win32/thread.c

   1 /*
   2  * Win32 kernel functions
   3  *
   4  * Copyright 1995 Martin von Loewis
   5  * Copyright 1997 Onno Hovers
   6  */
   7
   8 #include <string.h>
   9 #include <unistd.h>
  10
  11 #include "winbase.h"
  12 #include "windef.h"
  13 #include "winerror.h"
  14
  15
  16 /*
  17  * FIXME:
  18  * The c functions do not protect from non-interlocked accesses
  19  * This is no problem as long as we do not have multiple Win32 threads
  20  * or processes.
  21  * The assembly macro's do protect from non-interlocked access,
  22  * but they will only work for i386 systems with GCC.
  23  */
  24
  25 /************************************************************************
  26 *           InterlockedIncrement                        [KERNEL32]      *
  27 *                                                                       *
  28 * InterlockedIncrement adds 1 to a long variable and returns            *
  29 *  -  a negative number if the result < 0                               *
  30 *  -  zero if the result == 0                                           *
  31 *  -  a positive number if the result > 0                               *
  32 *                                                                       *
  33 * The returned number need not be equal to the result!!!!               *
  34 ************************************************************************/
  35
  36 LONG WINAPI InterlockedIncrement(LPLONG lpAddend)
  37 {
  38 #if defined(__i386__)&&defined(__GNUC__)
  39         long ret;
  40         __asm__
  41         (
  42            "\tlock\n"   /* for SMP systems */
  43            "\tincl      (%1)\n"
  44            "\tje        2f\n"
  45            "\tjl        1f\n"
  46            "\tincl      %0\n"
  47            "\tjmp       2f\n"
  48            "1:\tdec     %0\n"
  49            "2:\n"
  50            :"=r" (ret):"r" (lpAddend), "0" (0): "memory"
  51         );
  52         return ret;
  53 #else
  54         LONG ret;
  55         /* StopAllThreadsAndProcesses() */
  56
  57         (*lpAddend)++;
  58         ret=*lpAddend;
  59
  60         /* ResumeAllThreadsAndProcesses() */
  61         return ret;
  62 #endif
  63 }
  64
  65 /************************************************************************
  66 *           InterlockedDecrement                        [KERNEL32]      *
  67 *                                                                       *
  68 * InterlockedIncrement adds 1 to a long variable and returns            *
  69 *  -  a negative number if the result < 0                               *
  70 *  -  zero if the result == 0                                           *
  71 *  -  a positive number if the result > 0                               *
  72 *                                                                       *
  73 * The returned number need not be equal to the result!!!!               *
  74 ************************************************************************/
  75
  76 LONG WINAPI InterlockedDecrement(LPLONG lpAddend)
  77 {
  78 #if defined(__i386__)&&defined(__GNUC__)
  79         LONG ret;
  80         __asm__
  81         (
  82            "\tlock\n"   /* for SMP systems */
  83            "\tdecl      (%1)\n"
  84            "\tje        2f\n"
  85            "\tjl        1f\n"
  86            "\tincl      %0\n"
  87            "\tjmp       2f\n"
  88            "1:\tdec     %0\n"
  89            "2:\n"
  90            :"=r" (ret):"r" (lpAddend), "0" (0): "memory"
  91         );
  92         return ret;
  93 #else
  94         LONG ret;
  95         /* StopAllThreadsAndProcesses() */
  96
  97         (*lpAddend)--;
  98         ret=*lpAddend;
  99
 100         /* ResumeAllThreadsAndProcesses() */
 101         return ret;
 102 #endif
 103 }
 104
 105 /************************************************************************
 106  *           InterlockedExchange                                [KERNEL32.???]
 107  *
 108  * Atomically exchanges a pair of values.
 109  *
 110  * RETURNS
 111  *      Prior value of value pointed to by Target
 112  */
 113 LONG WINAPI InterlockedExchange(
 114             LPLONG target, /* Address of 32-bit value to exchange */
 115             LONG value     /* New value for the value pointed to by target */
 116 ) {
 117 #if defined(__i386__)&&defined(__GNUC__)
 118         LONG ret;
 119         __asm__ ( /* lock for SMP systems */
 120                   "lock\n\txchgl %0,(%1)"
 121                   :"=r" (ret):"r" (target), "0" (value):"memory" );
 122         return ret;
 123 #else
 124         LONG ret;
 125         /* StopAllThreadsAndProcesses() */
 126
 127         ret=*target;
 128         *target=value;
 129
 130         /* ResumeAllThreadsAndProcesses() */
 131         return ret;
 132 #endif
 133 }
 134
 135 /************************************************************************
 136  *           InterlockedCompareExchange         [KERNEL32.879]
 137  *
 138  * Atomically compares Destination and Comperand, and if found equal exchanges
 139  * the value of Destination with Exchange
 140  *
 141  * RETURNS
 142  *      Prior value of value pointed to by Destination
 143  */
 144 PVOID WINAPI InterlockedCompareExchange(
 145             PVOID *Destination, /* Address of 32-bit value to exchange */
 146             PVOID Exchange,      /* change value, 32 bits */
 147             PVOID Comperand      /* value to compare, 32 bits */
 148 ) {
 149 #if defined(__i386__)&&defined(__GNUC__)
 150         PVOID ret;
 151         __asm__ ( /* lock for SMP systems */
 152                   "lock\n\t"
 153                   "cmpxchgl %2,(%1)"
 154                   :"=r" (ret)
 155                   :"r" (Destination),"r" (Exchange), "0" (Comperand)
 156                   :"memory" );
 157         return ret;
 158 #else
 159         PVOID ret;
 160         /* StopAllThreadsAndProcesses() */
 161
 162         ret=*Destination;
 163         if(*Destination==Comperand) *Destination=Exchange;
 164
 165         /* ResumeAllThreadsAndProcesses() */
 166         return ret;
 167 #endif
 168 }
 169
 170 /************************************************************************
 171  *           InterlockedExchangeAdd                     [KERNEL32.880]
 172  *
 173  * Atomically adds Increment to Addend and returns the previous value of
 174  * Addend
 175  *
 176  * RETURNS
 177  *      Prior value of value pointed to by cwAddendTarget
 178  */
 179 LONG WINAPI InterlockedExchangeAdd(
 180             PLONG Addend, /* Address of 32-bit value to exchange */
 181             LONG Increment /* Value to add */
 182 ) {
 183 #if defined(__i386__)&&defined(__GNUC__)
 184         LONG ret;
 185         __asm__ ( /* lock for SMP systems */
 186                   "lock\n\t"
 187                   "xaddl %0,(%1)"
 188                   :"=r" (ret)
 189                   :"r" (Addend), "0" (Increment)
 190                   :"memory" );
 191         return ret;
 192 #else
 193         LONG ret;
 194         /* StopAllThreadsAndProcesses() */
 195
 196         ret = *Addend;
 197         *Addend += Increment;
 198
 199         /* ResumeAllThreadsAndProcesses() */
 200         return ret;
 201 #endif
 202 }