v3.0.12a Removed custom signal handling.

CHANGELOG.md

@@ -1,6 +1,11 @@
 Changelog
 =========
 
+__3.0.12a__
+----------
+
+* Removed signal handling.
+
 __3.0.11a__
 ----------
 

README.md

@@ -252,36 +252,14 @@ Implementation
 The library is implemented with a QSharedMemory block which is thread safe and
 guarantees a race condition will not occur. It also uses a QLocalSocket to
 notify the main process that a new instance had been spawned and thus invoke the
-`instanceStarted()` signal.
+`instanceStarted()` signal and for messaging the primary instance.
 
-To handle an issue on `*nix` systems, where the operating system owns the shared
-memory block and if the program crashes the memory remains untouched, the
-library binds to the following signals and closes the program with
-`error code = 128 + signum` where signum is the number representation of the
-signal listed below. Handling the signal is required in order to safely delete
-the `QSharedMemory` block. Each of these signals are potentially lethal and will
-results in process termination.
-
-*   `SIGHUP` - `1`, Hangup.
-*   `SIGINT` - `2`, Terminal interrupt signal
-*   `SIGQUIT` - `3`, Terminal quit signal.
-*   `SIGILL` - `4`, Illegal instruction.
-*   `SIGABRT` - `6`, Process abort signal.
-*   `SIGBUS` - `7`, Access to an undefined portion of a memory object.
-*   `SIGFPE` - `8`, Erroneous arithmetic operation (such as division by zero).
-*   `SIGSEGV` - `11`, Invalid memory reference.
-*   `SIGSYS` - `12`, Bad system call.
-*   `SIGPIPE` - `13`, Write on a pipe with no one to read it.
-*   `SIGALRM` - `14`, Alarm clock.
-*   `SIGTERM` - `15`, Termination signal.
-*   `SIGXCPU` - `24`, CPU time limit exceeded.
-*   `SIGXFSZ` - `25`, File size limit exceeded.
-
-Additionally the library can recover from being killed with uncatchable signals
-and will reset the memory block given that there are no other instances running.
+Additionally the library can recover from being forcefully killed on *nix
+systems and will reset the memory block given that there are no other
+instances running.
 
 License
 -------
 This library and it's supporting documentation are released under
-`The MIT License (MIT)` with the exception of some of the examples distributed
-under the BSD license.
+`The MIT License (MIT)` with the exception of the Qt calculator examples which
+is distributed under the BSD license.

singleapplication_p.cpp

@@ -45,11 +45,6 @@
 #include "singleapplication.h"
 #include "singleapplication_p.h"
 
-#ifdef Q_OS_UNIX
-    #include <signal.h>
-    #include <unistd.h>
-#endif
-
 #ifdef Q_OS_WIN
     #include <windows.h>
     #include <lmcons.h>
@@ -150,11 +145,6 @@ void SingleApplicationPrivate::startPrimary()
 {
     Q_Q(SingleApplication);
 
-#ifdef Q_OS_UNIX
-    // Handle any further termination signals to ensure the
-    // QSharedMemory block is deleted even if the process crashes
-    crashHandler();
-#endif
     // Successful creation means that no main process exists
     // So we start a QLocalServer to listen for connections
     QLocalServer::removeServer( blockServerName );
@@ -188,11 +178,6 @@ void SingleApplicationPrivate::startPrimary()
 
 void SingleApplicationPrivate::startSecondary()
 {
-#ifdef Q_OS_UNIX
-    // Handle any further termination signals to ensure the
-    // QSharedMemory block is deleted even if the process crashes
-    crashHandler();
-#endif
 }
 
 void SingleApplicationPrivate::connectToPrimary( int msecs, ConnectionType connectionType )
@@ -263,34 +248,6 @@ qint64 SingleApplicationPrivate::primaryPid()
     return pid;
 }
 
-#ifdef Q_OS_UNIX
-    void SingleApplicationPrivate::crashHandler()
-    {
-        // Handle any further termination signals to ensure the
-        // QSharedMemory block is deleted even if the process crashes
-        signal( SIGHUP,  SingleApplicationPrivate::terminate ); // 1
-        signal( SIGINT,  SingleApplicationPrivate::terminate ); // 2
-        signal( SIGQUIT, SingleApplicationPrivate::terminate ); // 3
-        signal( SIGILL,  SingleApplicationPrivate::terminate ); // 4
-        signal( SIGABRT, SingleApplicationPrivate::terminate ); // 6
-        signal( SIGFPE,  SingleApplicationPrivate::terminate ); // 8
-        signal( SIGBUS,  SingleApplicationPrivate::terminate ); // 10
-        signal( SIGSEGV, SingleApplicationPrivate::terminate ); // 11
-        signal( SIGSYS,  SingleApplicationPrivate::terminate ); // 12
-        signal( SIGPIPE, SingleApplicationPrivate::terminate ); // 13
-        signal( SIGALRM, SingleApplicationPrivate::terminate ); // 14
-        signal( SIGTERM, SingleApplicationPrivate::terminate ); // 15
-        signal( SIGXCPU, SingleApplicationPrivate::terminate ); // 24
-        signal( SIGXFSZ, SingleApplicationPrivate::terminate ); // 25
-    }
-
-    [[noreturn]] void SingleApplicationPrivate::terminate( int signum )
-    {
-        delete (static_cast <SingleApplication*>( QCoreApplication::instance() ))->d_ptr;
-        ::exit( 128 + signum );
-    }
-#endif
-
 /**
  * @brief Executed when a connection has been made to the LocalServer
  */

singleapplication_p.h

@@ -66,11 +66,6 @@ public:
     quint16 blockChecksum();
     qint64 primaryPid();
 
-#ifdef Q_OS_UNIX
-    void crashHandler();
-    [[noreturn]] static void terminate( int signum );
-#endif
-
     SingleApplication *q_ptr;
     QSharedMemory *memory;
     QLocalSocket *socket;