-- --
-- B o d y --
-- --
--- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2011, 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- --
+-- 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. 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, 51 Franklin Street, Fifth Floor, --
--- Boston, MA 02110-1301, USA. --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
--- 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. --
+-- 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 GNU/Linux (GNU/LinuxThreads) version of this package
--- This package contains all the GNULL primitives that interface directly
--- with the underlying OS.
+-- 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.
+-- Turn off polling, we do not want ATC polling to take place during tasking
+-- operations. It causes infinite loops and other problems.
with Interfaces.C;
--- used for int
--- size_t
+with System.Task_Info;
with System.Tasking.Debug;
--- used for Known_Tasks
-
with System.Interrupt_Management;
--- used for Keep_Unmasked
--- Abort_Task_Interrupt
--- Interrupt_ID
-
with System.OS_Primitives;
--- used for Delay_Modes
+with System.Stack_Checking.Operations;
+with System.Multiprocessors;
with System.Soft_Links;
--- used for Abort_Defer/Undefer
-
-with Ada.Exceptions;
--- used for Raise_Exception
--- Raise_From_Signal_Handler
--- Exception_Id
-
-with Unchecked_Conversion;
-with Unchecked_Deallocation;
+-- 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 SSL renames System.Soft_Links;
+ package SC renames System.Stack_Checking.Operations;
+
use System.Tasking.Debug;
use System.Tasking;
use Interfaces.C;
use System.OS_Interface;
use System.Parameters;
use System.OS_Primitives;
+ use System.Task_Info;
----------------
-- Local Data --
-- 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
- ATCB_Key : aliased pthread_key_t;
- -- Key used to find the Ada Task_Id associated with a thread
-
Environment_Task_Id : Task_Id;
-- A variable to hold Task_Id for the environment task
-- 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.
+ -- We start at 100 (reserve some special values for using in error checks)
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");
- -- 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;
+ Locking_Policy : Character;
+ pragma Import (C, Locking_Policy, "__gl_locking_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
+
+ Null_Thread_Id : constant pthread_t := pthread_t'Last;
+ -- Constant to indicate that the thread identifier has not yet been
+ -- initialized.
+
--------------------
-- Local Packages --
--------------------
function Self return Task_Id;
pragma Inline (Self);
- -- Return a pointer to the Ada Task Control Block of the calling task.
+ -- 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
+ ----------------------------------
+ -- ATCB allocation/deallocation --
+ ----------------------------------
+
+ package body ATCB_Allocation is separate;
+ -- The body of this package is shared across several targets
+
---------------------------------
-- Support for foreign threads --
---------------------------------
-- Local Subprograms --
-----------------------
- subtype unsigned_long is Interfaces.C.unsigned_long;
-
procedure Abort_Handler (signo : Signal);
- function To_pthread_t is new Unchecked_Conversion
- (unsigned_long, System.OS_Interface.pthread_t);
-
-------------------
-- Abort_Handler --
-------------------
Old_Set : aliased sigset_t;
begin
- if ZCX_By_Default and then GCC_ZCX_Support then
+ -- 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;
-- Make sure signals used for RTS internal purpose are unmasked
- Result := pthread_sigmask (SIG_UNBLOCK,
- Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
+ Result :=
+ pthread_sigmask
+ (SIG_UNBLOCK,
+ Unblocked_Signal_Mask'Access,
+ Old_Set'Access);
pragma Assert (Result = 0);
raise Standard'Abort_Signal;
-- 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.
+ -- 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 : access Lock)
+ L : not null access Lock)
is
pragma Unreferenced (Prio);
- Result : Interfaces.C.int;
begin
- Result := pthread_mutex_init (L, Mutex_Attr'Access);
+ if Locking_Policy = 'R' then
+ declare
+ RWlock_Attr : aliased pthread_rwlockattr_t;
+ Result : Interfaces.C.int;
- pragma Assert (Result = 0 or else Result = ENOMEM);
+ begin
+ -- Set the rwlock to prefer writer to avoid writers starvation
- if Result = ENOMEM then
- Ada.Exceptions.Raise_Exception (Storage_Error'Identity,
- "Failed to allocate a lock");
+ Result := pthread_rwlockattr_init (RWlock_Attr'Access);
+ pragma Assert (Result = 0);
+
+ Result := pthread_rwlockattr_setkind_np
+ (RWlock_Attr'Access,
+ PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
+ pragma Assert (Result = 0);
+
+ Result := pthread_rwlock_init (L.RW'Access, RWlock_Attr'Access);
+
+ pragma Assert (Result = 0 or else Result = ENOMEM);
+
+ if Result = ENOMEM then
+ raise Storage_Error with "Failed to allocate a lock";
+ end if;
+ end;
+
+ else
+ declare
+ Result : Interfaces.C.int;
+
+ begin
+ Result := pthread_mutex_init (L.WO'Access, null);
+
+ pragma Assert (Result = 0 or else Result = ENOMEM);
+
+ if Result = ENOMEM then
+ raise Storage_Error with "Failed to allocate a lock";
+ end if;
+ end;
end if;
end Initialize_Lock;
- procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
+ procedure Initialize_Lock
+ (L : not null access RTS_Lock;
+ Level : Lock_Level)
+ is
pragma Unreferenced (Level);
Result : Interfaces.C.int;
begin
- Result := pthread_mutex_init (L, Mutex_Attr'Access);
+ Result := pthread_mutex_init (L, null);
pragma Assert (Result = 0 or else Result = ENOMEM);
-- Finalize_Lock --
-------------------
- procedure Finalize_Lock (L : access Lock) is
+ procedure Finalize_Lock (L : not null access Lock) is
Result : Interfaces.C.int;
begin
- Result := pthread_mutex_destroy (L);
+ if Locking_Policy = 'R' then
+ Result := pthread_rwlock_destroy (L.RW'Access);
+ else
+ Result := pthread_mutex_destroy (L.WO'Access);
+ end if;
pragma Assert (Result = 0);
end Finalize_Lock;
- procedure Finalize_Lock (L : access RTS_Lock) is
+ procedure Finalize_Lock (L : not null access RTS_Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (L);
-- Write_Lock --
----------------
- procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
+ procedure Write_Lock
+ (L : not null access Lock;
+ Ceiling_Violation : out Boolean)
+ is
Result : Interfaces.C.int;
begin
- Result := pthread_mutex_lock (L);
+ if Locking_Policy = 'R' then
+ Result := pthread_rwlock_wrlock (L.RW'Access);
+ else
+ Result := pthread_mutex_lock (L.WO'Access);
+ end if;
+
Ceiling_Violation := Result = EINVAL;
-- Assume the cause of EINVAL is a priority ceiling violation
end Write_Lock;
procedure Write_Lock
- (L : access RTS_Lock;
+ (L : not null access RTS_Lock;
Global_Lock : Boolean := False)
is
Result : Interfaces.C.int;
-- Read_Lock --
---------------
- procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
+ procedure Read_Lock
+ (L : not null access Lock;
+ Ceiling_Violation : out Boolean)
+ is
+ Result : Interfaces.C.int;
begin
- Write_Lock (L, Ceiling_Violation);
+ if Locking_Policy = 'R' then
+ Result := pthread_rwlock_rdlock (L.RW'Access);
+ else
+ Result := pthread_mutex_lock (L.WO'Access);
+ end if;
+
+ Ceiling_Violation := Result = EINVAL;
+
+ -- Assume the cause of EINVAL is a priority ceiling violation
+
+ pragma Assert (Result = 0 or else Result = EINVAL);
end Read_Lock;
------------
-- Unlock --
------------
- procedure Unlock (L : access Lock) is
+ procedure Unlock (L : not null access Lock) is
Result : Interfaces.C.int;
begin
- Result := pthread_mutex_unlock (L);
+ if Locking_Policy = 'R' then
+ Result := pthread_rwlock_unlock (L.RW'Access);
+ else
+ Result := pthread_mutex_unlock (L.WO'Access);
+ end if;
pragma Assert (Result = 0);
end Unlock;
- procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is
+ procedure Unlock
+ (L : not null access RTS_Lock;
+ Global_Lock : Boolean := False)
+ is
Result : Interfaces.C.int;
begin
if not Single_Lock or else Global_Lock then
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 --
-----------
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;
+ Result :=
+ pthread_cond_wait
+ (cond => Self_ID.Common.LL.CV'Access,
+ mutex => (if Single_Lock
+ then Single_RTS_Lock'Access
+ else Self_ID.Common.LL.L'Access));
-- EINTR is not considered a failure
is
pragma Unreferenced (Reason);
- Check_Time : constant Duration := Monotonic_Clock;
+ Base_Time : constant Duration := Monotonic_Clock;
+ Check_Time : Duration := Base_Time;
Abs_Time : Duration;
Request : aliased timespec;
Result : Interfaces.C.int;
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;
+ Abs_Time :=
+ (if Mode = Relative
+ then Duration'Min (Time, Max_Sensible_Delay) + Check_Time
+ else Duration'Min (Check_Time + Max_Sensible_Delay, Time));
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 Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
+
+ Result :=
+ pthread_cond_timedwait
+ (cond => Self_ID.Common.LL.CV'Access,
+ mutex => (if Single_Lock
+ then Single_RTS_Lock'Access
+ else Self_ID.Common.LL.L'Access),
+ abstime => Request'Access);
+
+ Check_Time := Monotonic_Clock;
+ exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
- exit when Abs_Time <= Monotonic_Clock;
+ if Result = 0 or else Result = EINTR then
+
+ -- Somebody may have called Wakeup for us
- if Result = 0 or Result = EINTR then
- -- somebody may have called Wakeup for us
Timedout := False;
exit;
end if;
-- Timed_Delay --
-----------------
- -- This is for use in implementing delay statements, so
- -- we assume the caller is abort-deferred but is holding
- -- no locks.
+ -- 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)
+ (Self_ID : Task_Id;
+ Time : Duration;
+ Mode : ST.Delay_Modes)
is
- Check_Time : constant Duration := Monotonic_Clock;
+ Base_Time : constant Duration := Monotonic_Clock;
+ Check_Time : Duration := Base_Time;
Abs_Time : Duration;
Request : aliased timespec;
- Result : Interfaces.C.int;
+
+ Result : Interfaces.C.int;
+ pragma Warnings (Off, Result);
begin
if Single_Lock then
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;
+ Abs_Time :=
+ (if Mode = Relative
+ then Time + Check_Time
+ else Duration'Min (Check_Time + Max_Sensible_Delay, Time));
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;
+ Result :=
+ pthread_cond_timedwait
+ (cond => Self_ID.Common.LL.CV'Access,
+ mutex => (if Single_Lock
+ then Single_RTS_Lock'Access
+ else Self_ID.Common.LL.L'Access),
+ abstime => Request'Access);
- exit when Abs_Time <= Monotonic_Clock;
+ Check_Time := Monotonic_Clock;
+ exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
pragma Assert (Result = 0 or else
Result = ETIMEDOUT or else
---------------------
function Monotonic_Clock return Duration is
- TV : aliased struct_timeval;
- Result : Interfaces.C.int;
+ use Interfaces;
+
+ type timeval is array (1 .. 2) of C.long;
+
+ procedure timeval_to_duration
+ (T : not null access timeval;
+ sec : not null access C.long;
+ usec : not null access C.long);
+ pragma Import (C, timeval_to_duration, "__gnat_timeval_to_duration");
+
+ Micro : constant := 10**6;
+ sec : aliased C.long;
+ usec : aliased C.long;
+ TV : aliased timeval;
+ Result : int;
+
+ function gettimeofday
+ (Tv : access timeval;
+ Tz : System.Address := System.Null_Address) return int;
+ pragma Import (C, gettimeofday, "gettimeofday");
+
begin
Result := gettimeofday (TV'Access, System.Null_Address);
pragma Assert (Result = 0);
- return To_Duration (TV);
+ timeval_to_duration (TV'Access, sec'Access, usec'Access);
+ return Duration (sec) + Duration (usec) / Micro;
end Monotonic_Clock;
-------------------
Result : Interfaces.C.int;
Param : aliased struct_sched_param;
+ function Get_Policy (Prio : System.Any_Priority) return Character;
+ pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
+ -- Get priority specific dispatching policy
+
+ Priority_Specific_Policy : constant Character := Get_Policy (Prio);
+ -- Upper case first character of the policy name corresponding to the
+ -- task as set by a Priority_Specific_Dispatching pragma.
+
begin
T.Common.Current_Priority := Prio;
- -- Priorities are in range 1 .. 99 on GNU/Linux, so we map
- -- map 0 .. 31 to 1 .. 32
+ -- Priorities are 1 .. 99 on GNU/Linux, so we map 0 .. 98 to 1 .. 99
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);
+ if Dispatching_Policy = 'R'
+ or else Priority_Specific_Policy = 'R'
+ or else Time_Slice_Val > 0
+ then
+ Result :=
+ pthread_setschedparam
+ (T.Common.LL.Thread, SCHED_RR, Param'Access);
- elsif Dispatching_Policy = 'F' or else Time_Slice_Val = 0 then
- Result := pthread_setschedparam
- (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
+ elsif Dispatching_Policy = 'F'
+ or else Priority_Specific_Policy = 'F'
+ or else Time_Slice_Val = 0
+ then
+ Result :=
+ pthread_setschedparam
+ (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
else
Param.sched_priority := 0;
- Result := pthread_setschedparam
- (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
+ Result :=
+ pthread_setschedparam
+ (T.Common.LL.Thread,
+ SCHED_OTHER, Param'Access);
end if;
pragma Assert (Result = 0 or else Result = EPERM);
procedure Enter_Task (Self_ID : Task_Id) is
begin
+ if Self_ID.Common.Task_Info /= null
+ and then Self_ID.Common.Task_Info.CPU_Affinity = No_CPU
+ then
+ raise Invalid_CPU_Number;
+ end if;
+
Self_ID.Common.LL.Thread := pthread_self;
+ Self_ID.Common.LL.LWP := lwp_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;
+ if Use_Alternate_Stack
+ and then Self_ID.Common.Task_Alternate_Stack /= Null_Address
+ 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;
- --------------
- -- 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 --
-------------------
--------------------
procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
- Result : Interfaces.C.int;
+ Cond_Attr : aliased pthread_condattr_t;
+ Result : Interfaces.C.int;
begin
-- Give the task a unique serial number
Next_Serial_Number := Next_Serial_Number + 1;
pragma Assert (Next_Serial_Number /= 0);
- Self_ID.Common.LL.Thread := To_pthread_t (-1);
+ Self_ID.Common.LL.Thread := Null_Thread_Id;
if not Single_Lock then
- Result := pthread_mutex_init (Self_ID.Common.LL.L'Access,
- Mutex_Attr'Access);
+ Result :=
+ pthread_mutex_init (Self_ID.Common.LL.L'Access, null);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result /= 0 then
end if;
end if;
- Result := pthread_cond_init (Self_ID.Common.LL.CV'Access,
- Cond_Attr'Access);
+ Result := pthread_condattr_init (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);
if Result = 0 then
Priority : System.Any_Priority;
Succeeded : out Boolean)
is
- Attributes : aliased pthread_attr_t;
- Result : Interfaces.C.int;
+ Attributes : aliased pthread_attr_t;
+ Adjusted_Stack_Size : Interfaces.C.size_t;
+ Result : Interfaces.C.int;
+
+ use type System.Multiprocessors.CPU_Range;
begin
+ -- Check whether both Dispatching_Domain and CPU are specified for
+ -- the task, and the CPU value is not contained within the range of
+ -- processors for the domain.
+
+ if T.Common.Domain /= null
+ and then T.Common.Base_CPU /= System.Multiprocessors.Not_A_Specific_CPU
+ and then
+ (T.Common.Base_CPU not in T.Common.Domain'Range
+ or else not T.Common.Domain (T.Common.Base_CPU))
+ then
+ Succeeded := False;
+ return;
+ end if;
+
+ Adjusted_Stack_Size :=
+ Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
+
Result := pthread_attr_init (Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
end if;
Result :=
- pthread_attr_setstacksize
- (Attributes'Access, Interfaces.C.size_t (Stack_Size));
+ pthread_attr_setstacksize (Attributes'Access, Adjusted_Stack_Size);
pragma Assert (Result = 0);
Result :=
(Attributes'Access, PTHREAD_CREATE_DETACHED);
pragma Assert (Result = 0);
+ -- Set the required attributes for the creation of the thread
+
+ -- Note: Previously, we called pthread_setaffinity_np (after thread
+ -- creation but before thread activation) to set the affinity but it was
+ -- not behaving as expected. Setting the required attributes for the
+ -- creation of the thread works correctly and it is more appropriate.
+
+ -- Do nothing if required support not provided by the operating system
+
+ if pthread_attr_setaffinity_np'Address = System.Null_Address then
+ null;
+
+ -- Support is available
+
+ elsif T.Common.Base_CPU /= System.Multiprocessors.Not_A_Specific_CPU then
+ declare
+ CPUs : constant size_t :=
+ Interfaces.C.size_t
+ (System.Multiprocessors.Number_Of_CPUs);
+ CPU_Set : constant cpu_set_t_ptr := CPU_ALLOC (CPUs);
+ Size : constant size_t := CPU_ALLOC_SIZE (CPUs);
+
+ begin
+ CPU_ZERO (Size, CPU_Set);
+ System.OS_Interface.CPU_SET
+ (int (T.Common.Base_CPU), Size, CPU_Set);
+ Result :=
+ pthread_attr_setaffinity_np (Attributes'Access, Size, CPU_Set);
+ pragma Assert (Result = 0);
+
+ CPU_FREE (CPU_Set);
+ end;
+
+ -- Handle Task_Info
+
+ elsif T.Common.Task_Info /= null then
+ Result :=
+ pthread_attr_setaffinity_np
+ (Attributes'Access,
+ CPU_SETSIZE / 8,
+ T.Common.Task_Info.CPU_Affinity'Access);
+ pragma Assert (Result = 0);
+
+ -- Handle dispatching domains
+
+ -- To avoid changing CPU affinities when not needed, we set the
+ -- affinity only when assigning to a domain other than the default
+ -- one, or when the default one has been modified.
+
+ elsif T.Common.Domain /= null and then
+ (T.Common.Domain /= ST.System_Domain
+ or else T.Common.Domain.all /=
+ (Multiprocessors.CPU'First ..
+ Multiprocessors.Number_Of_CPUs => True))
+ then
+ declare
+ CPUs : constant size_t :=
+ Interfaces.C.size_t
+ (System.Multiprocessors.Number_Of_CPUs);
+ CPU_Set : constant cpu_set_t_ptr := CPU_ALLOC (CPUs);
+ Size : constant size_t := CPU_ALLOC_SIZE (CPUs);
+
+ begin
+ CPU_ZERO (Size, CPU_Set);
+
+ -- Set the affinity to all the processors belonging to the
+ -- dispatching domain.
+
+ for Proc in T.Common.Domain'Range loop
+ if T.Common.Domain (Proc) then
+ System.OS_Interface.CPU_SET (int (Proc), Size, CPU_Set);
+ end if;
+ end loop;
+
+ Result :=
+ pthread_attr_setaffinity_np (Attributes'Access, Size, CPU_Set);
+ pragma Assert (Result = 0);
+
+ CPU_FREE (CPU_Set);
+ end;
+ end if;
+
-- Since the initial signal mask of a thread is inherited from the
-- creator, and the Environment task has all its signals masked, we
-- do not need to manipulate caller's signal mask at this point.
-- All tasks in RTS will have All_Tasks_Mask initially.
- 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);
+ -- 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 or else Result = ENOMEM);
+
+ if Result /= 0 then
+ Succeeded := False;
+ Result := pthread_attr_destroy (Attributes'Access);
+ pragma Assert (Result = 0);
+ return;
+ end if;
- Succeeded := Result = 0;
+ Succeeded := True;
Result := pthread_attr_destroy (Attributes'Access);
pragma Assert (Result = 0);
------------------
procedure Finalize_TCB (T : Task_Id) is
- Result : Interfaces.C.int;
- Tmp : Task_Id := T;
- Is_Self : constant Boolean := T = Self;
-
- procedure Free is new
- Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
+ Result : Interfaces.C.int;
begin
if not Single_Lock then
Known_Tasks (T.Known_Tasks_Index) := null;
end if;
- Free (Tmp);
+ SC.Invalidate_Stack_Cache (T.Common.Compiler_Data.Pri_Stack_Info'Access);
- if Is_Self then
- Specific.Set (null);
- end if;
+ ATCB_Allocation.Free_ATCB (T);
end Finalize_TCB;
---------------
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);
+ 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;
----------------
procedure Initialize (S : in out Suspension_Object) is
Result : Interfaces.C.int;
+
begin
- -- Initialize internal state. It is always initialized to False (ARM
- -- D.10 par. 6).
+ -- Initialize internal state (always to False (RM D.10(6)))
S.State := False;
S.Waiting := False;
-- Initialize internal mutex
- Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
+ Result := pthread_mutex_init (S.L'Access, null);
pragma Assert (Result = 0 or else Result = ENOMEM);
-- Initialize internal condition variable
- Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
+ Result := pthread_cond_init (S.CV'Access, null);
pragma Assert (Result = 0 or else Result = ENOMEM);
--------------
procedure Finalize (S : in out Suspension_Object) is
- Result : Interfaces.C.int;
+ Result : Interfaces.C.int;
+
begin
-- Destroy internal mutex
---------------
procedure Set_False (S : in out Suspension_Object) is
- Result : Interfaces.C.int;
+ Result : Interfaces.C.int;
+
begin
+ SSL.Abort_Defer.all;
+
Result := pthread_mutex_lock (S.L'Access);
pragma Assert (Result = 0);
Result := pthread_mutex_unlock (S.L'Access);
pragma Assert (Result = 0);
+
+ SSL.Abort_Undefer.all;
end Set_False;
--------------
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);
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;
------------------------
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
- -- (ARM D.10 par. 10).
+ -- (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
S.State := False;
else
S.Waiting := True;
- Result := pthread_cond_wait (S.CV'Access, S.L'Access);
+
+ loop
+ -- Loop in case pthread_cond_wait returns earlier than expected
+ -- (e.g. in case of EINTR caused by a signal). This should not
+ -- happen with the current Linux implementation of pthread, but
+ -- POSIX does not guarantee it so this may change in future.
+
+ 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;
- end if;
- Result := pthread_mutex_unlock (S.L'Access);
- pragma Assert (Result = 0);
+ Result := pthread_mutex_unlock (S.L'Access);
+ pragma Assert (Result = 0);
+
+ SSL.Abort_Undefer.all;
+ end if;
end Suspend_Until_True;
----------------
end if;
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 --
----------------
old_act : aliased struct_sigaction;
Tmp_Set : aliased sigset_t;
Result : Interfaces.C.int;
+ -- Whether to use an alternate signal stack for stack overflows
function State
(Int : System.Interrupt_Management.Interrupt_ID) return Character;
-- 's' Interrupt_State pragma set state to System (use "default"
-- system handler)
+ use type System.Multiprocessors.CPU_Range;
+
begin
Environment_Task_Id := Environment_Task;
end if;
end loop;
- Result := pthread_mutexattr_init (Mutex_Attr'Access);
- pragma Assert (Result = 0);
-
- Result := pthread_condattr_init (Cond_Attr'Access);
- pragma Assert (Result = 0);
-
Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
-- Initialize the global RTS lock
Specific.Initialize (Environment_Task);
- Enter_Task (Environment_Task);
+ if Use_Alternate_Stack then
+ Environment_Task.Common.Task_Alternate_Stack :=
+ Alternate_Stack'Address;
+ end if;
- -- Install the abort-signal handler
+ -- Make environment task known here because it doesn't go through
+ -- Activate_Tasks, which does it for all other tasks.
- if State (System.Interrupt_Management.Abort_Task_Interrupt)
- /= Default
+ 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;
act'Unchecked_Access,
old_act'Unchecked_Access);
pragma Assert (Result = 0);
+ Abort_Handler_Installed := True;
end if;
+
+ -- pragma CPU and dispatching domains for the environment task
+
+ Set_Task_Affinity (Environment_Task);
end Initialize;
+ -----------------------
+ -- Set_Task_Affinity --
+ -----------------------
+
+ procedure Set_Task_Affinity (T : ST.Task_Id) is
+ use type System.Multiprocessors.CPU_Range;
+
+ begin
+ -- Do nothing if there is no support for setting affinities or the
+ -- underlying thread has not yet been created. If the thread has not
+ -- yet been created then the proper affinity will be set during its
+ -- creation.
+
+ if pthread_setaffinity_np'Address /= System.Null_Address
+ and then T.Common.LL.Thread /= Null_Thread_Id
+ then
+ declare
+ CPUs : constant size_t :=
+ Interfaces.C.size_t
+ (System.Multiprocessors.Number_Of_CPUs);
+ CPU_Set : cpu_set_t_ptr := null;
+ Size : constant size_t := CPU_ALLOC_SIZE (CPUs);
+
+ Result : Interfaces.C.int;
+
+ begin
+ -- We look at the specific CPU (Base_CPU) first, then at the
+ -- Task_Info field, and finally at the assigned dispatching
+ -- domain, if any.
+
+ if T.Common.Base_CPU /= Multiprocessors.Not_A_Specific_CPU then
+
+ -- Set the affinity to an unique CPU
+
+ CPU_Set := CPU_ALLOC (CPUs);
+ System.OS_Interface.CPU_ZERO (Size, CPU_Set);
+ System.OS_Interface.CPU_SET
+ (int (T.Common.Base_CPU), Size, CPU_Set);
+
+ -- Handle Task_Info
+
+ elsif T.Common.Task_Info /= null then
+ CPU_Set := T.Common.Task_Info.CPU_Affinity'Access;
+
+ -- Handle dispatching domains
+
+ elsif T.Common.Domain /= null and then
+ (T.Common.Domain /= ST.System_Domain
+ or else T.Common.Domain.all /=
+ (Multiprocessors.CPU'First ..
+ Multiprocessors.Number_Of_CPUs => True))
+ then
+ -- Set the affinity to all the processors belonging to the
+ -- dispatching domain. To avoid changing CPU affinities when
+ -- not needed, we set the affinity only when assigning to a
+ -- domain other than the default one, or when the default one
+ -- has been modified.
+
+ CPU_Set := CPU_ALLOC (CPUs);
+ System.OS_Interface.CPU_ZERO (Size, CPU_Set);
+
+ for Proc in T.Common.Domain'Range loop
+ System.OS_Interface.CPU_SET (int (Proc), Size, CPU_Set);
+ end loop;
+ end if;
+
+ -- We set the new affinity if needed. Otherwise, the new task
+ -- will inherit its creator's CPU affinity mask (according to
+ -- the documentation of pthread_setaffinity_np), which is
+ -- consistent with Ada's required semantics.
+
+ if CPU_Set /= null then
+ Result :=
+ pthread_setaffinity_np (T.Common.LL.Thread, Size, CPU_Set);
+ pragma Assert (Result = 0);
+
+ CPU_FREE (CPU_Set);
+ end if;
+ end;
+ end if;
+ end Set_Task_Affinity;
+
end System.Task_Primitives.Operations;
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