ENH: add trapFpe and setNaN optimisationSwitch (issue #517)

- allows configuration without an environment variable.
  For compatibility still respect FOAM_SIGFPE and FOAM_SETNAN
  env-variables

- The env-variables are now treated as true/false switch values.
  Previously there was just a check for env exists or not, but this
  can be fairly fragile for a user's environment.

applications/utilities/parallelProcessing/redistributePar/redistributePar.C

@@ -59,6 +59,7 @@ Usage
 \*---------------------------------------------------------------------------*/
 
 #include "argList.H"
+#include "sigFpe.H"
 #include "Time.H"
 #include "fvMesh.H"
 #include "fvMeshTools.H"
@@ -2277,7 +2278,7 @@ int main(int argc, char *argv[])
     bool newTimes = args.optionFound("newTimes");
 
 
-    if (env("FOAM_SIGFPE"))
+    if (Foam::sigFpe::requested())
     {
         WarningInFunction
             << "Detected floating point exception trapping (FOAM_SIGFPE)."
@@ -2287,7 +2288,6 @@ int main(int argc, char *argv[])
     }
 
 
-
     const HashSet<word> selectedFields(0);
     const HashSet<word> selectedLagrangianFields(0);
 

bin/tools/foamConfigurePaths

@@ -39,8 +39,9 @@ usage: ${0##*/}
   -foamVersion ver        specify project version (eg, 1612)
   -projectName name       specify project directory name (eg, openfoam1612)
   -archOption 32|64       specify 'WM_ARCH_OPTION' architecture option
+  -SP | -float32          specify 'WM_PRECISION_OPTION'
+  -DP | -float64          specify 'WM_PRECISION_OPTION'
   -int32  | -int64        specify 'WM_LABEL_SIZE'
-  -SP     | -DP           specify 'WM_PRECISION_OPTION'
   -system name            specify 'system' compiler to be used
   -third  name            specify 'ThirdParty' compiler to be used
   -boost ver              specify 'boost_version'
@@ -63,7 +64,7 @@ usage: ${0##*/}
   -scotch-path dir        specify 'SCOTCH_ARCH_PATH' (eg, /opt/OpenFOAM-scotch_6.0.4)
   -vtk  ver               specify 'vtk_version' (eg, VTK-7.1.0)
   -mesa ver               specify 'mesa_version' (eg, mesa-13.0.1)
-  -sigfpe | -no-sigfpe    activate/deactivate FOAM_SIGFPE handling
+  -sigfpe | -no-sigfpe    [defunct - now under etc/controlDict]
   gmp-VERSION             for ThirdParty gcc (gmp-system for system library)
   mpfr-VERSION            for ThirdParty gcc (mpfr-system for system library)
   mpc-VERSION             for ThirdParty gcc (mpc-system for system library)
@@ -251,6 +252,18 @@ do
         shift
         ;;
 
+    -SP | -float32)
+        # Replace WM_PRECISION_OPTION=...
+        replace etc/bashrc  WM_PRECISION_OPTION "SP"
+        adjusted=true
+        ;;
+
+    -DP | -float64)
+        # Replace WM_PRECISION_OPTION=...
+        replace etc/bashrc  WM_PRECISION_OPTION "DP"
+        adjusted=true
+        ;;
+
     -int32 | -int64)
         # Replace WM_LABEL_SIZE=...
         optionValue="${1#-int}"
@@ -258,13 +271,6 @@ do
         adjusted=true
         ;;
 
-    -SP | -DP)
-        # Replace WM_PRECISION_OPTION=...
-        optionValue="${1#-}"
-        replace etc/bashrc  WM_PRECISION_OPTION "$optionValue"
-        adjusted=true
-        ;;
-
     -system)
         # Replace WM_COMPILER_TYPE=... and WM_COMPILER=...
         [ "$#" -ge 2 ] || die "'$1' option requires an argument"
@@ -471,20 +477,8 @@ do
         adjusted=true
         ;;
 
-    -sigfpe)
+    -sigfpe | -no-sigfpe)
-        # Enable FOAM_SIGFPE handling
+        echo "Enable/disable FOAM_SIGFPE now via controlDict" 1>&2
-        _inlineSed etc/bashrc \
-            "[a-z][a-z]* FOAM_SIGFPE.*" \
-            "export FOAM_SIGFPE=" \
-            "Activate FOAM_SIGFPE handling"
-        ;;
-
-    -no-sigfpe)
-        # Disable FOAM_SIGFPE handling
-        _inlineSed etc/bashrc \
-            "[a-z][a-z]* FOAM_SIGFPE.*" \
-            "unset FOAM_SIGFPE" \
-            "Deactivate FOAM_SIGFPE handling"
         ;;
 
     *)

etc/bashrc

@@ -96,13 +96,13 @@ export WM_MPLIB=SYSTEMOPENMPI
 #    WM_OSTYPE = POSIX
 #export WM_OSTYPE=POSIX
 
-#- Floating-point signal handling:
+#- Alternative to 'trapFpe' controlDict entry
-#    set or unset
+#  for floating-point exceptions (true|false)
-export FOAM_SIGFPE=
+#export FOAM_SIGFPE=true
 
-#- memory initialisation:
+#- Alternative to 'setNaN' controlDict entry
-#    set or unset
+#  for memory initialisation (true|false)
-#export FOAM_SETNAN=
+#export FOAM_SETNAN=false
 
 
 ################################################################################

etc/controlDict

@@ -79,6 +79,14 @@ OptimisationSwitches
     // global reduction, even if multi-pass is not needed)
     maxCommsSize    0;
 
+    // Trap floating point exception.
+    // Can override with FOAM_SIGFPE (true|false)
+    trapFpe         1;
+
+    // Initialization malloced memory to NaN.
+    // Can override with FOAM_SETNAN (true|false)
+    setNaN          0;
+
     // Force dumping (at next timestep) upon signal (-1 to disable)
     writeNowSignal              -1; // 10;
 

etc/cshrc

@@ -93,13 +93,13 @@ setenv WM_MPLIB SYSTEMOPENMPI
 #    WM_OSTYPE = POSIX
 #setenv WM_OSTYPE POSIX
 
-#- Floating-point signal handling:
+#- Alternative to 'trapFpe' controlDict entry
-#    set or unset
+#  for floating-point exceptions (true|false)
-setenv FOAM_SIGFPE
+#setenv FOAM_SIGFPE true
 
-#- memory initialisation:
+#- Alternative to 'setNaN' controlDict entry
-#    set or unset
+#  for memory initialisation (true|false)
-#setenv FOAM_SETNAN
+#setenv FOAM_SETNAN false
 
 
 ################################################################################

src/OSspecific/POSIX/signals/sigFpe.C

@@ -28,6 +28,7 @@ License
 #include "JobInfo.H"
 #include "OSspecific.H"
 #include "IOstreams.H"
+#include "Switch.H"
 
 #ifdef LINUX_GNUC
     #ifndef __USE_GNU
@@ -43,17 +44,41 @@ License
 
 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
+bool Foam::sigFpe::switchFpe_(Foam::debug::optimisationSwitch("trapFpe", 0));
+bool Foam::sigFpe::switchNan_(Foam::debug::optimisationSwitch("setNaN", 0));
+
+bool Foam::sigFpe::sigActive_ = false;
+bool Foam::sigFpe::mallocNanActive_ = false;
+
 struct sigaction Foam::sigFpe::oldAction_;
 
-bool Foam::sigFpe::sigFpeActive_ = false;
+
+// File-scope function.
+// Controlled by env variable containing a bool (true|false|on|off ...)
+// or by the specified flag
+static bool isTrue(const char* envName, const bool flag)
+{
+    const std::string str = Foam::getEnv(envName);
+
+    if (str.size())
+    {
+        Foam::Switch sw(str, true); // silently ignore bad input
+        if (sw.valid())
+        {
+            return sw;
+        }
+    }
+
+    // Env was not set or did not contain a valid bool value
+    return flag;
+}
+
 
 void Foam::sigFpe::fillNan(UList<scalar>& lst)
 {
     lst = std::numeric_limits<scalar>::signaling_NaN();
 }
 
-bool Foam::sigFpe::mallocNanActive_ = false;
-
 
 #ifdef LINUX
 extern "C"
@@ -128,9 +153,15 @@ Foam::sigFpe::~sigFpe()
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
+bool Foam::sigFpe::requested()
+{
+    return isTrue("FOAM_SIGFPE", switchFpe_);
+}
+
+
 void Foam::sigFpe::set(const bool verbose)
 {
-    if (!sigFpeActive_ && env("FOAM_SIGFPE"))
+    if (!sigActive_ && requested())
     {
         bool supported = false;
 
@@ -155,7 +186,7 @@ void Foam::sigFpe::set(const bool verbose)
                 << abort(FatalError);
         }
 
-        sigFpeActive_ = true;
+        sigActive_ = true;
 
         #elif defined(sgiN32) || defined(sgiN32Gcc)
         supported = true;
@@ -179,28 +210,28 @@ void Foam::sigFpe::set(const bool verbose)
             nullptr
         );
 
-        sigFpeActive_ = true;
+        sigActive_ = true;
 
         #endif
 
 
         if (verbose)
         {
+            Info<< "trapFpe: Floating point exception trapping ";
+
             if (supported)
             {
-                Info<< "sigFpe : Enabling floating point exception trapping"
+                Info<< "enabled (FOAM_SIGFPE)." << endl;
-                    << " (FOAM_SIGFPE)." << endl;
             }
             else
             {
-                Info<< "sigFpe : Floating point exception trapping"
+                Info<< "- not supported on this platform" << endl;
-                    << " - not supported on this platform" << endl;
             }
         }
     }
 
 
-    if (env("FOAM_SETNAN"))
+    if (isTrue("FOAM_SETNAN", switchNan_))
     {
         #ifdef LINUX
         mallocNanActive_ = true;
@@ -208,15 +239,15 @@ void Foam::sigFpe::set(const bool verbose)
 
         if (verbose)
         {
+            Info<< "setNaN : Initialise allocated memory to NaN ";
+
             if (mallocNanActive_)
             {
-                Info<< "SetNaN : Initialising allocated memory to NaN"
+                Info<< "enabled (FOAM_SETNAN)." << endl;
-                    << " (FOAM_SETNAN)." << endl;
             }
             else
             {
-                Info<< "SetNaN : Initialise allocated memory to NaN"
+                Info<< " - not supported on this platform" << endl;
-                    << " - not supported on this platform" << endl;
             }
         }
     }
@@ -227,7 +258,7 @@ void Foam::sigFpe::unset(const bool verbose)
 {
     #ifdef LINUX_GNUC
     // Reset signal
-    if (sigFpeActive_)
+    if (sigActive_)
     {
         if (verbose)
         {
@@ -256,7 +287,7 @@ void Foam::sigFpe::unset(const bool verbose)
                 << "Cannot reset SIGFPE trapping"
                 << abort(FatalError);
         }
-        sigFpeActive_ = false;
+        sigActive_ = false;
     }
     #endif
 

src/OSspecific/POSIX/signals/sigFpe.H

@@ -27,17 +27,24 @@ Class
 Description
     Set up trapping for floating point exceptions (signal FPE).
 
-    Controlled by two env vars:
+    Defined by controlDict InfoSwitch entries:
-      - \par FOAM_SIGFPE
+    - \par trapFpe
-        Exception trapping
+      Enable floating point exception trapping.
-      - \par FOAM_SETNAN
-        Initialization of all malloced memory to NaN. If FOAM_SIGFPE
-        also set, this will cause usage of uninitialized scalars to trigger
-        an abort.
 
-    Can be used either directly through the static member functions or
+    - \par setNaN
-    through the scope of the object (constructor sets trapping; destructor
+      Initialization all malloced memory to NaN.
-    restores original).
+      Combined with \c trapFpe, this causes usage of uninitialized scalars
+      to trigger an abort.
+
+    Environment variables:
+      - \par FOAM_SIGFPE (true|false)
+        overrides \c trapFpe
+      - \par FOAM_SETNAN  (true|false)
+        overrides \c setNaN
+
+    Note that trapping can be set/removed through the static member functions
+    or through the scope of the object (constructor sets trapping; destructor
+    restores original). The class behaves as a singleton.
 
 SourceFiles
     sigFpe.C
@@ -73,12 +80,20 @@ class sigFpe
 {
     // Private data
 
+        //- Flag that floating point trapping should be used.
+        //  Can override with FOAM_SIGFPE env variable
+        static bool switchFpe_;
+
+        //- Flag that NaN initialisation should be used.
+        //  Can override with FOAM_SETNAN env variable
+        static bool switchNan_;
+
+        //- Flag to indicate floating point trapping is currently active
+        static bool sigActive_;
+
         //- Saved old signal trapping setting
         static struct sigaction oldAction_;
 
-        //- Flag to indicate floating point trapping is enabled
-        static bool sigFpeActive_;
-
 
     // Static data members
 
@@ -90,6 +105,11 @@ class sigFpe
 
 public:
 
+    // Public data
+
+        //- Flag to indicate mallocNan is enabled
+        static bool mallocNanActive_;
+
 
     // Constructors
 
@@ -103,6 +123,11 @@ public:
 
     // Member functions
 
+        //- Check if SIGFPE signals handler is to be enabled.
+        //  This is controlled by the trapFpe entry or the FOAM_SIGFPE
+        //  environment variable
+        static bool requested();
+
         //- Activate SIGFPE signal handler when FOAM_SIGFPE is %set
         //  Fill memory with NaN when FOAM_SETNAN is %set
         static void set(const bool verbose);
@@ -110,16 +135,13 @@ public:
         //- Deactivate SIGFPE signal handler and NaN memory initialisation
         static void unset(const bool verbose);
 
-        //- Flag to indicate mallocNan is enabled
-        static bool mallocNanActive_;
-
         #ifdef LINUX
         //- Malloc function which initializes to NaN
         static void* mallocNan(size_t size);
         #endif
 
         //- Fill block of data with NaN
-        static void fillNan(UList<scalar>&);
+        static void fillNan(UList<scalar>& lst);
 };
 
 

src/OSspecific/POSIX/signals/sigQuit.C

@@ -86,7 +86,7 @@ void Foam::sigQuit::set(const bool verbose)
         if (sigaction(SIGQUIT, &newAction, &oldAction_) < 0)
         {
             FatalErrorInFunction
-                << "Cannot call sigQuit::set() more than once"
+                << "Cannot call more than once"
                 << abort(FatalError);
         }
         sigActive_ = true;
@@ -101,7 +101,7 @@ void Foam::sigQuit::unset(const bool)
         if (sigaction(SIGQUIT, &oldAction_, nullptr) < 0)
         {
             FatalErrorInFunction
-            << "Cannot set SIGQUIT trapping"
+                << "Cannot unset SIGQUIT trapping"
                 << abort(FatalError);
         }
         sigActive_ = false;

src/OSspecific/POSIX/signals/sigSegv.C

@@ -86,7 +86,7 @@ void Foam::sigSegv::set(const bool)
         if (sigaction(SIGSEGV, &newAction, &oldAction_) < 0)
         {
             FatalErrorInFunction
-                << "Cannot call sigSegv::set() more than once"
+                << "Cannot call more than once"
                 << abort(FatalError);
         }
         sigActive_ = true;
@@ -101,7 +101,7 @@ void Foam::sigSegv::unset(const bool)
         if (sigaction(SIGSEGV, &oldAction_, nullptr) < 0)
         {
             FatalErrorInFunction
-                << "Cannot set SIGSEGV trapping"
+                << "Cannot unset SIGSEGV trapping"
                 << abort(FatalError);
         }
         sigActive_ = false;

src/OSspecific/POSIX/signals/sigStopAtWriteNow.C

@@ -78,7 +78,6 @@ addstopAtWriteNowSignalToOpt addstopAtWriteNowSignalToOpt_
 
 Foam::Time const* Foam::sigStopAtWriteNow::runTimePtr_ = nullptr;
 
-
 struct sigaction Foam::sigStopAtWriteNow::oldAction_;
 
 
@@ -109,7 +108,8 @@ void Foam::sigStopAtWriteNow::sigHandler(int)
 
 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
-Foam::sigStopAtWriteNow::sigStopAtWriteNow(){}
+Foam::sigStopAtWriteNow::sigStopAtWriteNow()
+{}
 
 
 Foam::sigStopAtWriteNow::sigStopAtWriteNow

src/OSspecific/POSIX/signals/sigStopAtWriteNow.H

@@ -67,6 +67,7 @@ class sigStopAtWriteNow
 
     // Private Member Functions
 
+        //- Handler for caught signals
         static void sigHandler(int);
 
 

src/OSspecific/POSIX/signals/sigWriteNow.C

@@ -33,13 +33,13 @@ License
 
 namespace Foam
 {
-
 // Signal number to catch
 int sigWriteNow::signal_
 (
     debug::optimisationSwitch("writeNowSignal", -1)
 );
 
+
 // Register re-reader
 class addwriteNowSignalToOpt
 :
@@ -75,7 +75,6 @@ addwriteNowSignalToOpt addwriteNowSignalToOpt_("writeNowSignal");
 
 Foam::Time* Foam::sigWriteNow::runTimePtr_ = nullptr;
 
-
 struct sigaction Foam::sigWriteNow::oldAction_;
 
 

src/OSspecific/POSIX/signals/sigWriteNow.H

@@ -66,6 +66,7 @@ class sigWriteNow
 
     // Private Member Functions
 
+        //- Handler for caught signals
         static void sigHandler(int);
 
 

tutorials/multiphase/interDyMFoam/RAS/motorBike/Allrun

@@ -8,8 +8,8 @@ cd ${0%/*} || exit 1    # Run from this directory
 
 runParallel $(getApplication)
 
-unset FOAM_SIGFPE
+# Disable trapping of floating-point exceptions
-runParallel -s reconstruct redistributePar -reconstruct
+FOAM_SIGFPE=false runParallel -s reconstruct redistributePar -reconstruct
 
 # A bit more testing of decomposing
 \cp system/controlDict_nextWrite system/controlDict