scheduler/critsection.c

   1 /*
   2  * Win32 critical sections
   3  *
   4  * Copyright 1998 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8 #include <errno.h>
   9 #include <stdio.h>
  10 #include <sys/types.h>
  11 #include "winerror.h"
  12 #include "winbase.h"
  13 #include "ntddk.h"
  14 #include "heap.h"
  15 #include "debugtools.h"
  16 #include "thread.h"
  17
  18 DEFAULT_DEBUG_CHANNEL(win32);
  19 DECLARE_DEBUG_CHANNEL(relay);
  20
  21 /***********************************************************************
  22  *           get_semaphore
  23  */
  24 static inline HANDLE get_semaphore( CRITICAL_SECTION *crit )
  25 {
  26     HANDLE ret = crit->LockSemaphore;
  27     if (!ret)
  28     {
  29         HANDLE sem = CreateSemaphoreA( NULL, 0, 1, NULL );
  30         if (!(ret = (HANDLE)InterlockedCompareExchange( (PVOID *)&crit->LockSemaphore,
  31                                                         (PVOID)sem, 0 )))
  32             ret = sem;
  33         else
  34             CloseHandle(sem);  /* somebody beat us to it */
  35     }
  36     return ret;
  37 }
  38
  39 /***********************************************************************
  40  *           InitializeCriticalSection   (KERNEL32.472) (NTDLL.406)
  41  */
  42 void WINAPI InitializeCriticalSection( CRITICAL_SECTION *crit )
  43 {
  44     crit->LockCount      = -1;
  45     crit->RecursionCount = 0;
  46     crit->OwningThread   = 0;
  47     crit->LockSemaphore  = 0;
  48 }
  49
  50
  51 /***********************************************************************
  52  *           DeleteCriticalSection   (KERNEL32.185) (NTDLL.327)
  53  */
  54 void WINAPI DeleteCriticalSection( CRITICAL_SECTION *crit )
  55 {
  56     if (crit->RecursionCount && crit->OwningThread != GetCurrentThreadId())
  57         ERR("Deleting owned critical section (%p)\n", crit );
  58
  59     crit->LockCount      = -1;
  60     crit->RecursionCount = 0;
  61     crit->OwningThread   = 0;
  62     if (crit->LockSemaphore) CloseHandle( crit->LockSemaphore );
  63     crit->LockSemaphore  = 0;
  64 }
  65
  66
  67 /***********************************************************************
  68  *           EnterCriticalSection   (KERNEL32.195) (NTDLL.344)
  69  */
  70 void WINAPI EnterCriticalSection( CRITICAL_SECTION *crit )
  71 {
  72     if (InterlockedIncrement( &crit->LockCount ))
  73     {
  74         if (crit->OwningThread == GetCurrentThreadId())
  75         {
  76             crit->RecursionCount++;
  77             return;
  78         }
  79
  80         /* Now wait for it */
  81         for (;;)
  82         {
  83             EXCEPTION_RECORD rec;
  84             HANDLE sem = get_semaphore( crit );
  85
  86             DWORD res = WaitForSingleObject( sem, 5000L );
  87             if ( res == WAIT_TIMEOUT )
  88             {
  89                 ERR("Critical section %p wait timed out, retrying (60 sec)\n", crit );
  90                 res = WaitForSingleObject( sem, 60000L );
  91                 if ( res == WAIT_TIMEOUT && TRACE_ON(relay) )
  92                 {
  93                     ERR("Critical section %p wait timed out, retrying (5 min)\n", crit );
  94                     res = WaitForSingleObject( sem, 300000L );
  95                 }
  96             }
  97             if (res == STATUS_WAIT_0) break;
  98
  99             rec.ExceptionCode    = EXCEPTION_CRITICAL_SECTION_WAIT;
 100             rec.ExceptionFlags   = 0;
 101             rec.ExceptionRecord  = NULL;
 102             rec.ExceptionAddress = RtlRaiseException;  /* sic */
 103             rec.NumberParameters = 1;
 104             rec.ExceptionInformation[0] = (DWORD)crit;
 105             RtlRaiseException( &rec );
 106         }
 107     }
 108     crit->OwningThread   = GetCurrentThreadId();
 109     crit->RecursionCount = 1;
 110 }
 111
 112
 113 /***********************************************************************
 114  *           TryEnterCriticalSection   (KERNEL32.898) (NTDLL.969)
 115  */
 116 BOOL WINAPI TryEnterCriticalSection( CRITICAL_SECTION *crit )
 117 {
 118     BOOL ret = FALSE;
 119     if (InterlockedCompareExchange( (PVOID *)&crit->LockCount,
 120                                     (PVOID)0L, (PVOID)-1L ) == (PVOID)-1L)
 121     {
 122         crit->OwningThread   = GetCurrentThreadId();
 123         crit->RecursionCount = 1;
 124         ret = TRUE;
 125     }
 126     else if (crit->OwningThread == GetCurrentThreadId())
 127     {
 128         InterlockedIncrement( &crit->LockCount );
 129         crit->RecursionCount++;
 130         ret = TRUE;
 131     }
 132     return ret;
 133 }
 134
 135
 136 /***********************************************************************
 137  *           LeaveCriticalSection   (KERNEL32.494) (NTDLL.426)
 138  */
 139 void WINAPI LeaveCriticalSection( CRITICAL_SECTION *crit )
 140 {
 141     if (crit->OwningThread != GetCurrentThreadId()) return;
 142
 143     if (--crit->RecursionCount)
 144     {
 145         InterlockedDecrement( &crit->LockCount );
 146         return;
 147     }
 148     crit->OwningThread = 0;
 149     if (InterlockedDecrement( &crit->LockCount ) >= 0)
 150     {
 151         /* Someone is waiting */
 152         HANDLE sem = get_semaphore( crit );
 153         ReleaseSemaphore( sem, 1, NULL );
 154     }
 155 }
 156
 157
 158 /***********************************************************************
 159  *           MakeCriticalSectionGlobal   (KERNEL32.515)
 160  */
 161 void WINAPI MakeCriticalSectionGlobal( CRITICAL_SECTION *crit )
 162 {
 163     crit->LockSemaphore = ConvertToGlobalHandle( get_semaphore( crit ) );
 164 }
 165
 166
 167 /***********************************************************************
 168  *           ReinitializeCriticalSection   (KERNEL32.581)
 169  */
 170 void WINAPI ReinitializeCriticalSection( CRITICAL_SECTION *crit )
 171 {
 172     if ( !crit->LockSemaphore )
 173         InitializeCriticalSection( crit );
 174 }
 175
 176
 177 /***********************************************************************
 178  *           UninitializeCriticalSection   (KERNEL32.703)
 179  */
 180 void WINAPI UninitializeCriticalSection( CRITICAL_SECTION *crit )
 181 {
 182     DeleteCriticalSection( crit );
 183 }
 184
 185 #ifdef __i386__
 186
 187 /***********************************************************************
 188  *              InterlockCompareExchange (KERNEL32.@)
 189  */
 190 PVOID WINAPI InterlockedCompareExchange( PVOID *dest, PVOID xchg, PVOID compare );
 191 __ASM_GLOBAL_FUNC(InterlockedCompareExchange,
 192                   "movl 12(%esp),%eax\n\t"
 193                   "movl 8(%esp),%ecx\n\t"
 194                   "movl 4(%esp),%edx\n\t"
 195                   "lock; cmpxchgl %ecx,(%edx)\n\t"
 196                   "ret $12");
 197
 198 /***********************************************************************
 199  *              InterlockedExchange (KERNEL32.@)
 200  */
 201 LONG WINAPI InterlockedExchange( PLONG dest, LONG val );
 202 __ASM_GLOBAL_FUNC(InterlockedExchange,
 203                   "movl 8(%esp),%eax\n\t"
 204                   "movl 4(%esp),%edx\n\t"
 205                   "lock; xchgl %eax,(%edx)\n\t"
 206                   "ret $8");
 207
 208 /***********************************************************************
 209  *              InterlockedExchangeAdd (KERNEL32.@)
 210  */
 211 LONG WINAPI InterlockedExchangeAdd( PLONG dest, LONG incr );
 212 __ASM_GLOBAL_FUNC(InterlockedExchangeAdd,
 213                   "movl 8(%esp),%eax\n\t"
 214                   "movl 4(%esp),%edx\n\t"
 215                   "lock; xaddl %eax,(%edx)\n\t"
 216                   "ret $8");
 217
 218 /***********************************************************************
 219  *              InterlockedIncrement (KERNEL32.@)
 220  */
 221 LONG WINAPI InterlockedIncrement( PLONG dest );
 222 __ASM_GLOBAL_FUNC(InterlockedIncrement,
 223                   "movl 4(%esp),%edx\n\t"
 224                   "movl $1,%eax\n\t"
 225                   "lock; xaddl %eax,(%edx)\n\t"
 226                   "incl %eax\n\t"
 227                   "ret $4");
 228
 229 /***********************************************************************
 230  *              InterlockDecrement (KERNEL32.@)
 231  */
 232 LONG WINAPI InterlockedDecrement( PLONG dest );
 233 __ASM_GLOBAL_FUNC(InterlockedDecrement,
 234                   "movl 4(%esp),%edx\n\t"
 235                   "movl $-1,%eax\n\t"
 236                   "lock; xaddl %eax,(%edx)\n\t"
 237                   "decl %eax\n\t"
 238                   "ret $4");
 239
 240 #elif defined(__sparc__) && defined(__sun__)
 241
 242 /*
 243  * As the earlier Sparc processors lack necessary atomic instructions,
 244  * I'm simply falling back to the library-provided _lwp_mutex routines
 245  * to ensure mutual exclusion in a way appropriate for the current
 246  * architecture.
 247  *
 248  * FIXME:  If we have the compare-and-swap instruction (Sparc v9 and above)
 249  *         we could use this to speed up the Interlocked operations ...
 250  */
 251
 252 #include <synch.h>
 253 static lwp_mutex_t interlocked_mutex = DEFAULTMUTEX;
 254
 255 /***********************************************************************
 256  *              InterlockedCompareExchange (KERNEL32.@)
 257  */
 258 PVOID WINAPI InterlockedCompareExchange( PVOID *dest, PVOID xchg, PVOID compare )
 259 {
 260     _lwp_mutex_lock( &interlocked_mutex );
 261
 262     if ( *dest == compare )
 263         *dest = xchg;
 264     else
 265         compare = *dest;
 266
 267     _lwp_mutex_unlock( &interlocked_mutex );
 268     return compare;
 269 }
 270
 271 /***********************************************************************
 272  *              InterlockedExchange (KERNEL32.@)
 273  */
 274 LONG WINAPI InterlockedExchange( PLONG dest, LONG val )
 275 {
 276     LONG retv;
 277     _lwp_mutex_lock( &interlocked_mutex );
 278
 279     retv = *dest;
 280     *dest = val;
 281
 282     _lwp_mutex_unlock( &interlocked_mutex );
 283     return retv;
 284 }
 285
 286 /***********************************************************************
 287  *              InterlockedExchangeAdd (KERNEL32.@)
 288  */
 289 LONG WINAPI InterlockedExchangeAdd( PLONG dest, LONG incr )
 290 {
 291     LONG retv;
 292     _lwp_mutex_lock( &interlocked_mutex );
 293
 294     retv = *dest;
 295     *dest += incr;
 296
 297     _lwp_mutex_unlock( &interlocked_mutex );
 298     return retv;
 299 }
 300
 301 /***********************************************************************
 302  *              InterlockedIncrement (KERNEL32.@)
 303  */
 304 LONG WINAPI InterlockedIncrement( PLONG dest )
 305 {
 306     LONG retv;
 307     _lwp_mutex_lock( &interlocked_mutex );
 308
 309     retv = ++*dest;
 310
 311     _lwp_mutex_unlock( &interlocked_mutex );
 312     return retv;
 313 }
 314
 315 /***********************************************************************
 316  *              InterlockedDecrement (KERNEL32.@)
 317  */
 318 LONG WINAPI InterlockedDecrement( PLONG dest )
 319 {
 320     LONG retv;
 321     _lwp_mutex_lock( &interlocked_mutex );
 322
 323     retv = --*dest;
 324
 325     _lwp_mutex_unlock( &interlocked_mutex );
 326     return retv;
 327 }
 328
 329 #else
 330 #error You must implement the Interlocked* functions for your CPU
 331 #endif