scheduler/fiber.c

   1 /*
   2  * Fiber support
   3  *
   4  * Copyright 2002 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  * FIXME:
  21  * - proper handling of 16-bit stack and signal stack
  22  */
  23
  24 #include <setjmp.h>
  25
  26 #include "winbase.h"
  27 #include "winerror.h"
  28 #include "thread.h"
  29
  30 struct fiber_data
  31 {
  32     LPVOID                param;       /* 00 fiber param */
  33     void                 *except;      /* 04 saved exception handlers list */
  34     void                 *stack_top;   /* 08 top of fiber stack */
  35     void                 *stack_low;   /* 0c fiber stack low-water mark */
  36     void                 *stack_base;  /* 10 base of the fiber stack */
  37     jmp_buf               jmpbuf;      /* 14 setjmp buffer (on Windows: CONTEXT) */
  38     DWORD                 flags;       /*    fiber flags */
  39     LPFIBER_START_ROUTINE start;       /*    start routine */
  40 };
  41
  42
  43 /* call the fiber initial function once we have switched stack */
  44 static void start_fiber(void)
  45 {
  46     struct fiber_data *fiber = NtCurrentTeb()->fiber;
  47     LPFIBER_START_ROUTINE start = fiber->start;
  48
  49     fiber->start = NULL;
  50     start( fiber->param );
  51     ExitThread( 1 );
  52 }
  53
  54
  55 /***********************************************************************
  56  *           CreateFiber   (KERNEL32.@)
  57  */
  58 LPVOID WINAPI CreateFiber( SIZE_T stack, LPFIBER_START_ROUTINE start, LPVOID param )
  59 {
  60     return CreateFiberEx( stack, 0, 0, start, param );
  61 }
  62
  63
  64 /***********************************************************************
  65  *           CreateFiberEx   (KERNEL32.@)
  66  */
  67 LPVOID WINAPI CreateFiberEx( SIZE_T stack_commit, SIZE_T stack_reserve, DWORD flags,
  68                              LPFIBER_START_ROUTINE start, LPVOID param )
  69 {
  70     struct fiber_data *fiber;
  71
  72     if (!(fiber = HeapAlloc( GetProcessHeap(), 0, sizeof(*fiber) )))
  73     {
  74         SetLastError( ERROR_NOT_ENOUGH_MEMORY );
  75         return NULL;
  76     }
  77
  78     /* FIXME: should use the thread stack allocation routines here */
  79     if (!stack_reserve) stack_reserve = 1024*1024;
  80     if(!(fiber->stack_base = VirtualAlloc( 0, stack_reserve, MEM_COMMIT, PAGE_EXECUTE_READWRITE )))
  81     {
  82         HeapFree( GetProcessHeap(), 0, fiber );
  83         return NULL;
  84     }
  85     fiber->stack_top  = (char *)fiber->stack_base + stack_reserve;
  86     fiber->stack_low  = fiber->stack_base;
  87     fiber->param      = param;
  88     fiber->except     = (void *)-1;
  89     fiber->start      = start;
  90     fiber->flags      = flags;
  91     return fiber;
  92 }
  93
  94
  95 /***********************************************************************
  96  *           DeleteFiber   (KERNEL32.@)
  97  */
  98 void WINAPI DeleteFiber( LPVOID fiber_ptr )
  99 {
 100     struct fiber_data *fiber = fiber_ptr;
 101
 102     if (!fiber) return;
 103     if (fiber == NtCurrentTeb()->fiber)
 104     {
 105         HeapFree( GetProcessHeap(), 0, fiber );
 106         ExitThread(1);
 107     }
 108     VirtualFree( fiber->stack_base, 0, MEM_RELEASE );
 109     HeapFree( GetProcessHeap(), 0, fiber );
 110 }
 111
 112
 113 /***********************************************************************
 114  *           ConvertThreadToFiber   (KERNEL32.@)
 115  */
 116 LPVOID WINAPI ConvertThreadToFiber( LPVOID param )
 117 {
 118     return ConvertThreadToFiberEx( param, 0 );
 119 }
 120
 121
 122 /***********************************************************************
 123  *           ConvertThreadToFiberEx   (KERNEL32.@)
 124  */
 125 LPVOID WINAPI ConvertThreadToFiberEx( LPVOID param, DWORD flags )
 126 {
 127     struct fiber_data *fiber;
 128
 129     if (!(fiber = HeapAlloc( GetProcessHeap(), 0, sizeof(*fiber) )))
 130     {
 131         SetLastError( ERROR_NOT_ENOUGH_MEMORY );
 132         return NULL;
 133     }
 134     fiber->param      = param;
 135     fiber->except     = NtCurrentTeb()->except;
 136     fiber->stack_top  = NtCurrentTeb()->stack_top;
 137     fiber->stack_low  = NtCurrentTeb()->stack_low;
 138     fiber->stack_base = NtCurrentTeb()->stack_base;
 139     fiber->start      = NULL;
 140     fiber->flags      = flags;
 141     NtCurrentTeb()->fiber = fiber;
 142     return fiber;
 143 }
 144
 145
 146 /***********************************************************************
 147  *           ConvertFiberToThread   (KERNEL32.@)
 148  */
 149 BOOL WINAPI ConvertFiberToThread(void)
 150 {
 151     struct fiber_data *fiber = NtCurrentTeb()->fiber;
 152
 153     if (fiber)
 154     {
 155         NtCurrentTeb()->fiber = NULL;
 156         HeapFree( GetProcessHeap(), 0, fiber );
 157     }
 158     return TRUE;
 159 }
 160
 161
 162 /***********************************************************************
 163  *           SwitchToFiber   (KERNEL32.@)
 164  */
 165 void WINAPI SwitchToFiber( LPVOID fiber )
 166 {
 167     struct fiber_data *new_fiber = fiber;
 168     struct fiber_data *current_fiber = NtCurrentTeb()->fiber;
 169
 170     current_fiber->except    = NtCurrentTeb()->except;
 171     current_fiber->stack_low = NtCurrentTeb()->stack_low;
 172     /* stack_base and stack_top never change */
 173
 174     /* FIXME: should save floating point context if requested in fiber->flags */
 175     if (!setjmp( current_fiber->jmpbuf ))
 176     {
 177         NtCurrentTeb()->fiber      = new_fiber;
 178         NtCurrentTeb()->except     = new_fiber->except;
 179         NtCurrentTeb()->stack_top  = new_fiber->stack_top;
 180         NtCurrentTeb()->stack_low  = new_fiber->stack_low;
 181         NtCurrentTeb()->stack_base = new_fiber->stack_base;
 182         if (new_fiber->start)  /* first time */
 183             SYSDEPS_SwitchToThreadStack( start_fiber );
 184         else
 185             longjmp( new_fiber->jmpbuf, 1 );
 186     }
 187 }