diff options
Diffstat (limited to 'gcc/ada/s-tassta.adb')
| -rw-r--r-- | gcc/ada/s-tassta.adb | 79 |
1 files changed, 72 insertions, 7 deletions
diff --git a/gcc/ada/s-tassta.adb b/gcc/ada/s-tassta.adb index e0a6c946348..d6fe66c1f4e 100644 --- a/gcc/ada/s-tassta.adb +++ b/gcc/ada/s-tassta.adb @@ -149,6 +149,9 @@ package body System.Tasking.Stages is -- trigger an automatic stack alignment suitable for GCC's assumptions if -- need be. + -- "Vulnerable_..." in the procedure names below means they must be called + -- with abort deferred. + procedure Vulnerable_Complete_Task (Self_ID : Task_Id); -- Complete the calling task. This procedure must be called with -- abort deferred. It should only be called by Complete_Task and @@ -520,9 +523,11 @@ package body System.Tasking.Stages is begin -- If Master is greater than the current master, it means that Master -- has already awaited its dependent tasks. This raises Program_Error, - -- by 4.8(10.3/2). See AI-280. + -- by 4.8(10.3/2). See AI-280. Ignore this check for foreign threads. - if Master > Self_ID.Master_Within then + if Self_ID.Master_of_Task /= Foreign_Task_Level + and then Master > Self_ID.Master_Within + then raise Program_Error with "create task after awaiting termination"; end if; @@ -877,6 +882,53 @@ package body System.Tasking.Stages is end if; end Free_Task; + --------------------------- + -- Move_Activation_Chain -- + --------------------------- + + procedure Move_Activation_Chain + (From, To : Activation_Chain_Access; + New_Master : Master_ID) + is + Self_ID : constant Task_Id := STPO.Self; + C : Task_Id; + + begin + pragma Debug + (Debug.Trace (Self_ID, "Move_Activation_Chain", 'C')); + + -- Nothing to do if From is empty, and we can check that without + -- deferring aborts. + + C := From.all.T_ID; + + if C = null then + return; + end if; + + Initialization.Defer_Abort (Self_ID); + + -- Loop through the From chain, changing their Master_of_Task + -- fields, and to find the end of the chain. + + loop + C.Master_of_Task := New_Master; + exit when C.Common.Activation_Link = null; + C := C.Common.Activation_Link; + end loop; + + -- Hook From in at the start of To + + C.Common.Activation_Link := To.all.T_ID; + To.all.T_ID := From.all.T_ID; + + -- Set From to empty + + From.all.T_ID := null; + + Initialization.Undefer_Abort (Self_ID); + end Move_Activation_Chain; + ------------------ -- Task_Wrapper -- ------------------ @@ -1407,7 +1459,7 @@ package body System.Tasking.Stages is C := All_Tasks_List; while C /= null loop - if C.Common.Activator = Self_ID then + if C.Common.Activator = Self_ID and then C.Master_of_Task = CM then return False; end if; @@ -1449,13 +1501,24 @@ package body System.Tasking.Stages is -- zero for new tasks, and the task should not exit the -- sleep-loops that use this count until the count reaches zero. + -- While we're counting, if we run across any unactivated tasks that + -- belong to this master, we summarily terminate them as required by + -- RM-9.2(6). + Lock_RTS; Write_Lock (Self_ID); C := All_Tasks_List; while C /= null loop - if C.Common.Activator = Self_ID then + + -- Terminate unactivated (never-to-be activated) tasks + + if C.Common.Activator = Self_ID and then C.Master_of_Task = CM then pragma Assert (C.Common.State = Unactivated); + -- Usually, C.Common.Activator = Self_ID implies C.Master_of_Task + -- = CM. The only case where C is pending activation by this + -- task, but the master of C is not CM is in Ada 2005, when C is + -- part of a return object of a build-in-place function. Write_Lock (C); C.Common.Activator := null; @@ -1465,6 +1528,8 @@ package body System.Tasking.Stages is Unlock (C); end if; + -- Count it if dependent on this master + if C.Common.Parent = Self_ID and then C.Master_of_Task = CM then Write_Lock (C); @@ -1733,9 +1798,9 @@ package body System.Tasking.Stages is -- Complete the calling task - -- This procedure must be called with abort deferred. (That's why the - -- name has "Vulnerable" in it.) It should only be called by Complete_Task - -- and Finalize_Global_Tasks (for the environment task). + -- This procedure must be called with abort deferred. It should only be + -- called by Complete_Task and Finalize_Global_Tasks (for the environment + -- task). -- The effect is similar to that of Complete_Master. Differences include -- the closing of entries here, and computation of the number of active |