1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . T A S K I N G . Q U E U I N G --
9 -- Copyright (C) 1992-2024, Free Software Foundation, Inc. --
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 3, or (at your option) any later ver- --
14 -- sion. GNAT 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. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
30 ------------------------------------------------------------------------------
32 with System
.Tasking
.Protected_Objects
.Entries
;
34 package System
.Tasking
.Queuing
is
36 package POE
renames System
.Tasking
.Protected_Objects
.Entries
;
38 procedure Broadcast_Program_Error
40 Object
: POE
.Protection_Entries_Access
;
41 Pending_Call
: Entry_Call_Link
);
42 -- Raise Program_Error in all tasks calling the protected entries of Object
43 -- The exception will not be raised immediately for the calling task; it
44 -- will be deferred until it calls Check_Exception.
46 procedure Enqueue
(E
: in out Entry_Queue
; Call
: Entry_Call_Link
);
47 -- Enqueue Call at the end of entry_queue E
49 procedure Dequeue
(E
: in out Entry_Queue
; Call
: Entry_Call_Link
);
50 -- Dequeue Call from entry_queue E
52 function Head
(E
: Entry_Queue
) return Entry_Call_Link
;
54 -- Return the head of entry_queue E
56 procedure Dequeue_Head
57 (E
: in out Entry_Queue
;
58 Call
: out Entry_Call_Link
);
59 -- Remove and return the head of entry_queue E
61 function Onqueue
(Call
: Entry_Call_Link
) return Boolean;
62 pragma Inline
(Onqueue
);
63 -- Return True if Call is on any entry_queue at all
65 function Count_Waiting
(E
: Entry_Queue
) return Natural;
66 -- Return number of calls on the waiting queue of E
68 procedure Select_Task_Entry_Call
70 Open_Accepts
: Accept_List_Access
;
71 Call
: out Entry_Call_Link
;
72 Selection
: out Select_Index
;
73 Open_Alternative
: out Boolean);
74 -- Select an entry for rendezvous. On exit:
75 -- Call will contain a pointer to the entry call record selected;
76 -- Selection will contain the index of the alternative selected
77 -- Open_Alternative will be True if there were any open alternatives
79 procedure Select_Protected_Entry_Call
81 Object
: POE
.Protection_Entries_Access
;
82 Call
: out Entry_Call_Link
);
83 -- Select an entry of a protected object
85 procedure Enqueue_Call
(Entry_Call
: Entry_Call_Link
);
86 procedure Dequeue_Call
(Entry_Call
: Entry_Call_Link
);
87 -- Enqueue (dequeue) the call to (from) whatever server they are
88 -- calling, whether a task or a protected object.
90 procedure Requeue_Call_With_New_Prio
91 (Entry_Call
: Entry_Call_Link
; Prio
: System
.Any_Priority
);
92 -- Change Priority of the call and re insert to the queue when priority
93 -- queueing is in effect. When FIFO is enforced, this routine
94 -- should not have any effect.
96 end System
.Tasking
.Queuing
;