scheduler/semaphore.c

   1 /*
   2  * Win32 semaphores
   3  *
   4  * Copyright 1998 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8 #include "windows.h"
   9 #include "winerror.h"
  10 #include "k32obj.h"
  11 #include "process.h"
  12 #include "thread.h"
  13 #include "heap.h"
  14 #include "server/request.h"
  15 #include "server.h"
  16
  17 typedef struct
  18 {
  19     K32OBJ        header;
  20 } SEMAPHORE;
  21
  22 static void SEMAPHORE_Destroy( K32OBJ *obj );
  23
  24 const K32OBJ_OPS SEMAPHORE_Ops =
  25 {
  26     SEMAPHORE_Destroy      /* destroy */
  27 };
  28
  29
  30 /***********************************************************************
  31  *           CreateSemaphore32A   (KERNEL32.174)
  32  */
  33 HANDLE32 WINAPI CreateSemaphore32A( SECURITY_ATTRIBUTES *sa, LONG initial,
  34                                     LONG max, LPCSTR name )
  35 {
  36     struct create_semaphore_request req;
  37     struct create_semaphore_reply reply;
  38     int len = name ? strlen(name) + 1 : 0;
  39     HANDLE32 handle;
  40     SEMAPHORE *sem;
  41
  42     /* Check parameters */
  43
  44     if ((max <= 0) || (initial < 0) || (initial > max))
  45     {
  46         SetLastError( ERROR_INVALID_PARAMETER );
  47         return 0;
  48     }
  49
  50     req.initial = (unsigned int)initial;
  51     req.max     = (unsigned int)max;
  52     req.inherit = (sa && (sa->nLength>=sizeof(*sa)) && sa->bInheritHandle);
  53
  54     CLIENT_SendRequest( REQ_CREATE_SEMAPHORE, -1, 2, &req, sizeof(req), name, len );
  55     CLIENT_WaitReply( &len, NULL, 1, &reply, sizeof(reply) );
  56     CHECK_LEN( len, sizeof(reply) );
  57     if (reply.handle == -1) return 0;
  58
  59     SYSTEM_LOCK();
  60     sem = (SEMAPHORE *)K32OBJ_Create( K32OBJ_SEMAPHORE, sizeof(*sem),
  61                                       name, reply.handle, SEMAPHORE_ALL_ACCESS,
  62                                       sa, &handle);
  63     if (sem) K32OBJ_DecCount( &sem->header );
  64     SYSTEM_UNLOCK();
  65     if (handle == INVALID_HANDLE_VALUE32) handle = 0;
  66     return handle;
  67 }
  68
  69
  70 /***********************************************************************
  71  *           CreateSemaphore32W   (KERNEL32.175)
  72  */
  73 HANDLE32 WINAPI CreateSemaphore32W( SECURITY_ATTRIBUTES *sa, LONG initial,
  74                                     LONG max, LPCWSTR name )
  75 {
  76     LPSTR nameA = HEAP_strdupWtoA( GetProcessHeap(), 0, name );
  77     HANDLE32 ret = CreateSemaphore32A( sa, initial, max, nameA );
  78     if (nameA) HeapFree( GetProcessHeap(), 0, nameA );
  79     return ret;
  80 }
  81
  82
  83 /***********************************************************************
  84  *           OpenSemaphore32A   (KERNEL32.545)
  85  */
  86 HANDLE32 WINAPI OpenSemaphore32A( DWORD access, BOOL32 inherit, LPCSTR name )
  87 {
  88     HANDLE32 handle = 0;
  89     K32OBJ *obj;
  90     struct open_named_obj_request req;
  91     struct open_named_obj_reply reply;
  92     int len = name ? strlen(name) + 1 : 0;
  93
  94     req.type    = OPEN_SEMAPHORE;
  95     req.access  = access;
  96     req.inherit = inherit;
  97     CLIENT_SendRequest( REQ_OPEN_NAMED_OBJ, -1, 2, &req, sizeof(req), name, len );
  98     CLIENT_WaitReply( &len, NULL, 1, &reply, sizeof(reply) );
  99     CHECK_LEN( len, sizeof(reply) );
 100     if (reply.handle != -1)
 101     {
 102         SYSTEM_LOCK();
 103         if ((obj = K32OBJ_FindNameType( name, K32OBJ_SEMAPHORE )) != NULL)
 104         {
 105             handle = HANDLE_Alloc( PROCESS_Current(), obj, access, inherit, reply.handle );
 106             K32OBJ_DecCount( obj );
 107             if (handle == INVALID_HANDLE_VALUE32)
 108                 handle = 0; /* must return 0 on failure, not -1 */
 109         }
 110         else CLIENT_CloseHandle( reply.handle );
 111         SYSTEM_UNLOCK();
 112     }
 113     return handle;
 114 }
 115
 116
 117 /***********************************************************************
 118  *           OpenSemaphore32W   (KERNEL32.546)
 119  */
 120 HANDLE32 WINAPI OpenSemaphore32W( DWORD access, BOOL32 inherit, LPCWSTR name )
 121 {
 122     LPSTR nameA = HEAP_strdupWtoA( GetProcessHeap(), 0, name );
 123     HANDLE32 ret = OpenSemaphore32A( access, inherit, nameA );
 124     if (nameA) HeapFree( GetProcessHeap(), 0, nameA );
 125     return ret;
 126 }
 127
 128
 129 /***********************************************************************
 130  *           ReleaseSemaphore   (KERNEL32.583)
 131  */
 132 BOOL32 WINAPI ReleaseSemaphore( HANDLE32 handle, LONG count, LONG *previous )
 133 {
 134     struct release_semaphore_request req;
 135     struct release_semaphore_reply reply;
 136     int len;
 137
 138     if (count < 0)
 139     {
 140         SetLastError( ERROR_INVALID_PARAMETER );
 141         return FALSE;
 142     }
 143     req.handle = HANDLE_GetServerHandle( PROCESS_Current(), handle,
 144                                          K32OBJ_SEMAPHORE, SEMAPHORE_MODIFY_STATE );
 145     if (req.handle == -1) return FALSE;
 146     req.count = (unsigned int)count;
 147     CLIENT_SendRequest( REQ_RELEASE_SEMAPHORE, -1, 1, &req, sizeof(req) );
 148     if (CLIENT_WaitReply( &len, NULL, 1, &reply, sizeof(reply) )) return FALSE;
 149     CHECK_LEN( len, sizeof(reply) );
 150     if (previous) *previous = reply.prev_count;
 151     return TRUE;
 152 }
 153
 154
 155 /***********************************************************************
 156  *           SEMAPHORE_Destroy
 157  */
 158 static void SEMAPHORE_Destroy( K32OBJ *obj )
 159 {
 160     SEMAPHORE *sem = (SEMAPHORE *)obj;
 161     assert( obj->type == K32OBJ_SEMAPHORE );
 162     /* There cannot be any thread on the list since the ref count is 0 */
 163     obj->type = K32OBJ_UNKNOWN;
 164     HeapFree( SystemHeap, 0, sem );
 165 }