diff options
Diffstat (limited to 'gcc/ada/5gtaprop.adb')
| -rw-r--r-- | gcc/ada/5gtaprop.adb | 276 |
1 files changed, 110 insertions, 166 deletions
diff --git a/gcc/ada/5gtaprop.adb b/gcc/ada/5gtaprop.adb index 28284745641..c2718ddcc13 100644 --- a/gcc/ada/5gtaprop.adb +++ b/gcc/ada/5gtaprop.adb @@ -6,9 +6,9 @@ -- -- -- B o d y -- -- -- --- $Revision: 1.1 $ +-- $Revision$ -- -- --- Copyright (C) 1991-2001, Florida State University -- +-- Copyright (C) 1992-2001, 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- -- @@ -29,8 +29,7 @@ -- covered by the GNU Public License. -- -- -- -- GNARL was developed by the GNARL team at Florida State University. It is -- --- now maintained by Ada Core Technologies Inc. in cooperation with Florida -- --- State University (http://www.gnat.com). -- +-- now maintained by Ada Core Technologies, Inc. (http://www.gnat.com). -- -- -- ------------------------------------------------------------------------------ @@ -106,15 +105,16 @@ package body System.Task_Primitives.Operations is -- The followings are logically constants, but need to be initialized -- at run time. - All_Tasks_L : aliased System.Task_Primitives.RTS_Lock; - -- See comments on locking rules in System.Tasking (spec). + Single_RTS_Lock : aliased RTS_Lock; + -- This is a lock to allow only one thread of control in the RTS at + -- a time; it is used to execute in mutual exclusion from all other tasks. + -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List Environment_Task_ID : Task_ID; -- A variable to hold Task_ID for the environment task. Locking_Policy : Character; - pragma Import (C, Locking_Policy, "__gl_locking_policy", - "__gl_locking_policy"); + pragma Import (C, Locking_Policy, "__gl_locking_policy"); Clock_Address : constant System.Address := System.Storage_Elements.To_Address (16#200F90#); @@ -169,7 +169,7 @@ package body System.Task_Primitives.Operations is -- Note: mutexes and cond_variables needed per-task basis are -- initialized in Initialize_TCB and the Storage_Error is - -- handled. Other mutexes (such as All_Tasks_Lock, Memory_Lock...) + -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...) -- used in RTS is initialized before any status change of RTS. -- Therefore rasing Storage_Error in the following routines -- should be able to be handled safely. @@ -267,7 +267,6 @@ package body System.Task_Primitives.Operations is procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is Result : Interfaces.C.int; - begin Result := pthread_mutex_lock (L); @@ -275,20 +274,24 @@ package body System.Task_Primitives.Operations is pragma Assert (Result /= FUNC_ERR); end Write_Lock; - procedure Write_Lock (L : access RTS_Lock) is + procedure Write_Lock + (L : access RTS_Lock; Global_Lock : Boolean := False) + is Result : Interfaces.C.int; - begin - Result := pthread_mutex_lock (L); - pragma Assert (Result = 0); + if not Single_Lock or else Global_Lock then + Result := pthread_mutex_lock (L); + pragma Assert (Result = 0); + end if; end Write_Lock; procedure Write_Lock (T : Task_ID) is Result : Interfaces.C.int; - begin - Result := pthread_mutex_lock (T.Common.LL.L'Access); - pragma Assert (Result = 0); + if not Single_Lock then + Result := pthread_mutex_lock (T.Common.LL.L'Access); + pragma Assert (Result = 0); + end if; end Write_Lock; --------------- @@ -306,132 +309,55 @@ package body System.Task_Primitives.Operations is procedure Unlock (L : access Lock) is Result : Interfaces.C.int; - begin Result := pthread_mutex_unlock (L); pragma Assert (Result = 0); end Unlock; - procedure Unlock (L : access RTS_Lock) is + procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is Result : Interfaces.C.int; - begin - Result := pthread_mutex_unlock (L); - pragma Assert (Result = 0); + if not Single_Lock or else Global_Lock then + Result := pthread_mutex_unlock (L); + pragma Assert (Result = 0); + end if; end Unlock; procedure Unlock (T : Task_ID) is Result : Interfaces.C.int; - begin - Result := pthread_mutex_unlock (T.Common.LL.L'Access); - pragma Assert (Result = 0); + if not Single_Lock then + Result := pthread_mutex_unlock (T.Common.LL.L'Access); + pragma Assert (Result = 0); + end if; end Unlock; - ------------- - -- Sleep -- - ------------- + ----------- + -- Sleep -- + ----------- procedure Sleep (Self_ID : ST.Task_ID; - Reason : System.Tasking.Task_States) is - + Reason : System.Tasking.Task_States) + is Result : Interfaces.C.int; - begin - pragma Assert (Self_ID = Self); - Result := pthread_cond_wait (Self_ID.Common.LL.CV'Access, - Self_ID.Common.LL.L'Access); + if Single_Lock then + Result := pthread_cond_wait + (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access); + else + Result := pthread_cond_wait + (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access); + end if; + -- EINTR is not considered a failure. pragma Assert (Result = 0 or else Result = EINTR); end Sleep; - -- Note that we are relying heaviliy here on the GNAT feature - -- that Calendar.Time, System.Real_Time.Time, Duration, and - -- System.Real_Time.Time_Span are all represented in the same - -- way, i.e., as a 64-bit count of nanoseconds. - -- This allows us to always pass the timeout value as a Duration. - - -- ????? ......... - -- We are taking liberties here with the semantics of the delays. - -- That is, we make no distinction between delays on the Calendar clock - -- and delays on the Real_Time clock. That is technically incorrect, if - -- the Calendar clock happens to be reset or adjusted. - -- To solve this defect will require modification to the compiler - -- interface, so that it can pass through more information, to tell - -- us here which clock to use! - - -- cond_timedwait will return if any of the following happens: - -- 1) some other task did cond_signal on this condition variable - -- In this case, the return value is 0 - -- 2) the call just returned, for no good reason - -- This is called a "spurious wakeup". - -- In this case, the return value may also be 0. - -- 3) the time delay expires - -- In this case, the return value is ETIME - -- 4) this task received a signal, which was handled by some - -- handler procedure, and now the thread is resuming execution - -- UNIX calls this an "interrupted" system call. - -- In this case, the return value is EINTR - - -- If the cond_timedwait returns 0 or EINTR, it is still - -- possible that the time has actually expired, and by chance - -- a signal or cond_signal occurred at around the same time. - - -- We have also observed that on some OS's the value ETIME - -- will be returned, but the clock will show that the full delay - -- has not yet expired. - - -- For these reasons, we need to check the clock after return - -- from cond_timedwait. If the time has expired, we will set - -- Timedout = True. - - -- This check might be omitted for systems on which the - -- cond_timedwait() never returns early or wakes up spuriously. - - -- Annex D requires that completion of a delay cause the task - -- to go to the end of its priority queue, regardless of whether - -- the task actually was suspended by the delay. Since - -- cond_timedwait does not do this on Solaris, we add a call - -- to thr_yield at the end. We might do this at the beginning, - -- instead, but then the round-robin effect would not be the - -- same; the delayed task would be ahead of other tasks of the - -- same priority that awoke while it was sleeping. - - -- For Timed_Sleep, we are expecting possible cond_signals - -- to indicate other events (e.g., completion of a RV or - -- completion of the abortable part of an async. select), - -- we want to always return if interrupted. The caller will - -- be responsible for checking the task state to see whether - -- the wakeup was spurious, and to go back to sleep again - -- in that case. We don't need to check for pending abort - -- or priority change on the way in our out; that is the - -- caller's responsibility. - - -- For Timed_Delay, we are not expecting any cond_signals or - -- other interruptions, except for priority changes and aborts. - -- Therefore, we don't want to return unless the delay has - -- actually expired, or the call has been aborted. In this - -- case, since we want to implement the entire delay statement - -- semantics, we do need to check for pending abort and priority - -- changes. We can quietly handle priority changes inside the - -- procedure, since there is no entry-queue reordering involved. - ----------------- -- Timed_Sleep -- ----------------- - -- This is for use within the run-time system, so abort is - -- assumed to be already deferred, and the caller should be - -- holding its own ATCB lock. - -- Yielded should be False unles we know for certain that the - -- operation resulted in the calling task going to the end of - -- the dispatching queue for its priority. - -- ????? - -- This version presumes the worst, so Yielded is always False. - -- On some targets, if cond_timedwait always yields, we could - -- set Yielded to True just before the cond_timedwait call. - procedure Timed_Sleep (Self_ID : Task_ID; Time : Duration; @@ -461,8 +387,16 @@ package body System.Task_Primitives.Operations is exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level or else Self_ID.Pending_Priority_Change; - Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access, - Self_ID.Common.LL.L'Access, Request'Access); + if Single_Lock then + Result := pthread_cond_timedwait + (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access, + Request'Access); + + else + Result := pthread_cond_timedwait + (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access, + Request'Access); + end if; exit when Abs_Time <= Monotonic_Clock; @@ -482,10 +416,6 @@ package body System.Task_Primitives.Operations is -- Timed_Delay -- ----------------- - -- This is for use in implementing delay statements, so - -- we assume the caller is abort-deferred but is holding - -- no locks. - procedure Timed_Delay (Self_ID : Task_ID; Time : Duration; @@ -495,13 +425,18 @@ package body System.Task_Primitives.Operations is Abs_Time : Duration; Request : aliased struct_timeval; Result : Interfaces.C.int; - begin + begin -- Only the little window between deferring abort and -- locking Self_ID is the reason we need to -- check for pending abort and priority change below! :( SSL.Abort_Defer.all; + + if Single_Lock then + Lock_RTS; + end if; + Write_Lock (Self_ID); if Mode = Relative then @@ -523,8 +458,13 @@ package body System.Task_Primitives.Operations is exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level; - Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access, - Self_ID.Common.LL.L'Access, Request'Access); + if Single_Lock then + Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access, + Single_RTS_Lock'Access, Request'Access); + else + Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access, + Self_ID.Common.LL.L'Access, Request'Access); + end if; exit when Abs_Time <= Monotonic_Clock; @@ -538,6 +478,11 @@ package body System.Task_Primitives.Operations is end if; Unlock (Self_ID); + + if Single_Lock then + Unlock_RTS; + end if; + pthread_yield; SSL.Abort_Undefer.all; end Timed_Delay; @@ -578,10 +523,9 @@ package body System.Task_Primitives.Operations is procedure Wakeup (T : ST.Task_ID; - Reason : System.Tasking.Task_States) is - + Reason : System.Tasking.Task_States) + is Result : Interfaces.C.int; - begin Result := pthread_cond_signal (T.Common.LL.CV'Access); pragma Assert (Result = 0); @@ -608,7 +552,6 @@ package body System.Task_Primitives.Operations is Loss_Of_Inheritance : Boolean := False) is Result : Interfaces.C.int; - begin T.Common.Current_Priority := Prio; Result := pthread_setprio (T.Common.LL.Thread, Interfaces.C.int (Prio)); @@ -631,9 +574,7 @@ package body System.Task_Primitives.Operations is procedure Enter_Task (Self_ID : Task_ID) is Result : Interfaces.C.int; - begin - Self_ID.Common.LL.Thread := pthread_self; Self_ID.Common.LL.LWP := sproc_self; @@ -642,17 +583,17 @@ package body System.Task_Primitives.Operations is pragma Assert (Result = 0); - Lock_All_Tasks_List; + Lock_RTS; - for I in Known_Tasks'Range loop - if Known_Tasks (I) = null then - Known_Tasks (I) := Self_ID; - Self_ID.Known_Tasks_Index := I; + for J in Known_Tasks'Range loop + if Known_Tasks (J) = null then + Known_Tasks (J) := Self_ID; + Self_ID.Known_Tasks_Index := J; exit; end if; end loop; - Unlock_All_Tasks_List; + Unlock_RTS; end Enter_Task; -------------- @@ -669,31 +610,31 @@ package body System.Task_Primitives.Operations is ---------------------- procedure Initialize_TCB (Self_ID : Task_ID; Succeeded : out Boolean) is - Result : Interfaces.C.int; + Result : Interfaces.C.int; Cond_Attr : aliased pthread_condattr_t; begin - Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level); + if not Single_Lock then + Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level); + end if; Result := pthread_condattr_init (Cond_Attr'Access); pragma Assert (Result = 0 or else Result = ENOMEM); - if Result /= 0 then - Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access); - pragma Assert (Result = 0); - Succeeded := False; - return; + if Result = 0 then + Result := pthread_cond_init (Self_ID.Common.LL.CV'Access, + Cond_Attr'Access); + pragma Assert (Result = 0 or else Result = ENOMEM); end if; - Result := pthread_cond_init (Self_ID.Common.LL.CV'Access, - Cond_Attr'Access); - pragma Assert (Result = 0 or else Result = ENOMEM); - if Result = 0 then Succeeded := True; else - Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access); - pragma Assert (Result = 0); + if not Single_Lock then + Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access); + pragma Assert (Result = 0); + end if; + Succeeded := False; end if; @@ -723,6 +664,7 @@ package body System.Task_Primitives.Operations is (System.Task_Info.Resource_Vector_T, System.OS_Interface.resource_t); use System.Task_Info; + begin if Stack_Size = Unspecified_Size then Adjusted_Stack_Size := @@ -809,8 +751,11 @@ package body System.Task_Primitives.Operations is Tmp : Task_ID := T; begin - Result := pthread_mutex_destroy (T.Common.LL.L'Access); - pragma Assert (Result = 0); + if not Single_Lock then + Result := pthread_mutex_destroy (T.Common.LL.L'Access); + pragma Assert (Result = 0); + end if; + Result := pthread_cond_destroy (T.Common.LL.CV'Access); pragma Assert (Result = 0); @@ -836,7 +781,6 @@ package body System.Task_Primitives.Operations is procedure Abort_Task (T : Task_ID) is Result : Interfaces.C.int; - begin Result := pthread_kill (T.Common.LL.Thread, Interfaces.C.int (System.Interrupt_Management.Abort_Task_Interrupt)); @@ -873,23 +817,23 @@ package body System.Task_Primitives.Operations is return Environment_Task_ID; end Environment_Task; - ------------------------- - -- Lock_All_Tasks_List -- - ------------------------- + -------------- + -- Lock_RTS -- + -------------- - procedure Lock_All_Tasks_List is + procedure Lock_RTS is begin - Write_Lock (All_Tasks_L'Access); - end Lock_All_Tasks_List; + Write_Lock (Single_RTS_Lock'Access, Global_Lock => True); + end Lock_RTS; - --------------------------- - -- Unlock_All_Tasks_List -- - --------------------------- + ---------------- + -- Unlock_RTS -- + ---------------- - procedure Unlock_All_Tasks_List is + procedure Unlock_RTS is begin - Unlock (All_Tasks_L'Access); - end Unlock_All_Tasks_List; + Unlock (Single_RTS_Lock'Access, Global_Lock => True); + end Unlock_RTS; ------------------ -- Suspend_Task -- @@ -929,7 +873,7 @@ package body System.Task_Primitives.Operations is begin Environment_Task_ID := Environment_Task; - Initialize_Lock (All_Tasks_L'Access, All_Tasks_Level); + Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level); -- Initialize the lock used to synchronize chain of all ATCBs. Enter_Task (Environment_Task); |