId())
 191     {
 192         interlocked_inc( &crit->LockCount );
 193         crit->RecursionCount++;
 194         ret = TRUE;
 195     }
 196     return ret;
 197 }
 198
 199
 200 /***********************************************************************
 201  *           RtlLeaveCriticalSection   (NTDLL.@)
 202  */
 203 NTSTATUS WINAPI RtlLeaveCriticalSection( RTL_CRITICAL_SECTION *crit )
 204 {
 205     if (--crit->RecursionCount) interlocked_dec( &crit->LockCount );
 206     else
 207     {
 208         crit->OwningThread = 0;
 209         if (interlocked_dec( &crit->LockCount ) >= 0)
 210         {
 211             /* someone is waiting */
 212             RtlpUnWaitCriticalSection( crit );
 213         }
 214     }
 215     return STATUS_SUCCESS;
 216 }