TABLE OF CONTENTS

/Syncpipe [ Modules ]

[ Top ] [ Modules ]

DESCRIPTION

A synced Pipe is an object dedicated to Task communication. A Task can write and read an undefined number of bytes into the Pipe. Unlike the normal Pipe object, the sending and the receiving tasks are synchronized together with the queue mode action, then the data is copied directly from one Task to another.

SEE ALSO

    /Messagequeue, /Mutex, /Pipe, /Semaphore, /Signal

Syncpipe/Syncpipe_Header [ Object Headers ]

[ Top ] [ Syncpipe ] [ Object Headers ]

DESCRIPTION

Header structure of the Syncpipe object

DECLARATION

Const Os_syncpipe_hdr_senddata_ptr = 0
Const Os_syncpipe_hdr_recvdata_ptr = 2
Const Os_syncpipe_hdr_msgsize_ptr = 4
Const Os_syncpipe_hdr_sendtask_ptr = 6
Const Os_syncpipe_hdr_recvtask_ptr = 8
Const Os_syncpipe_hdr_size = 10

Syncpipe/Os_syncpipe_create [ Functions ]

[ Top ] [ Syncpipe ] [ Functions ]

DESCRIPTION

Creates a new Syncpipe object

DECLARATION

Function Os_syncpipe_create() As Word

SOURCE

   Local Syncpipe As Word

   Syncpipe = Malloc(os_syncpipe_hdr_size)
   If Syncpipe = 0 Then
      Os_syncpipe_create = 0
      Exit Function
   End If
   Os_mem_clear Syncpipe , Os_syncpipe_hdr_size

   Os_syncpipe_create = Syncpipe
End Function

Syncpipe/Os_syncpipe_kill [ Functions ]

[ Top ] [ Syncpipe ] [ Functions ]

DESCRIPTION

Kills a Syncpipe object

DECLARATION

Sub Os_syncpipe_kill(byref Syncpipe As Word)

SOURCE

   Free Syncpipe
End Sub

Syncpipe/Os_syncpipe_receive [ Functions ]

[ Top ] [ Syncpipe ] [ Functions ]

DESCRIPTION

Receives an undefined count of bytes from the Pipe, synchronizes the receiving Task with the sender according to the queue mode action.

DECLARATION

Function Os_syncpipe_receive(byref Syncpipe As Word , Byref Recvpointer As Word , Byref Size As Word , Byval Queuemode As Word) As Byte

SEE ALSO

    Syncpipe/Os_syncpipe_send

SOURCE

   Local Sendpointer As Word

   Os_enter_critical
   Sendpointer = Getword(Syncpipe , Os_syncpipe_hdr_senddata_ptr)
   If Sendpointer = 0 Then
      ' no sender   '
      Select Case Queuemode
      Case Os_queuemode_noblock:
         ' return error   '
         Os_exit_critical
         Os_syncpipe_receive = False
         Exit Function
      Case Os_queuemode_block:
         ' suspend and wait to send a message   '
         Os_task_suspendmode Os_task_active , Os_task_suspend_nowakeup , 0
      Case Else
         ' suspend and wait to send a message or timeout   '
         Os_task_suspendmode Os_task_active , Os_task_suspend_timersingleshot , Queuemode
      End Select

      ' suspend   '
      Setword Syncpipe , Os_syncpipe_hdr_recvtask_ptr , Os_task_active
      Setword Syncpipe , Os_syncpipe_hdr_recvdata_ptr , Recvpointer
      Os_exit_critical
      Os_task_suspend Os_task_active
      Os_enter_critical
      Sendpointer = Getword(Syncpipe , Os_syncpipe_hdr_senddata_ptr)
      If Sendpointer = 0 Then
         ' timeout error   '
         Os_exit_critical
         Os_syncpipe_receive = False
         Exit Function
      End If
   End If

   If Sendpointer = 1 Then
      Setword Syncpipe , Os_syncpipe_hdr_senddata_ptr , 0
      Setword Syncpipe , Os_syncpipe_hdr_recvdata_ptr , 0
      Os_exit_critical
   Else
      Os_mem_copy Sendpointer , Recvpointer , Size
      Sendpointer = Getword(Syncpipe , Os_syncpipe_hdr_sendtask_ptr)
      Setword Syncpipe , Os_syncpipe_hdr_senddata_ptr , 0
      Setword Syncpipe , Os_syncpipe_hdr_recvdata_ptr , 1
      Os_exit_critical
      Os_event_task = Sendpointer
      Os_task_event
   End If

   Os_syncpipe_receive = True
End Function

Syncpipe/Os_syncpipe_send [ Functions ]

[ Top ] [ Syncpipe ] [ Functions ]

DESCRIPTION

Sends an undefined count of bytes into the Pipe, synchronizes the sending Task with the receiver according to the queue mode action.

DECLARATION

Function Os_syncpipe_send(byref Syncpipe As Word , Byref Sendpointer As Word , Byval Size As Word , Byval Queuemode As Word) As Byte

SEE ALSO

    Syncpipe/Os_syncpipe_receive

SOURCE

   Local Recvpointer As Word

   Os_enter_critical
   Recvpointer = Getword(Syncpipe , Os_syncpipe_hdr_recvdata_ptr)
   If Recvpointer = 0 Then
      ' no receiver   '
      Select Case Queuemode
      Case Os_queuemode_noblock:
         ' return error   '
         Os_exit_critical
         Os_syncpipe_send = False
         Exit Function
      Case Os_queuemode_block:
         ' suspend and wait to send a message   '
         Os_task_suspendmode Os_task_active , Os_task_suspend_nowakeup , 0
      Case Else
         ' suspend and wait to send a message or timeout   '
         Os_task_suspendmode Os_task_active , Os_task_suspend_timersingleshot , Queuemode
      End Select

      ' suspend   '
      Setword Syncpipe , Os_syncpipe_hdr_sendtask_ptr , Os_task_active
      Setword Syncpipe , Os_syncpipe_hdr_senddata_ptr , Sendpointer
      Setword Syncpipe , Os_syncpipe_hdr_msgsize_ptr , Size
      Os_exit_critical
      Os_task_suspend Os_task_active
      Os_enter_critical
      Recvpointer = Getword(Syncpipe , Os_syncpipe_hdr_recvdata_ptr)
      If Recvpointer = 0 Then
         ' timeout error   '
         Os_exit_critical
         Os_syncpipe_send = False
         Exit Function
      End If
   End If

   If Recvpointer = 1 Then
      Setword Syncpipe , Os_syncpipe_hdr_senddata_ptr , 0
      Setword Syncpipe , Os_syncpipe_hdr_recvdata_ptr , 0
      Os_exit_critical
   Else
      Os_mem_copy Sendpointer , Recvpointer , Size
      Recvpointer = Getword(Syncpipe , Os_syncpipe_hdr_recvtask_ptr)
      Setword Syncpipe , Os_syncpipe_hdr_senddata_ptr , 1
      Setword Syncpipe , Os_syncpipe_hdr_recvdata_ptr , 0
      Os_exit_critical
      Os_event_task = Recvpointer
      Os_task_event
   End If

   Os_syncpipe_send = True
End Function