ENH: signals: refactored to make static methods

The signal handling can now be set and unset. This latter is important
for external libraries (e.g. VTK/OpenGL) that do not work with it.

src/OSspecific/POSIX/signals/sigFpe.C

@@ -45,6 +45,8 @@ License
 
 struct sigaction Foam::sigFpe::oldAction_;
 
+bool Foam::sigFpe::sigFpeActive_ = false;
+
 void Foam::sigFpe::fillNan(UList<scalar>& lst)
 {
     lst = std::numeric_limits<scalar>::signaling_NaN();
@@ -114,7 +116,7 @@ void Foam::sigFpe::sigHandler(int)
 
 Foam::sigFpe::sigFpe()
 {
-    oldAction_.sa_handler = NULL;
+    set(false);
 }
 
 
@@ -122,28 +124,7 @@ Foam::sigFpe::sigFpe()
 
 Foam::sigFpe::~sigFpe()
 {
-    if (env("FOAM_SIGFPE"))
+    unset(false);
-    {
-        #ifdef LINUX_GNUC
-        // Reset signal
-        if (oldAction_.sa_handler && sigaction(SIGFPE, &oldAction_, NULL) < 0)
-        {
-            FatalErrorIn
-            (
-                "Foam::sigFpe::~sigFpe()"
-            )   << "Cannot reset SIGFPE trapping"
-                << abort(FatalError);
-        }
-        #endif
-    }
-
-    if (env("FOAM_SETNAN"))
-    {
-        #ifdef LINUX
-        // Disable initialization to NaN
-        mallocNanActive_ = false;
-        #endif
-    }
 }
 
 
@@ -151,16 +132,7 @@ Foam::sigFpe::~sigFpe()
 
 void Foam::sigFpe::set(const bool verbose)
 {
-    if (oldAction_.sa_handler)
+    if (!sigFpeActive_ && env("FOAM_SIGFPE"))
-    {
-        FatalErrorIn
-        (
-            "Foam::sigFpe::set()"
-        )   << "Cannot call sigFpe::set() more than once"
-            << abort(FatalError);
-    }
-
-    if (env("FOAM_SIGFPE"))
     {
         bool supported = false;
 
@@ -187,6 +159,7 @@ void Foam::sigFpe::set(const bool verbose)
                 << abort(FatalError);
         }
 
+        sigFpeActive_ = true;
 
         #elif defined(sgiN32) || defined(sgiN32Gcc)
         supported = true;
@@ -209,6 +182,9 @@ void Foam::sigFpe::set(const bool verbose)
             _ABORT_ON_ERROR,
             NULL
         );
+
+        sigFpeActive_ = true;
+
         #endif
 
 
@@ -251,4 +227,52 @@ void Foam::sigFpe::set(const bool verbose)
 }
 
 
+void Foam::sigFpe::unset(const bool verbose)
+{
+    #ifdef LINUX_GNUC
+    // Reset signal
+    if (sigFpeActive_)
+    {
+        if (verbose)
+        {
+            Info<< "sigFpe : Disabling floating point exception trapping"
+                << endl;
+        }
+
+        if (sigaction(SIGFPE, &oldAction_, NULL) < 0)
+        {
+            FatalErrorIn
+            (
+                "Foam::sigFpe::unset(const bool)"
+            )   << "Cannot reset SIGFPE trapping"
+                << abort(FatalError);
+        }
+
+        // Reset exception raising
+        int oldExcept = fedisableexcept
+        (
+            FE_DIVBYZERO
+          | FE_INVALID
+          | FE_OVERFLOW
+        );
+
+        if (oldExcept == -1)
+        {
+            FatalErrorIn
+            (
+                "sigFpe::unset(const bool)"
+            )   << "Cannot reset SIGFPE trapping"
+                << abort(FatalError);
+        }
+        sigFpeActive_ = false;
+    }
+    #endif
+
+    #ifdef LINUX
+    // Disable initialization to NaN
+    mallocNanActive_ = false;
+    #endif
+}
+
+
 // ************************************************************************* //

src/OSspecific/POSIX/signals/sigFpe.H

@@ -35,6 +35,10 @@ Description
         also set, this will cause usage of uninitialized scalars to trigger
         an abort.
 
+    Can be used either directly through the static member functions or
+    through the scope of the object (constructor sets trapping; destructor
+    restores original).
+
 SourceFiles
     sigFpe.C
 
@@ -72,6 +76,9 @@ class sigFpe
         //- Saved old signal trapping setting
         static struct sigaction oldAction_;
 
+        //- Flag to indicate floating point trapping is enabled
+        static bool sigFpeActive_;
+
 
     // Static data members
 
@@ -98,7 +105,10 @@ public:
 
         //- Activate SIGFPE signal handler when FOAM_SIGFPE is %set
         //  Fill memory with NaN when FOAM_SETNAN is %set
-        void set(const bool verbose);
+        static void set(const bool verbose);
+
+        //- Deactivate SIGFPE signal handler and NaN memory initialisation
+        static void unset(const bool verbose);
 
         //- Flag to indicate mallocNan is enabled
         static bool mallocNanActive_;

src/OSspecific/POSIX/signals/sigInt.C

@@ -32,6 +32,8 @@ License
 
 struct sigaction Foam::sigInt::oldAction_;
 
+bool Foam::sigInt::sigActive_ = false;
+
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
@@ -59,7 +61,7 @@ void Foam::sigInt::sigHandler(int)
 
 Foam::sigInt::sigInt()
 {
-    oldAction_.sa_handler = NULL;
+    set(false);
 }
 
 
@@ -67,15 +69,7 @@ Foam::sigInt::sigInt()
 
 Foam::sigInt::~sigInt()
 {
-    // Reset old handling
+    unset(false);
-    if (sigaction(SIGINT, &oldAction_, NULL) < 0)
-    {
-        FatalErrorIn
-        (
-            "Foam::sigInt::~sigInt()"
-        )   << "Cannot reset SIGINT trapping"
-            << abort(FatalError);
-    }
 }
 
 
@@ -83,15 +77,8 @@ Foam::sigInt::~sigInt()
 
 void Foam::sigInt::set(const bool)
 {
-    if (oldAction_.sa_handler)
+    if (!sigActive_)
     {
-        FatalErrorIn
-        (
-            "Foam::sigInt::set()"
-        )   << "Cannot call sigInt::set() more than once"
-            << abort(FatalError);
-    }
-
         struct sigaction newAction;
         newAction.sa_handler = sigHandler;
         newAction.sa_flags = SA_NODEFER;
@@ -104,6 +91,25 @@ void Foam::sigInt::set(const bool)
             )   << "Cannot set SIGINT trapping"
                 << abort(FatalError);
         }
+        sigActive_ = true;
+    }
+}
+
+
+void Foam::sigInt::unset(const bool)
+{
+    if (sigActive_)
+    {
+        if (sigaction(SIGINT, &oldAction_, NULL) < 0)
+        {
+            FatalErrorIn
+            (
+                "Foam::sigInt::unset()"
+            )   << "Cannot reset SIGINT trapping"
+                << abort(FatalError);
+        }
+        sigActive_ = false;
+    }
 }
 
 

src/OSspecific/POSIX/signals/sigInt.H

@@ -30,6 +30,10 @@ Description
     The standard interupt handler is overridden to ensure that the
     runningJob file is removed.
 
+    Can be used either directly through the static member functions or
+    through the scope of the object (constructor sets trapping; destructor
+    restores original).
+
 See Also
     Foam::JobInfo
 
@@ -59,6 +63,9 @@ class sigInt
         //- Saved old signal trapping setting
         static struct sigaction oldAction_;
 
+        //- Flag to indicate signal trapping is enabled
+        static bool sigActive_;
+
 
     // Private Member Functions
 
@@ -80,7 +87,10 @@ public:
     // Member functions
 
         //- Activate SIGINT signal handler
-        void set(const bool verbose);
+        static void set(const bool verbose);
+
+        //- Deactivate SIGINT signal handler
+        static void unset(const bool verbose);
 };
 
 

src/OSspecific/POSIX/signals/sigQuit.C

@@ -32,6 +32,8 @@ License
 
 struct sigaction Foam::sigQuit::oldAction_;
 
+bool Foam::sigQuit::sigActive_ = false;
+
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
@@ -61,7 +63,7 @@ void Foam::sigQuit::sigHandler(int)
 
 Foam::sigQuit::sigQuit()
 {
-    oldAction_.sa_handler = NULL;
+    set(false);
 }
 
 
@@ -69,15 +71,7 @@ Foam::sigQuit::sigQuit()
 
 Foam::sigQuit::~sigQuit()
 {
-    // Reset old handling
+    unset(false);
-    if (oldAction_.sa_handler && sigaction(SIGQUIT, &oldAction_, NULL) < 0)
-    {
-        FatalErrorIn
-        (
-            "Foam::sigQuit::~sigQuit()"
-        )   << "Cannot reset SIGQUIT trapping"
-            << abort(FatalError);
-    }
 }
 
 
@@ -85,15 +79,8 @@ Foam::sigQuit::~sigQuit()
 
 void Foam::sigQuit::set(const bool verbose)
 {
-    if (oldAction_.sa_handler)
+    if (!sigActive_)
     {
-        FatalErrorIn
-        (
-            "Foam::sigQuit::set()"
-        )   << "Cannot call sigQuit::set() more than once"
-            << abort(FatalError);
-    }
-
         struct sigaction newAction;
         newAction.sa_handler = sigHandler;
         newAction.sa_flags = SA_NODEFER;
@@ -106,6 +93,25 @@ void Foam::sigQuit::set(const bool verbose)
             )   << "Cannot set SIGQUIT trapping"
                 << abort(FatalError);
         }
+        sigActive_ = true;
+    }
+}
+
+
+void Foam::sigQuit::unset(const bool)
+{
+    if (sigActive_)
+    {
+        if (sigaction(SIGQUIT, &oldAction_, NULL) < 0)
+        {
+            FatalErrorIn
+            (
+                "Foam::sigQuit::unset()"
+            )   << "Cannot reset SIGQUIT trapping"
+                << abort(FatalError);
+        }
+        sigActive_ = false;
+    }
 }
 
 

src/OSspecific/POSIX/signals/sigQuit.H

@@ -29,6 +29,9 @@ Description
 
     The standard interupt handler is overridden to ensure that the
     runningJob file is removed.
+    Can be used either directly through the static member functions or
+    through the scope of the object (constructor sets trapping; destructor
+    restores original).
 
 See Also
     Foam::JobInfo
@@ -59,6 +62,9 @@ class sigQuit
         //- Saved old signal trapping setting
         static struct sigaction oldAction_;
 
+        //- Flag to indicate signal trapping is enabled
+        static bool sigActive_;
+
 
     // Private Member Functions
 
@@ -81,7 +87,10 @@ public:
     // Member functions
 
         //- Activate SIGQUIT signal handler
-        void set(const bool verbose);
+        static void set(const bool verbose);
+
+        //- Deactivate SIGQUIT signal handler
+        static void unset(const bool verbose);
 };
 
 

src/OSspecific/POSIX/signals/sigSegv.C

@@ -32,6 +32,8 @@ License
 
 struct sigaction Foam::sigSegv::oldAction_;
 
+bool Foam::sigSegv::sigActive_ = false;
+
 
 // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
@@ -61,7 +63,7 @@ void Foam::sigSegv::sigHandler(int)
 
 Foam::sigSegv::sigSegv()
 {
-    oldAction_.sa_handler = NULL;
+    set(false);
 }
 
 
@@ -69,15 +71,7 @@ Foam::sigSegv::sigSegv()
 
 Foam::sigSegv::~sigSegv()
 {
-    // Reset old handling
+    unset(false);
-    if (sigaction(SIGSEGV, &oldAction_, NULL) < 0)
-    {
-        FatalErrorIn
-        (
-            "Foam::sigSegv::~sigSegv()"
-        )   << "Cannot reset SIGSEGV trapping"
-            << abort(FatalError);
-    }
 }
 
 
@@ -85,15 +79,8 @@ Foam::sigSegv::~sigSegv()
 
 void Foam::sigSegv::set(const bool)
 {
-    if (oldAction_.sa_handler)
+    if (!sigActive_)
     {
-        FatalErrorIn
-        (
-            "Foam::sigSegv::set()"
-        )   << "Cannot call sigSegv::set() more than once"
-            << abort(FatalError);
-    }
-
         struct sigaction newAction;
         newAction.sa_handler = sigHandler;
         newAction.sa_flags = SA_NODEFER;
@@ -106,6 +93,25 @@ void Foam::sigSegv::set(const bool)
             )   << "Cannot set SIGSEGV trapping"
                 << abort(FatalError);
         }
+        sigActive_ = true;
+    }
+}
+
+
+void Foam::sigSegv::unset(const bool)
+{
+    if (sigActive_)
+    {
+        if (sigaction(SIGSEGV, &oldAction_, NULL) < 0)
+        {
+            FatalErrorIn
+            (
+                "Foam::sigSegv::unset()"
+            )   << "Cannot reset SIGSEGV trapping"
+                << abort(FatalError);
+        }
+        sigActive_ = false;
+    }
 }
 
 

src/OSspecific/POSIX/signals/sigSegv.H

@@ -29,6 +29,9 @@ Description
 
     The standard interupt handler is overridden to ensure that the
     runningJob file is removed.
+    Can be used either directly through the static member functions or
+    through the scope of the object (constructor sets trapping; destructor
+    restores original).
 
 See Also
     Foam::JobInfo
@@ -59,6 +62,9 @@ class sigSegv
         //- Saved old signal trapping setting
         static struct sigaction oldAction_;
 
+        //- Flag to indicate signal trapping is enabled
+        static bool sigActive_;
+
 
     // Private Member Functions
 
@@ -81,7 +87,10 @@ public:
     // Member functions
 
         //- Activate SIGSEGV signal handler
-        void set(const bool verbose);
+        static void set(const bool verbose);
+
+        //- Deactivate SIGSEGV signal handler
+        static void unset(const bool verbose);
 };
 
 

src/OpenFOAM/global/argList/argList.C

@@ -33,6 +33,10 @@ License
 #include "labelList.H"
 #include "regIOobject.H"
 #include "dynamicCode.H"
+#include "sigFpe.H"
+#include "sigInt.H"
+#include "sigQuit.H"
+#include "sigSegv.H"
 
 #include <cctype>
 
@@ -868,10 +872,10 @@ void Foam::argList::parse
 
         // Switch on signal trapping. We have to wait until after Pstream::init
         // since this sets up its own ones.
-        sigFpe_.set(bannerEnabled);
+        sigFpe::set(bannerEnabled);
-        sigInt_.set(bannerEnabled);
+        sigInt::set(bannerEnabled);
-        sigQuit_.set(bannerEnabled);
+        sigQuit::set(bannerEnabled);
-        sigSegv_.set(bannerEnabled);
+        sigSegv::set(bannerEnabled);
 
         if (bannerEnabled)
         {

src/OpenFOAM/global/argList/argList.H

@@ -86,11 +86,6 @@ SourceFiles
 #include "IStringStream.H"
 #include "OSspecific.H"
 
-#include "sigFpe.H"
-#include "sigInt.H"
-#include "sigQuit.H"
-#include "sigSegv.H"
-
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
 namespace Foam
@@ -118,12 +113,6 @@ class argList
         fileName case_;
         string argListStr_;
 
-        // Signal handlers
-        sigFpe sigFpe_;
-        sigInt sigInt_;
-        sigQuit sigQuit_;
-        sigSegv sigSegv_;
-
 
     // Private Member Functions
 

src/postProcessing/functionObjects/graphics/runTimePostProcessing/runTimePostProcessing.C

@@ -31,6 +31,7 @@ License
 #include "surface.H"
 #include "text.H"
 #include "Time.H"
+#include "sigFpe.H"
 
 // VTK includes
 #include "vtkPolyDataMapper.h"
@@ -143,6 +144,10 @@ void Foam::runTimePostProcessing::write()
     Info<< type() << " " << name_ <<  " output:" << nl
         << "    Constructing scene" << endl;
 
+    // Unset any floating point trapping (some low-level rendering functionality
+    // does not like it)
+    sigFpe::unset(false);
+
     // Initialise render window
     vtkSmartPointer<vtkRenderWindow> renderWindow =
         vtkSmartPointer<vtkRenderWindow>::New();
@@ -204,6 +209,9 @@ void Foam::runTimePostProcessing::write()
             surfaces_[i].updateActors(position);
         }
     }
+
+    // Reset any floating point trapping
+    sigFpe::set(false);
 }