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_get_fd,                 /* get_fd */
  40     no_flush,                  /* flush */
  41     no_get_file_info,          /* get_file_info */
  42     no_destroy                 /* destroy */
  43 };
  44
  45
  46 static struct msg_queue *create_msg_queue( struct thread *thread )
  47 {
  48     struct msg_queue *queue;
  49
  50     if ((queue = alloc_object( &msg_queue_ops, -1 )))
  51     {
  52         queue->signaled = 0;
  53         queue->thread = thread;
  54         thread->queue = queue;
  55         if (!thread->process->queue)
  56             thread->process->queue = (struct msg_queue *)grab_object( queue );
  57     }
  58     return queue;
  59 }
  60
  61 static int msg_queue_add_queue( struct object *obj, struct wait_queue_entry *entry )
  62 {
  63     struct msg_queue *queue = (struct msg_queue *)obj;
  64     struct process *process = entry->thread->process;
  65
  66     /* if waiting on the main process queue, set the idle event */
  67     if (entry->thread == queue->thread && process->queue == queue)
  68     {
  69         if (process->idle_event) set_event( process->idle_event );
  70     }
  71     add_queue( obj, entry );
  72     return 1;
  73 }
  74
  75 static void msg_queue_remove_queue(struct object *obj, struct wait_queue_entry *entry )
  76 {
  77     struct msg_queue *queue = (struct msg_queue *)obj;
  78     struct process *process = entry->thread->process;
  79
  80     remove_queue( obj, entry );
  81
  82     /* if waiting on the main process queue, reset the idle event */
  83     if (entry->thread == queue->thread && process->queue == queue)
  84     {
  85         if (process->idle_event) reset_event( process->idle_event );
  86     }
  87 }
  88
  89 static void msg_queue_dump( struct object *obj, int verbose )
  90 {
  91     struct msg_queue *queue = (struct msg_queue *)obj;
  92     fprintf( stderr, "Msg queue signaled=%d owner=%p\n", queue->signaled, queue->thread );
  93 }
  94
  95 static int msg_queue_signaled( struct object *obj, struct thread *thread )
  96 {
  97     struct msg_queue *queue = (struct msg_queue *)obj;
  98     return queue->signaled;
  99 }
 100
 101 static int msg_queue_satisfied( struct object *obj, struct thread *thread )
 102 {
 103     struct msg_queue *queue = (struct msg_queue *)obj;
 104     queue->signaled = 0;
 105     return 0;  /* Not abandoned */
 106 }
 107
 108 /* get the message queue of the current thread */
 109 DECL_HANDLER(get_msg_queue)
 110 {
 111     struct msg_queue *queue = current->queue;
 112
 113     req->handle = 0;
 114     if (!queue) queue = create_msg_queue( current );
 115     if (queue) req->handle = alloc_handle( current->process, queue, SYNCHRONIZE, 0 );
 116 }
 117
 118 /* wake up a message queue */
 119 DECL_HANDLER(wake_queue)
 120 {
 121     struct msg_queue *queue = (struct msg_queue *)get_handle_obj( current->process, req->handle,
 122                                                                   0, &msg_queue_ops );
 123     if (queue)
 124     {
 125         queue->signaled = 1;
 126         wake_up( &queue->obj, 0 );
 127         release_object( queue );
 128     }
 129 }