Split libuev.c into smaller files to help linker

Split libuev.c into one file per watcher type, mostly to give a better
overview and ease of maintenance, but also to help the linker.

Unfortunately this steals a few bytes when linking a full blown app, but
for apps that, e.g., only need I/O watchers and no timers the resulting
binary will be smaller.  This applies to static binaries that are more
common in embedded systems.

$ size libuev.a libuev.so.1
   text	   data	    bss	    dec	    hex	filename
    999	      0	      0	    999	    3e7	main.o (ex libuev.a)
     90	      0	      0	     90	     5a	io.o (ex libuev.a)
    490	      0	      0	    490	    1ea	timer.o (ex libuev.a)
   4380	    696	      8	   5084	   13dc	libuev.so.1

Also, move uev.h back to top from include/libuev/uev.h since a separate
namespace is not needed after the removal of the OpenBSD queue.h copy.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

timer.c

@@ -0,0 +1,137 @@
+/* libuev - Micro event loop library
+ *
+ * Copyright (c) 2012  Flemming Madsen <flemming!madsen()madsensoft!dk>
+ * Copyright (c) 2013  Joachim Nilsson <troglobit()gmail!com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <errno.h>
+#include <sys/timerfd.h>
+#include <unistd.h>		/* close(), read() */
+
+#include "uev.h"
+
+
+static struct timespec msec2tspec(int msec)
+{
+	struct timespec ts;
+
+	ts.tv_sec  =  msec / 1000;
+	ts.tv_nsec = (msec % 1000) * 1000000;
+
+	return ts;
+}
+
+/**
+ * Create a timer watcher
+ * @param ctx     A valid libuev context
+ * @param handler Timer callback
+ * @param data    Optional callback argument
+ * @param timeout Timeout in milliseconds before @param handler is called
+ * @param period  For periodic timers this is the period time that @param timeout is reset to
+ *
+ * For one-shot timers you set @param period to zero and only use @param
+ * timeout.  For periodic timers you likely set @param timeout to either
+ * zero, to call it as soon as the event loop starts, or to the same
+ * value as @param period.  When the timer expires, the @param handler
+ * is called, with the optional @param data argument.  A non-periodic
+ * timer ends its life there, while a periodic task's @param timeout is
+ * reset to the @param period and restarted.
+ *
+ * @return The new timer, or %NULL if invalid pointers or out or memory.
+ */
+uev_io_t *uev_timer_create(uev_t *ctx, uev_cb_t *handler, void *data, int timeout, int period)
+{
+	int fd;
+	uev_io_t *w;
+
+	fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
+	if (fd < 0)
+		return NULL;
+
+	w = uev_watcher_create(ctx, UEV_TIMER_TYPE, fd, UEV_DIR_INBOUND, handler, data);
+	if (!w)
+		goto exit;
+
+	if (uev_timer_set(ctx, w, timeout, period)) {
+		uev_watcher_delete(ctx, w);
+	exit:
+		close(fd);
+		return NULL;
+	}
+
+	return w;
+}
+
+/**
+ * Reset or reschedule a timer
+ * @param ctx  A valid libuev context
+ * @param w    I/O watcher
+ *
+ * @return POSIX OK(0) or non-zero with @param errno set.
+ */
+int uev_timer_set(uev_t *ctx, uev_io_t *w, int timeout, int period)
+{
+	struct itimerspec time;
+
+	if (!ctx || !w) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	w->timeout = timeout;
+	w->period  = period;
+
+	if (!ctx->running)
+		return 0;
+
+	time.it_value    = msec2tspec(timeout);
+	time.it_interval = msec2tspec(period);
+
+	return timerfd_settime(w->fd, 0, &time, NULL);
+}
+
+/**
+ * Delete a timer watcher
+ * @param ctx  A valid libuev context
+ * @param w    I/O watcher
+ *
+ * @return POSIX OK(0) or non-zero with @param errno set.
+ */
+int uev_timer_delete(uev_t *ctx, uev_io_t *w)
+{
+	if (!ctx || !w) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	uev_timer_set(ctx, w, 0, 0);
+
+	return uev_watcher_delete(ctx, w);
+}
+
+/**
+ * Local Variables:
+ *  version-control: t
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */