(PECL sync >= 1.0.0) Increases the count of the semaphore

(PECL ev >= 0.2.0) Make a single, non-blocking sweep over the embedded loop.

(PHP 4, PHP 5, PHP 7) Execute an external program and display raw output

(PECL eio >= 0.5.0b) Repositions the offset of the open file associated with the fd

(PECL eio >= 0.0.1dev) Opens a file resource

(PHP 5 >= 5.2.0, PHP 7) Calculate the group access list

(PECL eio >= 0.0.1dev) Read value of a symbolic link.

(PHP 5, PHP 7) Waits on or returns the status of a forked child

(PECL ev >= 0.2.0) Establishes the current time by querying the kernel, updating the time returned by Ev::now

(PECL eio >= 0.0.1dev) Can be to be called whenever there are pending requests that need finishing.