1------------------------------------------------------------------------------
2--                                                                          --
3--                GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS               --
4--                                                                          --
5--                 S Y S T E M . T A S K I N G . Q U E U I N G              --
6--                                                                          --
7--                                  S p e c                                 --
8--                                                                          --
9--         Copyright (C) 1992-2001, Free Software Foundation, Inc.          --
10--                                                                          --
11-- GNARL is free software; you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
14-- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
17-- for  more details.  You should have  received  a copy of the GNU General --
18-- Public License  distributed with GNARL; see file COPYING.  If not, write --
19-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
20-- MA 02111-1307, USA.                                                      --
21--                                                                          --
22-- As a special exception,  if other files  instantiate  generics from this --
23-- unit, or you link  this unit with other files  to produce an executable, --
24-- this  unit  does not  by itself cause  the resulting  executable  to  be --
25-- covered  by the  GNU  General  Public  License.  This exception does not --
26-- however invalidate  any other reasons why  the executable file  might be --
27-- covered by the  GNU Public License.                                      --
28--                                                                          --
29-- GNARL was developed by the GNARL team at Florida State University.       --
30-- Extensive contributions were provided by Ada Core Technologies, Inc.     --
31--                                                                          --
32------------------------------------------------------------------------------
33
34with System.Tasking.Protected_Objects.Entries;
35
36package System.Tasking.Queuing is
37
38   package POE renames System.Tasking.Protected_Objects.Entries;
39
40   procedure Broadcast_Program_Error
41     (Self_ID      : Task_ID;
42      Object       : POE.Protection_Entries_Access;
43      Pending_Call : Entry_Call_Link;
44      RTS_Locked   : Boolean := False);
45   --  Raise Program_Error in all tasks calling the protected entries of Object
46   --  The exception will not be raised immediately for the calling task; it
47   --  will be deferred until it calls Check_Exception.
48   --  RTS_Locked indicates whether the global RTS lock is taken (only
49   --  relevant if Single_Lock is True).
50
51   procedure Enqueue (E : in out Entry_Queue; Call : Entry_Call_Link);
52   --  Enqueue Call at the end of entry_queue E
53
54   procedure Dequeue (E : in out Entry_Queue; Call : Entry_Call_Link);
55   --  Dequeue Call from entry_queue E
56
57   function Head (E : in Entry_Queue) return Entry_Call_Link;
58   --  Return the head of entry_queue E
59   pragma Inline (Head);
60
61   procedure Dequeue_Head
62     (E    : in out Entry_Queue;
63      Call : out Entry_Call_Link);
64   --  Remove and return the head of entry_queue E
65
66   function Onqueue (Call : Entry_Call_Link) return Boolean;
67   --  Return True if Call is on any entry_queue at all
68   pragma Inline (Onqueue);
69
70   function Count_Waiting (E : in Entry_Queue) return Natural;
71   --  Return number of calls on the waiting queue of E
72
73   procedure Select_Task_Entry_Call
74     (Acceptor         : Task_ID;
75      Open_Accepts     : Accept_List_Access;
76      Call             : out Entry_Call_Link;
77      Selection        : out Select_Index;
78      Open_Alternative : out Boolean);
79   --  Select an entry for rendezvous.  On exit:
80   --    Call will contain a pointer to the entry call record selected;
81   --    Selection will contain the index of the alternative selected
82   --    Open_Alternative will be True if there were any open alternatives
83
84   procedure Select_Protected_Entry_Call
85     (Self_ID   : Task_ID;
86      Object    : POE.Protection_Entries_Access;
87      Call      : out Entry_Call_Link);
88   --  Select an entry of a protected object
89
90   procedure Enqueue_Call (Entry_Call : Entry_Call_Link);
91   procedure Dequeue_Call (Entry_Call : Entry_Call_Link);
92   --  Enqueue (dequeue) the call to (from) whatever server they are
93   --  calling, whether a task or a protected object.
94
95   procedure Requeue_Call_With_New_Prio
96     (Entry_Call : Entry_Call_Link; Prio : System.Any_Priority);
97   --  Change Priority of the call and re insert to the queue when priority
98   --  queueing is in effect. When FIFO is inforced, this routine
99   --  should not have any effect.
100
101end System.Tasking.Queuing;
102