+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
--- --
--- S Y S T E M . T A S K _ P R I M I T I V E S . O P E R A T I O N S --
--- --
--- B o d y --
--- --
--- $Revision: 1.2 $
--- --
--- Copyright (C) 1991-2001, Florida State University --
--- --
--- 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 2, or (at your option) any later ver- --
--- sion. GNARL 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. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNARL; see file COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
--- --
--- As a special exception, if other files instantiate generics from this --
--- unit, or you link this unit with other files to produce an executable, --
--- this unit does not by itself cause the resulting executable to be --
--- covered by the GNU General Public License. This exception does not --
--- however invalidate any other reasons why the executable file might be --
--- 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). --
--- --
-------------------------------------------------------------------------------
-
--- This is a Solaris (native) version of this package
-
--- This package contains all the GNULL primitives that interface directly
--- with the underlying OS.
-
-pragma Polling (Off);
--- Turn off polling, we do not want ATC polling to take place during
--- tasking operations. It causes infinite loops and other problems.
-
-with System.Tasking.Debug;
--- used for Known_Tasks
-
-with Ada.Exceptions;
--- used for Raise_Exception
-
-with GNAT.OS_Lib;
--- used for String_Access, Getenv
-
-with Interfaces.C;
--- used for int
--- size_t
-
-with System.Interrupt_Management;
--- used for Keep_Unmasked
--- Abort_Task_Interrupt
--- Interrupt_ID
-
-with System.Interrupt_Management.Operations;
--- used for Set_Interrupt_Mask
--- All_Tasks_Mask
-pragma Elaborate_All (System.Interrupt_Management.Operations);
-
-with System.Parameters;
--- used for Size_Type
-
-with System.Tasking;
--- used for Ada_Task_Control_Block
--- Task_ID
--- ATCB components and types
-
-with System.Task_Info;
--- to initialize Task_Info for a C thread, in function Self
-
-with System.Soft_Links;
--- used for Defer/Undefer_Abort
--- to initialize TSD for a C thread, in function Self
-
--- Note that we do not use System.Tasking.Initialization directly since
--- this is a higher level package that we shouldn't depend on. For example
--- when using the restricted run time, it is replaced by
--- System.Tasking.Restricted.Initialization
-
-with System.OS_Primitives;
--- used for Delay_Modes
-
-with Unchecked_Conversion;
-with Unchecked_Deallocation;
-
-package body System.Task_Primitives.Operations is
-
- use System.Tasking.Debug;
- use System.Tasking;
- use Interfaces.C;
- use System.OS_Interface;
- use System.Parameters;
- use Ada.Exceptions;
- use System.OS_Primitives;
-
- package SSL renames System.Soft_Links;
-
- ------------------
- -- Local Data --
- ------------------
-
- ATCB_Magic_Code : constant := 16#ADAADAAD#;
- -- This is used to allow us to catch attempts to call Self
- -- from outside an Ada task, with high probability.
- -- For an Ada task, Task_Wrapper.Magic_Number = ATCB_Magic_Code.
-
- -- The following are logically constants, but need to be initialized
- -- at run time.
-
- Environment_Task_ID : Task_ID;
- -- A variable to hold Task_ID for the environment task.
- -- If we use this variable to get the Task_ID, we need the following
- -- ATCB_Key only for non-Ada threads.
-
- Unblocked_Signal_Mask : aliased sigset_t;
- -- The set of signals that should unblocked in all tasks
-
- ATCB_Key : aliased thread_key_t;
- -- Key used to find the Ada Task_ID associated with a thread,
- -- at least for C threads unknown to the Ada run-time system.
-
- All_Tasks_L : aliased System.Task_Primitives.RTS_Lock;
- -- See comments on locking rules in System.Tasking (spec).
-
- Next_Serial_Number : Task_Serial_Number := 100;
- -- We start at 100, to reserve some special values for
- -- using in error checking.
- -- The following are internal configuration constants needed.
-
- ------------------------
- -- Priority Support --
- ------------------------
-
- Dynamic_Priority_Support : constant Boolean := True;
- -- controls whether we poll for pending priority changes during sleeps
-
- Priority_Ceiling_Emulation : constant Boolean := True;
- -- controls whether we emulate priority ceiling locking
-
- -- To get a scheduling close to annex D requirements, we use the real-time
- -- class provided for LWP's and map each task/thread to a specific and
- -- unique LWP (there is 1 thread per LWP, and 1 LWP per thread).
-
- -- The real time class can only be set when the process has root
- -- priviledges, so in the other cases, we use the normal thread scheduling
- -- and priority handling.
-
- Using_Real_Time_Class : Boolean := False;
- -- indicates wether the real time class is being used (i.e the process
- -- has root priviledges).
-
- Prio_Param : aliased struct_pcparms;
- -- Hold priority info (Real_Time) initialized during the package
- -- elaboration.
-
- -------------------------------------
- -- External Configuration Values --
- -------------------------------------
-
- Time_Slice_Val : Interfaces.C.long;
- pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
-
- Locking_Policy : Character;
- pragma Import (C, Locking_Policy, "__gl_locking_policy");
-
- Dispatching_Policy : Character;
- pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
-
- --------------------------------
- -- Foreign Threads Detection --
- --------------------------------
-
- -- The following are used to allow the Self function to
- -- automatically generate ATCB's for C threads that happen to call
- -- Ada procedure, which in turn happen to call the Ada run-time system.
-
- type Fake_ATCB;
- type Fake_ATCB_Ptr is access Fake_ATCB;
- type Fake_ATCB is record
- Stack_Base : Interfaces.C.unsigned := 0;
- -- A value of zero indicates the node is not in use.
- Next : Fake_ATCB_Ptr;
- Real_ATCB : aliased Ada_Task_Control_Block (0);
- end record;
-
- Fake_ATCB_List : Fake_ATCB_Ptr;
- -- A linear linked list.
- -- The list is protected by All_Tasks_L;
- -- Nodes are added to this list from the front.
- -- Once a node is added to this list, it is never removed.
-
- Fake_Task_Elaborated : aliased Boolean := True;
- -- Used to identified fake tasks (i.e., non-Ada Threads).
-
- Next_Fake_ATCB : Fake_ATCB_Ptr;
- -- Used to allocate one Fake_ATCB in advance. See comment in New_Fake_ATCB
-
- ------------
- -- Checks --
- ------------
-
- Check_Count : Integer := 0;
- Old_Owner : Task_ID;
- Lock_Count : Integer := 0;
- Unlock_Count : Integer := 0;
-
- function To_Lock_Ptr is
- new Unchecked_Conversion (RTS_Lock_Ptr, Lock_Ptr);
- function To_Task_ID is
- new Unchecked_Conversion (Owner_ID, Task_ID);
- function To_Owner_ID is
- new Unchecked_Conversion (Task_ID, Owner_ID);
-
- -----------------------
- -- Local Subprograms --
- -----------------------
-
- function sysconf (name : System.OS_Interface.int)
- return processorid_t;
- pragma Import (C, sysconf, "sysconf");
-
- SC_NPROCESSORS_CONF : constant System.OS_Interface.int := 14;
-
- function Num_Procs (name : System.OS_Interface.int := SC_NPROCESSORS_CONF)
- return processorid_t renames sysconf;
-
- procedure Abort_Handler
- (Sig : Signal;
- Code : access siginfo_t;
- Context : access ucontext_t);
-
- function To_thread_t is new Unchecked_Conversion
- (Integer, System.OS_Interface.thread_t);
-
- function To_Task_ID is new Unchecked_Conversion (System.Address, Task_ID);
-
- function To_Address is new Unchecked_Conversion (Task_ID, System.Address);
-
- type Ptr is access Task_ID;
- function To_Ptr is new Unchecked_Conversion (Interfaces.C.unsigned, Ptr);
- function To_Ptr is new Unchecked_Conversion (System.Address, Ptr);
-
- type Iptr is access Interfaces.C.unsigned;
- function To_Iptr is new Unchecked_Conversion (Interfaces.C.unsigned, Iptr);
-
- function Thread_Body_Access is
- new Unchecked_Conversion (System.Address, Thread_Body);
-
- function New_Fake_ATCB (Stack_Base : Interfaces.C.unsigned) return Task_ID;
- -- Allocate and Initialize a new ATCB. This code can safely be called from
- -- a foreign thread, as it doesn't access implicitly or explicitly
- -- "self" before having initialized the new ATCB.
-
- ------------
- -- Checks --
- ------------
-
- function Check_Initialize_Lock (L : Lock_Ptr; Level : Lock_Level)
- return Boolean;
- pragma Inline (Check_Initialize_Lock);
-
- function Check_Lock (L : Lock_Ptr) return Boolean;
- pragma Inline (Check_Lock);
-
- function Record_Lock (L : Lock_Ptr) return Boolean;
- pragma Inline (Record_Lock);
-
- function Check_Sleep (Reason : Task_States) return Boolean;
- pragma Inline (Check_Sleep);
-
- function Record_Wakeup
- (L : Lock_Ptr;
- Reason : Task_States) return Boolean;
- pragma Inline (Record_Wakeup);
-
- function Check_Wakeup
- (T : Task_ID;
- Reason : Task_States) return Boolean;
- pragma Inline (Check_Wakeup);
-
- function Check_Unlock (L : Lock_Ptr) return Boolean;
- pragma Inline (Check_Lock);
-
- function Check_Finalize_Lock (L : Lock_Ptr) return Boolean;
- pragma Inline (Check_Finalize_Lock);
-
- -------------------
- -- New_Fake_ATCB --
- -------------------
-
- function New_Fake_ATCB (Stack_Base : Interfaces.C.unsigned)
- return Task_ID
- is
- Self_ID : Task_ID;
- P, Q : Fake_ATCB_Ptr;
- Succeeded : Boolean;
- Result : Interfaces.C.int;
-
- begin
- -- This section is ticklish.
- -- We dare not call anything that might require an ATCB, until
- -- we have the new ATCB in place.
- -- Note: we don't use "Write_Lock (All_Tasks_L'Access);" because
- -- we don't yet have an ATCB, and so can't pass the safety check.
-
- Result := mutex_lock (All_Tasks_L.L'Access);
- Q := null;
- P := Fake_ATCB_List;
-
- while P /= null loop
- if P.Stack_Base = 0 then
- Q := P;
- elsif thr_kill (P.Real_ATCB.Common.LL.Thread, 0) /= 0 then
- -- ????
- -- If a C thread that has dependent Ada tasks terminates
- -- abruptly, e.g. as a result of cancellation, any dependent
- -- tasks are likely to hang up in termination.
- P.Stack_Base := 0;
- Q := P;
- end if;
-
- P := P.Next;
- end loop;
-
- if Q = null then
-
- -- Create a new ATCB with zero entries.
-
- Self_ID := Next_Fake_ATCB.Real_ATCB'Access;
- Next_Fake_ATCB.Stack_Base := Stack_Base;
- Next_Fake_ATCB.Next := Fake_ATCB_List;
- Fake_ATCB_List := Next_Fake_ATCB;
- Next_Fake_ATCB := null;
-
- else
-
- -- Reuse an existing fake ATCB.
-
- Self_ID := Q.Real_ATCB'Access;
- Q.Stack_Base := Stack_Base;
- end if;
-
- -- Do the standard initializations
-
- System.Tasking.Initialize_ATCB
- (Self_ID, null, Null_Address, Null_Task, Fake_Task_Elaborated'Access,
- System.Priority'First, Task_Info.Unspecified_Task_Info, 0, Self_ID,
- Succeeded);
- pragma Assert (Succeeded);
-
- -- Record this as the Task_ID for the current thread.
-
- Self_ID.Common.LL.Thread := thr_self;
- Result := thr_setspecific (ATCB_Key, To_Address (Self_ID));
- pragma Assert (Result = 0);
-
- -- Finally, it is safe to use an allocator in this thread.
-
- if Next_Fake_ATCB = null then
- Next_Fake_ATCB := new Fake_ATCB;
- end if;
-
- Self_ID.Master_of_Task := 0;
- Self_ID.Master_Within := Self_ID.Master_of_Task + 1;
-
- for L in Self_ID.Entry_Calls'Range loop
- Self_ID.Entry_Calls (L).Self := Self_ID;
- Self_ID.Entry_Calls (L).Level := L;
- end loop;
-
- Self_ID.Common.State := Runnable;
- Self_ID.Awake_Count := 1;
-
- -- Since this is not an ordinary Ada task, we will start out undeferred
-
- Self_ID.Deferral_Level := 0;
-
- -- Give the task a unique serial number.
-
- Self_ID.Serial_Number := Next_Serial_Number;
- Next_Serial_Number := Next_Serial_Number + 1;
- pragma Assert (Next_Serial_Number /= 0);
-
- System.Soft_Links.Create_TSD (Self_ID.Common.Compiler_Data);
-
- -- ????
- -- The following call is commented out to avoid dependence on
- -- the System.Tasking.Initialization package.
-
- -- It seems that if we want Ada.Task_Attributes to work correctly
- -- for C threads we will need to raise the visibility of this soft
- -- link to System.Soft_Links.
-
- -- We are putting that off until this new functionality is otherwise
- -- stable.
-
- -- System.Tasking.Initialization.Initialize_Attributes_Link.all (T);
-
- -- Must not unlock until Next_ATCB is again allocated.
-
- 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;
-
- Result := mutex_unlock (All_Tasks_L.L'Access);
-
- -- We cannot use "Unlock (All_Tasks_L'Access);" because
- -- we did not use Write_Lock, and so would not pass the checks.
-
- return Self_ID;
- end New_Fake_ATCB;
-
- -------------------
- -- Abort_Handler --
- -------------------
-
- -- Target-dependent binding of inter-thread Abort signal to
- -- the raising of the Abort_Signal exception.
-
- -- The technical issues and alternatives here are essentially
- -- the same as for raising exceptions in response to other
- -- signals (e.g. Storage_Error). See code and comments in
- -- the package body System.Interrupt_Management.
-
- -- Some implementations may not allow an exception to be propagated
- -- out of a handler, and others might leave the signal or
- -- interrupt that invoked this handler masked after the exceptional
- -- return to the application code.
-
- -- GNAT exceptions are originally implemented using setjmp()/longjmp().
- -- On most UNIX systems, this will allow transfer out of a signal handler,
- -- which is usually the only mechanism available for implementing
- -- asynchronous handlers of this kind. However, some
- -- systems do not restore the signal mask on longjmp(), leaving the
- -- abort signal masked.
-
- -- Alternative solutions include:
-
- -- 1. Change the PC saved in the system-dependent Context
- -- parameter to point to code that raises the exception.
- -- Normal return from this handler will then raise
- -- the exception after the mask and other system state has
- -- been restored (see example below).
- -- 2. Use siglongjmp()/sigsetjmp() to implement exceptions.
- -- 3. Unmask the signal in the Abortion_Signal exception handler
- -- (in the RTS).
-
- -- The following procedure would be needed if we can't longjmp out of
- -- a signal handler. (See below.)
-
- -- procedure Raise_Abort_Signal is
- -- begin
- -- raise Standard'Abort_Signal;
- -- end if;
-
- -- ???
- -- The comments above need revising. They are partly obsolete.
-
- procedure Abort_Handler
- (Sig : Signal;
- Code : access siginfo_t;
- Context : access ucontext_t)
- is
- Self_ID : Task_ID := Self;
- Result : Interfaces.C.int;
- Old_Set : aliased sigset_t;
-
- begin
- -- Assuming it is safe to longjmp out of a signal handler, the
- -- following code can be used:
-
- if Self_ID.Deferral_Level = 0
- and then Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
- and then not Self_ID.Aborting
- then
- -- You can comment the following out,
- -- to make all aborts synchronous, for debugging.
-
- Self_ID.Aborting := True;
-
- -- Make sure signals used for RTS internal purpose are unmasked
-
- Result := thr_sigsetmask (SIG_UNBLOCK,
- Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
- pragma Assert (Result = 0);
-
- raise Standard'Abort_Signal;
-
- -- ?????
- -- Must be certain that the implementation of "raise"
- -- does not make any OS/thread calls, or at least that
- -- if it makes any, they are safe for interruption by
- -- async. signals.
- end if;
-
- -- Otherwise, something like this is required:
- -- if not Abort_Is_Deferred.all then
- -- -- Overwrite the return PC address with the address of the
- -- -- special raise routine, and "return" to that routine's
- -- -- starting address.
- -- Context.PC := Raise_Abort_Signal'Address;
- -- return;
- -- end if;
-
- end Abort_Handler;
-
- -------------------
- -- Stack_Guard --
- -------------------
-
- -- The underlying thread system sets a guard page at the
- -- bottom of a thread stack, so nothing is needed.
-
- procedure Stack_Guard (T : ST.Task_ID; On : Boolean) is
- begin
- null;
- end Stack_Guard;
-
- --------------------
- -- Get_Thread_Id --
- --------------------
-
- function Get_Thread_Id (T : ST.Task_ID) return OSI.Thread_Id is
- begin
- return T.Common.LL.Thread;
- end Get_Thread_Id;
-
- -----------
- -- Self --
- -----------
-
- function Self return Task_ID is separate;
-
- ---------------------
- -- Initialize_Lock --
- ---------------------
-
- -- 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_L, 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.
-
- procedure Initialize_Lock
- (Prio : System.Any_Priority;
- L : access Lock)
- is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Initialize_Lock (Lock_Ptr (L), PO_Level));
-
- if Priority_Ceiling_Emulation then
- L.Ceiling := Prio;
- end if;
-
- Result := mutex_init (L.L'Access, USYNC_THREAD, System.Null_Address);
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- if Result = ENOMEM then
- Raise_Exception (Storage_Error'Identity, "Failed to allocate a lock");
- end if;
- end Initialize_Lock;
-
- procedure Initialize_Lock
- (L : access RTS_Lock;
- Level : Lock_Level)
- is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Initialize_Lock
- (To_Lock_Ptr (RTS_Lock_Ptr (L)), Level));
- Result := mutex_init (L.L'Access, USYNC_THREAD, System.Null_Address);
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- if Result = ENOMEM then
- Raise_Exception (Storage_Error'Identity, "Failed to allocate a lock");
- end if;
- end Initialize_Lock;
-
- -------------------
- -- Finalize_Lock --
- -------------------
-
- procedure Finalize_Lock (L : access Lock) is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Finalize_Lock (Lock_Ptr (L)));
- Result := mutex_destroy (L.L'Access);
- pragma Assert (Result = 0);
- end Finalize_Lock;
-
- procedure Finalize_Lock (L : access RTS_Lock) is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Finalize_Lock (To_Lock_Ptr (RTS_Lock_Ptr (L))));
- Result := mutex_destroy (L.L'Access);
- pragma Assert (Result = 0);
- end Finalize_Lock;
-
- ----------------
- -- Write_Lock --
- ----------------
-
- procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Lock (Lock_Ptr (L)));
-
- if Priority_Ceiling_Emulation and then Locking_Policy = 'C' then
- declare
- Self_Id : constant Task_ID := Self;
- Saved_Priority : System.Any_Priority;
-
- begin
- if Self_Id.Common.LL.Active_Priority > L.Ceiling then
- Ceiling_Violation := True;
- return;
- end if;
-
- Saved_Priority := Self_Id.Common.LL.Active_Priority;
-
- if Self_Id.Common.LL.Active_Priority < L.Ceiling then
- Set_Priority (Self_Id, L.Ceiling);
- end if;
-
- Result := mutex_lock (L.L'Access);
- pragma Assert (Result = 0);
- Ceiling_Violation := False;
-
- L.Saved_Priority := Saved_Priority;
- end;
-
- else
- Result := mutex_lock (L.L'Access);
- pragma Assert (Result = 0);
- Ceiling_Violation := False;
- end if;
-
- pragma Assert (Record_Lock (Lock_Ptr (L)));
- end Write_Lock;
-
- procedure Write_Lock (L : access RTS_Lock) is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Lock (To_Lock_Ptr (RTS_Lock_Ptr (L))));
- Result := mutex_lock (L.L'Access);
- pragma Assert (Result = 0);
- pragma Assert (Record_Lock (To_Lock_Ptr (RTS_Lock_Ptr (L))));
- end Write_Lock;
-
- procedure Write_Lock (T : Task_ID) is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Lock (To_Lock_Ptr (T.Common.LL.L'Access)));
- Result := mutex_lock (T.Common.LL.L.L'Access);
- pragma Assert (Result = 0);
- pragma Assert (Record_Lock (To_Lock_Ptr (T.Common.LL.L'Access)));
- end Write_Lock;
-
- ---------------
- -- Read_Lock --
- ---------------
-
- procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
- begin
- Write_Lock (L, Ceiling_Violation);
- end Read_Lock;
-
- ------------
- -- Unlock --
- ------------
-
- procedure Unlock (L : access Lock) is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Unlock (Lock_Ptr (L)));
-
- if Priority_Ceiling_Emulation and then Locking_Policy = 'C' then
- declare
- Self_Id : constant Task_ID := Self;
-
- begin
- Result := mutex_unlock (L.L'Access);
- pragma Assert (Result = 0);
-
- if Self_Id.Common.LL.Active_Priority > L.Saved_Priority then
- Set_Priority (Self_Id, L.Saved_Priority);
- end if;
- end;
- else
- Result := mutex_unlock (L.L'Access);
- pragma Assert (Result = 0);
- end if;
- end Unlock;
-
- procedure Unlock (L : access RTS_Lock) is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Unlock (To_Lock_Ptr (RTS_Lock_Ptr (L))));
- Result := mutex_unlock (L.L'Access);
- pragma Assert (Result = 0);
- end Unlock;
-
- procedure Unlock (T : Task_ID) is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Unlock (To_Lock_Ptr (T.Common.LL.L'Access)));
- Result := mutex_unlock (T.Common.LL.L.L'Access);
- pragma Assert (Result = 0);
- end Unlock;
-
- -- For the time delay implementation, we need to make sure we
- -- achieve following criteria:
-
- -- 1) We have to delay at least for the amount requested.
- -- 2) We have to give up CPU even though the actual delay does not
- -- result in blocking.
- -- 3) Except for restricted run-time systems that do not support
- -- ATC or task abort, the delay must be interrupted by the
- -- abort_task operation.
- -- 4) The implementation has to be efficient so that the delay overhead
- -- is relatively cheap.
- -- (1)-(3) are Ada requirements. Even though (2) is an Annex-D
- -- requirement we still want to provide the effect in all cases.
- -- The reason is that users may want to use short delays to implement
- -- their own scheduling effect in the absence of language provided
- -- scheduling policies.
-
- ---------------------
- -- Monotonic_Clock --
- ---------------------
-
- function Monotonic_Clock return Duration is
- TS : aliased timespec;
- Result : Interfaces.C.int;
-
- begin
- Result := clock_gettime (CLOCK_REALTIME, TS'Unchecked_Access);
- pragma Assert (Result = 0);
- return To_Duration (TS);
- end Monotonic_Clock;
-
- -------------------
- -- RT_Resolution --
- -------------------
-
- function RT_Resolution return Duration is
- begin
- return 10#1.0#E-6;
- end RT_Resolution;
-
- -----------
- -- Yield --
- -----------
-
- procedure Yield (Do_Yield : Boolean := True) is
- begin
- if Do_Yield then
- System.OS_Interface.thr_yield;
- end if;
- end Yield;
-
- ------------------
- -- Set_Priority --
- ------------------
-
- procedure Set_Priority
- (T : Task_ID;
- Prio : System.Any_Priority;
- Loss_Of_Inheritance : Boolean := False)
- is
- Result : Interfaces.C.int;
- Param : aliased struct_pcparms;
-
- use Task_Info;
-
- begin
- T.Common.Current_Priority := Prio;
-
- if Priority_Ceiling_Emulation then
- T.Common.LL.Active_Priority := Prio;
- end if;
-
- if Using_Real_Time_Class then
- Param.pc_cid := Prio_Param.pc_cid;
- Param.rt_pri := pri_t (Prio);
- Param.rt_tqsecs := Prio_Param.rt_tqsecs;
- Param.rt_tqnsecs := Prio_Param.rt_tqnsecs;
-
- Result := Interfaces.C.int (
- priocntl (PC_VERSION, P_LWPID, T.Common.LL.LWP, PC_SETPARMS,
- Param'Address));
-
- else
- if T.Common.Task_Info /= null
- and then not T.Common.Task_Info.Bound_To_LWP
- then
- -- The task is not bound to a LWP, so use thr_setprio
-
- Result :=
- thr_setprio (T.Common.LL.Thread, Interfaces.C.int (Prio));
-
- else
-
- -- The task is bound to a LWP, use priocntl
- -- ??? TBD
-
- null;
- end if;
- end if;
- end Set_Priority;
-
- ------------------
- -- Get_Priority --
- ------------------
-
- function Get_Priority (T : Task_ID) return System.Any_Priority is
- begin
- return T.Common.Current_Priority;
- end Get_Priority;
-
- ----------------
- -- Enter_Task --
- ----------------
-
- procedure Enter_Task (Self_ID : Task_ID) is
- Result : Interfaces.C.int;
- Proc : processorid_t; -- User processor #
- Last_Proc : processorid_t; -- Last processor #
-
- use System.Task_Info;
- begin
- Self_ID.Common.LL.Thread := thr_self;
-
- Self_ID.Common.LL.LWP := lwp_self;
-
- if Self_ID.Common.Task_Info /= null then
- if Self_ID.Common.Task_Info.New_LWP
- and then Self_ID.Common.Task_Info.CPU /= CPU_UNCHANGED
- then
- Last_Proc := Num_Procs - 1;
-
- if Self_ID.Common.Task_Info.CPU = ANY_CPU then
- Result := 0;
- Proc := 0;
-
- while Proc < Last_Proc loop
- Result := p_online (Proc, PR_STATUS);
- exit when Result = PR_ONLINE;
- Proc := Proc + 1;
- end loop;
-
- Result := processor_bind (P_LWPID, P_MYID, Proc, null);
- pragma Assert (Result = 0);
-
- else
- -- Use specified processor
-
- if Self_ID.Common.Task_Info.CPU < 0
- or else Self_ID.Common.Task_Info.CPU > Last_Proc
- then
- raise Invalid_CPU_Number;
- end if;
-
- Result := processor_bind
- (P_LWPID, P_MYID, Self_ID.Common.Task_Info.CPU, null);
- pragma Assert (Result = 0);
- end if;
- end if;
- end if;
-
- Result := thr_setspecific (ATCB_Key, To_Address (Self_ID));
- pragma Assert (Result = 0);
-
- -- We need the above code even if we do direct fetch of Task_ID in Self
- -- for the main task on Sun, x86 Solaris and for gcc 2.7.2.
-
- Lock_All_Tasks_List;
-
- for I in Known_Tasks'Range loop
- if Known_Tasks (I) = null then
- Known_Tasks (I) := Self_ID;
- Self_ID.Known_Tasks_Index := I;
- exit;
- end if;
- end loop;
- Unlock_All_Tasks_List;
- end Enter_Task;
-
- --------------
- -- New_ATCB --
- --------------
-
- function New_ATCB (Entry_Num : Task_Entry_Index) return Task_ID is
- begin
- return new Ada_Task_Control_Block (Entry_Num);
- end New_ATCB;
-
- ----------------------
- -- Initialize_TCB --
- ----------------------
-
- procedure Initialize_TCB (Self_ID : Task_ID; Succeeded : out Boolean) is
- Result : Interfaces.C.int;
-
- begin
- -- Give the task a unique serial number.
-
- Self_ID.Serial_Number := Next_Serial_Number;
- Next_Serial_Number := Next_Serial_Number + 1;
- pragma Assert (Next_Serial_Number /= 0);
-
- Self_ID.Common.LL.Thread := To_thread_t (-1);
- Result := mutex_init
- (Self_ID.Common.LL.L.L'Access, USYNC_THREAD, System.Null_Address);
- Self_ID.Common.LL.L.Level :=
- Private_Task_Serial_Number (Self_ID.Serial_Number);
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- if Result = 0 then
- Result := cond_init (Self_ID.Common.LL.CV'Access, USYNC_THREAD, 0);
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- if Result /= 0 then
- Result := mutex_destroy (Self_ID.Common.LL.L.L'Access);
- pragma Assert (Result = 0);
- Succeeded := False;
- else
- Succeeded := True;
- end if;
-
- else
- Succeeded := False;
- end if;
- end Initialize_TCB;
-
- -----------------
- -- Create_Task --
- -----------------
-
- procedure Create_Task
- (T : Task_ID;
- Wrapper : System.Address;
- Stack_Size : System.Parameters.Size_Type;
- Priority : System.Any_Priority;
- Succeeded : out Boolean)
- is
- Result : Interfaces.C.int;
- Adjusted_Stack_Size : Interfaces.C.size_t;
- Opts : Interfaces.C.int := THR_DETACHED;
-
- Page_Size : constant System.Parameters.Size_Type := 4096;
- -- This constant is for reserving extra space at the
- -- end of the stack, which can be used by the stack
- -- checking as guard page. The idea is that we need
- -- to have at least Stack_Size bytes available for
- -- actual use.
-
- use System.Task_Info;
- begin
- if Stack_Size = System.Parameters.Unspecified_Size then
- Adjusted_Stack_Size :=
- Interfaces.C.size_t (Default_Stack_Size + Page_Size);
-
- elsif Stack_Size < Minimum_Stack_Size then
- Adjusted_Stack_Size :=
- Interfaces.C.size_t (Minimum_Stack_Size + Page_Size);
-
- else
- Adjusted_Stack_Size :=
- Interfaces.C.size_t (Stack_Size + Page_Size);
- end if;
-
- -- Since the initial signal mask of a thread is inherited from the
- -- creator, and the Environment task has all its signals masked, we
- -- do not need to manipulate caller's signal mask at this point.
- -- All tasks in RTS will have All_Tasks_Mask initially.
-
- if T.Common.Task_Info /= null then
-
- if T.Common.Task_Info.New_LWP then
- Opts := Opts + THR_NEW_LWP;
- end if;
-
- if T.Common.Task_Info.Bound_To_LWP then
- Opts := Opts + THR_BOUND;
- end if;
-
- else
- Opts := THR_DETACHED + THR_BOUND;
- end if;
-
- Result := thr_create
- (System.Null_Address,
- Adjusted_Stack_Size,
- Thread_Body_Access (Wrapper),
- To_Address (T),
- Opts,
- T.Common.LL.Thread'Access);
-
- Succeeded := Result = 0;
- pragma Assert
- (Result = 0
- or else Result = ENOMEM
- or else Result = EAGAIN);
- end Create_Task;
-
- ------------------
- -- Finalize_TCB --
- ------------------
-
- procedure Finalize_TCB (T : Task_ID) is
- Result : Interfaces.C.int;
- Tmp : Task_ID := T;
-
- procedure Free is new
- Unchecked_Deallocation (Ada_Task_Control_Block, Task_ID);
-
- begin
- T.Common.LL.Thread := To_thread_t (0);
- Result := mutex_destroy (T.Common.LL.L.L'Access);
- pragma Assert (Result = 0);
- Result := cond_destroy (T.Common.LL.CV'Access);
- pragma Assert (Result = 0);
-
- if T.Known_Tasks_Index /= -1 then
- Known_Tasks (T.Known_Tasks_Index) := null;
- end if;
-
- Free (Tmp);
- end Finalize_TCB;
-
- ---------------
- -- Exit_Task --
- ---------------
-
- -- This procedure must be called with abort deferred.
- -- It can no longer call Self or access
- -- the current task's ATCB, since the ATCB has been deallocated.
-
- procedure Exit_Task is
- begin
- thr_exit (System.Null_Address);
- end Exit_Task;
-
- ----------------
- -- Abort_Task --
- ----------------
-
- procedure Abort_Task (T : Task_ID) is
- Result : Interfaces.C.int;
- begin
- pragma Assert (T /= Self);
-
- Result := thr_kill (T.Common.LL.Thread,
- Signal (System.Interrupt_Management.Abort_Task_Interrupt));
- null;
-
- pragma Assert (Result = 0);
- end Abort_Task;
-
- -------------
- -- Sleep --
- -------------
-
- procedure Sleep
- (Self_ID : Task_ID;
- Reason : Task_States)
- is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Sleep (Reason));
-
- if Dynamic_Priority_Support
- and then Self_ID.Pending_Priority_Change
- then
- Self_ID.Pending_Priority_Change := False;
- Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority;
- Set_Priority (Self_ID, Self_ID.Common.Base_Priority);
- end if;
-
- Result := cond_wait
- (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L.L'Access);
- pragma Assert (Result = 0 or else Result = EINTR);
- pragma Assert (Record_Wakeup
- (To_Lock_Ptr (Self_ID.Common.LL.L'Access), Reason));
- 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;
- Mode : ST.Delay_Modes;
- Reason : System.Tasking.Task_States;
- Timedout : out Boolean;
- Yielded : out Boolean)
- is
- Check_Time : constant Duration := Monotonic_Clock;
- Abs_Time : Duration;
- Request : aliased timespec;
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Sleep (Reason));
- Timedout := True;
- Yielded := False;
-
- if Mode = Relative then
- Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
- else
- Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
- end if;
-
- if Abs_Time > Check_Time then
- Request := To_Timespec (Abs_Time);
-
- loop
- exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
- or else (Dynamic_Priority_Support and then
- Self_ID.Pending_Priority_Change);
-
- Result := cond_timedwait (Self_ID.Common.LL.CV'Access,
- Self_ID.Common.LL.L.L'Access, Request'Access);
-
- exit when Abs_Time <= Monotonic_Clock;
-
- if Result = 0 or Result = EINTR then
- -- somebody may have called Wakeup for us
- Timedout := False;
- exit;
- end if;
-
- pragma Assert (Result = ETIME);
- end loop;
- end if;
-
- pragma Assert (Record_Wakeup
- (To_Lock_Ptr (Self_ID.Common.LL.L'Access), Reason));
- end Timed_Sleep;
-
- -----------------
- -- 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;
- Mode : ST.Delay_Modes)
- is
- Check_Time : constant Duration := Monotonic_Clock;
- Abs_Time : Duration;
- Request : aliased timespec;
- Result : Interfaces.C.int;
-
- 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;
- Write_Lock (Self_ID);
-
- if Mode = Relative then
- Abs_Time := Time + Check_Time;
- else
- Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
- end if;
-
- if Abs_Time > Check_Time then
- Request := To_Timespec (Abs_Time);
- Self_ID.Common.State := Delay_Sleep;
-
- pragma Assert (Check_Sleep (Delay_Sleep));
-
- loop
- if Dynamic_Priority_Support and then
- Self_ID.Pending_Priority_Change then
- Self_ID.Pending_Priority_Change := False;
- Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority;
- Set_Priority (Self_ID, Self_ID.Common.Base_Priority);
- end if;
-
- exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
-
- Result := cond_timedwait (Self_ID.Common.LL.CV'Access,
- Self_ID.Common.LL.L.L'Access, Request'Access);
-
- exit when Abs_Time <= Monotonic_Clock;
-
- pragma Assert (Result = 0 or else
- Result = ETIME or else
- Result = EINTR);
- end loop;
-
- pragma Assert (Record_Wakeup
- (To_Lock_Ptr (Self_ID.Common.LL.L'Access), Delay_Sleep));
-
- Self_ID.Common.State := Runnable;
- end if;
-
- Unlock (Self_ID);
- thr_yield;
- SSL.Abort_Undefer.all;
- end Timed_Delay;
-
- ------------
- -- Wakeup --
- ------------
-
- procedure Wakeup
- (T : Task_ID;
- Reason : Task_States)
- is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Check_Wakeup (T, Reason));
- Result := cond_signal (T.Common.LL.CV'Access);
- pragma Assert (Result = 0);
- end Wakeup;
-
- ---------------------------
- -- Check_Initialize_Lock --
- ---------------------------
-
- -- The following code is intended to check some of the invariant
- -- assertions related to lock usage, on which we depend.
-
- function Check_Initialize_Lock
- (L : Lock_Ptr;
- Level : Lock_Level)
- return Boolean
- is
- Self_ID : constant Task_ID := Self;
-
- begin
- -- Check that caller is abort-deferred
-
- if Self_ID.Deferral_Level <= 0 then
- return False;
- end if;
-
- -- Check that the lock is not yet initialized
-
- if L.Level /= 0 then
- return False;
- end if;
-
- L.Level := Lock_Level'Pos (Level) + 1;
- return True;
- end Check_Initialize_Lock;
-
- ----------------
- -- Check_Lock --
- ----------------
-
- function Check_Lock (L : Lock_Ptr) return Boolean is
- Self_ID : Task_ID := Self;
- P : Lock_Ptr;
-
- begin
- -- Check that the argument is not null
-
- if L = null then
- return False;
- end if;
-
- -- Check that L is not frozen
-
- if L.Frozen then
- return False;
- end if;
-
- -- Check that caller is abort-deferred
-
- if Self_ID.Deferral_Level <= 0 then
- return False;
- end if;
-
- -- Check that caller is not holding this lock already
-
- if L.Owner = To_Owner_ID (Self_ID) then
- return False;
- end if;
-
- -- Check that TCB lock order rules are satisfied
-
- P := Self_ID.Common.LL.Locks;
- if P /= null then
- if P.Level >= L.Level
- and then (P.Level > 2 or else L.Level > 2)
- then
- return False;
- end if;
- end if;
-
- return True;
- end Check_Lock;
-
- -----------------
- -- Record_Lock --
- -----------------
-
- function Record_Lock (L : Lock_Ptr) return Boolean is
- Self_ID : Task_ID := Self;
- P : Lock_Ptr;
-
- begin
- Lock_Count := Lock_Count + 1;
-
- -- There should be no owner for this lock at this point
-
- if L.Owner /= null then
- return False;
- end if;
-
- -- Record new owner
-
- L.Owner := To_Owner_ID (Self_ID);
-
- -- Check that TCB lock order rules are satisfied
-
- P := Self_ID.Common.LL.Locks;
-
- if P /= null then
- L.Next := P;
- end if;
-
- Self_ID.Common.LL.Locking := null;
- Self_ID.Common.LL.Locks := L;
- return True;
- end Record_Lock;
-
- -----------------
- -- Check_Sleep --
- -----------------
-
- function Check_Sleep (Reason : Task_States) return Boolean is
- Self_ID : Task_ID := Self;
- P : Lock_Ptr;
-
- begin
- -- Check that caller is abort-deferred
-
- if Self_ID.Deferral_Level <= 0 then
- return False;
- end if;
-
- -- Check that caller is holding own lock, on top of list
-
- if Self_ID.Common.LL.Locks /=
- To_Lock_Ptr (Self_ID.Common.LL.L'Access)
- then
- return False;
- end if;
-
- -- Check that TCB lock order rules are satisfied
-
- if Self_ID.Common.LL.Locks.Next /= null then
- return False;
- end if;
-
- Self_ID.Common.LL.L.Owner := null;
- P := Self_ID.Common.LL.Locks;
- Self_ID.Common.LL.Locks := Self_ID.Common.LL.Locks.Next;
- P.Next := null;
- return True;
- end Check_Sleep;
-
- -------------------
- -- Record_Wakeup --
- -------------------
-
- function Record_Wakeup
- (L : Lock_Ptr;
- Reason : Task_States)
- return Boolean
- is
- Self_ID : Task_ID := Self;
- P : Lock_Ptr;
-
- begin
- -- Record new owner
-
- L.Owner := To_Owner_ID (Self_ID);
-
- -- Check that TCB lock order rules are satisfied
-
- P := Self_ID.Common.LL.Locks;
-
- if P /= null then
- L.Next := P;
- end if;
-
- Self_ID.Common.LL.Locking := null;
- Self_ID.Common.LL.Locks := L;
- return True;
- end Record_Wakeup;
-
- ------------------
- -- Check_Wakeup --
- ------------------
-
- function Check_Wakeup
- (T : Task_ID;
- Reason : Task_States)
- return Boolean
- is
- Self_ID : Task_ID := Self;
-
- begin
- -- Is caller holding T's lock?
-
- if T.Common.LL.L.Owner /= To_Owner_ID (Self_ID) then
- return False;
- end if;
-
- -- Are reasons for wakeup and sleep consistent?
-
- if T.Common.State /= Reason then
- return False;
- end if;
-
- return True;
- end Check_Wakeup;
-
- ------------------
- -- Check_Unlock --
- ------------------
-
- function Check_Unlock (L : Lock_Ptr) return Boolean is
- Self_ID : Task_ID := Self;
- P : Lock_Ptr;
-
- begin
- Unlock_Count := Unlock_Count + 1;
-
- if L = null then
- return False;
- end if;
-
- if L.Buddy /= null then
- return False;
- end if;
-
- if L.Level = 4 then
- Check_Count := Unlock_Count;
- end if;
-
- if Unlock_Count - Check_Count > 1000 then
- Check_Count := Unlock_Count;
- Old_Owner := To_Task_ID (All_Tasks_L.Owner);
- end if;
-
- -- Check that caller is abort-deferred
-
- if Self_ID.Deferral_Level <= 0 then
- return False;
- end if;
-
- -- Check that caller is holding this lock, on top of list
-
- if Self_ID.Common.LL.Locks /= L then
- return False;
- end if;
-
- -- Record there is no owner now
-
- L.Owner := null;
- P := Self_ID.Common.LL.Locks;
- Self_ID.Common.LL.Locks := Self_ID.Common.LL.Locks.Next;
- P.Next := null;
- return True;
- end Check_Unlock;
-
- --------------------
- -- Check_Finalize --
- --------------------
-
- function Check_Finalize_Lock (L : Lock_Ptr) return Boolean is
- Self_ID : Task_ID := Self;
-
- begin
- -- Check that caller is abort-deferred
-
- if Self_ID.Deferral_Level <= 0 then
- return False;
- end if;
-
- -- Check that no one is holding this lock
-
- if L.Owner /= null then
- return False;
- end if;
-
- L.Frozen := True;
- return True;
- end Check_Finalize_Lock;
-
- ----------------
- -- Check_Exit --
- ----------------
-
- function Check_Exit (Self_ID : Task_ID) return Boolean is
- begin
- -- Check that caller is just holding Global_Task_Lock
- -- and no other locks
-
- if Self_ID.Common.LL.Locks = null then
- return False;
- end if;
-
- -- 2 = Global_Task_Level
-
- if Self_ID.Common.LL.Locks.Level /= 2 then
- return False;
- end if;
-
- if Self_ID.Common.LL.Locks.Next /= null then
- return False;
- end if;
-
- -- Check that caller is abort-deferred
-
- if Self_ID.Deferral_Level <= 0 then
- return False;
- end if;
-
- return True;
- end Check_Exit;
-
- --------------------
- -- Check_No_Locks --
- --------------------
-
- function Check_No_Locks (Self_ID : Task_ID) return Boolean is
- begin
- return Self_ID.Common.LL.Locks = null;
- end Check_No_Locks;
-
- ----------------------
- -- Environment_Task --
- ----------------------
-
- function Environment_Task return Task_ID is
- begin
- return Environment_Task_ID;
- end Environment_Task;
-
- -------------------------
- -- Lock_All_Tasks_List --
- -------------------------
-
- procedure Lock_All_Tasks_List is
- begin
- Write_Lock (All_Tasks_L'Access);
- end Lock_All_Tasks_List;
-
- ---------------------------
- -- Unlock_All_Tasks_List --
- ---------------------------
-
- procedure Unlock_All_Tasks_List is
- begin
- Unlock (All_Tasks_L'Access);
- end Unlock_All_Tasks_List;
-
- ------------------
- -- Suspend_Task --
- ------------------
-
- function Suspend_Task
- (T : ST.Task_ID;
- Thread_Self : Thread_Id) return Boolean is
- begin
- if T.Common.LL.Thread /= Thread_Self then
- return thr_suspend (T.Common.LL.Thread) = 0;
- else
- return True;
- end if;
- end Suspend_Task;
-
- -----------------
- -- Resume_Task --
- -----------------
-
- function Resume_Task
- (T : ST.Task_ID;
- Thread_Self : Thread_Id) return Boolean is
- begin
- if T.Common.LL.Thread /= Thread_Self then
- return thr_continue (T.Common.LL.Thread) = 0;
- else
- return True;
- end if;
- end Resume_Task;
-
- ----------------
- -- Initialize --
- ----------------
-
- procedure Initialize (Environment_Task : ST.Task_ID) is
- act : aliased struct_sigaction;
- old_act : aliased struct_sigaction;
- Tmp_Set : aliased sigset_t;
- Result : Interfaces.C.int;
-
- procedure Configure_Processors;
- -- Processors configuration
- -- The user can specify a processor which the program should run
- -- on to emulate a single-processor system. This can be easily
- -- done by setting environment variable GNAT_PROCESSOR to one of
- -- the following :
- --
- -- -2 : use the default configuration (run the program on all
- -- available processors) - this is the same as having
- -- GNAT_PROCESSOR unset
- -- -1 : let the RTS choose one processor and run the program on
- -- that processor
- -- 0 .. Last_Proc : run the program on the specified processor
- --
- -- Last_Proc is equal to the value of the system variable
- -- _SC_NPROCESSORS_CONF, minus one.
-
- procedure Configure_Processors is
-
- Proc_Acc : constant GNAT.OS_Lib.String_Access :=
- GNAT.OS_Lib.Getenv ("GNAT_PROCESSOR");
- begin
- if Proc_Acc.all'Length /= 0 then
-
- -- Environment variable is defined
-
- declare
- Proc : aliased processorid_t; -- User processor #
- Last_Proc : processorid_t; -- Last processor #
-
- begin
- Last_Proc := Num_Procs - 1;
-
- if Last_Proc = -1 then
-
- -- Unable to read system variable _SC_NPROCESSORS_CONF
- -- Ignore environment variable GNAT_PROCESSOR
-
- null;
-
- else
- Proc := processorid_t'Value (Proc_Acc.all);
-
- if Proc < -2 or Proc > Last_Proc then
- raise Constraint_Error;
-
- elsif Proc = -2 then
-
- -- Use the default configuration
-
- null;
-
- elsif Proc = -1 then
-
- -- Choose a processor
-
- Result := 0;
- while Proc < Last_Proc loop
- Proc := Proc + 1;
- Result := p_online (Proc, PR_STATUS);
- exit when Result = PR_ONLINE;
- end loop;
-
- pragma Assert (Result = PR_ONLINE);
- Result := processor_bind (P_PID, P_MYID, Proc, null);
- pragma Assert (Result = 0);
-
- else
- -- Use user processor
-
- Result := processor_bind (P_PID, P_MYID, Proc, null);
- pragma Assert (Result = 0);
- end if;
- end if;
-
- exception
- when Constraint_Error =>
-
- -- Illegal environment variable GNAT_PROCESSOR - ignored
-
- null;
- end;
- end if;
- end Configure_Processors;
-
- -- Start of processing for Initialize
-
- begin
- Environment_Task_ID := Environment_Task;
-
- -- This is done in Enter_Task, but this is too late for the
- -- Environment Task, since we need to call Self in Check_Locks when
- -- the run time is compiled with assertions on.
-
- Result := thr_setspecific (ATCB_Key, To_Address (Environment_Task));
- pragma Assert (Result = 0);
-
- -- Initialize the lock used to synchronize chain of all ATCBs.
-
- Initialize_Lock (All_Tasks_L'Access, All_Tasks_Level);
-
- Enter_Task (Environment_Task);
-
- -- Install the abort-signal handler
-
- -- Set sa_flags to SA_NODEFER so that during the handler execution
- -- we do not change the Signal_Mask to be masked for the Abort_Signal.
- -- This is a temporary fix to the problem that the Signal_Mask is
- -- not restored after the exception (longjmp) from the handler.
- -- The right fix should be made in sigsetjmp so that we save
- -- the Signal_Set and restore it after a longjmp.
- -- In that case, this field should be changed back to 0. ???
-
- act.sa_flags := 16;
-
- act.sa_handler := Abort_Handler'Address;
- Result := sigemptyset (Tmp_Set'Access);
- pragma Assert (Result = 0);
- act.sa_mask := Tmp_Set;
-
- Result :=
- sigaction (
- Signal (System.Interrupt_Management.Abort_Task_Interrupt),
- act'Unchecked_Access,
- old_act'Unchecked_Access);
- pragma Assert (Result = 0);
-
- Configure_Processors;
-
- -- Create a free ATCB for use on the Fake_ATCB_List.
-
- Next_Fake_ATCB := new Fake_ATCB;
- end Initialize;
-
--- Package elaboration
-
-begin
- declare
- Result : Interfaces.C.int;
-
- begin
- -- Mask Environment task for all signals. The original mask of the
- -- Environment task will be recovered by Interrupt_Server task
- -- during the elaboration of s-interr.adb.
-
- System.Interrupt_Management.Operations.Set_Interrupt_Mask
- (System.Interrupt_Management.Operations.All_Tasks_Mask'Access);
-
- -- Prepare the set of signals that should unblocked in all tasks
-
- Result := sigemptyset (Unblocked_Signal_Mask'Access);
- pragma Assert (Result = 0);
-
- for J in Interrupt_Management.Interrupt_ID loop
- if System.Interrupt_Management.Keep_Unmasked (J) then
- Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
- pragma Assert (Result = 0);
- end if;
- end loop;
-
- -- We need the following code to support automatic creation of fake
- -- ATCB's for C threads that call the Ada run-time system, even if
- -- we use a faster way of getting Self for real Ada tasks.
-
- Result := thr_keycreate (ATCB_Key'Access, System.Null_Address);
- pragma Assert (Result = 0);
- end;
-
- if Dispatching_Policy = 'F' then
- declare
- Result : Interfaces.C.long;
- Class_Info : aliased struct_pcinfo;
- Secs, Nsecs : Interfaces.C.long;
-
- begin
-
- -- If a pragma Time_Slice is specified, takes the value in account.
-
- if Time_Slice_Val > 0 then
- -- Convert Time_Slice_Val (microseconds) into seconds and
- -- nanoseconds
-
- Secs := Time_Slice_Val / 1_000_000;
- Nsecs := (Time_Slice_Val rem 1_000_000) * 1_000;
-
- -- Otherwise, default to no time slicing (i.e run until blocked)
-
- else
- Secs := RT_TQINF;
- Nsecs := RT_TQINF;
- end if;
-
- -- Get the real time class id.
-
- Class_Info.pc_clname (1) := 'R';
- Class_Info.pc_clname (2) := 'T';
- Class_Info.pc_clname (3) := ASCII.Nul;
-
- Result := priocntl (PC_VERSION, P_LWPID, P_MYID, PC_GETCID,
- Class_Info'Address);
-
- -- Request the real time class
-
- Prio_Param.pc_cid := Class_Info.pc_cid;
- Prio_Param.rt_pri := pri_t (Class_Info.rt_maxpri);
- Prio_Param.rt_tqsecs := Secs;
- Prio_Param.rt_tqnsecs := Nsecs;
-
- Result := priocntl (PC_VERSION, P_LWPID, P_MYID, PC_SETPARMS,
- Prio_Param'Address);
-
- Using_Real_Time_Class := Result /= -1;
- end;
- end if;
-end System.Task_Primitives.Operations;
projects / msp430-gcc.git / blobdiff