Initial project import

tools/v/vlib/os/notify/backend_darwin.c.v

@@ -0,0 +1,227 @@
+module notify
+
+import time
+import os
+
+#insert "@VEXEROOT/vlib/os/notify/kqueue.h"
+
+pub struct C.kevent {
+mut:
+	ident  u32
+	filter i16
+	flags  u16
+	fflags u32
+	data   int
+	udata  voidptr
+}
+
+fn C.kqueue() i32
+fn C.__kevent__(i32, voidptr, i32, voidptr, i32, voidptr) i32
+fn C.EV_SET(voidptr, u32, i16, u16, u32, i32, voidptr)
+
+// KqueueNotifier provides methods that implement FdNotifier using the
+// kqueue I/O event notification facility (macos, freeBSD, xxxBSD...unix only)
+struct KqueueNotifier {
+	kqueue_fd int
+}
+
+// KqueueEvent describes an event that occurred for a file descriptor in
+// the watch list
+struct KqueueEvent {
+pub:
+	fd   int
+	kind FdEventType
+}
+
+// new creates a new KqueueNotifier.
+// The FdNotifier interface is returned to allow OS specific
+// implementations without exposing the concrete type
+pub fn new() !FdNotifier {
+	fd := C.kqueue()
+	if fd == -1 {
+		return error(os.posix_get_error_msg(C.errno))
+	}
+	// Needed to circumvent V limitations
+	x := &KqueueNotifier{
+		kqueue_fd: fd
+	}
+	return x
+}
+
+// filter types
+const kqueue_read = i16(C.EVFILT_READ)
+const kqueue_write = i16(C.EVFILT_WRITE)
+const kqueue_aio = i16(C.EVFILT_AIO)
+const kqueue_vnode = i16(C.EVFILT_VNODE)
+const kqueue_proc = i16(C.EVFILT_PROC)
+const kqueue_signal = i16(C.EVFILT_SIGNAL)
+const kqueue_timer = i16(C.EVFILT_TIMER)
+const kqueue_machport = i16(C.EVFILT_MACHPORT)
+const kqueue_fs = i16(C.EVFILT_FS)
+const kqueue_user = i16(C.EVFILT_USER)
+const kqueue_vm = i16(C.EVFILT_VM)
+const kqueue_exception = i16(C.EVFILT_EXCEPT)
+const kqueue_syscount = i16(C.EVFILT_SYSCOUNT)
+
+// actions
+const kqueue_add = u16(C.EV_ADD)
+const kqueue_delete = u16(C.EV_DELETE)
+const kqueue_enable = u16(C.EV_ENABLE)
+const kqueue_disable = u16(C.EV_DISABLE)
+
+// flags
+const kqueue_oneshot = u16(C.EV_ONESHOT)
+const kqueue_edge_trigger = u16(C.EV_CLEAR) // kqueue_clear
+
+const kqueue_receipt = u16(C.EV_RECEIPT)
+const kqueue_dispatch = u16(C.EV_DISPATCH)
+const kqueue_udata_specific = u16(C.EV_UDATA_SPECIFIC)
+const kqueue_dispatch2 = u16(C.EV_DISPATCH | C.EV_UDATA_SPECIFIC)
+const kqueue_vanished = u16(C.EV_VANISHED)
+const kqueue_sysflags = u16(C.EV_SYSFLAGS)
+const kqueue_flag0 = u16(C.EV_FLAG0)
+const kqueue_flag1 = u16(C.EV_FLAG1)
+
+// returned values
+const kqueue_eof = u16(C.EV_EOF)
+const kqueue_error = u16(C.EV_ERROR)
+
+// ctl is a helper method for add, modify, and remove
+fn (mut kn KqueueNotifier) ctl(fd int, filter i16, flags u16) ! {
+	event := [1]C.kevent{}
+	C.EV_SET(&event[0], fd, filter, flags, 0, 0, unsafe { nil })
+	if C.__kevent__(kn.kqueue_fd, &event[0], 1, unsafe { nil }, 0, unsafe { nil }) == -1 {
+		return error(os.posix_get_error_msg(C.errno))
+	}
+}
+
+// add adds a file descriptor to the watch list
+fn (mut kn KqueueNotifier) add(fd int, events FdEventType, conf ...FdConfigFlags) ! {
+	filter := filter_to_mask(events)
+	flags := flags_to_mask(...conf)
+	kn.ctl(fd, filter, flags)!
+}
+
+// modify sets an existing entry in the watch list to the provided events and configuration
+fn (mut kn KqueueNotifier) modify(fd int, events FdEventType, conf ...FdConfigFlags) ! {
+	kn.add(fd, events, ...conf)!
+}
+
+// remove removes a file descriptor from the watch list
+fn (mut kn KqueueNotifier) remove(fd int) ! {
+	filter := kqueue_read | kqueue_write | kqueue_exception
+	flags := kqueue_delete
+	kn.ctl(fd, filter, flags)!
+}
+
+// wait waits to be notified of events on the watch list,
+// returns at most 512 events
+fn (mut kn KqueueNotifier) wait(timeout time.Duration) []FdEvent {
+	// arbitrary 512 limit; events will round robin on successive
+	// waits if the number exceeds this
+	// NOTE: we use a fixed size array here for stack allocation; this has
+	//       the added bonus of making KqueueNotifier thread safe
+	events := [512]C.kevent{}
+	// populate events with the new events
+	to := &C.timespec{0, timeout.nanoseconds()}
+	count := C.__kevent__(kn.kqueue_fd, unsafe { nil }, 0, &events[0], events.len, to)
+
+	if count > 0 {
+		mut arr := []FdEvent{cap: count}
+		for i := 0; i < count; i++ {
+			fd := int(events[i].ident)
+			kind := event_mask_to_flag(events[i].filter, events[i].flags)
+			if kind.is_empty() {
+				// NOTE: tcc only reports the first event for some
+				// reason, leaving subsequent structs in the array as 0
+				// (or possibly garbage)
+				panic('encountered an empty event kind; this is most likely due to using tcc')
+			}
+			arr << &KqueueEvent{
+				fd:   fd
+				kind: kind
+			}
+		}
+		return arr
+	}
+	return []
+}
+
+// close closes the KqueueNotifier,
+// any successive calls to add, modify, remove, and wait should fail
+fn (mut kn KqueueNotifier) close() ! {
+	if C.close(kn.kqueue_fd) == -1 {
+		return error(os.posix_get_error_msg(C.errno))
+	}
+}
+
+// event_mask_to_flag is a helper function that converts a bitmask
+// returned by kevent() wait to FdEventType
+fn event_mask_to_flag(filter i16, flags u16) FdEventType {
+	mut res := unsafe { FdEventType(0) }
+
+	if filter & kqueue_read != 0 {
+		res.set(.read)
+	}
+	if filter & kqueue_write != 0 {
+		res.set(.write)
+	}
+	if filter & kqueue_exception != 0 {
+		res.set(.exception)
+	}
+
+	if flags & kqueue_eof != 0 {
+		res.set(.hangup)
+	}
+	if flags & kqueue_error != 0 {
+		res.set(.error)
+	}
+
+	return res
+}
+
+// filter_to_mask is a helper function that converts FdEventType
+// to a bitmask used by the C functions
+fn filter_to_mask(events FdEventType) i16 {
+	mut mask := i16(0)
+	if events.has(.read) {
+		mask |= kqueue_read
+	}
+	if events.has(.write) {
+		mask |= kqueue_write
+	}
+	if events.has(.exception) {
+		mask |= kqueue_exception
+	}
+	if events.has(.peer_hangup) {
+		panic("Kqueue does not support 'peer_hangup' event type.")
+	}
+	if events.has(.error) {
+		panic("Kqueue does not support 'error' event type.")
+	}
+	if events.has(.hangup) {
+		panic("Kqueue does not support 'hangup' event type.")
+	}
+	return mask
+}
+
+// flags_to_mask is a helper function that converts FdConfigFlags
+// to a bitmask used by the C functions
+fn flags_to_mask(confs ...FdConfigFlags) u16 {
+	mut mask := kqueue_add | kqueue_enable
+	for conf in confs {
+		if conf.has(.edge_trigger) {
+			mask |= kqueue_edge_trigger
+		}
+		if conf.has(.one_shot) {
+			mask |= kqueue_oneshot
+		}
+		if conf.has(.wake_up) {
+			panic("Kqueue does not support 'wake_up' flag.")
+		}
+		if conf.has(.exclusive) {
+			panic("Kqueue does not support 'exclusive' flag.")
+		}
+	}
+	return mask
+}