Package org.zeromq

Class ZContext

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public class ZContext
extends java.lang.Object
implements java.io.Closeable
    ZContext provides a high-level ZeroMQ context management class It manages open sockets in the context and automatically closes these before terminating the context. It provides a simple way to set the linger timeout on sockets, and configure contexts for number of I/O threads. Sets-up signal (interrupt) handling for the process.

    • Field Detail

      • context

        private final ZMQ.Context context
        Reference to underlying Context object

      • sockets

        private final java.util.Set<ZMQ.Socket> sockets
        List of sockets managed by this ZContext

      • selectors

        private final java.util.Set<java.nio.channels.Selector> selectors
        List of selectors managed by this ZContext

      • shadows

        private final java.util.Set<ZContext> shadows
        List of ZContext in the shadows

      • ioThreads

        private final int ioThreads
        Number of io threads allocated to this context, default 1

      • main

        private final boolean main
        Indicates if context object is owned by main thread (useful for multi-threaded applications)

      • linger

        private volatile int linger
        Linger timeout, default 0

      • pipehwm

        private int pipehwm
        Send/receive HWM for pipes

      • sndhwm

        private volatile int sndhwm
        ZMQ_SNDHWM for normal sockets

      • rcvhwm

        private volatile int rcvhwm
        ZMQ_RCVHWM for normal sockets

    • Constructor Detail

      • ZContext

        public ZContext()
        Class Constructor

      • ZContext

        public ZContext​(int ioThreads)

      • ZContext

        private ZContext​(ZContext parent,
                 int ioThreads)

    • Method Detail

      • destroy

        public void destroy()
        Destructor. Call this to gracefully terminate context and close any managed 0MQ sockets

      • createSocket

        public ZMQ.Socket createSocket​(SocketType type)
        Creates a new managed socket within this ZContext instance. Use this to get automatic management of the socket at shutdown.

        The newly created socket will inherited it's linger value from the one defined for this context.

        Parameters:
        type - socket type
        Returns:
        Newly created Socket object

      • createSocket

        @Deprecated
public ZMQ.Socket createSocket​(int type)
        Deprecated.
        use createSocket(SocketType)
        Parameters:
        type - socket type (see ZMQ static class members)
        Returns:
        Newly created Socket object

      • destroySocket

        @Deprecated
public void destroySocket​(ZMQ.Socket s)
        Deprecated.
        Not to be used any more. ZMQ.Socket handle the close itself. It also override linger settings.
        Destroys a managed socket within this context and remove from sockets list. This method should be used only for fast or emergency close as is set linger instead of using the socket current value.
        Parameters:
        s - ZMQ.Socket object to destroy

      • closeSocket

        void closeSocket​(ZMQ.Socket s)
        Close managed socket within this context and remove from sockets list. There is no need to call this method as any ZMQ.Socket created by this context will call it on termination.
        Parameters:
        s - ZMQ.Socket object to destroy

      • createSelector

        @Deprecated
public java.nio.channels.Selector createSelector()
        Deprecated.
        this was exposed by mistake.
        Creates a selector. It needs to be closed by closeSelector(Selector).
        Returns:
        a newly created selector.

      • selector

        java.nio.channels.Selector selector()
        Creates a selector. Resource will be released when context will be closed.
        Returns:
        a newly created selector.

      • closeSelector

        @Deprecated
public void closeSelector​(java.nio.channels.Selector selector)
        Deprecated.
        createSelector() was exposed by mistake. while waiting for the API to disappear, this method is provided to allow releasing resources.
        Closes a selector. This is a DRAFT method, and may change without notice.
        Parameters:
        selector - the selector to close. It needs to have been created by createSelector().

      • createPoller

        public ZMQ.Poller createPoller​(int size)

      • shadow

        @Deprecated
public static ZContext shadow​(ZContext ctx)
        Deprecated.
        use the instance method directly
        Creates new shadow context. Shares same underlying org.zeromq.Context instance but has own list of managed sockets, io thread count etc.
        Parameters:
        ctx - Original ZContext to create shadow of
        Returns:
        New ZContext

      • shadow

        public ZContext shadow()
        Creates new shadow context. Shares same underlying org.zeromq.Context instance but has own list of managed sockets, io thread count etc.
        Returns:
        New ZContext

      • fork

        public ZMQ.Socket fork​(ZThread.IAttachedRunnable runnable,
                       java.lang.Object... args)
        Create an attached thread, An attached thread gets a ctx and a PAIR pipe back to its parent. It must monitor its pipe, and exit if the pipe becomes unreadable
        Parameters:
        runnable - attached thread
        args - forked runnable args
        Returns:
        pipe or null if there was an error

      • getIoThreads

        public int getIoThreads()
        Returns:
        the ioThreads

      • setIoThreads

        @Deprecated
public void setIoThreads​(int ioThreads)
        Deprecated.
        This value should not be changed after the context is initialized.
        A deprecated function that does nothing.
        Parameters:
        ioThreads - the number of ioThreads to set

      • getLinger

        public int getLinger()
        Returns:
        the default linger for sockets.

      • setLinger

        public void setLinger​(int linger)
        Parameters:
        linger - the linger that will inherited by created socket.

      • setRcvHWM

        public void setRcvHWM​(int rcvhwm)
        Set initial receive HWM for all new normal sockets created in context. You can set this per-socket after the socket is created. The default, no matter the underlying ZeroMQ version, is 1,000.
        Parameters:
        rcvhwm - the rcvhwm

      • setSndHWM

        public void setSndHWM​(int sndhwm)
        Set initial receive HWM for all new normal sockets created in context. You can set this per-socket after the socket is created. The default, no matter the underlying ZeroMQ version, is 1,000.
        Parameters:
        sndhwm - the sndhwm

      • setUncaughtExceptionHandler

        public void setUncaughtExceptionHandler​(java.lang.Thread.UncaughtExceptionHandler handler)
        Set the handler invoked when a Poller abruptly terminates due to an uncaught exception.

        It default to the value of Thread.getDefaultUncaughtExceptionHandler()

        Parameters:
        handler - The object to use as this thread's uncaught exception handler. If null then this thread has no explicit handler.

      • getUncaughtExceptionHandler

        public java.lang.Thread.UncaughtExceptionHandler getUncaughtExceptionHandler()
        Returns:
        The handler invoked when a Poller abruptly terminates due to an uncaught exception.

      • setNotificationExceptionHandler

        public void setNotificationExceptionHandler​(java.lang.Thread.UncaughtExceptionHandler handler)
        In Poller.run(), some non-fatal exceptions can be thrown. This handler will be notified, so they can be logged.

        Default to Throwable.printStackTrace()

        Parameters:
        handler - The object to use as this thread's handler for recoverable exceptions notifications.

      • getNotificationExceptionHandler

        public java.lang.Thread.UncaughtExceptionHandler getNotificationExceptionHandler()
        Returns:
        The handler invoked when a non-fatal exceptions is thrown in zmq.poll.Poller#run()

      • isMain

        public boolean isMain()
        Returns:
        the main

      • isEmpty

        public boolean isEmpty()
        Returns:
        true if no shadow context, no sockets and no selectors are alive.

      • setMain

        @Deprecated
public void setMain​(boolean main)
        Deprecated.
        This value should not be changed after the context is initialized.
        Parameters:
        main - whether or not the context is being set to main

      • getContext

        public ZMQ.Context getContext()
        Returns:
        the context

      • setContext

        @Deprecated
public void setContext​(ZMQ.Context ctx)
        Deprecated.
        This value should not be changed after the ZContext is initialized.
        Parameters:
        ctx - sets the underlying zmq.Context associated with this ZContext wrapper object

      • getSockets

        public java.util.List<ZMQ.Socket> getSockets()
        Return a copy of the list of currently open sockets. Order is not meaningful.
        Returns:
        the sockets

      • close

        public void close()
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable

      • isClosed

        public boolean isClosed()