win32/thread.c

   1 /*
   2  * Win32 kernel functions
   3  *
   4  * Copyright 1995 Martin von Loewis
   5  * Copyright 1997 Onno Hovers
   6  */
   7
   8 #include <unistd.h>
   9 #include <string.h>
  10 #include "windef.h"
  11 #include "winerror.h"
  12 #include "debug.h"
  13
  14
  15 /*
  16  * FIXME:
  17  * The c functions do not protect from non-interlocked accesses
  18  * This is no problem as long as we do not have multiple Win32 threads
  19  * or processes.
  20  * The assembly macro's do protect from non-interlocked access,
  21  * but they will only work for i386 systems with GCC.
  22  */
  23
  24 /************************************************************************
  25 *           InterlockedIncrement                        [KERNEL32]      *
  26 *                                                                       *
  27 * InterlockedIncrement adds 1 to a long variable and returns            *
  28 *  -  a negative number if the result < 0                               *
  29 *  -  zero if the result == 0                                           *
  30 *  -  a positive number if the result > 0                               *
  31 *                                                                       *
  32 * The returned number need not be equal to the result!!!!               *
  33 ************************************************************************/
  34
  35 LONG WINAPI InterlockedIncrement(LPLONG lpAddend)
  36 {
  37 #if defined(__i386__)&&defined(__GNUC__)
  38         long ret;
  39         __asm__
  40         (
  41            "\tlock\n"   /* for SMP systems */
  42            "\tincl      (%1)\n"
  43            "\tje        2f\n"
  44            "\tjl        1f\n"
  45            "\tincl      %0\n"
  46            "\tjmp       2f\n"
  47            "1:\tdec     %0\n"
  48            "2:\n"
  49            :"=r" (ret):"r" (lpAddend), "0" (0): "memory"
  50         );
  51         return ret;
  52 #else
  53         LONG ret;
  54         /* StopAllThreadsAndProcesses() */
  55
  56         (*lpAddend)++;
  57         ret=*lpAddend;
  58
  59         /* ResumeAllThreadsAndProcesses() */
  60         return ret;
  61 #endif
  62 }
  63
  64 /************************************************************************
  65 *           InterlockedDecrement                        [KERNEL32]      *
  66 *                                                                       *
  67 * InterlockedIncrement adds 1 to a long variable and returns            *
  68 *  -  a negative number if the result < 0                               *
  69 *  -  zero if the result == 0                                           *
  70 *  -  a positive number if the result > 0                               *
  71 *                                                                       *
  72 * The returned number need not be equal to the result!!!!               *
  73 ************************************************************************/
  74
  75 LONG WINAPI InterlockedDecrement(LPLONG lpAddend)
  76 {
  77 #if defined(__i386__)&&defined(__GNUC__)
  78         LONG ret;
  79         __asm__
  80         (
  81            "\tlock\n"   /* for SMP systems */
  82            "\tdecl      (%1)\n"
  83            "\tje        2f\n"
  84            "\tjl        1f\n"
  85            "\tincl      %0\n"
  86            "\tjmp       2f\n"
  87            "1:\tdec     %0\n"
  88            "2:\n"
  89            :"=r" (ret):"r" (lpAddend), "0" (0): "memory"
  90         );
  91         return ret;
  92 #else
  93         LONG ret;
  94         /* StopAllThreadsAndProcesses() */
  95
  96         (*lpAddend)--;
  97         ret=*lpAddend;
  98
  99         /* ResumeAllThreadsAndProcesses() */
 100         return ret;
 101 #endif
 102 }
 103
 104 /************************************************************************
 105  *           InterlockedExchange                                [KERNEL32.???]
 106  *
 107  * Atomically exchanges a pair of values.
 108  *
 109  * RETURNS
 110  *      Prior value of value pointed to by Target
 111  */
 112 LONG WINAPI InterlockedExchange(
 113             LPLONG target, /* Address of 32-bit value to exchange */
 114             LONG value     /* New value for the value pointed to by target */
 115 ) {
 116 #if defined(__i386__)&&defined(__GNUC__)
 117         LONG ret;
 118         __asm__ ( /* lock for SMP systems */
 119                   "lock\n\txchgl %0,(%1)"
 120                   :"=r" (ret):"r" (target), "0" (value):"memory" );
 121         return ret;
 122 #else
 123         LONG ret;
 124         /* StopAllThreadsAndProcesses() */
 125
 126         ret=*target;
 127         *target=value;
 128
 129         /* ResumeAllThreadsAndProcesses() */
 130         return ret;
 131 #endif
 132 }
 133
 134 /************************************************************************
 135  *           InterlockedCompareExchange         [KERNEL32.879]
 136  *
 137  * Atomically compares Destination and Comperand, and if found equal exchanges
 138  * the value of Destination with Exchange
 139  *
 140  * RETURNS
 141  *      Prior value of value pointed to by Destination
 142  */
 143 PVOID WINAPI InterlockedCompareExchange(
 144             PVOID *Destination, /* Address of 32-bit value to exchange */
 145             PVOID Exchange,      /* change value, 32 bits */
 146             PVOID Comperand      /* value to compare, 32 bits */
 147 ) {
 148 #if defined(__i386__)&&defined(__GNUC__)
 149         PVOID ret;
 150         __asm__ ( /* lock for SMP systems */
 151                   "lock\n\t"
 152                   "cmpxchgl %2,(%1)"
 153                   :"=r" (ret)
 154                   :"r" (Destination),"r" (Exchange), "0" (Comperand)
 155                   :"memory" );
 156         return ret;
 157 #else
 158         PVOID ret;
 159         /* StopAllThreadsAndProcesses() */
 160
 161         ret=*Destination;
 162         if(*Destination==Comperand) *Destination=Exchange;
 163
 164         /* ResumeAllThreadsAndProcesses() */
 165         return ret;
 166 #endif
 167 }
 168
 169 /************************************************************************
 170  *           InterlockedExchangeAdd                     [KERNEL32.880]
 171  *
 172  * Atomically adds Increment to Addend and returns the previous value of
 173  * Addend
 174  *
 175  * RETURNS
 176  *      Prior value of value pointed to by cwAddendTarget
 177  */
 178 LONG WINAPI InterlockedExchangeAdd(
 179             PLONG Addend, /* Address of 32-bit value to exchange */
 180             LONG Increment /* Value to add */
 181 ) {
 182 #if defined(__i386__)&&defined(__GNUC__)
 183         LONG ret;
 184         __asm__ ( /* lock for SMP systems */
 185                   "lock\n\t"
 186                   "xaddl %0,(%1)"
 187                   :"=r" (ret)
 188                   :"r" (Addend), "0" (Increment)
 189                   :"memory" );
 190         return ret;
 191 #else
 192         LONG ret;
 193         /* StopAllThreadsAndProcesses() */
 194
 195         ret = *Addend;
 196         *Addend += Increment;
 197
 198         /* ResumeAllThreadsAndProcesses() */
 199         return ret;
 200 #endif
 201 }