server/event.c

/*
 * Server-side event management
 *
 * Copyright (C) 1998 Alexandre Julliard
 */

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>

#include "winerror.h"
#include "winnt.h"

#include "handle.h"
#include "thread.h"
#include "request.h"

struct event
{
    struct object  obj;             /* object header */
    int            manual_reset;    /* is it a manual reset event? */
    int            signaled;        /* event has been signaled */
};

static void event_dump( struct object *obj, int verbose );
static int event_signaled( struct object *obj, struct thread *thread );
static int event_satisfied( struct object *obj, struct thread *thread );

static const struct object_ops event_ops =
{
    sizeof(struct event),
    event_dump,
    add_queue,
    remove_queue,
    event_signaled,
    event_satisfied,
    no_read_fd,
    no_write_fd,
    no_flush,
    no_get_file_info,
    no_destroy
};


static struct event *create_event( const char *name, size_t len,
                                   int manual_reset, int initial_state )
{
    struct event *event;

    if ((event = create_named_object( &event_ops, name, len )))
    {
        if (get_error() != ERROR_ALREADY_EXISTS)
        {
            /* initialize it if it didn't already exist */
            event->manual_reset = manual_reset;
            event->signaled     = initial_state;
        }
    }
    return event;
}

static int pulse_event( int handle )
{
    struct event *event;

    if (!(event = (struct event *)get_handle_obj( current->process, handle,
                                                  EVENT_MODIFY_STATE, &event_ops )))
        return 0;
    event->signaled = 1;
    /* wake up all waiters if manual reset, a single one otherwise */
    wake_up( &event->obj, !event->manual_reset );
    event->signaled = 0;
    release_object( event );
    return 1;
}

static int set_event( int handle )
{
    struct event *event;

    if (!(event = (struct event *)get_handle_obj( current->process, handle,
                                                  EVENT_MODIFY_STATE, &event_ops )))
        return 0;
    event->signaled = 1;
    /* wake up all waiters if manual reset, a single one otherwise */
    wake_up( &event->obj, !event->manual_reset );
    release_object( event );
    return 1;
}

static int reset_event( int handle )
{
    struct event *event;

    if (!(event = (struct event *)get_handle_obj( current->process, handle,
                                                  EVENT_MODIFY_STATE, &event_ops )))
        return 0;
    event->signaled = 0;
    release_object( event );
    return 1;
}

static void event_dump( struct object *obj, int verbose )
{
    struct event *event = (struct event *)obj;
    assert( obj->ops == &event_ops );
    fprintf( stderr, "Event manual=%d signaled=%d name='%s'\n",
             event->manual_reset, event->signaled,
             get_object_name( &event->obj ) );
}

static int event_signaled( struct object *obj, struct thread *thread )
{
    struct event *event = (struct event *)obj;
    assert( obj->ops == &event_ops );
    return event->signaled;
}

static int event_satisfied( struct object *obj, struct thread *thread )
{
    struct event *event = (struct event *)obj;
    assert( obj->ops == &event_ops );
    /* Reset if it's an auto-reset event */
    if (!event->manual_reset) event->signaled = 0;
    return 0;  /* Not abandoned */
}

/* create an event */
DECL_HANDLER(create_event)
{
    size_t len = get_req_strlen( req->name );
    struct event *event;

    req->handle = -1;
    if ((event = create_event( req->name, len, req->manual_reset, req->initial_state )))
    {
        req->handle = alloc_handle( current->process, event, EVENT_ALL_ACCESS, req->inherit );
        release_object( event );
    }
}

/* open a handle to an event */
DECL_HANDLER(open_event)
{
    size_t len = get_req_strlen( req->name );
    req->handle = open_object( req->name, len, &event_ops, req->access, req->inherit );
}

/* do an event operation */
DECL_HANDLER(event_op)
{
    switch(req->op)
    {
    case PULSE_EVENT:
        pulse_event( req->handle );
        break;
    case SET_EVENT:
        set_event( req->handle );
        break;
    case RESET_EVENT:
        reset_event( req->handle );
        break;
    default:
        fatal_protocol_error( current, "event_op: invalid operation %d\n", req->op );
    }
}