[nixio] add timerfd and numexp functions to get timer notifications via fds

mote/v2/openwrt/package/luci/libs/nixio/src/file.c

@@ -223,6 +223,22 @@ static int nixio_file_read(lua_State *L) {
 	}
 }
 
+static int nixio_file_numexp(lua_State *L) {
+	int fd = nixio__checkfd(L, 1);
+	uint64_t numexp;
+	int readc;
+
+	do {
+		readc = read(fd, &numexp, sizeof(uint64_t));
+	} while (readc == -1 && errno == EINTR);
+
+	if (readc < 0) {
+		return nixio__perror(L);
+	} else {
+		lua_pushnumber(L, (lua_Number)numexp);
+		return 1;
+	}
+}
 
 static int nixio_file_seek(lua_State *L) {
 	int fd = nixio__checkfd(L, 1);
@@ -350,6 +366,7 @@ static int nixio_file__tostring(lua_State *L) {
 static const luaL_reg M[] = {
 	{"write",		nixio_file_write},
 	{"read",		nixio_file_read},
+	{"numexp",		nixio_file_numexp},
 	{"tell",		nixio_file_tell},
 	{"seek",		nixio_file_seek},
 	{"stat",		nixio_file_stat},

mote/v2/openwrt/package/luci/libs/nixio/src/poll.c

@@ -195,8 +195,57 @@ static int nixio_poll(lua_State *L) {
 
 #ifdef __linux__
 
+#include <stdint.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <sys/timerfd.h>
+
+static int nixio_timerfd(lua_State *L) {
+	struct itimerspec its;
+
+	its.it_value.tv_sec = (time_t)luaL_optinteger(L, 1, 0);
+	its.it_value.tv_nsec = (long)luaL_optinteger(L, 2, 0);
+
+	its.it_interval.tv_sec = (time_t)luaL_optinteger(L, 3, 0);
+	its.it_interval.tv_nsec = (long)luaL_optinteger(L, 4, 0);
+
+	/* Create a timer object and associated fd */
+	int fd = timerfd_create(CLOCK_REALTIME, 0);
+
+	if (fd == -1) {
+		return nixio__perror(L);
+	}
+
+	/* Workaround for TFD_NONBLOCK 'invalid argument' in uClibc*/
+	int flags;
+	flags = fcntl(fd, F_GETFL);
+	if (flags == -1)
+		return nixio__perror(L);
+	flags |= O_NONBLOCK;
+	if(fcntl(fd, F_SETFL, flags) == -1)
+		return nixio__perror(L);
+
+	/* Arm the timer */
+	if (timerfd_settime(fd, 0, &its ,NULL) == -1) {
+		close(fd);
+		return nixio__perror(L);
+	}
+
+	/* Create a userdatum for fd */
+	int *udata = lua_newuserdata(L, sizeof(int));
+	if (!udata) {
+		close(fd);
+		return luaL_error(L, "out of memory");
+	}
+
+	*udata = fd;
+
+	luaL_getmetatable(L, NIXIO_FILE_META);
+	lua_setmetatable(L, -2);
+
+	return 1;
+}
+
 #include <signal.h>
 #include <sys/signalfd.h>
 
@@ -263,6 +312,7 @@ static int nixio_setitimerfd(lua_State *L) {
 /* module table */
 static const luaL_reg R[] = {
 #ifdef __linux__
+	{"timerfd",	nixio_timerfd},
 	{"setitimerfd",	nixio_setitimerfd},
 #endif
 	{"gettimeofday", nixio_gettimeofday},