------------------------------------------------------------------------------ -- -- -- 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 -- -- -- -- -- -- 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- -- -- 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. (http://www.gnat.com). -- -- -- ------------------------------------------------------------------------------ -- This is a GNU/Linux (GNU/LinuxThreads) 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 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 with Ada.Exceptions; -- used for Raise_Exception -- Raise_From_Signal_Handler -- Exception_Id with System.Soft_Links; -- used for Defer/Undefer_Abort -- 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 System.Soft_Links; -- used for Get_Machine_State_Addr 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 System.OS_Primitives; package SSL renames System.Soft_Links; ------------------ -- Local Data -- ------------------ Max_Stack_Size : constant := 2000 * 1024; -- GNU/LinuxThreads does not return an error value when requesting -- a task stack size which is too large, so we have to check this -- ourselves. -- The followings are logically constants, but need to be initialized -- at run time. 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. Unblocked_Signal_Mask : aliased sigset_t; -- The set of signals that should unblocked in all tasks -- The followings are internal configuration constants needed. Priority_Ceiling_Emulation : constant Boolean := True; 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. Time_Slice_Val : Integer; pragma Import (C, Time_Slice_Val, "__gl_time_slice_val"); Dispatching_Policy : Character; pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy"); FIFO_Within_Priorities : constant Boolean := Dispatching_Policy = 'F'; -- Indicates whether FIFO_Within_Priorities is set. -- The following are effectively constants, but they need to -- be initialized by calling a pthread_ function. Mutex_Attr : aliased pthread_mutexattr_t; Cond_Attr : aliased pthread_condattr_t; ----------------------- -- Local Subprograms -- ----------------------- subtype unsigned_short is Interfaces.C.unsigned_short; subtype unsigned_long is Interfaces.C.unsigned_long; procedure Abort_Handler (signo : Signal; gs : unsigned_short; fs : unsigned_short; es : unsigned_short; ds : unsigned_short; edi : unsigned_long; esi : unsigned_long; ebp : unsigned_long; esp : unsigned_long; ebx : unsigned_long; edx : unsigned_long; ecx : unsigned_long; eax : unsigned_long; trapno : unsigned_long; err : unsigned_long; eip : unsigned_long; cs : unsigned_short; eflags : unsigned_long; esp_at_signal : unsigned_long; ss : unsigned_short; fpstate : System.Address; oldmask : unsigned_long; cr2 : unsigned_long); function To_Task_ID is new Unchecked_Conversion (System.Address, Task_ID); function To_Address is new Unchecked_Conversion (Task_ID, System.Address); function To_pthread_t is new Unchecked_Conversion (Integer, System.OS_Interface.pthread_t); -------------------- -- Local Packages -- -------------------- package Specific is procedure Initialize (Environment_Task : Task_ID); pragma Inline (Initialize); -- Initialize various data needed by this package. procedure Set (Self_Id : Task_ID); pragma Inline (Set); -- Set the self id for the current task. function Self return Task_ID; pragma Inline (Self); -- Return a pointer to the Ada Task Control Block of the calling task. end Specific; package body Specific is separate; -- The body of this package is target specific. ------------------- -- 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). -- Note that with the new exception mechanism, it is not correct to -- simply "raise" an exception from a signal handler, that's why we -- use Raise_From_Signal_Handler procedure Abort_Handler (signo : Signal; gs : unsigned_short; fs : unsigned_short; es : unsigned_short; ds : unsigned_short; edi : unsigned_long; esi : unsigned_long; ebp : unsigned_long; esp : unsigned_long; ebx : unsigned_long; edx : unsigned_long; ecx : unsigned_long; eax : unsigned_long; trapno : unsigned_long; err : unsigned_long; eip : unsigned_long; cs : unsigned_short; eflags : unsigned_long; esp_at_signal : unsigned_long; ss : unsigned_short; fpstate : System.Address; oldmask : unsigned_long; cr2 : unsigned_long) is Self_Id : Task_ID := Self; Result : Interfaces.C.int; Old_Set : aliased sigset_t; function To_Machine_State_Ptr is new Unchecked_Conversion (Address, Machine_State_Ptr); -- These are not directly visible procedure Raise_From_Signal_Handler (E : Ada.Exceptions.Exception_Id; M : System.Address); pragma Import (Ada, Raise_From_Signal_Handler, "ada__exceptions__raise_from_signal_handler"); pragma No_Return (Raise_From_Signal_Handler); mstate : Machine_State_Ptr; message : aliased constant String := "" & ASCII.Nul; -- a null terminated String. begin 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 Self_Id.Aborting := True; -- Make sure signals used for RTS internal purpose are unmasked Result := pthread_sigmask (SIG_UNBLOCK, Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access); pragma Assert (Result = 0); mstate := To_Machine_State_Ptr (SSL.Get_Machine_State_Addr.all); mstate.eip := eip; mstate.ebx := ebx; mstate.esp := esp_at_signal; mstate.ebp := ebp; mstate.esi := esi; mstate.edi := edi; Raise_From_Signal_Handler (Standard'Abort_Signal'Identity, message'Address); end if; end Abort_Handler; -------------- -- Lock_RTS -- -------------- procedure Lock_RTS is begin Write_Lock (Single_RTS_Lock'Access, Global_Lock => True); end Lock_RTS; ---------------- -- Unlock_RTS -- ---------------- procedure Unlock_RTS is begin Unlock (Single_RTS_Lock'Access, Global_Lock => True); end Unlock_RTS; ----------------- -- Stack_Guard -- ----------------- -- The underlying thread system extends the memory (up to 2MB) when -- 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 renames Specific.Self; --------------------- -- 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 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. procedure Initialize_Lock (Prio : System.Any_Priority; L : access Lock) is Result : Interfaces.C.int; begin if Priority_Ceiling_Emulation then L.Ceiling := Prio; end if; Result := pthread_mutex_init (L.L'Access, Mutex_Attr'Access); pragma Assert (Result = 0 or else Result = ENOMEM); if Result = ENOMEM then Ada.Exceptions.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 Result := pthread_mutex_init (L, Mutex_Attr'Access); pragma Assert (Result = 0 or else Result = ENOMEM); if Result = ENOMEM then raise Storage_Error; end if; end Initialize_Lock; ------------------- -- Finalize_Lock -- ------------------- procedure Finalize_Lock (L : access Lock) is Result : Interfaces.C.int; begin Result := pthread_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 Result := pthread_mutex_destroy (L); 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 if Priority_Ceiling_Emulation then declare Self_ID : constant Task_ID := Self; begin if Self_ID.Common.LL.Active_Priority > L.Ceiling then Ceiling_Violation := True; return; end if; L.Saved_Priority := Self_ID.Common.LL.Active_Priority; if Self_ID.Common.LL.Active_Priority < L.Ceiling then Self_ID.Common.LL.Active_Priority := L.Ceiling; end if; Result := pthread_mutex_lock (L.L'Access); pragma Assert (Result = 0); Ceiling_Violation := False; end; else Result := pthread_mutex_lock (L.L'Access); Ceiling_Violation := Result = EINVAL; -- assumes the cause of EINVAL is a priority ceiling violation pragma Assert (Result = 0 or else Result = EINVAL); end if; end Write_Lock; procedure Write_Lock (L : access RTS_Lock; Global_Lock : Boolean := False) is Result : Interfaces.C.int; begin 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 if not Single_Lock then Result := pthread_mutex_lock (T.Common.LL.L'Access); pragma Assert (Result = 0); end if; 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 if Priority_Ceiling_Emulation then declare Self_ID : constant Task_ID := Self; begin Result := pthread_mutex_unlock (L.L'Access); pragma Assert (Result = 0); if Self_ID.Common.LL.Active_Priority > L.Saved_Priority then Self_ID.Common.LL.Active_Priority := L.Saved_Priority; end if; end; else Result := pthread_mutex_unlock (L.L'Access); pragma Assert (Result = 0); end if; end Unlock; procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is Result : Interfaces.C.int; begin 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 if not Single_Lock then Result := pthread_mutex_unlock (T.Common.LL.L'Access); pragma Assert (Result = 0); end if; end Unlock; ----------- -- Sleep -- ----------- procedure Sleep (Self_ID : Task_ID; Reason : System.Tasking.Task_States) is Result : Interfaces.C.int; begin pragma Assert (Self_ID = Self); 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; ----------------- -- 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. 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 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 Self_ID.Pending_Priority_Change; 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; if Result = 0 or Result = EINTR then -- somebody may have called Wakeup for us Timedout := False; exit; end if; pragma Assert (Result = ETIMEDOUT); end loop; end if; 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; if Single_Lock then Lock_RTS; end if; 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; loop if 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; 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; pragma Assert (Result = 0 or else Result = ETIMEDOUT or else Result = EINTR); end loop; Self_ID.Common.State := Runnable; end if; Unlock (Self_ID); if Single_Lock then Unlock_RTS; end if; Result := sched_yield; SSL.Abort_Undefer.all; end Timed_Delay; --------------------- -- Monotonic_Clock -- --------------------- function Monotonic_Clock return Duration is TV : aliased struct_timeval; Result : Interfaces.C.int; begin Result := gettimeofday (TV'Access, System.Null_Address); pragma Assert (Result = 0); return To_Duration (TV); end Monotonic_Clock; ------------------- -- RT_Resolution -- ------------------- function RT_Resolution return Duration is begin return 10#1.0#E-6; end RT_Resolution; ------------ -- Wakeup -- ------------ procedure Wakeup (T : Task_ID; Reason : System.Tasking.Task_States) is Result : Interfaces.C.int; begin Result := pthread_cond_signal (T.Common.LL.CV'Access); pragma Assert (Result = 0); end Wakeup; ----------- -- Yield -- ----------- procedure Yield (Do_Yield : Boolean := True) is Result : Interfaces.C.int; begin if Do_Yield then Result := sched_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_sched_param; begin T.Common.Current_Priority := Prio; if Priority_Ceiling_Emulation then if T.Common.LL.Active_Priority < Prio then T.Common.LL.Active_Priority := Prio; end if; end if; -- Priorities are in range 1 .. 99 on GNU/Linux, so we map -- map 0 .. 31 to 1 .. 32 Param.sched_priority := Interfaces.C.int (Prio) + 1; if Time_Slice_Val > 0 then Result := pthread_setschedparam (T.Common.LL.Thread, SCHED_RR, Param'Access); elsif FIFO_Within_Priorities or else Time_Slice_Val = 0 then Result := pthread_setschedparam (T.Common.LL.Thread, SCHED_FIFO, Param'Access); else Result := pthread_setschedparam (T.Common.LL.Thread, SCHED_OTHER, Param'Access); end if; pragma Assert (Result = 0 or else Result = EPERM); 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 begin Self_ID.Common.LL.Thread := pthread_self; Specific.Set (Self_ID); Lock_RTS; 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_RTS; 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_pthread_t (-1); if not Single_Lock then Result := pthread_mutex_init (Self_ID.Common.LL.L'Access, Mutex_Attr'Access); pragma Assert (Result = 0 or else Result = ENOMEM); if Result /= 0 then Succeeded := False; return; end if; 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 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; 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 Attributes : aliased pthread_attr_t; Result : Interfaces.C.int; function Thread_Body_Access is new Unchecked_Conversion (System.Address, Thread_Body); begin Result := pthread_attr_init (Attributes'Access); pragma Assert (Result = 0 or else Result = ENOMEM); if Result /= 0 or else Stack_Size > Max_Stack_Size then Succeeded := False; return; end if; Result := pthread_attr_setdetachstate (Attributes'Access, PTHREAD_CREATE_DETACHED); pragma Assert (Result = 0); -- 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. Result := pthread_create (T.Common.LL.Thread'Access, Attributes'Access, Thread_Body_Access (Wrapper), To_Address (T)); pragma Assert (Result = 0 or else Result = EAGAIN); Succeeded := Result = 0; Result := pthread_attr_destroy (Attributes'Access); pragma Assert (Result = 0); Set_Priority (T, Priority); 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 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); if T.Known_Tasks_Index /= -1 then Known_Tasks (T.Known_Tasks_Index) := null; end if; Free (Tmp); end Finalize_TCB; --------------- -- Exit_Task -- --------------- procedure Exit_Task is begin pthread_exit (System.Null_Address); end Exit_Task; ---------------- -- Abort_Task -- ---------------- procedure Abort_Task (T : Task_ID) is Result : Interfaces.C.int; begin Result := pthread_kill (T.Common.LL.Thread, Signal (System.Interrupt_Management.Abort_Task_Interrupt)); pragma Assert (Result = 0); end Abort_Task; ---------------- -- Check_Exit -- ---------------- -- Dummy versions. The only currently working versions is for solaris -- (native). function Check_Exit (Self_ID : ST.Task_ID) return Boolean is begin return True; end Check_Exit; -------------------- -- Check_No_Locks -- -------------------- function Check_No_Locks (Self_ID : ST.Task_ID) return Boolean is begin return True; end Check_No_Locks; ---------------------- -- Environment_Task -- ---------------------- function Environment_Task return Task_ID is begin return Environment_Task_ID; end Environment_Task; ------------------ -- 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 pthread_kill (T.Common.LL.Thread, SIGSTOP) = 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 pthread_kill (T.Common.LL.Thread, SIGCONT) = 0; else return True; end if; end Resume_Task; ---------------- -- Initialize -- ---------------- procedure Initialize (Environment_Task : Task_ID) is act : aliased struct_sigaction; old_act : aliased struct_sigaction; Tmp_Set : aliased sigset_t; Result : Interfaces.C.int; begin Environment_Task_ID := Environment_Task; Result := pthread_mutexattr_init (Mutex_Attr'Access); pragma Assert (Result = 0 or else Result = ENOMEM); Result := pthread_condattr_init (Cond_Attr'Access); pragma Assert (Result = 0 or else Result = ENOMEM); Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level); -- Initialize the global RTS lock Specific.Initialize (Environment_Task); Enter_Task (Environment_Task); -- Install the abort-signal handler act.sa_flags := 0; act.sa_handler := Abort_Handler'Address; Result := sigemptyset (Tmp_Set'Access); pragma Assert (Result = 0); act.sa_mask := Tmp_Set; Result := sigaction (Signal (Interrupt_Management.Abort_Task_Interrupt), act'Unchecked_Access, old_act'Unchecked_Access); pragma Assert (Result = 0); end Initialize; 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; end; end System.Task_Primitives.Operations;