submitted 1.2.0

Foundation/include/Poco/SignalHandler.h

@@ -0,0 +1,144 @@
+//
+// SignalHandler.h
+//
+// $Id: //poco/1.2/Foundation/include/Poco/SignalHandler.h#1 $
+//
+// Library: Foundation
+// Package: Threading
+// Module:  SignalHandler
+//
+// Definition of the SignalHandler class.
+//
+// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
+// and Contributors.
+//
+// Permission is hereby granted, free of charge, to any person or organization
+// obtaining a copy of the software and accompanying documentation covered by
+// this license (the "Software") to use, reproduce, display, distribute,
+// execute, and transmit the Software, and to prepare derivative works of the
+// Software, and to permit third-parties to whom the Software is furnished to
+// do so, all subject to the following:
+// 
+// The copyright notices in the Software and this entire statement, including
+// the above license grant, this restriction and the following disclaimer,
+// must be included in all copies of the Software, in whole or in part, and
+// all derivative works of the Software, unless such copies or derivative
+// works are solely in the form of machine-executable object code generated by
+// a source language processor.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+//
+
+
+#ifndef Foundation_SignalHandler_INCLUDED
+#define Foundation_SignalHandler_INCLUDED
+
+
+#include "Poco/Foundation.h"
+
+
+#if defined(POCO_OS_FAMILY_UNIX)
+
+
+#include <vector>
+#include <setjmp.h>
+
+
+namespace Poco {
+
+
+class Foundation_API SignalHandler
+	/// This helper class simplifies the handling of POSIX signals.
+	///
+	/// The class provides a signal handler (installed with
+	/// installHandlers()) that translates certain POSIX
+	/// signals (SIGILL, SIGBUS, SIGSEGV, SIGSYS) into 
+	/// C++ exceptions.
+	///
+	/// Internally, a stack of sigjmp_buf structs is maintained for
+	/// each thread. The constructor pushes a new sigjmp_buf onto
+	/// the current thread's stack. The destructor pops the sigjmp_buf
+	/// from the stack.
+	///
+	/// The poco_throw_on_signal macro creates an instance of SignalHandler
+	/// on the stack, which results in a new sigjmp_buf being created.
+	/// The sigjmp_buf is then set-up with sigsetjmp().
+	///
+	/// The handleSignal() method, which is invoked when a signal arrives,
+	/// checks if a sigjmp_buf is available for the current thread.
+	/// If so, siglongjmp() is used to jump out of the signal handler.
+	///
+	/// Typical usage is as follows:
+	///
+	///     try
+	///     {
+	///          poco_throw_on_signal;
+	///          ...
+	///     }
+	///     catch (Poco::SignalException&)
+	///     {
+	///         ...
+	///     }
+	///
+	/// The best way to deal with a SignalException is to log as much context
+	/// information as possible, to aid in debugging, and then to exit.
+{
+public:
+	SignalHandler();
+		/// Creates the SignalHandler.
+
+	~SignalHandler();
+		/// Destroys the SignalHandler.
+
+	sigjmp_buf& jumpBuffer();
+		/// Returns the top-most sigjmp_buf for the current thread.
+
+	static void throwSignalException(int sig);
+		/// Throws a SignalException with a textual description  
+		/// of the given signal as argument. 
+	
+	static void install();
+		/// Installs signal handlers for SIGILL, SIGBUS, SIGSEGV
+		/// and SIGSYS.
+
+protected:
+	static void handleSignal(int sig);
+		/// The actual signal handler.
+
+	struct JumpBuffer
+		/// sigjmp_buf cannot be used to instantiate a std::vector,
+		/// so we provide a wrapper struct.
+	{
+		sigjmp_buf buf;
+	};
+	typedef std::vector<JumpBuffer> JumpBufferVec;
+
+	static JumpBufferVec& jumpBufferVec();
+		/// Returns the JumpBufferVec for the current thread.
+
+private:
+	static JumpBufferVec _jumpBufferVec;
+	
+	friend class ThreadImpl;
+};
+
+
+#define poco_throw_on_signal \
+	Poco::SignalHandler _poco_signalHandler; \
+	int _poco_signal = sigsetjmp(_poco_signalHandler.jumpBuffer(), 1); \
+	if (_poco_signal) _poco_signalHandler.throwSignalException(_poco_signal);
+
+
+} // namespace Poco
+
+
+#endif // POCO_OS_FAMILY_UNIX
+
+
+#endif // Foundation_SignalHandler_INCLUDED