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author | Pierre-Marie de Rodat <pmderodat@gcc.gnu.org> | 2017-11-09 12:10:30 +0000 |
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committer | Pierre-Marie de Rodat <pmderodat@gcc.gnu.org> | 2017-11-09 12:10:30 +0000 |
commit | 3ec54569383fc11ffdb560aae6a7868be5525d19 (patch) | |
tree | df3d3c2d38f9e33c6d76942ad5a05d20abb8af83 /gcc/ada/libgnarl/s-taprop__qnx.adb | |
parent | 6214b83bf1b6d05c9ff3bdb419975851bc131b97 (diff) | |
download | gcc-3ec54569383fc11ffdb560aae6a7868be5525d19.zip gcc-3ec54569383fc11ffdb560aae6a7868be5525d19.tar.gz gcc-3ec54569383fc11ffdb560aae6a7868be5525d19.tar.bz2 |
[multiple changes]
2017-11-09 Pascal Obry <obry@adacore.com>
* libgnarl/s-taprop__mingw.adb: On Windows, initialize the thead handle
only for foreign threads. We initialize the thread handle only if not
yet initialized. This happens in Enter_Task for foreign threads only.
But for native threads (Ada tasking) we do want to keep the real
handle (from Create_Task) to be able to free the corresponding
resources in Finalize_TCB (CloseHandle).
2017-11-09 Yannick Moy <moy@adacore.com>
* sem_attr.adb (Analyze_Attribute): Default initialize P_Type,
P_Base_Type.
(Error_Attr_P): Fix name in pragma No_Return.
(Unexpected_Argument): Add pragma No_Return.
(Placement_Error): Add pragma No_Return.
2017-11-09 Javier Miranda <miranda@adacore.com>
* exp_disp.adb (Elab_Flag_Needed): Elaboration flag not needed when the
dispatch table is statically built.
(Make_DT): Declare constant the Interface_Table object associated with
an statically built dispatch table. For this purpose the Offset_To_Top
value of each interface is computed using the dummy object.
* exp_ch3.adb (Build_Init_Procedure): Do not generate code initializing
the Offset_To_Top field of secondary dispatch tables when the dispatch
table is statically built.
(Initialize_Tag): Do not generate calls to Register_Interface_Offset
when the dispatch table is statically built.
* doc/gnat_rm/standard_and_implementation_defined_restrictions.rst:
Document the new GNAT restriction Static_Dispatch_Tables.
* gnat_rm.texi: Regenerate.
2017-11-09 Hristian Kirtchev <kirtchev@adacore.com>
* sem_aggr.adb (Resolve_Delta_Record_Aggregate): Reorder declarations
to avoid a dormant bug.
2017-11-09 Jerome Lambourg <lambourg@adacore.com>
* init.c: Define missing __gnat_alternate_stack for QNX. Set it to 0,
as such capability is not available on the OS.
* link.c: Make sure linker options for QNX are correct.
* libgnarl/s-osinte__qnx.ads: Add some missing bindings to pthread.
* libgnarl/s-taprop__qnx.adb: New, derived from s-taprop__posix.adb. This brings
in particular a workaround with locks priority ceiling where a higher
priority task is allowed to lock a lower ceiling priority lock. This
also fixes the scheduling of FIFO tasks when the priority of a task is
lowered.
* libgnat/system-qnx-aarch64.ads: Fix priority ranges.
2017-11-09 Yannick Moy <moy@adacore.com>
* erroutc.adb (Output_Error_Msgs): Justify CodePeer false positive
message.
* gnatbind.adb (Scan_Bind_Arg): Simplify test to remove always true
condition.
* namet.adb (Copy_One_Character): Add assumption for static analysis,
as knowledge that Hex(2) is in the range 0..255 is too complex for
CodePeer.
(Finalize): Add assumption for static analysis, as the fact that there
are symbols in the table depends on a global invariant at this point in
the program.
* set_targ.adb (Check_Spaces): Justify CodePeer false positive message.
* stylesw.adb (Save_Style_Check_Options): Rewrite to avoid test always
true.
From-SVN: r254573
Diffstat (limited to 'gcc/ada/libgnarl/s-taprop__qnx.adb')
-rw-r--r-- | gcc/ada/libgnarl/s-taprop__qnx.adb | 1355 |
1 files changed, 1355 insertions, 0 deletions
diff --git a/gcc/ada/libgnarl/s-taprop__qnx.adb b/gcc/ada/libgnarl/s-taprop__qnx.adb new file mode 100644 index 0000000..9689b67 --- /dev/null +++ b/gcc/ada/libgnarl/s-taprop__qnx.adb @@ -0,0 +1,1355 @@ +------------------------------------------------------------------------------ +-- -- +-- 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) 1992-2017, 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) + +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 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 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 + + Locking_Policy : 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 : Integer; + pragma Import (C, Time_Slice_Val, "__gl_time_slice_val"); + + Dispatching_Policy : 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 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 = 0 means no Ceiling Priority policy is set on this mutex + -- Else, Ceiling < current priority means Ceiling violation + -- (otherwise the current priority == ceiling) + if Ceiling > 0 and then 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; + Global_Lock : Boolean := False) + is + Result : Interfaces.C.int; + begin + if not Single_Lock or else Global_Lock then + Result := pthread_mutex_lock (L); + pragma Assert (Result = 0); + end if; + end Write_Lock; + + procedure Write_Lock (T : Task_Id) is + Result : Interfaces.C.int; + begin + if not Single_Lock then + Result := pthread_mutex_lock (T.Common.LL.L'Access); + pragma Assert (Result = 0); + end if; + end Write_Lock; + + --------------- + -- Read_Lock -- + --------------- + + procedure Read_Lock + (L : 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; Global_Lock : Boolean := False) + is + Result : Interfaces.C.int; + begin + if not Single_Lock or else Global_Lock then + Result := pthread_mutex_unlock (L); + pragma Assert (Result = 0); + end if; + end Unlock; + + procedure Unlock (T : Task_Id) is + Result : Interfaces.C.int; + begin + if not Single_Lock then + Result := pthread_mutex_unlock (T.Common.LL.L'Access); + pragma Assert (Result = 0); + end if; + end Unlock; + + ----------------- + -- 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 => (if Single_Lock + then Single_RTS_Lock'Access + else 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); + + if not Single_Lock then + 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; + 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 + if not Single_Lock then + Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access); + pragma Assert (Result = 0); + end if; + + Succeeded := False; + end if; + + 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 + if not Single_Lock then + Result := pthread_mutex_destroy (T.Common.LL.L'Access); + pragma Assert (Result = 0); + end if; + + Result := pthread_cond_destroy (T.Common.LL.CV'Access); + pragma Assert (Result = 0); + + if T.Known_Tasks_Index /= -1 then + Known_Tasks (T.Known_Tasks_Index) := null; + end if; + + 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, 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 + 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; |