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Api for polling external sockets

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This commit is contained in:
Bert Belder 2012-04-25 00:15:59 +02:00
parent e38755485e
commit e1154d70ce
1 changed files with 72 additions and 0 deletions
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72
include/uv.h
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@ -164,6 +164,7 @@ typedef enum {
#define XX(uc, lc) UV_##uc,
UV_HANDLE_TYPE_MAP(XX)
#undef XX
UV_POLL,
UV_FILE,
UV_HANDLE_TYPE_PRIVATE
UV_HANDLE_TYPE_MAX
@ -189,6 +190,7 @@ typedef struct uv_tcp_s uv_tcp_t;
typedef struct uv_udp_s uv_udp_t;
typedef struct uv_pipe_s uv_pipe_t;
typedef struct uv_tty_s uv_tty_t;
typedef struct uv_poll_s uv_poll_t;
typedef struct uv_timer_s uv_timer_t;
typedef struct uv_prepare_s uv_prepare_t;
typedef struct uv_check_s uv_check_t;
@ -288,6 +290,7 @@ typedef void (*uv_connect_cb)(uv_connect_t* req, int status);
typedef void (*uv_shutdown_cb)(uv_shutdown_t* req, int status);
typedef void (*uv_connection_cb)(uv_stream_t* server, int status);
typedef void (*uv_close_cb)(uv_handle_t* handle);
typedef void (*uv_poll_cb)(uv_poll_t* handle, int status, int events);
typedef void (*uv_timer_cb)(uv_timer_t* handle, int status);
/* TODO: do these really need a status argument? */
typedef void (*uv_async_cb)(uv_async_t* handle, int status);
@ -926,6 +929,74 @@ UV_EXTERN void uv_pipe_connect(uv_connect_t* req, uv_pipe_t* handle,
UV_EXTERN void uv_pipe_pending_instances(uv_pipe_t* handle, int count);
/*
* uv_poll_t is a subclass of uv_handle_t.
*
* The uv_poll watcher is used to watch file descriptors for readability and
* writability, similar to the purpose of poll(2).
*
* The purpose of uv_poll is to enable integrating external libraries that
* rely on the event loop to signal it about the socket status changes, like
* c-ares or libssh2. Using uv_poll_t for any other other purpose is not
* recommended; uv_tcp_t, uv_udp_t, etc. provide an implementation that is
* much faster and more scalable than what can be achieved with uv_poll_t,
* especially on Windows.
*
* It is possible that uv_poll occasionally signals that a file descriptor is
* readable or writable even when it isn't. The user should therefore always
* be prepared to handle EAGAIN or equivalent when it attempts to read from or
* write to the fd.
*
* It is not okay to have multiple active uv_poll watchers for the same socket.
* This can cause libuv to busyloop or otherwise malfunction.
*
* The user should not close a file descriptor while it is being polled by an
* active uv_poll watcher. This can cause the poll watcher to report an error,
* but it might also start polling another socket. However the fd can be safely
* closed immediately after a call to uv_poll_stop() or uv_close().
*
* On windows only sockets can be polled with uv_poll. On unix any file
* descriptor that would be accepted by poll(2) can be used with uv_poll.
*/
struct uv_poll_s {
UV_HANDLE_FIELDS
uv_poll_cb poll_cb;
UV_POLL_PRIVATE_FIELDS
};
enum uv_poll_event {
UV_READABLE = 1,
UV_WRITABLE = 2
};
/* Initialize the poll watcher using a file descriptor. */
UV_EXTERN int uv_poll_init(uv_loop_t* loop, uv_poll_t* handle, int fd);
/* Initialize the poll watcher using a socket descriptor. On unix this is */
/* identical to uv_poll_init. On windows it takes a SOCKET handle. */
UV_EXTERN int uv_poll_init_socket(uv_loop_t* loop, uv_poll_t* handle,
uv_platform_socket_t socket);
/*
* Starts polling the file descriptor. `events` is a bitmask consisting made up
* of UV_READABLE and UV_WRITABLE. As soon as an event is detected the callback
* will be called with `status` set to 0, and the detected events set en the
* `events` field.
*
* If an error happens while polling status may be set to -1 and the error
* code can be retrieved with uv_last_error. The user should not close the
* socket while uv_poll is active. If the user does that anyway, the callback
* *may* be called reporting an error status, but this is not guaranteed.
*
* Calling uv_poll_start on an uv_poll watcher that is already active is fine.
* Doing so will update the events mask that is being watched for.
*/
UV_EXTERN int uv_poll_start(uv_poll_t* handle, int events, uv_poll_cb cb);
/* Stops polling the file descriptor. */
UV_EXTERN int uv_poll_stop(uv_poll_t* handle);
/*
* uv_prepare_t is a subclass of uv_handle_t.
*
@ -1543,6 +1614,7 @@ struct uv_counters_s {
uint64_t udp_init;
uint64_t pipe_init;
uint64_t tty_init;
uint64_t poll_init;
uint64_t prepare_init;
uint64_t check_init;
uint64_t idle_init;