diff options
Diffstat (limited to 'gcc/ada/s-tasini.adb')
| -rw-r--r-- | gcc/ada/s-tasini.adb | 70 |
1 files changed, 35 insertions, 35 deletions
diff --git a/gcc/ada/s-tasini.adb b/gcc/ada/s-tasini.adb index c2bee15dc0f..6a1da15615e 100644 --- a/gcc/ada/s-tasini.adb +++ b/gcc/ada/s-tasini.adb @@ -6,7 +6,7 @@ -- -- -- B o d y -- -- -- --- Copyright (C) 1992-2004, Free Software Foundation, Inc. -- +-- Copyright (C) 1992-2005, 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- -- @@ -41,30 +41,30 @@ pragma Polling (Off); -- to poll it can cause infinite loops. with Ada.Exceptions; --- used for Exception_Occurrence_Access. +-- Used for Exception_Occurrence_Access with System.Tasking; pragma Elaborate_All (System.Tasking); --- ensure that the first step initializations have been performed +-- Ensure that the first step initializations have been performed with System.Task_Primitives; --- used for Lock +-- Used for Lock with System.Task_Primitives.Operations; --- used for Set_Priority +-- Used for Set_Priority -- Write_Lock -- Unlock -- Initialize_Lock with System.Soft_Links; --- used for the non-tasking routines (*_NT) that refer to global data. +-- Used for the non-tasking routines (*_NT) that refer to global data. -- They are needed here before the tasking run time has been elaborated. with System.Soft_Links.Tasking; -- Used for Init_Tasking_Soft_Links with System.Tasking.Debug; --- used for Trace +-- Used for Trace with System.Stack_Checking; @@ -88,7 +88,7 @@ package body System.Tasking.Initialization is function Current_Target_Exception return AE.Exception_Occurrence; pragma Import (Ada, Current_Target_Exception, "__gnat_current_target_exception"); - -- Import this subprogram from the private part of Ada.Exceptions. + -- Import this subprogram from the private part of Ada.Exceptions ---------------------------------------------------------------------- -- Tasking versions of some services needed by non-tasking programs -- @@ -150,7 +150,7 @@ package body System.Tasking.Initialization is -- Change_Base_Priority -- -------------------------- - -- Call only with abort deferred and holding Self_ID locked. + -- Call only with abort deferred and holding Self_ID locked procedure Change_Base_Priority (T : Task_Id) is begin @@ -269,7 +269,7 @@ package body System.Tasking.Initialization is -- while we had abort deferred below. loop - -- Temporarily defer abortion so that we can lock Self_ID. + -- Temporarily defer abort so that we can lock Self_ID Self_ID.Deferral_Level := Self_ID.Deferral_Level + 1; @@ -286,7 +286,7 @@ package body System.Tasking.Initialization is Unlock_RTS; end if; - -- Restore the original Deferral value. + -- Restore the original Deferral value Self_ID.Deferral_Level := Self_ID.Deferral_Level - 1; @@ -401,11 +401,11 @@ package body System.Tasking.Initialization is SSL.Tasking.Init_Tasking_Soft_Links; - -- Install tasking locks in the GCC runtime. + -- Install tasking locks in the GCC runtime Gnat_Install_Locks (Task_Lock'Access, Task_Unlock'Access); - -- Abortion is deferred in a new ATCB, so we need to undefer abortion + -- Abort is deferred in a new ATCB, so we need to undefer abort -- at this stage to make the environment task abortable. Undefer_Abort (Environment_Task); @@ -426,15 +426,16 @@ package body System.Tasking.Initialization is -- hurt to uncomment the above call, until the error is corrected for -- all targets. - -- See extended comments in package body System.Tasking.Abortion - -- for the overall design of the implementation of task abort. + -- See extended comments in package body System.Tasking.Abort for the + -- overall design of the implementation of task abort. + -- ??? there is no such package ??? - -- If the task is sleeping it will be in an abort-deferred region, - -- and will not have Abort_Signal raised by Abort_Task. - -- Such an "abort deferral" is just to protect the RTS internals, - -- and not necessarily required to enforce Ada semantics. - -- Abort_Task should wake the task up and let it decide if it wants - -- to complete the aborted construct immediately. + -- If the task is sleeping it will be in an abort-deferred region, and + -- will not have Abort_Signal raised by Abort_Task. Such an "abort + -- deferral" is just to protect the RTS internals, and not necessarily + -- required to enforce Ada semantics. Abort_Task should wake the task up + -- and let it decide if it wants to complete the aborted construct + -- immediately. -- Note that the effect of the lowl-level Abort_Task is not persistent. -- If the target task is not blocked, this wakeup will be missed. @@ -452,14 +453,13 @@ package body System.Tasking.Initialization is -- implement delays). That still left the possibility of missed -- wakeups. - -- We cannot safely call Vulnerable_Complete_Activation here, - -- since that requires locking Self_ID.Parent. The anti-deadlock - -- lock ordering rules would then require us to release the lock - -- on Self_ID first, which would create a timing window for other - -- tasks to lock Self_ID. This is significant for tasks that may be - -- aborted before their execution can enter the task body, and so - -- they do not get a chance to call Complete_Task. The actual work - -- for this case is done in Terminate_Task. + -- We cannot safely call Vulnerable_Complete_Activation here, since that + -- requires locking Self_ID.Parent. The anti-deadlock lock ordering rules + -- would then require us to release the lock on Self_ID first, which would + -- create a timing window for other tasks to lock Self_ID. This is + -- significant for tasks that may be aborted before their execution can + -- enter the task body, and so they do not get a chance to call + -- Complete_Task. The actual work for this case is done in Terminate_Task. procedure Locked_Abort_To_Level (Self_ID : Task_Id; @@ -694,12 +694,12 @@ package body System.Tasking.Initialization is -- Precondition : Self does not hold any locks! - -- Undefer_Abort is called on any abortion completion point (aka. + -- Undefer_Abort is called on any abort completion point (aka. -- synchronization point). It performs the following actions if they -- are pending: (1) change the base priority, (2) abort the task. - -- The priority change has to occur before abortion. Otherwise, it would - -- take effect no earlier than the next abortion completion point. + -- The priority change has to occur before abort. Otherwise, it would + -- take effect no earlier than the next abort completion point. procedure Undefer_Abort (Self_ID : Task_Id) is begin @@ -761,8 +761,8 @@ package body System.Tasking.Initialization is -- Undefer_Abortion -- ---------------------- - -- Phase out RTS-internal use of Undefer_Abortion - -- to reduce overhead due to multiple calls to Self. + -- Phase out RTS-internal use of Undefer_Abortion to reduce overhead due + -- to multiple calls to Self. procedure Undefer_Abortion is Self_ID : Task_Id; @@ -806,7 +806,7 @@ package body System.Tasking.Initialization is -- Update_Exception -- ---------------------- - -- Call only when holding no locks. + -- Call only when holding no locks procedure Update_Exception (X : AE.Exception_Occurrence := Current_Target_Exception) |
