Refactor signal handling and replace signal handlers with thread-safe functions

core/base/inc/LinkDef2.h

@@ -131,6 +131,7 @@
 #pragma link C++ class TStringToken;
 #pragma link C++ class TSubString;
 #pragma link C++ class TSysEvtHandler;
+#pragma link C++ class TSigHandling+;
 #pragma link C++ class TSystem+;
 #pragma link C++ class TSystemFile+;
 #pragma link C++ class TSystemDirectory+;

core/base/inc/TSigHandling.h

@@ -0,0 +1,93 @@
+// @(#)root/base:$Id$
+// Author: Fons Rademakers   15/09/95
+
+/*************************************************************************
+ * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
+ * All rights reserved.                                                  *
+ *                                                                       *
+ * For the licensing terms see $ROOTSYS/LICENSE.                         *
+ * For the list of contributors see $ROOTSYS/README/CREDITS.             *
+ *************************************************************************/
+
+#ifndef ROOT_TSigHandling
+#define ROOT_TSigHandling
+
+
+//////////////////////////////////////////////////////////////////////////
+//                                                                      //
+// TSigHandling                                                         //
+//                                                                      //
+// Abstract base class defining a generic interface to the underlying   //
+// Operating System.                                                    //
+//                                                                      //
+//////////////////////////////////////////////////////////////////////////
+
+#include <stdio.h>
+#include <ctype.h>
+#include <fcntl.h>
+#ifndef WIN32
+#include <unistd.h>
+#endif
+
+#ifndef ROOT_TNamed
+#include "TNamed.h"
+#endif
+#ifndef ROOT_TString
+#include "TString.h"
+#endif
+#ifndef ROOT_TInetAddress
+#include "TInetAddress.h"
+#endif
+#ifndef ROOT_TTimer
+#include "TTimer.h"
+#endif
+#ifndef ROOT_ThreadLocalStorage
+#include "ThreadLocalStorage.h"
+#endif
+
+class TSeqCollection;
+class TFdSet;
+class TVirtualMutex;
+
+#ifdef __CINT__
+typedef void *Func_t;
+#else
+typedef void ((*Func_t)());
+#endif
+
+R__EXTERN const char  *gRootDir;
+R__EXTERN TVirtualMutex *gSystemMutex;
+
+class TSigHandling : public TNamed {
+
+protected:
+   TFdSet          *fSignals;          //!Signals that were trapped
+   Int_t            fSigcnt;           //Number of pending signals
+   TSeqCollection  *fSignalHandler;    //List of signal handlers
+
+public:
+   TSigHandling(const char *name = "Generic", const char *title = "Generic Signal Handling");
+   virtual ~TSigHandling();
+
+   //---- Misc
+   virtual void            Init();
+   virtual void            StackTrace();
+
+   //---- Handling of system signals
+   virtual Bool_t          HaveTrappedSignal(Bool_t pendingOnly);
+   virtual void            DispatchSignals(ESignals sig); 
+   virtual void            AddSignalHandler(TSignalHandler *sh);
+   virtual TSignalHandler *RemoveSignalHandler(TSignalHandler *sh);
+   virtual void            ResetSignal(ESignals sig, Bool_t reset = kTRUE);
+   virtual void            ResetSignals();
+   virtual void            IgnoreSignal(ESignals sig, Bool_t ignore = kTRUE);
+   virtual void            IgnoreInterrupt(Bool_t ignore = kTRUE);
+   virtual TSeqCollection *GetListOfSignalHandlers();
+   virtual void            SigAlarmInterruptsSyscalls(Bool_t) { }
+
+   ClassDef(TSigHandling,0)
+};
+
+R__EXTERN TSigHandling *gSigHandling;
+
+#endif

core/base/inc/TSystem.h

@@ -268,11 +268,9 @@ class TSystem : public TNamed {
    TFdSet          *fWritemask;        //!Files that should be checked for write events
    TFdSet          *fReadready;        //!Files with reads waiting
    TFdSet          *fWriteready;       //!Files with writes waiting
-   TFdSet          *fSignals;          //!Signals that were trapped
    Int_t            fNfd;              //Number of fd's in masks
    Int_t            fMaxrfd;           //Largest fd in read mask
    Int_t            fMaxwfd;           //Largest fd in write mask
-   Int_t            fSigcnt;           //Number of pending signals
    TString          fWdpath;           //Working directory
    TString          fHostname;         //Hostname
    Bool_t           fInsideNotify;     //Used by DispatchTimers()
@@ -284,7 +282,6 @@ class TSystem : public TNamed {
    Int_t            fLevel;            //Level of nested eventloops
 
    TSeqCollection  *fTimers;           //List of timers
-   TSeqCollection  *fSignalHandler;    //List of signal handlers
    TSeqCollection  *fFileHandler;      //List of file handlers
    TSeqCollection  *fStdExceptionHandler; //List of std::exception handlers
    TSeqCollection  *fOnExitList;       //List of items to be cleaned-up on exit
@@ -368,7 +365,7 @@ class TSystem : public TNamed {
    virtual void            ResetSignals();
    virtual void            IgnoreSignal(ESignals sig, Bool_t ignore = kTRUE);
    virtual void            IgnoreInterrupt(Bool_t ignore = kTRUE);
-   virtual TSeqCollection *GetListOfSignalHandlers() const { return fSignalHandler; }
+   virtual TSeqCollection *GetListOfSignalHandlers();
    virtual void            AddFileHandler(TFileHandler *fh);
    virtual TFileHandler   *RemoveFileHandler(TFileHandler *fh);
    virtual TSeqCollection *GetListOfFileHandlers() const { return fFileHandler; }

core/base/src/TROOT.cxx

@@ -145,6 +145,7 @@ namespace std {} using namespace std;
 #include "TUrl.h"
 #else
 #include "TUnixSystem.h"
+#include "TUnixSigHandling.h"
 #endif
 #elif defined(R__WIN32)
 #include "TWinNTSystem.h"
@@ -1690,6 +1691,7 @@ void TROOT::InitSystem()
       gSystem = new TMacOSXSystem;
 #else
       gSystem = new TUnixSystem;
+      gSigHandling = new TUnixSigHandling;
 #endif
 #elif defined(R__WIN32)
       gSystem = new TWinNTSystem;

core/base/src/TSigHandling.cxx

@@ -0,0 +1,171 @@
+// @(#)root/base:$Id: 8944840ba34631ec28efc779647618db43c0eee5 $
+// Author: Fons Rademakers   15/09/95
+
+/*************************************************************************
+ * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
+ * All rights reserved.                                                  *
+ *                                                                       *
+ * For the licensing terms see $ROOTSYS/LICENSE.                         *
+ * For the list of contributors see $ROOTSYS/README/CREDITS.             *
+ *************************************************************************/
+
+/** \class TSystem
+
+Abstract base class defining a generic interface to the underlying
+Operating System.
+This is not an ABC in the strict sense of the (C++) word. For
+every member function there is an implementation (often not more
+than a call to AbstractMethod() which prints a warning saying
+that the method should be overridden in a derived class), which
+allows a simple partial implementation for new OS'es.
+*/
+
+#ifdef WIN32
+#include <io.h>
+#endif
+#include <stdlib.h>
+#include <errno.h>
+#include <algorithm>
+#include <sys/stat.h>
+
+#include "Riostream.h"
+#include "TSystem.h"
+#include "TSigHandling.h"
+#include "TApplication.h"
+#include "TException.h"
+#include "TROOT.h"
+#include "TClass.h"
+#include "TClassTable.h"
+#include "TEnv.h"
+#include "TBrowser.h"
+#include "TString.h"
+#include "TOrdCollection.h"
+#include "TInterpreter.h"
+#include "TRegexp.h"
+#include "TTimer.h"
+#include "TObjString.h"
+#include "TError.h"
+#include "TPluginManager.h"
+#include "TUrl.h"
+#include "TVirtualMutex.h"
+#include "compiledata.h"
+#include "RConfigure.h"
+
+TSigHandling  *gSigHandling = 0;
+
+ClassImp(TSigHandling)
+
+////////////////////////////////////////////////////////////////////////////////
+/// Create a new OS interface.
+
+TSigHandling::TSigHandling(const char *name, const char *title) : TNamed(name, title)
+{
+   fSignals       = 0;
+   fSigcnt        = 0;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Delete the OS interface.
+
+TSigHandling::~TSigHandling()
+{
+   if (fSignalHandler) {
+      fSignalHandler->Delete();
+      SafeDelete(fSignalHandler);
+   }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Init the OS interface.
+void TSigHandling::Init()
+{
+   fSignalHandler = new TOrdCollection;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Add a signal handler to list of system signal handlers. Only adds
+/// the handler if it is not already in the list of signal handlers.
+
+Bool_t TSigHandling::HaveTrappedSignal(Bool_t)
+{
+   AbstractMethod("HaveTrappedSignal");
+   return kFALSE;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Dispatch signals.
+
+void TSigHandling::DispatchSignals(ESignals /*sig*/)
+{
+   AbstractMethod("DispatchSignals");
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
+/// Add a signal handler to list of system signal handlers. Only adds
+/// the handler if it is not already in the list of signal handlers.
+
+void TSigHandling::AddSignalHandler(TSignalHandler *)
+{
+   AbstractMethod("AddSignalHandler");
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Remove a signal handler from list of signal handlers. Returns
+/// the handler or 0 if the handler was not in the list of signal handlers.
+
+TSignalHandler *TSigHandling::RemoveSignalHandler(TSignalHandler *)
+{
+   AbstractMethod("RemoveSignalHandler");
+   return 0;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// If reset is true reset the signal handler for the specified signal
+/// to the default handler, else restore previous behaviour.
+
+void TSigHandling::ResetSignal(ESignals /*sig*/, Bool_t /*reset*/)
+{
+   AbstractMethod("ResetSignal");
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Reset signals handlers to previous behaviour.
+
+void TSigHandling::ResetSignals()
+{
+   AbstractMethod("ResetSignals");
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// If ignore is true ignore the specified signal, else restore previous
+/// behaviour.
+
+void TSigHandling::IgnoreSignal(ESignals /*sig*/, Bool_t /*ignore*/)
+{
+   AbstractMethod("IgnoreSignal");
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// If ignore is true ignore the interrupt signal, else restore previous
+/// behaviour. Typically call ignore interrupt before writing to disk.
+
+void TSigHandling::IgnoreInterrupt(Bool_t ignore)
+{
+   IgnoreSignal(kSigInterrupt, ignore);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Obtain the current signal handlers
+TSeqCollection *TSigHandling::GetListOfSignalHandlers()
+{
+   return fSignalHandler;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Print a stack trace.
+
+void TSigHandling::StackTrace()
+{
+   AbstractMethod("StackTrace");
+}