Files
libucore/include/ucore/iomux_waker.h
T
2014-09-12 01:11:41 +02:00

84 lines
2.3 KiB
C

#ifndef UC_IOMUX_WAKE_H_
#define UC_IOMUX_WAKE_H_
#include <pthread.h>
#include "iomux.h"
#ifdef __cplusplus
extern "C" {
#endif
struct IOMuxWaker;
typedef void (*uc_waker_cb)(struct IOMuxWaker *wk);
/** Usef for signalling an IOMux */
struct IOMuxSignaller {
int fd;
};
/** @file
* These are primitives to wake up an IOMux.
* An IOMux event loop can be woken up from e.g. an unix signal handler
* or another thread. The IOMuxWaker itself is not thread safe, it's members
* except for the signaller must not be accessed from anything other than the
* IOMux it's connected to.
* Only uc_iomux_waker_signal() can be called from another thread/signal handler
* than the IOMux it's connected to.
*
* Note that several signals to wake up a loop can get merged, the callback
* handler can be called only once for several signals.
*/
struct IOMuxWaker {
//private fields
struct IOMuxFD read_fd;
uc_waker_cb wake_cb;
//public fields
struct IOMuxSignaller signaller;
struct IOMux *mux;
void *cookie;
};
/** Initialize an IOMuxWaker.
* Must be called from the thread running the IOMux.
*
* @mux the IOMux to be woken up.
* @wk the waker to initialize
* @cb callback to invoke in the mux when signalled
* @return 0 on success, errno value if initializing fails
*/
int uc_iomux_waker_init(struct IOMux *mux, struct IOMuxWaker *wk, uc_waker_cb cb);
/** Destroy an IOMuxWaker.
* Must previously been successfully initialized.
* Must be called from the thread running the IOMux.
* Care must be taken so the IOMuxWaker is destroyed
* without race conditions with a thread that wants to _signal the
* waker.
* The embedded IOMuxSignaller of the IOMuxWaker can be used
* by someone else in the uc_iomux_waker_signal() function
*
* @param wk
* @return 0 on success, errno on failure (Things are seriously
* wrong if this fails)
*/
int uc_iomux_waker_destroy(struct IOMuxWaker *wk);
/** Signal an IOMux to wake up and run its callback handler.
* Is async signal safe.
* Several signals in a short time may result in the callback
* being run only once.
*
* @param wk
* @return 0 on success, errno on failure (Things are seriously
* wrong if this fails)
*/
int uc_iomux_waker_signal(struct IOMuxSignaller *signaller);
#ifdef __cplusplus
}
#endif
#endif