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Diffstat (limited to 'gcc-4.4.0/gcc/ada/s-taprop-vxworks.adb')
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diff --git a/gcc-4.4.0/gcc/ada/s-taprop-vxworks.adb b/gcc-4.4.0/gcc/ada/s-taprop-vxworks.adb new file mode 100644 index 000000000..40ded21b2 --- /dev/null +++ b/gcc-4.4.0/gcc/ada/s-taprop-vxworks.adb @@ -0,0 +1,1401 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT 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) 1992-2009, 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 3, or (at your option) any later ver- -- +-- sion. GNAT 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. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNARL was developed by the GNARL team at Florida State University. -- +-- Extensive contributions were provided by Ada Core Technologies, Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This is the VxWorks 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 Ada.Unchecked_Conversion; +with Ada.Unchecked_Deallocation; + +with Interfaces.C; + +with System.Tasking.Debug; +with System.Interrupt_Management; + +with System.Soft_Links; +-- We use System.Soft_Links instead of System.Tasking.Initialization +-- because the later 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.Stages. + +with System.VxWorks.Ext; + +package body System.Task_Primitives.Operations is + + package SSL renames System.Soft_Links; + + use System.Tasking.Debug; + use System.Tasking; + use System.OS_Interface; + use System.Parameters; + use type System.VxWorks.Ext.t_id; + use type Interfaces.C.int; + + subtype int is System.OS_Interface.int; + + Relative : constant := 0; + + ---------------- + -- Local Data -- + ---------------- + + -- 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 + + Time_Slice_Val : Integer; + 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"); + + function Get_Policy (Prio : System.Any_Priority) return Character; + pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching"); + -- Get priority specific dispatching policy + + Mutex_Protocol : Priority_Type; + + Foreign_Task_Elaborated : aliased Boolean := True; + -- Used to identified fake tasks (i.e., non-Ada Threads) + + type Set_Stack_Limit_Proc_Acc is access procedure; + pragma Convention (C, Set_Stack_Limit_Proc_Acc); + + Set_Stack_Limit_Hook : Set_Stack_Limit_Proc_Acc; + pragma Import (C, Set_Stack_Limit_Hook, "__gnat_set_stack_limit_hook"); + -- Procedure to be called when a task is created to set stack + -- limit. + + -------------------- + -- Local Packages -- + -------------------- + + package Specific is + + procedure Initialize; + pragma Inline (Initialize); + -- Initialize task specific data + + function Is_Valid_Task return Boolean; + pragma Inline (Is_Valid_Task); + -- Does executing thread have a TCB? + + procedure Set (Self_Id : Task_Id); + pragma Inline (Set); + -- Set the self id for the current task + + procedure Delete; + pragma Inline (Delete); + -- Delete the task specific data associated with 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 + + --------------------------------- + -- Support for foreign threads -- + --------------------------------- + + function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id; + -- Allocate and Initialize a new ATCB for the current Thread + + function Register_Foreign_Thread + (Thread : Thread_Id) return Task_Id is separate; + + ----------------------- + -- Local Subprograms -- + ----------------------- + + procedure Abort_Handler (signo : Signal); + -- Handler for the abort (SIGABRT) signal to handle asynchronous abort + + procedure Install_Signal_Handlers; + -- Install the default signal handlers for the current task + + function To_Address is + new Ada.Unchecked_Conversion (Task_Id, System.Address); + + ------------------- + -- Abort_Handler -- + ------------------- + + procedure Abort_Handler (signo : Signal) is + pragma Unreferenced (signo); + + Self_ID : constant Task_Id := Self; + Old_Set : aliased sigset_t; + + Result : int; + pragma Warnings (Off, Result); + + begin + -- It is not safe to raise an exception when using ZCX and the GCC + -- exception handling mechanism. + + if ZCX_By_Default and then GCC_ZCX_Support then + return; + end if; + + 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'Access, + Old_Set'Access); + pragma Assert (Result = 0); + + raise Standard'Abort_Signal; + end if; + end Abort_Handler; + + ----------------- + -- Stack_Guard -- + ----------------- + + procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is + pragma Unreferenced (T); + pragma Unreferenced (On); + + begin + -- Nothing needed (why not???) + + 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; + + ----------------------------- + -- Install_Signal_Handlers -- + ----------------------------- + + procedure Install_Signal_Handlers is + act : aliased struct_sigaction; + old_act : aliased struct_sigaction; + Tmp_Set : aliased sigset_t; + Result : int; + + begin + 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); + + Interrupt_Management.Initialize_Interrupts; + end Install_Signal_Handlers; + + --------------------- + -- Initialize_Lock -- + --------------------- + + procedure Initialize_Lock + (Prio : System.Any_Priority; + L : not null access Lock) + is + begin + L.Mutex := semMCreate (SEM_Q_PRIORITY + SEM_INVERSION_SAFE); + L.Prio_Ceiling := int (Prio); + L.Protocol := Mutex_Protocol; + pragma Assert (L.Mutex /= 0); + end Initialize_Lock; + + procedure Initialize_Lock + (L : not null access RTS_Lock; + Level : Lock_Level) + is + pragma Unreferenced (Level); + begin + L.Mutex := semMCreate (SEM_Q_PRIORITY + SEM_INVERSION_SAFE); + L.Prio_Ceiling := int (System.Any_Priority'Last); + L.Protocol := Mutex_Protocol; + pragma Assert (L.Mutex /= 0); + end Initialize_Lock; + + ------------------- + -- Finalize_Lock -- + ------------------- + + procedure Finalize_Lock (L : not null access Lock) is + Result : int; + begin + Result := semDelete (L.Mutex); + pragma Assert (Result = 0); + end Finalize_Lock; + + procedure Finalize_Lock (L : not null access RTS_Lock) is + Result : int; + begin + Result := semDelete (L.Mutex); + pragma Assert (Result = 0); + end Finalize_Lock; + + ---------------- + -- Write_Lock -- + ---------------- + + procedure Write_Lock + (L : not null access Lock; + Ceiling_Violation : out Boolean) + is + Result : int; + + begin + if L.Protocol = Prio_Protect + and then int (Self.Common.Current_Priority) > L.Prio_Ceiling + then + Ceiling_Violation := True; + return; + else + Ceiling_Violation := False; + end if; + + Result := semTake (L.Mutex, WAIT_FOREVER); + pragma Assert (Result = 0); + end Write_Lock; + + procedure Write_Lock + (L : not null access RTS_Lock; + Global_Lock : Boolean := False) + is + Result : int; + begin + if not Single_Lock or else Global_Lock then + Result := semTake (L.Mutex, WAIT_FOREVER); + pragma Assert (Result = 0); + end if; + end Write_Lock; + + procedure Write_Lock (T : Task_Id) is + Result : int; + begin + if not Single_Lock then + Result := semTake (T.Common.LL.L.Mutex, WAIT_FOREVER); + pragma Assert (Result = 0); + end if; + end Write_Lock; + + --------------- + -- Read_Lock -- + --------------- + + procedure Read_Lock + (L : not null access Lock; + Ceiling_Violation : out Boolean) + is + begin + Write_Lock (L, Ceiling_Violation); + end Read_Lock; + + ------------ + -- Unlock -- + ------------ + + procedure Unlock (L : not null access Lock) is + Result : int; + begin + Result := semGive (L.Mutex); + pragma Assert (Result = 0); + end Unlock; + + procedure Unlock + (L : not null access RTS_Lock; + Global_Lock : Boolean := False) + is + Result : int; + begin + if not Single_Lock or else Global_Lock then + Result := semGive (L.Mutex); + pragma Assert (Result = 0); + end if; + end Unlock; + + procedure Unlock (T : Task_Id) is + Result : int; + begin + if not Single_Lock then + Result := semGive (T.Common.LL.L.Mutex); + pragma Assert (Result = 0); + end if; + end Unlock; + + ----------------- + -- Set_Ceiling -- + ----------------- + + -- Dynamic priority ceilings are not supported by the underlying system + + procedure Set_Ceiling + (L : not null access Lock; + Prio : System.Any_Priority) + is + pragma Unreferenced (L, Prio); + begin + null; + end Set_Ceiling; + + ----------- + -- Sleep -- + ----------- + + procedure Sleep (Self_ID : Task_Id; Reason : System.Tasking.Task_States) is + pragma Unreferenced (Reason); + + Result : int; + + begin + pragma Assert (Self_ID = Self); + + -- Release the mutex before sleeping + + if Single_Lock then + Result := semGive (Single_RTS_Lock.Mutex); + else + Result := semGive (Self_ID.Common.LL.L.Mutex); + end if; + + pragma Assert (Result = 0); + + -- Perform a blocking operation to take the CV semaphore. Note that a + -- blocking operation in VxWorks will reenable task scheduling. When we + -- are no longer blocked and control is returned, task scheduling will + -- again be disabled. + + Result := semTake (Self_ID.Common.LL.CV, WAIT_FOREVER); + pragma Assert (Result = 0); + + -- Take the mutex back + + if Single_Lock then + Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER); + else + Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER); + end if; + + pragma Assert (Result = 0); + 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 + pragma Unreferenced (Reason); + + Orig : constant Duration := Monotonic_Clock; + Absolute : Duration; + Ticks : int; + Result : int; + Wakeup : Boolean := False; + + begin + Timedout := False; + Yielded := True; + + if Mode = Relative then + Absolute := Orig + Time; + + -- Systematically add one since the first tick will delay *at most* + -- 1 / Rate_Duration seconds, so we need to add one to be on the + -- safe side. + + Ticks := To_Clock_Ticks (Time); + + if Ticks > 0 and then Ticks < int'Last then + Ticks := Ticks + 1; + end if; + + else + Absolute := Time; + Ticks := To_Clock_Ticks (Time - Monotonic_Clock); + end if; + + if Ticks > 0 then + loop + -- Release the mutex before sleeping + + if Single_Lock then + Result := semGive (Single_RTS_Lock.Mutex); + else + Result := semGive (Self_ID.Common.LL.L.Mutex); + end if; + + pragma Assert (Result = 0); + + -- Perform a blocking operation to take the CV semaphore. Note + -- that a blocking operation in VxWorks will reenable task + -- scheduling. When we are no longer blocked and control is + -- returned, task scheduling will again be disabled. + + Result := semTake (Self_ID.Common.LL.CV, Ticks); + + if Result = 0 then + + -- Somebody may have called Wakeup for us + + Wakeup := True; + + else + if errno /= S_objLib_OBJ_TIMEOUT then + Wakeup := True; + + else + -- If Ticks = int'last, it was most probably truncated so + -- let's make another round after recomputing Ticks from + -- the absolute time. + + if Ticks /= int'Last then + Timedout := True; + + else + Ticks := To_Clock_Ticks (Absolute - Monotonic_Clock); + + if Ticks < 0 then + Timedout := True; + end if; + end if; + end if; + end if; + + -- Take the mutex back + + if Single_Lock then + Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER); + else + Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER); + end if; + + pragma Assert (Result = 0); + + exit when Timedout or Wakeup; + end loop; + + else + Timedout := True; + + -- Should never hold a lock while yielding + + if Single_Lock then + Result := semGive (Single_RTS_Lock.Mutex); + taskDelay (0); + Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER); + + else + Result := semGive (Self_ID.Common.LL.L.Mutex); + taskDelay (0); + Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER); + end if; + end if; + end Timed_Sleep; + + ----------------- + -- Timed_Delay -- + ----------------- + + -- This is for use in implementing delay statements, so we assume the + -- caller is holding no locks. + + procedure Timed_Delay + (Self_ID : Task_Id; + Time : Duration; + Mode : ST.Delay_Modes) + is + Orig : constant Duration := Monotonic_Clock; + Absolute : Duration; + Ticks : int; + Timedout : Boolean; + Aborted : Boolean := False; + + Result : int; + pragma Warnings (Off, Result); + + begin + if Mode = Relative then + Absolute := Orig + Time; + Ticks := To_Clock_Ticks (Time); + + if Ticks > 0 and then Ticks < int'Last then + + -- First tick will delay anytime between 0 and 1 / sysClkRateGet + -- seconds, so we need to add one to be on the safe side. + + Ticks := Ticks + 1; + end if; + + else + Absolute := Time; + Ticks := To_Clock_Ticks (Time - Orig); + end if; + + if Ticks > 0 then + + -- Modifying State, locking the TCB + + if Single_Lock then + Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER); + else + Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER); + end if; + + pragma Assert (Result = 0); + + Self_ID.Common.State := Delay_Sleep; + Timedout := False; + + loop + Aborted := Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level; + + -- Release the TCB before sleeping + + if Single_Lock then + Result := semGive (Single_RTS_Lock.Mutex); + else + Result := semGive (Self_ID.Common.LL.L.Mutex); + end if; + pragma Assert (Result = 0); + + exit when Aborted; + + Result := semTake (Self_ID.Common.LL.CV, Ticks); + + if Result /= 0 then + + -- If Ticks = int'last, it was most probably truncated + -- so let's make another round after recomputing Ticks + -- from the absolute time. + + if errno = S_objLib_OBJ_TIMEOUT and then Ticks /= int'Last then + Timedout := True; + else + Ticks := To_Clock_Ticks (Absolute - Monotonic_Clock); + + if Ticks < 0 then + Timedout := True; + end if; + end if; + end if; + + -- Take back the lock after having slept, to protect further + -- access to Self_ID. + + if Single_Lock then + Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER); + else + Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER); + end if; + + pragma Assert (Result = 0); + + exit when Timedout; + end loop; + + Self_ID.Common.State := Runnable; + + if Single_Lock then + Result := semGive (Single_RTS_Lock.Mutex); + else + Result := semGive (Self_ID.Common.LL.L.Mutex); + end if; + + else + taskDelay (0); + end if; + end Timed_Delay; + + --------------------- + -- Monotonic_Clock -- + --------------------- + + function Monotonic_Clock return Duration is + TS : aliased timespec; + Result : 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 1.0 / Duration (sysClkRateGet); + end RT_Resolution; + + ------------ + -- Wakeup -- + ------------ + + procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is + pragma Unreferenced (Reason); + Result : int; + begin + Result := semGive (T.Common.LL.CV); + pragma Assert (Result = 0); + end Wakeup; + + ----------- + -- Yield -- + ----------- + + procedure Yield (Do_Yield : Boolean := True) is + pragma Unreferenced (Do_Yield); + Result : int; + pragma Unreferenced (Result); + begin + Result := taskDelay (0); + end Yield; + + ------------------ + -- Set_Priority -- + ------------------ + + type Prio_Array_Type is array (System.Any_Priority) of Integer; + pragma Atomic_Components (Prio_Array_Type); + + Prio_Array : Prio_Array_Type; + -- Global array containing the id of the currently running task for each + -- priority. Note that we assume that we are on a single processor with + -- run-till-blocked scheduling. + + procedure Set_Priority + (T : Task_Id; + Prio : System.Any_Priority; + Loss_Of_Inheritance : Boolean := False) + is + Array_Item : Integer; + Result : int; + + begin + Result := + taskPrioritySet + (T.Common.LL.Thread, To_VxWorks_Priority (int (Prio))); + pragma Assert (Result = 0); + + if (Dispatching_Policy = 'F' or else Get_Policy (Prio) = 'F') + and then Loss_Of_Inheritance + and then Prio < T.Common.Current_Priority + then + -- Annex D requirement (RM D.2.2(9)): + + -- If the task drops its priority due to the loss of inherited + -- priority, it is added at the head of the ready queue for its + -- new active priority. + + Array_Item := Prio_Array (T.Common.Base_Priority) + 1; + Prio_Array (T.Common.Base_Priority) := Array_Item; + + loop + -- Give some processes a chance to arrive + + taskDelay (0); + + -- Then wait for our turn to proceed + + exit when Array_Item = Prio_Array (T.Common.Base_Priority) + or else Prio_Array (T.Common.Base_Priority) = 1; + end loop; + + Prio_Array (T.Common.Base_Priority) := + Prio_Array (T.Common.Base_Priority) - 1; + end if; + + T.Common.Current_Priority := Prio; + 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 + procedure Init_Float; + pragma Import (C, Init_Float, "__gnat_init_float"); + -- Properly initializes the FPU for PPC/MIPS systems + + begin + -- Store the user-level task id in the Thread field (to be used + -- internally by the run-time system) and the kernel-level task id in + -- the LWP field (to be used by the debugger). + + Self_ID.Common.LL.Thread := taskIdSelf; + Self_ID.Common.LL.LWP := getpid; + + Specific.Set (Self_ID); + + Init_Float; + + -- Install the signal handlers + + -- This is called for each task since there is no signal inheritance + -- between VxWorks tasks. + + Install_Signal_Handlers; + + 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; + + -- If stack checking is enabled, set the stack limit for this task + + if Set_Stack_Limit_Hook /= null then + Set_Stack_Limit_Hook.all; + end if; + 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; + + ------------------- + -- Is_Valid_Task -- + ------------------- + + function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task; + + ----------------------------- + -- Register_Foreign_Thread -- + ----------------------------- + + function Register_Foreign_Thread return Task_Id is + begin + if Is_Valid_Task then + return Self; + else + return Register_Foreign_Thread (taskIdSelf); + end if; + end Register_Foreign_Thread; + + -------------------- + -- Initialize_TCB -- + -------------------- + + procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is + begin + Self_ID.Common.LL.CV := semBCreate (SEM_Q_PRIORITY, SEM_EMPTY); + Self_ID.Common.LL.Thread := 0; + + if Self_ID.Common.LL.CV = 0 then + Succeeded := False; + + else + Succeeded := True; + + if not Single_Lock then + Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level); + end if; + 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 + Adjusted_Stack_Size : size_t; + begin + -- Ask for four extra bytes of stack space so that the ATCB pointer can + -- be stored below the stack limit, plus extra space for the frame of + -- Task_Wrapper. This is so the user gets the amount of stack requested + -- exclusive of the needs. + + -- We also have to allocate n more bytes for the task name storage and + -- enough space for the Wind Task Control Block which is around 0x778 + -- bytes. VxWorks also seems to carve out additional space, so use 2048 + -- as a nice round number. We might want to increment to the nearest + -- page size in case we ever support VxVMI. + + -- ??? - we should come back and visit this so we can set the task name + -- to something appropriate. + + Adjusted_Stack_Size := size_t (Stack_Size) + 2048; + + -- 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. + + -- We now compute the VxWorks task name and options, then spawn ... + + declare + Name : aliased String (1 .. T.Common.Task_Image_Len + 1); + Name_Address : System.Address; + -- Task name we are going to hand down to VxWorks + + function Get_Task_Options return int; + pragma Import (C, Get_Task_Options, "__gnat_get_task_options"); + -- Function that returns the options to be set for the task that we + -- are creating. We fetch the options assigned to the current task, + -- so offering some user level control over the options for a task + -- hierarchy, and force VX_FP_TASK because it is almost always + -- required. + + begin + -- If there is no Ada task name handy, let VxWorks choose one. + -- Otherwise, tell VxWorks what the Ada task name is. + + if T.Common.Task_Image_Len = 0 then + Name_Address := System.Null_Address; + else + Name (1 .. Name'Last - 1) := + T.Common.Task_Image (1 .. T.Common.Task_Image_Len); + Name (Name'Last) := ASCII.NUL; + Name_Address := Name'Address; + end if; + + -- Now spawn the VxWorks task for real + + T.Common.LL.Thread := + taskSpawn + (Name_Address, + To_VxWorks_Priority (int (Priority)), + Get_Task_Options, + Adjusted_Stack_Size, + Wrapper, + To_Address (T)); + end; + + if T.Common.LL.Thread = -1 then + Succeeded := False; + else + Succeeded := True; + Task_Creation_Hook (T.Common.LL.Thread); + Set_Priority (T, Priority); + end if; + end Create_Task; + + ------------------ + -- Finalize_TCB -- + ------------------ + + procedure Finalize_TCB (T : Task_Id) is + Result : int; + Tmp : Task_Id := T; + Is_Self : constant Boolean := (T = Self); + + procedure Free is new + Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id); + + begin + if not Single_Lock then + Result := semDelete (T.Common.LL.L.Mutex); + pragma Assert (Result = 0); + end if; + + T.Common.LL.Thread := 0; + + Result := semDelete (T.Common.LL.CV); + pragma Assert (Result = 0); + + if T.Known_Tasks_Index /= -1 then + Known_Tasks (T.Known_Tasks_Index) := null; + end if; + + Free (Tmp); + + if Is_Self then + Specific.Delete; + end if; + end Finalize_TCB; + + --------------- + -- Exit_Task -- + --------------- + + procedure Exit_Task is + begin + Specific.Set (null); + end Exit_Task; + + ---------------- + -- Abort_Task -- + ---------------- + + procedure Abort_Task (T : Task_Id) is + Result : int; + begin + Result := + kill + (T.Common.LL.Thread, + Signal (Interrupt_Management.Abort_Task_Interrupt)); + pragma Assert (Result = 0); + end Abort_Task; + + ---------------- + -- Initialize -- + ---------------- + + procedure Initialize (S : in out Suspension_Object) is + begin + -- Initialize internal state (always to False (RM D.10(6))) + + S.State := False; + S.Waiting := False; + + -- Initialize internal mutex + + -- Use simpler binary semaphore instead of VxWorks + -- mutual exclusion semaphore, because we don't need + -- the fancier semantics and their overhead. + + S.L := semBCreate (SEM_Q_FIFO, SEM_FULL); + + -- Initialize internal condition variable + + S.CV := semBCreate (SEM_Q_FIFO, SEM_EMPTY); + end Initialize; + + -------------- + -- Finalize -- + -------------- + + procedure Finalize (S : in out Suspension_Object) is + pragma Unmodified (S); + -- S may be modified on other targets, but not on VxWorks + + Result : STATUS; + + begin + -- Destroy internal mutex + + Result := semDelete (S.L); + pragma Assert (Result = OK); + + -- Destroy internal condition variable + + Result := semDelete (S.CV); + pragma Assert (Result = OK); + end Finalize; + + ------------------- + -- Current_State -- + ------------------- + + function Current_State (S : Suspension_Object) return Boolean is + begin + -- We do not want to use lock on this read operation. State is marked + -- as Atomic so that we ensure that the value retrieved is correct. + + return S.State; + end Current_State; + + --------------- + -- Set_False -- + --------------- + + procedure Set_False (S : in out Suspension_Object) is + Result : STATUS; + + begin + SSL.Abort_Defer.all; + + Result := semTake (S.L, WAIT_FOREVER); + pragma Assert (Result = OK); + + S.State := False; + + Result := semGive (S.L); + pragma Assert (Result = OK); + + SSL.Abort_Undefer.all; + end Set_False; + + -------------- + -- Set_True -- + -------------- + + procedure Set_True (S : in out Suspension_Object) is + Result : STATUS; + + begin + SSL.Abort_Defer.all; + + Result := semTake (S.L, WAIT_FOREVER); + pragma Assert (Result = OK); + + -- If there is already a task waiting on this suspension object then + -- we resume it, leaving the state of the suspension object to False, + -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves + -- the state to True. + + if S.Waiting then + S.Waiting := False; + S.State := False; + + Result := semGive (S.CV); + pragma Assert (Result = OK); + else + S.State := True; + end if; + + Result := semGive (S.L); + pragma Assert (Result = OK); + + SSL.Abort_Undefer.all; + end Set_True; + + ------------------------ + -- Suspend_Until_True -- + ------------------------ + + procedure Suspend_Until_True (S : in out Suspension_Object) is + Result : STATUS; + + begin + SSL.Abort_Defer.all; + + Result := semTake (S.L, WAIT_FOREVER); + + if S.Waiting then + + -- Program_Error must be raised upon calling Suspend_Until_True + -- if another task is already waiting on that suspension object + -- (ARM D.10 par. 10). + + Result := semGive (S.L); + pragma Assert (Result = OK); + + SSL.Abort_Undefer.all; + + raise Program_Error; + + else + -- Suspend the task if the state is False. Otherwise, the task + -- continues its execution, and the state of the suspension object + -- is set to False (ARM D.10 par. 9). + + if S.State then + S.State := False; + + Result := semGive (S.L); + pragma Assert (Result = 0); + + SSL.Abort_Undefer.all; + + else + S.Waiting := True; + + -- Release the mutex before sleeping + + Result := semGive (S.L); + pragma Assert (Result = OK); + + SSL.Abort_Undefer.all; + + Result := semTake (S.CV, WAIT_FOREVER); + pragma Assert (Result = 0); + end if; + end if; + end Suspend_Until_True; + + ---------------- + -- Check_Exit -- + ---------------- + + -- Dummy version + + function Check_Exit (Self_ID : ST.Task_Id) return Boolean is + pragma Unreferenced (Self_ID); + begin + return True; + end Check_Exit; + + -------------------- + -- Check_No_Locks -- + -------------------- + + function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is + pragma Unreferenced (Self_ID); + begin + return True; + end Check_No_Locks; + + ---------------------- + -- Environment_Task -- + ---------------------- + + function Environment_Task return Task_Id is + begin + return Environment_Task_Id; + end Environment_Task; + + -------------- + -- 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; + + ------------------ + -- Suspend_Task -- + ------------------ + + function Suspend_Task + (T : ST.Task_Id; + Thread_Self : Thread_Id) return Boolean + is + begin + if T.Common.LL.Thread /= 0 + and then T.Common.LL.Thread /= Thread_Self + then + return taskSuspend (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 /= 0 + and then T.Common.LL.Thread /= Thread_Self + then + return taskResume (T.Common.LL.Thread) = 0; + else + return True; + end if; + end Resume_Task; + + -------------------- + -- Stop_All_Tasks -- + -------------------- + + procedure Stop_All_Tasks + is + Thread_Self : constant Thread_Id := taskIdSelf; + C : Task_Id; + + Dummy : int; + pragma Unreferenced (Dummy); + + begin + Dummy := Int_Lock; + + C := All_Tasks_List; + while C /= null loop + if C.Common.LL.Thread /= 0 + and then C.Common.LL.Thread /= Thread_Self + then + Dummy := Task_Stop (C.Common.LL.Thread); + end if; + + C := C.Common.All_Tasks_Link; + end loop; + + Dummy := Int_Unlock; + end Stop_All_Tasks; + + --------------- + -- Stop_Task -- + --------------- + + function Stop_Task (T : ST.Task_Id) return Boolean is + begin + if T.Common.LL.Thread /= 0 then + return Task_Stop (T.Common.LL.Thread) = 0; + else + return True; + end if; + end Stop_Task; + + ------------------- + -- Continue_Task -- + ------------------- + + function Continue_Task (T : ST.Task_Id) return Boolean + is + begin + if T.Common.LL.Thread /= 0 then + return Task_Cont (T.Common.LL.Thread) = 0; + else + return True; + end if; + end Continue_Task; + + ---------------- + -- Initialize -- + ---------------- + + procedure Initialize (Environment_Task : Task_Id) is + Result : int; + + begin + Environment_Task_Id := Environment_Task; + + Interrupt_Management.Initialize; + Specific.Initialize; + + if Locking_Policy = 'C' then + Mutex_Protocol := Prio_Protect; + elsif Locking_Policy = 'I' then + Mutex_Protocol := Prio_Inherit; + else + Mutex_Protocol := Prio_None; + end if; + + if Time_Slice_Val > 0 then + Result := + Set_Time_Slice + (To_Clock_Ticks + (Duration (Time_Slice_Val) / Duration (1_000_000.0))); + + elsif Dispatching_Policy = 'R' then + Result := Set_Time_Slice (To_Clock_Ticks (0.01)); + + end if; + + Result := sigemptyset (Unblocked_Signal_Mask'Access); + pragma Assert (Result = 0); + + for J in Interrupt_Management.Signal_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; + + -- Initialize the lock used to synchronize chain of all ATCBs + + Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level); + + Enter_Task (Environment_Task); + end Initialize; + +end System.Task_Primitives.Operations; |