Poll Header Pdf For Free

The poll() function provides applications with a mechanism for multiplexing input/output over the following set of file descriptors: regular files. terminal and pseudoterminal devices. STREAMS-based files.

Poll returns a larget set of possible results for file descriptors like POLLRDNORM , POLLRDBAND , POLLIN , POLLHUP , POLLERR , while select just tells you there's input/output/error. poll can perform better than select if you have a sparse set of file descriptors.

If the value timeout is 0, poll() returns immediately. If the value of timeout is ?1, poll() blocks until a requested event occurs or until the call is interrupted.

POLLERR. An error has occurred on the device or stream. This flag is only valid in the revents bitmask; it shall be ignored in the events member. POLLHUP. A device has been disconnected, or a pipe or FIFO has been closed by the last process that had it open for writing.

The poll() method of Queue Interface returns and removes the element at the front end of the container. It deletes the element in the container. The method does not throws an exception when the Queue is empty, it returns null instead.

Now we have defined a poll() system call function. The first parameter of the poll() system call is the ufds structure used in the code. The second parameter specifies the total of pollfd structures in the fds series. And the last parameter is showing the integer type timeout value for the poll system call.

The poll() function provides applications with a mechanism for multiplexing input/output over a set of file descriptors. For each member of the array pointed to by fds, poll() shall examine the given file descriptor for the event(s) specified in events.

The poll() function identifies those file descriptors on which an application can read or write data, or on which an error event has occurred. listptr. A pointer to an array of pollfd structures, pollmsg structures, or to a pollist structure.