| ------------------------------------------------------------------------------ |
| -- -- |
| -- 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) 1992-2022, 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 a POSIX-like version of this package |
| |
| -- This package contains all the GNULL primitives that interface directly with |
| -- the underlying OS. |
| |
| -- Note: this file can only be used for POSIX compliant systems that implement |
| -- SCHED_FIFO and Ceiling Locking correctly. |
| |
| -- For configurations where SCHED_FIFO and priority ceiling are not a |
| -- requirement, this file can also be used (e.g AiX threads) |
| |
| with Ada.Unchecked_Conversion; |
| |
| with Interfaces.C; |
| |
| with System.Tasking.Debug; |
| with System.Interrupt_Management; |
| with System.OS_Constants; |
| with System.OS_Primitives; |
| with System.Task_Info; |
| |
| 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. |
| |
| package body System.Task_Primitives.Operations is |
| |
| package OSC renames System.OS_Constants; |
| package SSL renames System.Soft_Links; |
| |
| use System.Tasking.Debug; |
| use System.Tasking; |
| use Interfaces.C; |
| use System.OS_Interface; |
| use System.Parameters; |
| use System.OS_Primitives; |
| |
| ---------------- |
| -- 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 to protect All_Tasks_List |
| |
| Environment_Task_Id : Task_Id; |
| -- A variable to hold Task_Id for the environment task |
| |
| Locking_Policy : constant Character; |
| pragma Import (C, Locking_Policy, "__gl_locking_policy"); |
| -- Value of the pragma Locking_Policy: |
| -- 'C' for Ceiling_Locking |
| -- 'I' for Inherit_Locking |
| -- ' ' for none. |
| |
| Unblocked_Signal_Mask : aliased sigset_t; |
| -- The set of signals that should unblocked in all tasks |
| |
| -- The followings are internal configuration constants needed |
| |
| Next_Serial_Number : Task_Serial_Number := 100; |
| -- We start at 100, to reserve some special values for |
| -- using in error checking. |
| |
| Time_Slice_Val : constant Integer; |
| pragma Import (C, Time_Slice_Val, "__gl_time_slice_val"); |
| |
| Dispatching_Policy : constant Character; |
| pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy"); |
| |
| Foreign_Task_Elaborated : aliased Boolean := True; |
| -- Used to identified fake tasks (i.e., non-Ada Threads) |
| |
| Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0; |
| -- Whether to use an alternate signal stack for stack overflows |
| |
| Abort_Handler_Installed : Boolean := False; |
| -- True if a handler for the abort signal is installed |
| |
| type RTS_Lock_Ptr is not null access all RTS_Lock; |
| |
| function Init_Mutex (L : RTS_Lock_Ptr; Prio : Any_Priority) return int; |
| -- Initialize the mutex L. If Ceiling_Support is True, then set the ceiling |
| -- to Prio. Returns 0 for success, or ENOMEM for out-of-memory. |
| |
| function Get_Policy (Prio : System.Any_Priority) return Character; |
| pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching"); |
| -- Get priority specific dispatching policy |
| |
| -------------------- |
| -- Local Packages -- |
| -------------------- |
| |
| package Specific is |
| |
| procedure Initialize (Environment_Task : Task_Id); |
| pragma Inline (Initialize); |
| -- Initialize various data needed by this package |
| |
| 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 |
| |
| 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 |
| |
| package Monotonic is |
| |
| function Monotonic_Clock return Duration; |
| pragma Inline (Monotonic_Clock); |
| -- Returns an absolute time, represented as an offset relative to some |
| -- unspecified starting point, typically system boot time. This clock |
| -- is not affected by discontinuous jumps in the system time. |
| |
| function RT_Resolution return Duration; |
| pragma Inline (RT_Resolution); |
| -- Returns resolution of the underlying clock used to implement RT_Clock |
| |
| procedure Timed_Sleep |
| (Self_ID : ST.Task_Id; |
| Time : Duration; |
| Mode : ST.Delay_Modes; |
| Reason : System.Tasking.Task_States; |
| Timedout : out Boolean; |
| Yielded : out Boolean); |
| -- Combination of Sleep (above) and Timed_Delay |
| |
| procedure Timed_Delay |
| (Self_ID : ST.Task_Id; |
| Time : Duration; |
| Mode : ST.Delay_Modes); |
| -- Implement the semantics of the delay statement. |
| -- The caller should be abort-deferred and should not hold any locks. |
| |
| end Monotonic; |
| |
| package body Monotonic is separate; |
| |
| ---------------------------------- |
| -- ATCB allocation/deallocation -- |
| ---------------------------------- |
| |
| package body ATCB_Allocation is separate; |
| -- The body of this package is shared across several targets |
| |
| --------------------------------- |
| -- Support for foreign threads -- |
| --------------------------------- |
| |
| function Register_Foreign_Thread |
| (Thread : Thread_Id; |
| Sec_Stack_Size : Size_Type := Unspecified_Size) return Task_Id; |
| -- Allocate and initialize a new ATCB for the current Thread. The size of |
| -- the secondary stack can be optionally specified. |
| |
| function Register_Foreign_Thread |
| (Thread : Thread_Id; |
| Sec_Stack_Size : Size_Type := Unspecified_Size) |
| return Task_Id is separate; |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| procedure Abort_Handler (Sig : Signal); |
| -- Signal handler used to implement asynchronous abort. |
| -- See also comment before body, below. |
| |
| function To_Address is |
| new Ada.Unchecked_Conversion (Task_Id, System.Address); |
| |
| function GNAT_pthread_condattr_setup |
| (attr : access pthread_condattr_t) return int; |
| pragma Import (C, |
| GNAT_pthread_condattr_setup, "__gnat_pthread_condattr_setup"); |
| |
| ------------------- |
| -- 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. |
| |
| procedure Abort_Handler (Sig : Signal) is |
| pragma Unreferenced (Sig); |
| |
| T : constant Task_Id := Self; |
| Old_Set : aliased sigset_t; |
| |
| Result : Interfaces.C.int; |
| pragma Warnings (Off, Result); |
| |
| begin |
| -- It's not safe to raise an exception when using GCC ZCX mechanism. |
| -- Note that we still need to install a signal handler, since in some |
| -- cases (e.g. shutdown of the Server_Task in System.Interrupts) we |
| -- need to send the Abort signal to a task. |
| |
| if ZCX_By_Default then |
| return; |
| end if; |
| |
| if T.Deferral_Level = 0 |
| and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then |
| not T.Aborting |
| then |
| T.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 |
| Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread); |
| Page_Size : Address; |
| Res : Interfaces.C.int; |
| |
| begin |
| if Stack_Base_Available then |
| |
| -- Compute the guard page address |
| |
| Page_Size := Address (Get_Page_Size); |
| Res := |
| mprotect |
| (Stack_Base - (Stack_Base mod Page_Size) + Page_Size, |
| size_t (Page_Size), |
| prot => (if On then PROT_ON else PROT_OFF)); |
| pragma Assert (Res = 0); |
| end if; |
| 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; |
| |
| ---------------- |
| -- Init_Mutex -- |
| ---------------- |
| |
| function Init_Mutex (L : RTS_Lock_Ptr; Prio : Any_Priority) return int |
| is |
| Attributes : aliased pthread_mutexattr_t; |
| Result : int; |
| Result_2 : aliased int; |
| |
| begin |
| Result := pthread_mutexattr_init (Attributes'Access); |
| pragma Assert (Result = 0 or else Result = ENOMEM); |
| |
| if Result = ENOMEM then |
| return Result; |
| end if; |
| |
| if Locking_Policy = 'C' then |
| Result := pthread_mutexattr_setprotocol |
| (Attributes'Access, PTHREAD_PRIO_PROTECT); |
| pragma Assert (Result = 0); |
| |
| Result := pthread_mutexattr_getprotocol |
| (Attributes'Access, Result_2'Access); |
| if Result_2 /= PTHREAD_PRIO_PROTECT then |
| raise Program_Error with "setprotocol failed"; |
| end if; |
| |
| Result := pthread_mutexattr_setprioceiling |
| (Attributes'Access, To_Target_Priority (Prio)); |
| pragma Assert (Result = 0); |
| |
| elsif Locking_Policy = 'I' then |
| Result := pthread_mutexattr_setprotocol |
| (Attributes'Access, PTHREAD_PRIO_INHERIT); |
| pragma Assert (Result = 0); |
| end if; |
| |
| Result := pthread_mutex_init (L, Attributes'Access); |
| pragma Assert (Result = 0 or else Result = ENOMEM); |
| |
| Result_2 := pthread_mutexattr_destroy (Attributes'Access); |
| pragma Assert (Result_2 = 0); |
| |
| return Result; |
| end Init_Mutex; |
| |
| --------------------- |
| -- 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 raising Storage_Error in the following |
| -- routines should be able to be handled safely. |
| |
| procedure Initialize_Lock |
| (Prio : System.Any_Priority; |
| L : not null access Lock) |
| is |
| begin |
| if Init_Mutex (L.WO'Access, Prio) = ENOMEM then |
| raise Storage_Error with "Failed to allocate a lock"; |
| end if; |
| end Initialize_Lock; |
| |
| procedure Initialize_Lock |
| (L : not null access RTS_Lock; Level : Lock_Level) |
| is |
| pragma Unreferenced (Level); |
| |
| begin |
| if Init_Mutex (L.all'Access, Any_Priority'Last) = ENOMEM then |
| raise Storage_Error with "Failed to allocate a lock"; |
| end if; |
| end Initialize_Lock; |
| |
| ------------------- |
| -- Finalize_Lock -- |
| ------------------- |
| |
| procedure Finalize_Lock (L : not null access Lock) is |
| Result : Interfaces.C.int; |
| begin |
| Result := pthread_mutex_destroy (L.WO'Access); |
| pragma Assert (Result = 0); |
| end Finalize_Lock; |
| |
| procedure Finalize_Lock (L : not null 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 : not null access Lock; Ceiling_Violation : out Boolean) |
| is |
| Self : constant pthread_t := pthread_self; |
| Result : int; |
| Policy : aliased int; |
| Ceiling : aliased int; |
| Sched : aliased struct_sched_param; |
| |
| begin |
| Result := pthread_mutex_lock (L.WO'Access); |
| |
| -- The cause of EINVAL is a priority ceiling violation |
| |
| Ceiling_Violation := Result = EINVAL; |
| pragma Assert (Result = 0 or else Ceiling_Violation); |
| |
| -- Workaround bug in QNX on ceiling locks: tasks with priority higher |
| -- than the ceiling priority don't receive EINVAL upon trying to lock. |
| if Result = 0 and then Locking_Policy = 'C' then |
| Result := pthread_getschedparam (Self, Policy'Access, Sched'Access); |
| pragma Assert (Result = 0); |
| Result := pthread_mutex_getprioceiling (L.WO'Access, Ceiling'Access); |
| pragma Assert (Result = 0); |
| |
| -- Ceiling < current priority means Ceiling violation |
| -- (otherwise the current priority == ceiling) |
| if Ceiling < Sched.sched_curpriority then |
| Ceiling_Violation := True; |
| Result := pthread_mutex_unlock (L.WO'Access); |
| pragma Assert (Result = 0); |
| end if; |
| end if; |
| end Write_Lock; |
| |
| procedure Write_Lock (L : not null access RTS_Lock) is |
| Result : Interfaces.C.int; |
| begin |
| Result := pthread_mutex_lock (L); |
| pragma Assert (Result = 0); |
| end Write_Lock; |
| |
| procedure Write_Lock (T : Task_Id) is |
| Result : Interfaces.C.int; |
| begin |
| Result := pthread_mutex_lock (T.Common.LL.L'Access); |
| pragma Assert (Result = 0); |
| 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 : Interfaces.C.int; |
| begin |
| Result := pthread_mutex_unlock (L.WO'Access); |
| pragma Assert (Result = 0); |
| end Unlock; |
| |
| procedure Unlock (L : not null access RTS_Lock) is |
| Result : Interfaces.C.int; |
| begin |
| Result := pthread_mutex_unlock (L); |
| pragma Assert (Result = 0); |
| end Unlock; |
| |
| procedure Unlock (T : Task_Id) is |
| Result : Interfaces.C.int; |
| begin |
| Result := pthread_mutex_unlock (T.Common.LL.L'Access); |
| pragma Assert (Result = 0); |
| end Unlock; |
| |
| ----------------- |
| -- Set_Ceiling -- |
| ----------------- |
| |
| procedure Set_Ceiling |
| (L : not null access Lock; |
| Prio : System.Any_Priority) |
| is |
| Result : Interfaces.C.int; |
| begin |
| Result := pthread_mutex_setprioceiling |
| (L.WO'Access, To_Target_Priority (Prio), null); |
| pragma Assert (Result = 0); |
| end Set_Ceiling; |
| |
| ----------- |
| -- Sleep -- |
| ----------- |
| |
| procedure Sleep |
| (Self_ID : Task_Id; |
| Reason : System.Tasking.Task_States) |
| is |
| pragma Unreferenced (Reason); |
| |
| Result : Interfaces.C.int; |
| |
| begin |
| Result := |
| pthread_cond_wait |
| (cond => Self_ID.Common.LL.CV'Access, |
| mutex => Self_ID.Common.LL.L'Access); |
| |
| -- 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 : Task_States; |
| Timedout : out Boolean; |
| Yielded : out Boolean) renames Monotonic.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) renames Monotonic.Timed_Delay; |
| |
| --------------------- |
| -- Monotonic_Clock -- |
| --------------------- |
| |
| function Monotonic_Clock return Duration renames Monotonic.Monotonic_Clock; |
| |
| ------------------- |
| -- RT_Resolution -- |
| ------------------- |
| |
| function RT_Resolution return Duration renames Monotonic.RT_Resolution; |
| |
| ------------ |
| -- Wakeup -- |
| ------------ |
| |
| procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is |
| pragma Unreferenced (Reason); |
| 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; |
| pragma Unreferenced (Result); |
| 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 |
| pragma Unreferenced (Loss_Of_Inheritance); |
| Result : Interfaces.C.int; |
| Old : constant System.Any_Priority := T.Common.Current_Priority; |
| |
| begin |
| T.Common.Current_Priority := Prio; |
| Result := pthread_setschedprio |
| (T.Common.LL.Thread, To_Target_Priority (Prio)); |
| pragma Assert (Result = 0); |
| |
| if T.Common.LL.Thread = pthread_self |
| and then Old > Prio |
| then |
| -- When lowering the priority via a pthread_setschedprio, QNX ensures |
| -- that the running thread remains in the head of the FIFO for tne |
| -- new priority. Annex D expects the thread to be requeued so let's |
| -- yield to the other threads of the same priority. |
| Result := sched_yield; |
| pragma Assert (Result = 0); |
| 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 |
| begin |
| Self_ID.Common.LL.Thread := pthread_self; |
| Self_ID.Common.LL.LWP := lwp_self; |
| |
| Specific.Set (Self_ID); |
| |
| if Use_Alternate_Stack then |
| declare |
| Stack : aliased stack_t; |
| Result : Interfaces.C.int; |
| begin |
| Stack.ss_sp := Self_ID.Common.Task_Alternate_Stack; |
| Stack.ss_size := Alternate_Stack_Size; |
| Stack.ss_flags := 0; |
| Result := sigaltstack (Stack'Access, null); |
| pragma Assert (Result = 0); |
| end; |
| end if; |
| end Enter_Task; |
| |
| ------------------- |
| -- 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 (pthread_self); |
| end if; |
| end Register_Foreign_Thread; |
| |
| -------------------- |
| -- Initialize_TCB -- |
| -------------------- |
| |
| procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is |
| Result : Interfaces.C.int; |
| Cond_Attr : aliased pthread_condattr_t; |
| |
| 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); |
| |
| Result := Init_Mutex (Self_ID.Common.LL.L'Access, Any_Priority'Last); |
| pragma Assert (Result = 0); |
| |
| if Result /= 0 then |
| Succeeded := False; |
| return; |
| end if; |
| |
| Result := pthread_condattr_init (Cond_Attr'Access); |
| pragma Assert (Result = 0 or else Result = ENOMEM); |
| |
| if Result = 0 then |
| Result := GNAT_pthread_condattr_setup (Cond_Attr'Access); |
| pragma Assert (Result = 0); |
| |
| Result := |
| pthread_cond_init |
| (Self_ID.Common.LL.CV'Access, Cond_Attr'Access); |
| pragma Assert (Result = 0 or else Result = ENOMEM); |
| end if; |
| |
| if Result = 0 then |
| Succeeded := True; |
| else |
| Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access); |
| pragma Assert (Result = 0); |
| |
| Succeeded := False; |
| end if; |
| |
| Result := pthread_condattr_destroy (Cond_Attr'Access); |
| pragma Assert (Result = 0); |
| 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; |
| Adjusted_Stack_Size : Interfaces.C.size_t; |
| Page_Size : constant Interfaces.C.size_t := |
| Interfaces.C.size_t (Get_Page_Size); |
| Sched_Param : aliased struct_sched_param; |
| Result : Interfaces.C.int; |
| |
| Priority_Specific_Policy : constant Character := Get_Policy (Priority); |
| -- Upper case first character of the policy name corresponding to the |
| -- task as set by a Priority_Specific_Dispatching pragma. |
| |
| function Thread_Body_Access is new |
| Ada.Unchecked_Conversion (System.Address, Thread_Body); |
| |
| begin |
| Adjusted_Stack_Size := |
| Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size); |
| |
| if Stack_Base_Available then |
| |
| -- If Stack Checking is supported then allocate 2 additional pages: |
| |
| -- In the worst case, stack is allocated at something like |
| -- N * Get_Page_Size - epsilon, we need to add the size for 2 pages |
| -- to be sure the effective stack size is greater than what |
| -- has been asked. |
| |
| Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Page_Size; |
| end if; |
| |
| -- Round stack size as this is required by some OSes (Darwin) |
| |
| Adjusted_Stack_Size := Adjusted_Stack_Size + Page_Size - 1; |
| Adjusted_Stack_Size := |
| Adjusted_Stack_Size - Adjusted_Stack_Size mod Page_Size; |
| |
| Result := pthread_attr_init (Attributes'Access); |
| pragma Assert (Result = 0 or else Result = ENOMEM); |
| |
| if Result /= 0 then |
| Succeeded := False; |
| return; |
| end if; |
| |
| Result := |
| pthread_attr_setdetachstate |
| (Attributes'Access, PTHREAD_CREATE_DETACHED); |
| pragma Assert (Result = 0); |
| |
| Result := |
| pthread_attr_setstacksize |
| (Attributes'Access, Adjusted_Stack_Size); |
| pragma Assert (Result = 0); |
| |
| -- Set thread priority |
| T.Common.Current_Priority := Priority; |
| Sched_Param.sched_priority := To_Target_Priority (Priority); |
| |
| Result := pthread_attr_setinheritsched |
| (Attributes'Access, PTHREAD_EXPLICIT_SCHED); |
| pragma Assert (Result = 0); |
| |
| Result := pthread_attr_setschedparam |
| (Attributes'Access, Sched_Param'Access); |
| pragma Assert (Result = 0); |
| |
| if Time_Slice_Supported |
| and then (Dispatching_Policy = 'R' |
| or else Priority_Specific_Policy = 'R' |
| or else Time_Slice_Val > 0) |
| then |
| Result := pthread_attr_setschedpolicy |
| (Attributes'Access, SCHED_RR); |
| |
| elsif Dispatching_Policy = 'F' |
| or else Priority_Specific_Policy = 'F' |
| or else Time_Slice_Val = 0 |
| then |
| Result := pthread_attr_setschedpolicy |
| (Attributes'Access, SCHED_FIFO); |
| |
| else |
| Result := pthread_attr_setschedpolicy |
| (Attributes'Access, SCHED_OTHER); |
| end if; |
| |
| 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. |
| |
| -- Note: the use of Unrestricted_Access in the following call is needed |
| -- because otherwise we have an error of getting a access-to-volatile |
| -- value which points to a non-volatile object. But in this case it is |
| -- safe to do this, since we know we have no problems with aliasing and |
| -- Unrestricted_Access bypasses this check. |
| |
| Result := pthread_create |
| (T.Common.LL.Thread'Unrestricted_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); |
| end Create_Task; |
| |
| ------------------ |
| -- Finalize_TCB -- |
| ------------------ |
| |
| procedure Finalize_TCB (T : Task_Id) is |
| Result : Interfaces.C.int; |
| |
| begin |
| Result := pthread_mutex_destroy (T.Common.LL.L'Access); |
| pragma Assert (Result = 0); |
| |
| 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; |
| |
| ATCB_Allocation.Free_ATCB (T); |
| end Finalize_TCB; |
| |
| --------------- |
| -- Exit_Task -- |
| --------------- |
| |
| procedure Exit_Task is |
| begin |
| -- Mark this task as unknown, so that if Self is called, it won't |
| -- return a dangling pointer. |
| |
| Specific.Set (null); |
| end Exit_Task; |
| |
| ---------------- |
| -- Abort_Task -- |
| ---------------- |
| |
| procedure Abort_Task (T : Task_Id) is |
| Result : Interfaces.C.int; |
| begin |
| if Abort_Handler_Installed then |
| Result := |
| pthread_kill |
| (T.Common.LL.Thread, |
| Signal (System.Interrupt_Management.Abort_Task_Interrupt)); |
| pragma Assert (Result = 0); |
| end if; |
| end Abort_Task; |
| |
| ---------------- |
| -- Initialize -- |
| ---------------- |
| |
| procedure Initialize (S : in out Suspension_Object) is |
| Mutex_Attr : aliased pthread_mutexattr_t; |
| Cond_Attr : aliased pthread_condattr_t; |
| Result : Interfaces.C.int; |
| |
| begin |
| -- Initialize internal state (always to False (RM D.10 (6))) |
| |
| S.State := False; |
| S.Waiting := False; |
| |
| -- Initialize internal mutex |
| |
| Result := pthread_mutexattr_init (Mutex_Attr'Access); |
| pragma Assert (Result = 0 or else Result = ENOMEM); |
| |
| if Result = ENOMEM then |
| raise Storage_Error; |
| end if; |
| |
| Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access); |
| pragma Assert (Result = 0 or else Result = ENOMEM); |
| |
| if Result = ENOMEM then |
| Result := pthread_mutexattr_destroy (Mutex_Attr'Access); |
| pragma Assert (Result = 0); |
| |
| raise Storage_Error; |
| end if; |
| |
| Result := pthread_mutexattr_destroy (Mutex_Attr'Access); |
| pragma Assert (Result = 0); |
| |
| -- Initialize internal condition variable |
| |
| Result := pthread_condattr_init (Cond_Attr'Access); |
| pragma Assert (Result = 0 or else Result = ENOMEM); |
| |
| if Result /= 0 then |
| Result := pthread_mutex_destroy (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| -- Storage_Error is propagated as intended if the allocation of the |
| -- underlying OS entities fails. |
| |
| raise Storage_Error; |
| |
| else |
| Result := GNAT_pthread_condattr_setup (Cond_Attr'Access); |
| pragma Assert (Result = 0); |
| end if; |
| |
| Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access); |
| pragma Assert (Result = 0 or else Result = ENOMEM); |
| |
| if Result /= 0 then |
| Result := pthread_mutex_destroy (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| Result := pthread_condattr_destroy (Cond_Attr'Access); |
| pragma Assert (Result = 0); |
| |
| -- Storage_Error is propagated as intended if the allocation of the |
| -- underlying OS entities fails. |
| |
| raise Storage_Error; |
| end if; |
| |
| Result := pthread_condattr_destroy (Cond_Attr'Access); |
| pragma Assert (Result = 0); |
| end Initialize; |
| |
| -------------- |
| -- Finalize -- |
| -------------- |
| |
| procedure Finalize (S : in out Suspension_Object) is |
| Result : Interfaces.C.int; |
| |
| begin |
| -- Destroy internal mutex |
| |
| Result := pthread_mutex_destroy (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| -- Destroy internal condition variable |
| |
| Result := pthread_cond_destroy (S.CV'Access); |
| pragma Assert (Result = 0); |
| 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 : Interfaces.C.int; |
| |
| begin |
| SSL.Abort_Defer.all; |
| |
| Result := pthread_mutex_lock (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| S.State := False; |
| |
| Result := pthread_mutex_unlock (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| SSL.Abort_Undefer.all; |
| end Set_False; |
| |
| -------------- |
| -- Set_True -- |
| -------------- |
| |
| procedure Set_True (S : in out Suspension_Object) is |
| Result : Interfaces.C.int; |
| |
| begin |
| SSL.Abort_Defer.all; |
| |
| Result := pthread_mutex_lock (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| -- 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 (RM D.10(9)). Otherwise, it just leaves |
| -- the state to True. |
| |
| if S.Waiting then |
| S.Waiting := False; |
| S.State := False; |
| |
| Result := pthread_cond_signal (S.CV'Access); |
| pragma Assert (Result = 0); |
| |
| else |
| S.State := True; |
| end if; |
| |
| Result := pthread_mutex_unlock (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| SSL.Abort_Undefer.all; |
| end Set_True; |
| |
| ------------------------ |
| -- Suspend_Until_True -- |
| ------------------------ |
| |
| procedure Suspend_Until_True (S : in out Suspension_Object) is |
| Result : Interfaces.C.int; |
| |
| begin |
| SSL.Abort_Defer.all; |
| |
| Result := pthread_mutex_lock (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| if S.Waiting then |
| |
| -- Program_Error must be raised upon calling Suspend_Until_True |
| -- if another task is already waiting on that suspension object |
| -- (RM D.10(10)). |
| |
| Result := pthread_mutex_unlock (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| 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; |
| else |
| S.Waiting := True; |
| |
| loop |
| -- Loop in case pthread_cond_wait returns earlier than expected |
| -- (e.g. in case of EINTR caused by a signal). |
| |
| Result := pthread_cond_wait (S.CV'Access, S.L'Access); |
| pragma Assert (Result = 0 or else Result = EINTR); |
| |
| exit when not S.Waiting; |
| end loop; |
| end if; |
| |
| Result := pthread_mutex_unlock (S.L'Access); |
| pragma Assert (Result = 0); |
| |
| SSL.Abort_Undefer.all; |
| 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); |
| end Lock_RTS; |
| |
| ---------------- |
| -- Unlock_RTS -- |
| ---------------- |
| |
| procedure Unlock_RTS is |
| begin |
| Unlock (Single_RTS_Lock'Access); |
| end Unlock_RTS; |
| |
| ------------------ |
| -- Suspend_Task -- |
| ------------------ |
| |
| function Suspend_Task |
| (T : ST.Task_Id; |
| Thread_Self : Thread_Id) return Boolean |
| is |
| pragma Unreferenced (T, Thread_Self); |
| begin |
| return False; |
| end Suspend_Task; |
| |
| ----------------- |
| -- Resume_Task -- |
| ----------------- |
| |
| function Resume_Task |
| (T : ST.Task_Id; |
| Thread_Self : Thread_Id) return Boolean |
| is |
| pragma Unreferenced (T, Thread_Self); |
| begin |
| return False; |
| end Resume_Task; |
| |
| -------------------- |
| -- Stop_All_Tasks -- |
| -------------------- |
| |
| procedure Stop_All_Tasks is |
| begin |
| null; |
| end Stop_All_Tasks; |
| |
| --------------- |
| -- Stop_Task -- |
| --------------- |
| |
| function Stop_Task (T : ST.Task_Id) return Boolean is |
| pragma Unreferenced (T); |
| begin |
| return False; |
| end Stop_Task; |
| |
| ------------------- |
| -- Continue_Task -- |
| ------------------- |
| |
| function Continue_Task (T : ST.Task_Id) return Boolean is |
| pragma Unreferenced (T); |
| begin |
| return False; |
| end Continue_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; |
| |
| function State |
| (Int : System.Interrupt_Management.Interrupt_ID) return Character; |
| pragma Import (C, State, "__gnat_get_interrupt_state"); |
| -- Get interrupt state. Defined in a-init.c |
| -- The input argument is the interrupt number, |
| -- and the result is one of the following: |
| |
| Default : constant Character := 's'; |
| -- 'n' this interrupt not set by any Interrupt_State pragma |
| -- 'u' Interrupt_State pragma set state to User |
| -- 'r' Interrupt_State pragma set state to Runtime |
| -- 's' Interrupt_State pragma set state to System (use "default" |
| -- system handler) |
| |
| begin |
| Environment_Task_Id := Environment_Task; |
| |
| Interrupt_Management.Initialize; |
| |
| -- 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; |
| |
| -- Initialize the lock used to synchronize chain of all ATCBs |
| |
| Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level); |
| |
| Specific.Initialize (Environment_Task); |
| |
| if Use_Alternate_Stack then |
| Environment_Task.Common.Task_Alternate_Stack := |
| Alternate_Stack'Address; |
| end if; |
| |
| -- Make environment task known here because it doesn't go through |
| -- Activate_Tasks, which does it for all other tasks. |
| |
| Known_Tasks (Known_Tasks'First) := Environment_Task; |
| Environment_Task.Known_Tasks_Index := Known_Tasks'First; |
| |
| Enter_Task (Environment_Task); |
| |
| if State |
| (System.Interrupt_Management.Abort_Task_Interrupt) /= Default |
| then |
| 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 (System.Interrupt_Management.Abort_Task_Interrupt), |
| act'Unchecked_Access, |
| old_act'Unchecked_Access); |
| pragma Assert (Result = 0); |
| Abort_Handler_Installed := True; |
| end if; |
| end Initialize; |
| |
| ----------------------- |
| -- Set_Task_Affinity -- |
| ----------------------- |
| |
| procedure Set_Task_Affinity (T : ST.Task_Id) is |
| pragma Unreferenced (T); |
| |
| begin |
| -- Setting task affinity is not supported by the underlying system |
| |
| null; |
| end Set_Task_Affinity; |
| |
| end System.Task_Primitives.Operations; |
