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diff --git a/gcc/ada/s-tasini.ads b/gcc/ada/s-tasini.ads new file mode 100644 index 000000000..0b2f45092 --- /dev/null +++ b/gcc/ada/s-tasini.ads @@ -0,0 +1,190 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- +-- -- +-- S Y S T E M . T A S K I N G . I N I T I A L I Z A T I O N -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- +-- -- +-- GNARL is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNARL was developed by the GNARL team at Florida State University. -- +-- Extensive contributions were provided by Ada Core Technologies, Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides overall initialization of the tasking portion of the +-- RTS. This package must be elaborated before any tasking features are used. + +package System.Tasking.Initialization is + + procedure Remove_From_All_Tasks_List (T : Task_Id); + -- Remove T from All_Tasks_List. Call this function with RTS_Lock taken + + --------------------------------- + -- Tasking-Specific Soft Links -- + --------------------------------- + + -- These permit us to leave out certain portions of the tasking + -- run-time system if they are not used. They are only used internally + -- by the tasking run-time system. + + -- So far, the only example is support for Ada.Task_Attributes + + type Proc_T is access procedure (T : Task_Id); + + procedure Finalize_Attributes (T : Task_Id); + procedure Initialize_Attributes (T : Task_Id); + + Finalize_Attributes_Link : Proc_T := Finalize_Attributes'Access; + -- should be called with abort deferred and T.L write-locked + + Initialize_Attributes_Link : Proc_T := Initialize_Attributes'Access; + -- should be called with abort deferred, but holding no locks + + ------------------------- + -- Abort Defer/Undefer -- + ------------------------- + + -- Defer_Abort defers the affects of low-level abort and priority change + -- in the calling task until a matching Undefer_Abort call is executed. + + -- Undefer_Abort DOES MORE than just undo the effects of one call to + -- Defer_Abort. It is the universal "polling point" for deferred + -- processing, including the following: + + -- 1) base priority changes + + -- 2) abort/ATC + + -- Abort deferral MAY be nested (Self_ID.Deferral_Level is a count), but + -- to avoid waste and undetected errors, it generally SHOULD NOT be + -- nested. The symptom of over-deferring abort is that an exception may + -- fail to be raised, or an abort may fail to take place. + + -- Therefore, there are two sets of the inlineable defer/undefer routines, + -- which are the ones to be used inside GNARL. One set allows nesting. The + -- other does not. People who maintain the GNARL should try to avoid using + -- the nested versions, or at least look very critically at the places + -- where they are used. + + -- In general, any GNARL call that is potentially blocking, or whose + -- semantics require that it sometimes raise an exception, or that is + -- required to be an abort completion point, must be made with abort + -- Deferral_Level = 1. + + -- In general, non-blocking GNARL calls, which may be made from inside a + -- protected action, are likely to need to allow nested abort deferral. + + -- With some critical exceptions (which are supposed to be documented), + -- internal calls to the tasking runtime system assume abort is already + -- deferred, and do not modify the deferral level. + + -- There is also a set of non-inlineable defer/undefer routines, for direct + -- call from the compiler. These are not inlineable because they may need + -- to be called via pointers ("soft links"). For the sake of efficiency, + -- the version with Self_ID as parameter should used wherever possible. + -- These are all nestable. + + -- Non-nestable inline versions + + procedure Defer_Abort (Self_ID : Task_Id); + pragma Inline (Defer_Abort); + + procedure Undefer_Abort (Self_ID : Task_Id); + pragma Inline (Undefer_Abort); + + -- Nestable inline versions + + procedure Defer_Abort_Nestable (Self_ID : Task_Id); + pragma Inline (Defer_Abort_Nestable); + + procedure Undefer_Abort_Nestable (Self_ID : Task_Id); + pragma Inline (Undefer_Abort_Nestable); + + procedure Do_Pending_Action (Self_ID : Task_Id); + -- Only call with no locks, and when Self_ID.Pending_Action = True Perform + -- necessary pending actions (e.g. abort, priority change). This procedure + -- is usually called when needed as a result of calling Undefer_Abort, + -- although in the case of e.g. No_Abort restriction, it can be necessary + -- to force execution of pending actions. + + function Check_Abort_Status return Integer; + -- Returns Boolean'Pos (True) iff abort signal should raise + -- Standard.Abort_Signal. Only used by IRIX currently. + + -------------------------- + -- Change Base Priority -- + -------------------------- + + procedure Change_Base_Priority (T : Task_Id); + -- Change the base priority of T. Has to be called with the affected + -- task's ATCB write-locked. May temporarily release the lock. + + ---------------------- + -- Task Lock/Unlock -- + ---------------------- + + procedure Task_Lock (Self_ID : Task_Id); + pragma Inline (Task_Lock); + + procedure Task_Unlock (Self_ID : Task_Id); + pragma Inline (Task_Unlock); + -- These are versions of Lock_Task and Unlock_Task created for use + -- within the GNARL. + + procedure Final_Task_Unlock (Self_ID : Task_Id); + -- This version is only for use in Terminate_Task, when the task is + -- relinquishing further rights to its own ATCB. There is a very + -- interesting potential race condition there, where the old task may run + -- concurrently with a new task that is allocated the old tasks (now + -- reused) ATCB. The critical thing here is to not make any reference to + -- the ATCB after the lock is released. See also comments on + -- Terminate_Task and Unlock. + + procedure Wakeup_Entry_Caller + (Self_ID : Task_Id; + Entry_Call : Entry_Call_Link; + New_State : Entry_Call_State); + pragma Inline (Wakeup_Entry_Caller); + -- This is called at the end of service of an entry call, to abort the + -- caller if he is in an abortable part, and to wake up the caller if he + -- is on Entry_Caller_Sleep. Call it holding the lock of Entry_Call.Self. + -- + -- Timed_Call or Simple_Call: + -- The caller is waiting on Entry_Caller_Sleep, in Wait_For_Completion, + -- or Wait_For_Completion_With_Timeout. + -- + -- Conditional_Call: + -- The caller might be in Wait_For_Completion, + -- waiting for a rendezvous (possibly requeued without abort) to + -- complete. + -- + -- Asynchronous_Call: + -- The caller may be executing in the abortable part an async. select, + -- or on a time delay, if Entry_Call.State >= Was_Abortable. + + procedure Locked_Abort_To_Level + (Self_ID : Task_Id; + T : Task_Id; + L : ATC_Level); + pragma Inline (Locked_Abort_To_Level); + -- Abort a task to a specified ATC level. Call this only with T locked + +end System.Tasking.Initialization; |