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LISTEN registers the current session as a listener on the notification channel named channel. If the current session is already registered as a listener for this notification channel, nothing is done.


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Whenever the command NOTIFY channel is invoked, either by this session or another one connected to the same database, all the sessions currently listening on that notification channel are notified, and each will in turn notify its connected client application.

There is a race condition when first setting up a listening session: if concurrently-committing transactions are sending notify events, exactly which of those will the newly listening session receive? The answer is that the session will receive all events committed after an instant during the transaction's commit step. But that is slightly later than any database state that the transaction could have observed in queries. This leads to the following rule for using LISTEN: first execute (and commit!) that command, then in a new transaction inspect the database state as needed by the application logic, then rely on notifications to find out about subsequent changes to the database state. The first few received notifications might refer to updates already observed in the initial database inspection, but this is usually harmless.

The listen directivecan have several additional parameters specific to socket-related system calls.These parameters can be specified in anylisten directive, but only once for a givenaddress:port pair.

To accept connections, a socket is first created with thesocket function and bound to a local address with thebind function. A backlog for incoming connections is specified withlisten, and then the connections are accepted with theaccept function. Sockets that are connection oriented, those of type SOCK_STREAM for example, are used withlisten. The socket s is put into passive mode where incoming connection requests are acknowledged and queued pending acceptance by the process.

When calling the listen function in a Bluetooth application, it is strongly recommended that a much lower value be used for the backlog parameter (typically 2 to 4), since only a few client connections are accepted. This reduces the system resources that are allocated for use by the listening socket. This same recommendation applies to other network applications that expect only a few client connections.

Thelisten function is typically used by servers that can have more than one connection request at a time. If a connection request arrives and the queue is full, the client will receive an error with an indication ofWSAECONNREFUSED.

If there are no available socket descriptors,listen attempts to continue to function. If descriptors become available, a later call tolisten oraccept will refill the queue to the current or most recent value specified for the backlog parameter, if possible, and resume listening for incoming connections.

If the listen function is called on an already listening socket, it will return success without changing the value for the backlog parameter. Setting the backlog parameter to 0 in a subsequent call to listen on a listening socket is not considered a proper reset, especially if there are connections on the socket.

In English, listen and hear are two primary verbs relating to audial perception. To hear represents automatic, unconscious, or passive perception of sound, while listen generally represents intentional, conscious, or purposeful use of the sense of hearing. The difference is expressed in the following quotation:

The program includes a survey of the 1,000,000 closest stars to Earth. It scans the center of our galaxy and the entire galactic plane. Beyond the Milky Way, it listens for messages from the 100 closest galaxies to ours.

She also sang "Listen" during the finals on December 21, 2011.[78][79] A writer of Fox News Channel commented that the judges "didn't want to stop listening to Melanie Amaro" while she was singing a "soaring rendition" of the ballad.[80] Simon Cowell said, "I brought this show to America because I believe some of the greatest singers in the world are from this country, and you just proved that. I think you, based on that performance tonight, to me, should be the winner of 'The X Factor,' because you're going to represent this country all over the world."[79] L.A. Reid also commented, "That wasn't a $5 million performance. That was a $50 million performance."[80] Sarah Maloy of Billboard magazine felt that her performance was "as powerfully and passionately [sang] as she did the first time".[78] Lisa de Moraes of The Washington Post praised Amaro's rendition, writing that it contained a "determined look on her face, lots of generous spreading of the arms, and plenty of big notes".[81] Amaro eventually emerged as the winner of The X Factor, performing this song for the final time.[82]

After you subscribe, you can listen to Apple Podcasts Subscriptions in the Apple Podcasts app on your iPhone, iPad, Mac, Apple Watch, and HomePod. If you have Family Sharing set up, you can share your subscription with the members of your family group.

The Listen directive instructs Apache httpd to listen to only specific IP addresses or ports; by default it responds to requests on all IP interfaces. Listen is now a required directive. If it is not in the config file, the server will fail to start. This is a change from previous versions of Apache httpd.

The Listen directive tells the server to accept incoming requests on the specified port or address-and-port combination. If only a port number is specified, the server listens to the given port on all interfaces. If an IP address is given as well as a port, the server will listen on the given port and interface.

The maximum length of the queue of pending connections. Generally no tuning is needed or desired; however on some systems, it is desirable to increase this when under a TCP SYN flood attack. See the backlog parameter to the listen(2) system call.

A ratio between the number of (online) CPU cores and the number of listeners' buckets can be used to make Apache HTTP Server create num_cpu_cores / ratio listening buckets, each containing its own Listen-ing socket(s) on the same port(s), and then make each child handle a single bucket (with round-robin distribution of the buckets at children creation time).

Setting the SO_REUSEPORT option on the listening socket(s) consequently allows multiple processes (sharing the same EUID, e.g. root) to bind to the the same IP address and port, without the binding error raised by the system in the usual case.

The backlog argument provides a hint to the implementation which the implementation shall use to limit the number ofoutstanding connections in the socket's listen queue. Implementations may impose a limit on backlog and silently reduce thespecified value. Normally, a larger backlog argument value shall result in a larger or equal length of the listen queue.Implementations shall support values of backlog up to SOMAXCONN, defined in .

The implementation may have an upper limit on the length of the listen queue-either global or per accepting socket. Ifbacklog exceeds this limit, the length of the listen queue is set to the limit.

In addition to the listener data points described above that radio stations contract us to collect for their own purposes, we may also capture additional User data points in the context of contractual relationship with 3rd parties involved with the delivery of online advertising or analytics, including:

There are many reasons to listen to a document, such as proofreading, multitasking, or increased comprehension and learning. Word makes listening possible by using the text-to-speech (TTS) ability of your device to play back written text as spoken words.

You can listen to a document with the onSnapshot() method. An initialcall using the callback you provide creates a document snapshot immediately withthe current contents of the single document. Then, each timethe contents change, another call updates the document snapshot.

Local writes in your app will invoke snapshot listeners immediately.This is because of an important feature called "latency compensation."When you perform a write, your listeners will be notified with the newdata before the data is sent to the backend.

Retrieved documents have a metadata.hasPendingWrites property that indicateswhether the document has local changes that haven't been written to the backendyet. You can use this property to determine the source of events received byyour snapshot listener:

When you are no longer interested in listening to your data, you must detachyour listener so that your event callbacks stop getting called. This allows theclient to stop using bandwidth to receive updates. For example:

Raise your hand to be a part of an important effort to create a culture of listening! By signing up, you will join our year-round monthly newsletter with resources for educators. It is chock-full of stories, useful tools, and tips for success for participating in the Great Listen.

I have been living with anxiety disorders for many years now and I \nfound that the best release from my internal struggles was to write \nabout it. It felt so great to get down on paper what was going on in my \nhead. I felt like they were my best pieces because they were personal, \ncreative and from the heart. I came up with Listen, Lucy because I wanted \nto create an outlet where people can express themselves, creatively. We \nare all dealing with different issues whether it be depression, anxiety,\n illness or just daily struggles. I wanted to create a community where \npeople could tell their stories in whatever way they feel most \ncomfortable. Writing, art, videos, pictures, poems or any other way of \ntelling your story is happily accepted. (Please send to These issues tend to make people feel isolated, \nalone. I want to change that. Let\u2019s create a community where we all \nunderstand each other and connect when a lot of people don\u2019t have \nsomeone to lean on. You can express it in whatever way you feel, please \njust start your story off with \u201CListen, Lucy.\u201D 041b061a72


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