server/queue.c

   1 /*
   2  * Server-side message queues
   3  *
   4  * Copyright (C) 2000 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10
  11 #include "handle.h"
  12 #include "thread.h"
  13 #include "process.h"
  14 #include "request.h"
  15
  16 struct msg_queue
  17 {
  18     struct object  obj;             /* object header */
  19     struct thread *thread;          /* thread owning this queue */
  20     int            signaled;        /* queue has been signaled */
  21 };
  22
  23 static void msg_queue_dump( struct object *obj, int verbose );
  24 static int msg_queue_add_queue( struct object *obj, struct wait_queue_entry *entry );
  25 static void msg_queue_remove_queue( struct object *obj, struct wait_queue_entry *entry );
  26 static int msg_queue_signaled( struct object *obj, struct thread *thread );
  27 static int msg_queue_satisfied( struct object *obj, struct thread *thread );
  28
  29 static const struct object_ops msg_queue_ops =
  30 {
  31     sizeof(struct msg_queue),  /* size */
  32     msg_queue_dump,            /* dump */
  33     msg_queue_add_queue,       /* add_queue */
  34     msg_queue_remove_queue,    /* remove_queue */
  35     msg_queue_signaled,        /* signaled */
  36     msg_queue_satisfied,       /* satisfied */
  37     NULL,                      /* get_poll_events */
  38     NULL,                      /* poll_event */
  39     no_read_fd,                /* get_read_fd */
  40     no_write_fd,               /* get_write_fd */
  41     no_flush,                  /* flush */
  42     no_get_file_info,          /* get_file_info */
  43     no_destroy                 /* destroy */
  44 };
  45
  46
  47 static struct msg_queue *create_msg_queue( struct thread *thread )
  48 {
  49     struct msg_queue *queue;
  50
  51     if ((queue = alloc_object( &msg_queue_ops, -1 )))
  52     {
  53         queue->signaled = 0;
  54         queue->thread = thread;
  55         thread->queue = queue;
  56         if (!thread->process->queue)
  57             thread->process->queue = (struct msg_queue *)grab_object( queue );
  58     }
  59     return queue;
  60 }
  61
  62 static int msg_queue_add_queue( struct object *obj, struct wait_queue_entry *entry )
  63 {
  64     struct msg_queue *queue = (struct msg_queue *)obj;
  65     struct process *process = entry->thread->process;
  66
  67     /* if waiting on the main process queue, set the idle event */
  68     if (entry->thread == queue->thread && process->queue == queue)
  69     {
  70         if (process->idle_event) set_event( process->idle_event );
  71     }
  72     add_queue( obj, entry );
  73     return 1;
  74 }
  75
  76 static void msg_queue_remove_queue(struct object *obj, struct wait_queue_entry *entry )
  77 {
  78     struct msg_queue *queue = (struct msg_queue *)obj;
  79     struct process *process = entry->thread->process;
  80
  81     remove_queue( obj, entry );
  82
  83     /* if waiting on the main process queue, reset the idle event */
  84     if (entry->thread == queue->thread && process->queue == queue)
  85     {
  86         if (process->idle_event) reset_event( process->idle_event );
  87     }
  88 }
  89
  90 static void msg_queue_dump( struct object *obj, int verbose )
  91 {
  92     struct msg_queue *queue = (struct msg_queue *)obj;
  93     fprintf( stderr, "Msg queue signaled=%d owner=%p\n", queue->signaled, queue->thread );
  94 }
  95
  96 static int msg_queue_signaled( struct object *obj, struct thread *thread )
  97 {
  98     struct msg_queue *queue = (struct msg_queue *)obj;
  99     return queue->signaled;
 100 }
 101
 102 static int msg_queue_satisfied( struct object *obj, struct thread *thread )
 103 {
 104     struct msg_queue *queue = (struct msg_queue *)obj;
 105     queue->signaled = 0;
 106     return 0;  /* Not abandoned */
 107 }
 108
 109 /* get the message queue of the current thread */
 110 DECL_HANDLER(get_msg_queue)
 111 {
 112     struct msg_queue *queue = current->queue;
 113
 114     req->handle = -1;
 115     if (!queue) queue = create_msg_queue( current );
 116     if (queue) req->handle = alloc_handle( current->process, queue, SYNCHRONIZE, 0 );
 117 }
 118
 119 /* wake up a message queue */
 120 DECL_HANDLER(wake_queue)
 121 {
 122     struct msg_queue *queue = (struct msg_queue *)get_handle_obj( current->process, req->handle,
 123                                                                   0, &msg_queue_ops );
 124     if (queue)
 125     {
 126         queue->signaled = 1;
 127         wake_up( &queue->obj, 0 );
 128         release_object( queue );
 129     }
 130 }