diff options
Diffstat (limited to 'src/lib/util/io/signal_set.h')
| -rw-r--r-- | src/lib/util/io/signal_set.h | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/src/lib/util/io/signal_set.h b/src/lib/util/io/signal_set.h deleted file mode 100644 index 5d52559568..0000000000 --- a/src/lib/util/io/signal_set.h +++ /dev/null @@ -1,189 +0,0 @@ -// Copyright (C) 2014 Internet Systems Consortium, Inc. ("ISC") -// -// Permission to use, copy, modify, and/or distribute this software for any -// purpose with or without fee is hereby granted, provided that the above -// copyright notice and this permission notice appear in all copies. -// -// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH -// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY -// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, -// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM -// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE -// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR -// PERFORMANCE OF THIS SOFTWARE. - -#ifndef SIGNAL_SET_H -#define SIGNAL_SET_H - -#include <exceptions/exceptions.h> -#include <boost/function.hpp> -#include <boost/noncopyable.hpp> -#include <boost/shared_ptr.hpp> -#include <set> -#include <signal.h> - -namespace isc { -namespace util { -namespace io { - -/// @brief Exception thrown when the @c isc::util::io::SignalSet class -/// experiences an error. -class SignalSetError : public Exception { -public: - SignalSetError(const char* file, size_t line, const char* what) : - isc::Exception(file, line, what) { }; -}; - -/// @brief Forward declaration to the @c isc::util::io::SignalSet. -class SignalSet; -/// @brief Pointer to the @c isc::util::io::SignalSet. -typedef boost::shared_ptr<SignalSet> SignalSetPtr; -/// @brief Pointer to the signal handling function. -typedef boost::function<void(int signum)> SignalHandler; - -/// @brief Represents a collection of signals handled in a customized way. -/// -/// Kea processes must handle selected signals in a specialized way. For -/// example: SIGINT and SIGTERM must perform a graceful shut down of the -/// server. The SIGHUP signal is used to trigger server's reconfiguration. -/// -/// This class allows specifying signals which should be handled in a -/// specialized way as well as specifying a signal handler function. -/// When a signal is received the signal handler function is called and -/// the code of the received signal is recorded. This function doesn't -/// do anything beyond recording the signal number to minimize the time -/// spent on handling the signal and process interruption. The process -/// can later check the signals received and call the handlers on its -/// descretion by calling a @c isc::util::io::SignalSet::handleNext function. -/// -/// @note This class is not thread safe. It uses static variables and -/// functions to track a global state of signal registration and received -/// signals' queue. -class SignalSet : public boost::noncopyable { -public: - - /// @brief Constructor installing one signal. - /// - /// @param sig0 First signal. - /// @throw SignalSetError If attempting to add duplicated signal or - /// the signal is invalid. - SignalSet(const int sig0); - - /// @brief Constructor installing two signals. - /// - /// @param sig0 First signal. - /// @param sig1 Second signal. - /// @throw SignalSetError If attempting to add duplicated signal or - /// the signal is invalid. - SignalSet(const int sig0, const int sig1); - - /// @brief Constructor installing three signals. - /// - /// @param sig0 First signal. - /// @param sig1 Second signal. - /// @param sig2 Third signal. - /// @throw SignalSetError If attempting to add duplicated signal or - /// the signal is invalid. - SignalSet(const int sig0, const int sig1, const int sig2); - - /// @brief Destructor. - /// - /// Removes installed handlers. - ~SignalSet(); - - /// @brief Installs the handler for the specified signal. - /// - /// This function adds a signal to the set. When the signal is received - /// by the process, it will be recorded and a signal can be later handled - /// by the process. - /// - /// @param sig Signal code. - /// @throw SignalSetError if signal being added duplicates an existing - /// signal. - void add(const int sig); - - /// @brief Uninstalls all signals. - /// - /// This function calls @c isc::util::io::SignalSet::remove for each - /// installed signal. - void clear(); - - /// @brief Returns a code of the next received signal. - /// - /// @return A code of the next received signal or -1 if there are no - /// more signals received. - int getNext() const; - - /// @brief Calls a handler for the next received signal. - /// - /// This function handles the next received signal and removes it from the - /// queue of received signals. While the function is executed, all custom - /// signal handlers are blocked to prevent race condition. - /// - /// @param signal_handler A pointer to the signal handler function to - /// be used to handle the signal. - void handleNext(SignalHandler signal_handler); - - /// @brief Uninstalls signal handler for a specified signal. - /// - /// @param sig A code of the signal to be removed. - void remove(const int sig); - -private: - - /// @brief Blocks signals in the set. - /// - /// This function blocks the signals in a set to prevent race condition - /// between the signal handler and the new signal coming in. - void block() const { - maskSignals(SIG_BLOCK); - } - - /// @brief Removes the signal from the set. - /// - /// This function removes only a signal which is owned by this signal set. - /// - /// @param sig Signal to be removed. - /// @throw SignalSetError if the signal being removed is not owned by this - /// signal set. - void erase(const int sig); - - /// @brief Insert a signal to the set. - /// - /// @param sig Signal to be inserted. - /// @throw SignalSetError if a signal being inserted has already been - /// registered in this or other signal set. - void insert(const int sig); - - /// @brief Applies a mask to all signals in the set. - /// - /// This function is used by @c SignalSet::block and @c SignalSet::unblock - /// to apply the SIG_BLOCK and SIG_UNBLOCK mask to signals. - /// - /// @param mask A mask to be applied to all signals. - void maskSignals(const int mask) const; - - /// @brief Pops a next signal number from the static collection of signals. - /// - /// The static collection of signals is updated by the internal signal - /// handler being invoked when one of the installed signals is received by - /// the process. This function removes the first element of the collection. - void popNext(); - - /// @brief Unblocks signals in the set. - /// - /// This function unblocks the signals in a set. - void unblock() const { - maskSignals(SIG_UNBLOCK); - } - - /// @brief Stores the set of signals registered in this signal set. - std::set<int> local_signals_; -}; - -} -} -} - -#endif // SIGNAL_SET_H - |