spice/server/main_dispatcher.c
Alon Levy 776bdd6c95 server: introduce dispatcher
used for main_dispatcher only in this patch.

Dispatcher is meant to be used for Main<->any low frequency messages.

It's interface is meant to include the red_dispatcher usage:
 fixed size messages per message type
 some messages require an ack

Some methods are added to be used by RedDispatcher later:
 dispatcher_handle_read - to be called directly by RedDispatcher epoll
  based loop
 dispatcher_set_opaque - to be set from red_worker pthread
 dispatcher_init - allow NULL core as used by red_worker

Read and Write behavior:
 Sender: blocking write, blocking read for ack (if any).
 Reader: poll for any data, if such then blocking read for a
 message_type and following message. repeat until poll returns
 with no pending data to read.

FDO Bugzilla: 42463
2011-11-08 14:59:49 +02:00

98 lines
3.1 KiB
C

#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <pthread.h>
#include <assert.h>
#include "red_common.h"
#include "dispatcher.h"
#include "main_dispatcher.h"
/*
* Main Dispatcher
* ===============
*
* Communication channel between any non main thread and the main thread.
*
* The main thread is that from which spice_server_init is called.
*
* Messages are single sized, sent from the non-main thread to the main-thread.
* No acknowledge is sent back. This prevents a possible deadlock with the main
* thread already waiting on a response for the existing red_dispatcher used
* by the worker thread.
*
* All events have three functions:
* main_dispatcher_<event_name> - non static, public function
* main_dispatcher_self_<event_name> - handler for main thread
* main_dispatcher_handle_<event_name> - handler for callback from main thread
* seperate from self because it may send an ack or do other work in the future.
*/
typedef struct {
Dispatcher base;
SpiceCoreInterface *core;
} MainDispatcher;
MainDispatcher main_dispatcher;
enum {
MAIN_DISPATCHER_CHANNEL_EVENT = 0,
MAIN_DISPATCHER_NUM_MESSAGES
};
typedef struct MainDispatcherChannelEventMessage {
int event;
SpiceChannelEventInfo *info;
} MainDispatcherChannelEventMessage;
/* channel_event - calls core->channel_event, must be done in main thread */
static void main_dispatcher_self_handle_channel_event(
int event,
SpiceChannelEventInfo *info)
{
main_dispatcher.core->channel_event(event, info);
}
static void main_dispatcher_handle_channel_event(void *opaque,
void *payload)
{
MainDispatcherChannelEventMessage *channel_event = payload;
main_dispatcher_self_handle_channel_event(channel_event->event,
channel_event->info);
}
void main_dispatcher_channel_event(int event, SpiceChannelEventInfo *info)
{
MainDispatcherChannelEventMessage msg;
if (pthread_self() == main_dispatcher.base.self) {
main_dispatcher_self_handle_channel_event(event, info);
return;
}
msg.event = event;
msg.info = info;
dispatcher_send_message(&main_dispatcher.base, MAIN_DISPATCHER_CHANNEL_EVENT,
&msg);
}
static void dispatcher_handle_read(int fd, int event, void *opaque)
{
Dispatcher *dispatcher = opaque;
dispatcher_handle_recv_read(dispatcher);
}
void main_dispatcher_init(SpiceCoreInterface *core)
{
memset(&main_dispatcher, 0, sizeof(main_dispatcher));
main_dispatcher.core = core;
dispatcher_init(&main_dispatcher.base, MAIN_DISPATCHER_NUM_MESSAGES, &main_dispatcher.base);
core->watch_add(main_dispatcher.base.recv_fd, SPICE_WATCH_EVENT_READ,
dispatcher_handle_read, &main_dispatcher.base);
dispatcher_register_handler(&main_dispatcher.base, MAIN_DISPATCHER_CHANNEL_EVENT,
main_dispatcher_handle_channel_event,
sizeof(MainDispatcherChannelEventMessage), 0 /* no ack */);
}