src/apps/cortex/NodeManager/NodeSyncThread.h

   1 /*
   2  * Copyright (c) 1999-2000, Eric Moon.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions, and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions, and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  23  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  24  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  27  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31
  32 // NodeSyncThread.h [rewrite 14oct99]
  33 // * PURPOSE
  34 //   Provide continuous synchronization notices on
  35 //   a particular BMediaNode.  Notification is sent
  36 //   to a provided BMessenger.
  37 //
  38 //   As long as a NodeSyncThread object exists its thread
  39 //   is running.  The thread blocks indefinitely, waiting
  40 //   for a message to show up on an internal port.
  41 //
  42 //   Sync-notice requests (via the +++++ sync() operation)
  43 //   trigger a message sent to that port.  The thread wakes
  44 //   up, then calls BMediaRoster::SyncToNode() to wait
  45 //   until a particular performace time arrives for that node.
  46 //
  47 //   If SyncToNode() times out, an M_TIMED_OUT message is sent;
  48 //   otherwise, an M_SYNC_COMPLETE message is sent.
  49 //
  50 // * HISTORY
  51 //   e.moon             14oct99         Rewrite begun.
  52
  53 #ifndef __NodeSyncThread_H__
  54 #define __NodeSyncThread_H__
  55
  56 #include <MediaNode.h>
  57 #include <Messenger.h>
  58 #include <OS.h>
  59
  60 #include "cortex_defs.h"
  61 __BEGIN_CORTEX_NAMESPACE
  62
  63 class NodeSyncThread {
  64 public:                                                                                                 // *** messages
  65         enum message_t {
  66                 // 'nodeID' (int32)         media_node_id value
  67                 // 'perfTime' (int64)                           the performance time
  68                 // 'position' (int64)       corresponding (caller-provided) position
  69                 M_SYNC_COMPLETE                                                 =NodeSyncThread_message_base,
  70
  71                 // 'nodeID' (int32)         media_node_id value
  72                 // 'error' (int32)                                      status_t value from SyncToNode()
  73                 // 'perfTime' (int64)                           the performance time
  74                 // 'position' (int64)       corresponding (caller-provided) position
  75                 M_SYNC_FAILED
  76         };
  77
  78 public:                                                                                                 // *** dtor/ctors
  79         virtual ~NodeSyncThread();
  80
  81         NodeSyncThread(
  82                 const media_node&                                               node,
  83                 BMessenger*                                                                     messenger);
  84
  85 public:                                                                                                 // *** operations
  86         // trigger a sync operation: when 'perfTime' arrives
  87         // for the node, a M_SYNC_COMPLETE message with the given
  88         // position value will be sent,  unless the sync operation
  89         // times out, in which case M_TIMED_OUT will be sent.
  90         status_t sync(
  91                 bigtime_t                                                                               perfTime,
  92                 bigtime_t                                                                               position,
  93                 bigtime_t                                                                               timeout);
  94
  95 private:
  96
  97         // the node to watch
  98         media_node                                                                              m_node;
  99
 100         // the messenger to inform
 101         BMessenger*                                                                             m_messenger;
 102
 103         // if the thread is running, it has exclusive write access
 104         // to this flag.
 105         volatile bool                                                                   m_syncInProgress;
 106
 107         // thread guts
 108         thread_id                                                                                       m_thread;
 109         port_id                                                                                         m_port;
 110         char*                                                                                                   m_portBuffer;
 111         ssize_t                                                                                         m_portBufferSize;
 112
 113         enum _op_codes {
 114                 M_TRIGGER
 115         };
 116
 117         struct _sync_op {
 118                 bigtime_t       targetTime;
 119                 bigtime_t               position;
 120                 bigtime_t               timeout;
 121         };
 122
 123         static status_t _Sync(
 124                 void*                                                                                           cookie);
 125         void _sync();
 126 };
 127
 128 __END_CORTEX_NAMESPACE
 129 #endif /*__NodeSyncThread_H__*/