scheduler/services.c

   1 /*
   2  * Kernel Services Thread
   3  *
   4  * Copyright 1999 Ulrich Weigand
   5  */
   6
   7 #include <sys/time.h>
   8 #include <unistd.h>
   9
  10 #include "services.h"
  11 #include "process.h"
  12 #include "debugtools.h"
  13
  14 DEFAULT_DEBUG_CHANNEL(timer)
  15
  16 typedef struct _SERVICE
  17 {
  18    struct _SERVICE      *next;
  19    HANDLE               self;
  20
  21    PAPCFUNC             callback;
  22    ULONG_PTR            callback_arg;
  23
  24    BOOL                 disabled;
  25    HANDLE               object;
  26 } SERVICE;
  27
  28 typedef struct _SERVICETABLE
  29 {
  30    HANDLE               thread;
  31
  32    SERVICE              *first;
  33    DWORD                counter;
  34
  35 } SERVICETABLE;
  36
  37 /***********************************************************************
  38  *           SERVICE_Loop
  39  */
  40 static DWORD CALLBACK SERVICE_Loop( SERVICETABLE *service )
  41 {
  42     HANDLE      handles[MAXIMUM_WAIT_OBJECTS];
  43     int         count = 0;
  44     DWORD       retval = WAIT_FAILED;
  45
  46     while ( TRUE )
  47     {
  48         PAPCFUNC callback;
  49         ULONG_PTR callback_arg;
  50         SERVICE *s;
  51
  52         /* Check whether some condition is fulfilled */
  53
  54         HeapLock( GetProcessHeap() );
  55
  56         callback = NULL;
  57         callback_arg = 0L;
  58         for ( s = service->first; s; s = s->next )
  59         {
  60             if (s->disabled) continue;
  61
  62             if ( retval >= WAIT_OBJECT_0 && retval < WAIT_OBJECT_0 + count )
  63             {
  64                 if ( handles[retval - WAIT_OBJECT_0] == s->object )
  65                 {
  66                     retval = WAIT_TIMEOUT;
  67                     callback = s->callback;
  68                     callback_arg = s->callback_arg;
  69                     break;
  70                 }
  71             }
  72         }
  73
  74         HeapUnlock( GetProcessHeap() );
  75
  76         /* If found, call callback routine */
  77
  78         if ( callback )
  79         {
  80             callback( callback_arg );
  81             continue;
  82         }
  83
  84         /* If not found, determine wait condition */
  85
  86         HeapLock( GetProcessHeap() );
  87
  88         count = 0;
  89         for ( s = service->first; s; s = s->next )
  90         {
  91             if (s->disabled) continue;
  92
  93             if ( count < MAXIMUM_WAIT_OBJECTS )
  94                 handles[count++] = s->object;
  95         }
  96
  97         HeapUnlock( GetProcessHeap() );
  98
  99
 100         /* Wait until some condition satisfied */
 101
 102         TRACE("Waiting for %d objects\n", count );
 103
 104         retval = WaitForMultipleObjectsEx( count, handles, FALSE, INFINITE, TRUE );
 105
 106         TRACE("Wait returned: %ld\n", retval );
 107     }
 108
 109     return 0L;
 110 }
 111
 112 /***********************************************************************
 113  *           SERVICE_CreateServiceTable
 114  */
 115 static  BOOL    SERVICE_CreateServiceTable( void )
 116 {
 117     HANDLE              thread;
 118     SERVICETABLE        *service_table;
 119     PDB                 *pdb = PROCESS_Current();
 120
 121     service_table = HeapAlloc( GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(SERVICETABLE) );
 122     if ( !service_table )
 123     {
 124         return FALSE;
 125     }
 126
 127     /* service_table field in PDB must be set *BEFORE* calling CreateThread
 128      * otherwise the thread cleanup service will cause an infinite recursion
 129      * when installed
 130      */
 131     pdb->service_table = service_table;
 132
 133     thread = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)SERVICE_Loop,
 134                            service_table, 0, NULL );
 135     if ( thread == INVALID_HANDLE_VALUE )
 136     {
 137         pdb->service_table = 0;
 138         HeapFree( GetProcessHeap(), 0, service_table );
 139         return FALSE;
 140     }
 141
 142     service_table->thread = thread;
 143
 144     return TRUE;
 145 }
 146
 147 /***********************************************************************
 148  *           SERVICE_AddObject
 149  *
 150  * Warning: the object supplied by the caller must not be closed. It'll
 151  * be destroyed when the service is deleted. It's up to the caller
 152  * to ensure that object will not be destroyed in between.
 153  */
 154 HANDLE SERVICE_AddObject( HANDLE object,
 155                           PAPCFUNC callback, ULONG_PTR callback_arg )
 156 {
 157     SERVICE             *s;
 158     SERVICETABLE        *service_table;
 159     HANDLE              handle;
 160
 161     if ( object == INVALID_HANDLE_VALUE || !callback )
 162         return INVALID_HANDLE_VALUE;
 163
 164     if (PROCESS_Current()->service_table == 0 && !SERVICE_CreateServiceTable())
 165        return INVALID_HANDLE_VALUE;
 166     service_table = PROCESS_Current()->service_table;
 167
 168     s = HeapAlloc( GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(SERVICE) );
 169     if ( !s ) return INVALID_HANDLE_VALUE;
 170
 171     s->callback = callback;
 172     s->callback_arg = callback_arg;
 173     s->object = object;
 174     s->disabled = FALSE;
 175
 176     HeapLock( GetProcessHeap() );
 177
 178     s->self = handle = (HANDLE)++service_table->counter;
 179     s->next = service_table->first;
 180     service_table->first = s;
 181
 182     HeapUnlock( GetProcessHeap() );
 183
 184     QueueUserAPC( NULL, service_table->thread, 0L );
 185
 186     return handle;
 187 }
 188
 189 /***********************************************************************
 190  *           SERVICE_AddTimer
 191  */
 192 HANDLE SERVICE_AddTimer( LONG rate,
 193                          PAPCFUNC callback, ULONG_PTR callback_arg )
 194 {
 195     HANDLE handle, ret;
 196     LARGE_INTEGER when;
 197
 198     if ( !rate || !callback )
 199         return INVALID_HANDLE_VALUE;
 200
 201     handle = CreateWaitableTimerA( NULL, FALSE, NULL );
 202     if (!handle) return INVALID_HANDLE_VALUE;
 203
 204     rate = (rate + 500) / 1000;  /* us -> ms */
 205     if (!rate) rate = 1;
 206     when.s.LowPart = when.s.HighPart = 0;
 207     if (!SetWaitableTimer( handle, &when, rate, NULL, NULL, FALSE ))
 208     {
 209         CloseHandle( handle );
 210         return INVALID_HANDLE_VALUE;
 211     }
 212
 213     if ((ret = SERVICE_AddObject( handle, callback, callback_arg )) == INVALID_HANDLE_VALUE)
 214     {
 215         CloseHandle( handle );
 216         return INVALID_HANDLE_VALUE;
 217     }
 218     return ret;
 219 }
 220
 221 /***********************************************************************
 222  *           SERVICE_Delete
 223  */
 224 BOOL SERVICE_Delete( HANDLE service )
 225 {
 226     HANDLE              handle = INVALID_HANDLE_VALUE;
 227     BOOL                retv = FALSE;
 228     SERVICE             **s, *next;
 229     SERVICETABLE        *service_table;
 230
 231     /* service table must have been created on previous SERVICE_Add??? call */
 232     if ((service_table = PROCESS_Current()->service_table) == 0)
 233        return retv;
 234
 235     HeapLock( GetProcessHeap() );
 236
 237     for ( s = &service_table->first; *s; s = &(*s)->next )
 238     {
 239         if ( (*s)->self == service )
 240         {
 241             handle = (*s)->object;
 242             next = (*s)->next;
 243             HeapFree( GetProcessHeap(), 0, *s );
 244             *s = next;
 245             retv = TRUE;
 246             break;
 247         }
 248     }
 249
 250     HeapUnlock( GetProcessHeap() );
 251
 252     if ( handle != INVALID_HANDLE_VALUE )
 253         CloseHandle( handle );
 254
 255     QueueUserAPC( NULL, service_table->thread, 0L );
 256
 257     return retv;
 258 }
 259
 260 /***********************************************************************
 261  *           SERVICE_Enable
 262  */
 263 BOOL SERVICE_Enable( HANDLE service )
 264 {
 265     BOOL                retv = FALSE;
 266     SERVICE             *s;
 267     SERVICETABLE        *service_table;
 268
 269     /* service table must have been created on previous SERVICE_Add??? call */
 270     if ((service_table = PROCESS_Current()->service_table) == 0)
 271        return retv;
 272
 273     HeapLock( GetProcessHeap() );
 274
 275     for ( s = service_table->first; s; s = s->next )
 276     {
 277         if ( s->self == service )
 278         {
 279             s->disabled = FALSE;
 280             retv = TRUE;
 281             break;
 282         }
 283     }
 284
 285     HeapUnlock( GetProcessHeap() );
 286
 287     QueueUserAPC( NULL, service_table->thread, 0L );
 288
 289     return retv;
 290 }
 291
 292 /***********************************************************************
 293  *           SERVICE_Disable
 294  */
 295 BOOL SERVICE_Disable( HANDLE service )
 296 {
 297     BOOL                retv = TRUE;
 298     SERVICE             *s;
 299     SERVICETABLE        *service_table;
 300
 301     /* service table must have been created on previous SERVICE_Add??? call */
 302     if ((service_table = PROCESS_Current()->service_table) == 0)
 303        return retv;
 304
 305     HeapLock( GetProcessHeap() );
 306
 307     for ( s = service_table->first; s; s = s->next )
 308     {
 309         if ( s->self == service )
 310         {
 311             s->disabled = TRUE;
 312             retv = TRUE;
 313             break;
 314         }
 315     }
 316
 317     HeapUnlock( GetProcessHeap() );
 318
 319     QueueUserAPC( NULL, service_table->thread, 0L );
 320
 321     return retv;
 322 }
 323
 324