|
111
|
1 ------------------------------------------------------------------------------
|
|
|
2 -- --
|
|
|
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
|
|
|
4 -- --
|
|
|
5 -- S Y S T E M . T A S K I N G . E N T R Y _ C A L L S --
|
|
|
6 -- --
|
|
|
7 -- S p e c --
|
|
|
8 -- --
|
|
131
|
9 -- Copyright (C) 1992-2018, Free Software Foundation, Inc. --
|
|
111
|
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 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. --
|
|
|
17 -- --
|
|
|
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. --
|
|
|
21 -- --
|
|
|
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/>. --
|
|
|
26 -- --
|
|
|
27 -- GNARL was developed by the GNARL team at Florida State University. --
|
|
|
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
|
|
|
29 -- --
|
|
|
30 ------------------------------------------------------------------------------
|
|
|
31
|
|
|
32 -- This package provides internal RTS calls implementing operations
|
|
|
33 -- that apply to general entry calls, that is, calls to either
|
|
|
34 -- protected or task entries.
|
|
|
35
|
|
|
36 -- These declarations are not part of the GNARL Interface
|
|
|
37
|
|
|
38 package System.Tasking.Entry_Calls is
|
|
|
39
|
|
|
40 procedure Wait_For_Completion (Entry_Call : Entry_Call_Link);
|
|
|
41 -- This procedure suspends the calling task until the specified entry
|
|
|
42 -- call has either been completed or cancelled. It performs other
|
|
|
43 -- operations required of suspended tasks, such as performing
|
|
|
44 -- dynamic priority changes. On exit, the call will not be queued.
|
|
|
45 -- This waits for calls on task or protected entries.
|
|
|
46 -- Abortion must be deferred when calling this procedure.
|
|
|
47 -- Call this only when holding Self (= Entry_Call.Self) or global RTS lock.
|
|
|
48
|
|
|
49 procedure Wait_For_Completion_With_Timeout
|
|
|
50 (Entry_Call : Entry_Call_Link;
|
|
|
51 Wakeup_Time : Duration;
|
|
|
52 Mode : Delay_Modes;
|
|
|
53 Yielded : out Boolean);
|
|
|
54 -- Same as Wait_For_Completion but wait for a timeout with the value
|
|
|
55 -- specified in Wakeup_Time as well.
|
|
|
56 -- On return, Yielded indicates whether the wait has performed a yield.
|
|
|
57 -- Check_Exception must be called after calling this procedure.
|
|
|
58
|
|
|
59 procedure Wait_Until_Abortable
|
|
|
60 (Self_ID : Task_Id;
|
|
|
61 Call : Entry_Call_Link);
|
|
|
62 -- This procedure suspends the calling task until the specified entry
|
|
|
63 -- call is queued abortably or completes.
|
|
|
64 -- Abortion must be deferred when calling this procedure, and the global
|
|
|
65 -- RTS lock taken when Single_Lock.
|
|
|
66
|
|
|
67 procedure Try_To_Cancel_Entry_Call (Succeeded : out Boolean);
|
|
|
68 pragma Inline (Try_To_Cancel_Entry_Call);
|
|
|
69 -- Try to cancel async. entry call.
|
|
|
70 -- Effect includes Abort_To_Level and Wait_For_Completion.
|
|
|
71 -- Cancelled = True iff the cancellation was successful, i.e.,
|
|
|
72 -- the call was not Done before this call.
|
|
|
73 -- On return, the call is off-queue and the ATC level is reduced by one.
|
|
|
74
|
|
|
75 procedure Reset_Priority
|
|
|
76 (Acceptor : Task_Id;
|
|
|
77 Acceptor_Prev_Priority : Rendezvous_Priority);
|
|
|
78 pragma Inline (Reset_Priority);
|
|
|
79 -- Reset the priority of a task completing an accept statement to
|
|
|
80 -- the value it had before the call.
|
|
|
81 -- Acceptor should always be equal to Self.
|
|
|
82
|
|
|
83 procedure Check_Exception
|
|
|
84 (Self_ID : Task_Id;
|
|
|
85 Entry_Call : Entry_Call_Link);
|
|
|
86 pragma Inline (Check_Exception);
|
|
|
87 -- Raise any pending exception from the Entry_Call.
|
|
|
88 -- This should be called at the end of every compiler interface procedure
|
|
|
89 -- that implements an entry call.
|
|
|
90 -- In principle, the caller should not be abort-deferred (unless the
|
|
|
91 -- application program violates the Ada language rules by doing entry calls
|
|
|
92 -- from within protected operations -- an erroneous practice apparently
|
|
|
93 -- followed with success by some adventurous GNAT users).
|
|
|
94 -- Absolutely, the caller should not be holding any locks, or there
|
|
|
95 -- will be deadlock.
|
|
|
96
|
|
|
97 end System.Tasking.Entry_Calls;
|
