Add IOMuxWaker

include/ucore/iomux_waker.h

@@ -0,0 +1,73 @@
+#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);
+
+/** 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
+ * must not be accessed from anything other than the loop 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
+    int fds[2];
+    struct IOMuxFD read_fd;
+    uc_waker_cb wake_cb;
+
+    //public fields
+    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.
+ * 
+ * @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 IOMuxWaker *wk);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+