Sweden-Number/scheduler/semaphore.c

220 lines
6.0 KiB
C

/*
* Win32 semaphores
*
* Copyright 1998 Alexandre Julliard
*/
#include <assert.h>
#include "windows.h"
#include "winerror.h"
#include "k32obj.h"
#include "process.h"
#include "thread.h"
#include "heap.h"
typedef struct
{
K32OBJ header;
THREAD_QUEUE wait_queue;
LONG count;
LONG max;
} SEMAPHORE;
static BOOL32 SEMAPHORE_Signaled( K32OBJ *obj, DWORD thread_id );
static BOOL32 SEMAPHORE_Satisfied( K32OBJ *obj, DWORD thread_id );
static void SEMAPHORE_AddWait( K32OBJ *obj, DWORD thread_id );
static void SEMAPHORE_RemoveWait( K32OBJ *obj, DWORD thread_id );
static void SEMAPHORE_Destroy( K32OBJ *obj );
const K32OBJ_OPS SEMAPHORE_Ops =
{
SEMAPHORE_Signaled, /* signaled */
SEMAPHORE_Satisfied, /* satisfied */
SEMAPHORE_AddWait, /* add_wait */
SEMAPHORE_RemoveWait, /* remove_wait */
NULL, /* read */
NULL, /* write */
SEMAPHORE_Destroy /* destroy */
};
/***********************************************************************
* CreateSemaphore32A (KERNEL32.174)
*/
HANDLE32 WINAPI CreateSemaphore32A( SECURITY_ATTRIBUTES *sa, LONG initial,
LONG max, LPCSTR name )
{
HANDLE32 handle;
SEMAPHORE *sem;
/* Check parameters */
if ((max <= 0) || (initial < 0) || (initial > max))
{
SetLastError( ERROR_INVALID_PARAMETER );
return INVALID_HANDLE_VALUE32;
}
SYSTEM_LOCK();
sem = (SEMAPHORE *)K32OBJ_Create( K32OBJ_SEMAPHORE, sizeof(*sem),
name, SEMAPHORE_ALL_ACCESS, sa, &handle);
if (sem)
{
/* Finish initializing it */
sem->wait_queue = NULL;
sem->count = initial;
sem->max = max;
K32OBJ_DecCount( &sem->header );
}
SYSTEM_UNLOCK();
return handle;
}
/***********************************************************************
* CreateSemaphore32W (KERNEL32.175)
*/
HANDLE32 WINAPI CreateSemaphore32W( SECURITY_ATTRIBUTES *sa, LONG initial,
LONG max, LPCWSTR name )
{
LPSTR nameA = HEAP_strdupWtoA( GetProcessHeap(), 0, name );
HANDLE32 ret = CreateSemaphore32A( sa, initial, max, nameA );
if (nameA) HeapFree( GetProcessHeap(), 0, nameA );
return ret;
}
/***********************************************************************
* OpenSemaphore32A (KERNEL32.545)
*/
HANDLE32 WINAPI OpenSemaphore32A( DWORD access, BOOL32 inherit, LPCSTR name )
{
HANDLE32 handle = 0;
K32OBJ *obj;
SYSTEM_LOCK();
if ((obj = K32OBJ_FindNameType( name, K32OBJ_SEMAPHORE )) != NULL)
{
handle = HANDLE_Alloc( PROCESS_Current(), obj, access, inherit );
K32OBJ_DecCount( obj );
}
SYSTEM_UNLOCK();
return handle;
}
/***********************************************************************
* OpenSemaphore32W (KERNEL32.546)
*/
HANDLE32 WINAPI OpenSemaphore32W( DWORD access, BOOL32 inherit, LPCWSTR name )
{
LPSTR nameA = HEAP_strdupWtoA( GetProcessHeap(), 0, name );
HANDLE32 ret = OpenSemaphore32A( access, inherit, nameA );
if (nameA) HeapFree( GetProcessHeap(), 0, nameA );
return ret;
}
/***********************************************************************
* ReleaseSemaphore (KERNEL32.583)
*/
BOOL32 WINAPI ReleaseSemaphore( HANDLE32 handle, LONG count, LONG *previous )
{
SEMAPHORE *sem;
SYSTEM_LOCK();
if (!(sem = (SEMAPHORE *)HANDLE_GetObjPtr( PROCESS_Current(), handle,
K32OBJ_SEMAPHORE,
SEMAPHORE_MODIFY_STATE )))
{
SYSTEM_UNLOCK();
return FALSE;
}
if (previous) *previous = sem->count;
if (sem->count + count > sem->max)
{
SYSTEM_UNLOCK();
SetLastError( ERROR_TOO_MANY_POSTS );
return FALSE;
}
if (sem->count > 0)
{
/* There cannot be any thread waiting if the count is > 0 */
assert( sem->wait_queue == NULL );
sem->count += count;
}
else
{
sem->count = count;
SYNC_WakeUp( &sem->wait_queue, count );
}
K32OBJ_DecCount( &sem->header );
SYSTEM_UNLOCK();
return TRUE;
}
/***********************************************************************
* SEMAPHORE_Signaled
*/
static BOOL32 SEMAPHORE_Signaled( K32OBJ *obj, DWORD thread_id )
{
SEMAPHORE *sem = (SEMAPHORE *)obj;
assert( obj->type == K32OBJ_SEMAPHORE );
return (sem->count > 0);
}
/***********************************************************************
* SEMAPHORE_Satisfied
*
* Wait on this object has been satisfied.
*/
static BOOL32 SEMAPHORE_Satisfied( K32OBJ *obj, DWORD thread_id )
{
SEMAPHORE *sem = (SEMAPHORE *)obj;
assert( obj->type == K32OBJ_SEMAPHORE );
assert( sem->count > 0 );
sem->count--;
return FALSE; /* Not abandoned */
}
/***********************************************************************
* SEMAPHORE_AddWait
*
* Add current thread to object wait queue.
*/
static void SEMAPHORE_AddWait( K32OBJ *obj, DWORD thread_id )
{
SEMAPHORE *sem = (SEMAPHORE *)obj;
assert( obj->type == K32OBJ_SEMAPHORE );
THREAD_AddQueue( &sem->wait_queue, THREAD_ID_TO_THDB(thread_id) );
}
/***********************************************************************
* SEMAPHORE_RemoveWait
*
* Remove thread from object wait queue.
*/
static void SEMAPHORE_RemoveWait( K32OBJ *obj, DWORD thread_id )
{
SEMAPHORE *sem = (SEMAPHORE *)obj;
assert( obj->type == K32OBJ_SEMAPHORE );
THREAD_RemoveQueue( &sem->wait_queue, THREAD_ID_TO_THDB(thread_id) );
}
/***********************************************************************
* SEMAPHORE_Destroy
*/
static void SEMAPHORE_Destroy( K32OBJ *obj )
{
SEMAPHORE *sem = (SEMAPHORE *)obj;
assert( obj->type == K32OBJ_SEMAPHORE );
/* There cannot be any thread on the list since the ref count is 0 */
assert( sem->wait_queue == NULL );
obj->type = K32OBJ_UNKNOWN;
HeapFree( SystemHeap, 0, sem );
}