ada: Rework disabling signals when calling pthread_create on QNX

Use the correct pthread_sigmask instead of sigprocmask when disabling
signals on QNX. Furthermore make use of the already existing bindings to
implement that functionality in Ada instead of C. Enable signals in both
Create_Task and Enter_Task as they need to be enabled in both the parent
and the child.

gcc/ada/ChangeLog:

	* adaint.c: Remove __gnat_enable_signals, __gnat_disable_signals
	and related code for QNX.
	* libgnarl/s-taprop__qnx.adb: Disable and enable
	signals in Ada.

diff --git a/gcc/ada/adaint.c b/gcc/ada/adaint.c
index 7b78d91e0e72f10ead77bc8d4f9c08a359467541..adc39517280a8120359a24bd816a80ba49d72237 100644 (file)
--- a/gcc/ada/adaint.c
+++ b/gcc/ada/adaint.c
@@ -107,7 +107,6 @@
 #ifdef __QNX__
 #include <sys/syspage.h>
 #include <sys/time.h>
-#include <signal.h>
 #endif
 
 #ifdef IN_RTS
@@ -3720,68 +3719,6 @@ void __gnat_killprocesstree (int pid, int sig_num)
   */
 }
 
-#if defined (__QNX__)
-
-static __thread sigset_t set;
-static __thread sigset_t oset;
-static __thread int signals_disabled = 0;
-
-int __gnat_disable_signals(void)
-{
-    sigemptyset(&set);
-    sigaddset(&set, SIGHUP);
-    sigaddset(&set, SIGINT);
-    sigaddset(&set, SIGQUIT);
-    sigaddset(&set, SIGILL);
-    sigaddset(&set, SIGTRAP);
-    sigaddset(&set, SIGIOT);
-    sigaddset(&set, SIGABRT);
-    sigaddset(&set, SIGEMT);
-    sigaddset(&set, SIGDEADLK);
-    sigaddset(&set, SIGFPE);
-    sigaddset(&set, SIGKILL);
-    sigaddset(&set, SIGBUS);
-    sigaddset(&set, SIGSEGV);
-    sigaddset(&set, SIGSYS);
-    sigaddset(&set, SIGPIPE);
-    sigaddset(&set, SIGALRM);
-    sigaddset(&set, SIGTERM);
-    sigaddset(&set, SIGUSR1);
-    sigaddset(&set, SIGUSR2);
-    sigaddset(&set, SIGCHLD);
-    sigaddset(&set, SIGCLD);
-    sigaddset(&set, SIGPWR);
-    sigaddset(&set, SIGWINCH);
-    sigaddset(&set, SIGURG);
-    sigaddset(&set, SIGPOLL);
-    sigaddset(&set, SIGIO);
-    sigaddset(&set, SIGSTOP);
-    sigaddset(&set, SIGTSTP);
-    sigaddset(&set, SIGCONT);
-    sigaddset(&set, SIGTTIN);
-    sigaddset(&set, SIGTTOU);
-    sigaddset(&set, SIGVTALRM);
-    sigaddset(&set, SIGPROF);
-    sigaddset(&set, SIGXCPU);
-    sigaddset(&set, SIGXFSZ);
-    sigaddset(&set, SIGDOOM);
-
-    int ret = sigprocmask(SIG_BLOCK, &set, &oset);
-    signals_disabled = !ret;
-    return ret;
-}
-
-int __gnat_enable_signals(void)
-{
-    if (!signals_disabled) {
-        return 0;
-    }
-    signals_disabled = 0;
-    return sigprocmask(SIG_SETMASK, &oset, 0);
-}
-
-#endif
-
 #ifdef __cplusplus
 }
 #endif

diff --git a/gcc/ada/libgnarl/s-taprop__qnx.adb b/gcc/ada/libgnarl/s-taprop__qnx.adb
index b51f2b527082e058f93488b60359607e9aac67f8..c9a98e9eaa11266ed5f354e40a3ac457040fe5bd 100644 (file)
--- a/gcc/ada/libgnarl/s-taprop__qnx.adb
+++ b/gcc/ada/libgnarl/s-taprop__qnx.adb
@@ -96,6 +96,22 @@ package body System.Task_Primitives.Operations is
    Unblocked_Signal_Mask : aliased sigset_t;
    --  The set of signals that should unblocked in all tasks
 
+   Default_Signal_Mask : aliased sigset_t;
+   --  Default signal mask, used to restore signal mask after thread creation
+
+   Default_Signal_Mask_Initialized : Boolean := False;
+   --  Allow to not enable default signals if the default signal mask failed to
+   --  initialize.
+
+   procedure Disable_Signals;
+   --  Disable signals before calling pthread_create to avoid a potential
+   --  memory leak on QNX.
+
+   procedure Enable_Signals;
+   --  Enable signals after pthread_create and in the created task. Since the
+   --  created task inherits the disabled signals from the parent they have to
+   --  be enabled for each task separately.
+
    --  The followings are internal configuration constants needed
 
    Next_Serial_Number : Task_Serial_Number := 100;
@@ -654,6 +670,7 @@ package body System.Task_Primitives.Operations is
 
    procedure Enter_Task (Self_ID : Task_Id) is
    begin
+      Enable_Signals;
       Self_ID.Common.LL.LWP := lwp_self;
 
       Specific.Set (Self_ID);
@@ -765,17 +782,6 @@ package body System.Task_Primitives.Operations is
 
       function Thread_Body_Access is new
         Ada.Unchecked_Conversion (System.Address, Thread_Body);
-
-      function Disable_Signals return Interfaces.C.int with
-        Import,
-        Convention    => C,
-        External_Name => "__gnat_disable_signals";
-
-      function Enable_Signals return Interfaces.C.int with
-        Import,
-        Convention    => C,
-        External_Name => "__gnat_enable_signals";
-
    begin
       Adjusted_Stack_Size :=
          Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
@@ -862,20 +868,17 @@ package body System.Task_Primitives.Operations is
       --  Restricted.Stages is used). One can verify that by inspecting the
       --  Task_Wrapper procedures.
 
-      Result := Disable_Signals;
-      pragma Assert (Result = 0);
+      Disable_Signals;
       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);
+      Enable_Signals;
 
       Succeeded := Result = 0;
 
-      Result := Enable_Signals;
-      pragma Assert (Result = 0);
-
       Result := pthread_attr_destroy (Attributes'Access);
       pragma Assert (Result = 0);
    end Create_Task;
@@ -1292,6 +1295,10 @@ package body System.Task_Primitives.Operations is
          end if;
       end loop;
 
+      Result := pthread_sigmask
+         (SIG_SETMASK, null, Default_Signal_Mask'Access);
+      Default_Signal_Mask_Initialized := Result = 0;
+
       --  Initialize the lock used to synchronize chain of all ATCBs
 
       Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
@@ -1378,4 +1385,56 @@ package body System.Task_Primitives.Operations is
       pragma Assert (Result = 0);
    end Set_Task_Affinity;
 
+   ---------------------
+   -- Disable_Signals --
+   ---------------------
+
+   procedure Disable_Signals
+   is
+      Set    : aliased sigset_t;
+      Result : Interfaces.C.int;
+   begin
+      --  If the default signal mask is not initialized there is no point in
+      --  disabling signals since we can't enable them again. Not enabling them
+      --  might impact the runtimes functionality so we rather accept the
+      --  possible memory leak.
+      if not Default_Signal_Mask_Initialized then
+         return;
+      end if;
+
+      --  If any of the operations of setting up the signal mask fails we abort
+      --  disabling the signals. The function to enable the signals doesn't
+      --  need to care about this. It will simply restore the default signal
+      --  mask if it was successfully initialized. If the signals are not
+      --  disabled this is a no-op.
+      Result := sigemptyset (Set'Access);
+      if Result /= 0 then
+         return;
+      end if;
+      for S in SIGHUP .. SIGXFSZ loop
+         Result := sigaddset (Set'Access, Signal (S));
+         if Result /= 0 then
+            return;
+         end if;
+      end loop;
+      Result := pthread_sigmask (SIG_BLOCK, Set'Access, null);
+      pragma Assert (Result = 0);
+   end Disable_Signals;
+
+   --------------------
+   -- Enable_Signals --
+   --------------------
+
+   procedure Enable_Signals
+   is
+      Result : Interfaces.C.int;
+   begin
+      if not Default_Signal_Mask_Initialized then
+         return;
+      end if;
+      Result := pthread_sigmask
+         (SIG_SETMASK, Default_Signal_Mask'Access, null);
+      pragma Assert (Result = 0);
+   end Enable_Signals;
+
 end System.Task_Primitives.Operations;