# HG changeset patch
# User jbe
# Date 1428518298 -7200
# Node ID 8fce76ef321f1c4237b351571361372ea702999b
# Parent  11d03470ef199b6cfcdc963e93ac012a770a6bb8
Added moonbridge_io.poll(...)

diff -r 11d03470ef19 -r 8fce76ef321f moonbridge_io.c
--- a/moonbridge_io.c	Wed Apr 08 19:37:09 2015 +0200
+++ b/moonbridge_io.c	Wed Apr 08 20:38:18 2015 +0200
@@ -591,6 +591,82 @@
   return moonbr_io_tcpconnect_impl(L, 1);
 }
 
+static int moonbr_io_poll(lua_State *L) {
+  moonbr_io_handle_t *handle;
+  int fd, isnum;
+  int nfds = 0;
+  fd_set readfds, writefds, exceptfds;
+  struct timeval timeout = {0, };
+  int status;
+  FD_ZERO(&readfds);
+  FD_ZERO(&writefds);
+  FD_ZERO(&exceptfds);
+  if (!lua_isnoneornil(L, 1)) {
+    luaL_checktype(L, 1, LUA_TTABLE);
+    for (lua_pushnil(L); lua_next(L, 1); lua_pop(L, 1)) {
+      if (lua_toboolean(L, -1)) {
+        handle = luaL_testudata(L, -2, MOONBR_IO_HANDLE_MT_REGKEY);
+        if (handle) {
+          fd = handle->fd;
+          if (fd < 0) luaL_error(L, "Handle in illegal state");
+        } else {
+          fd = lua_tointegerx(L, -2, &isnum);
+          if (!isnum) luaL_error(L, "File descriptor is not an integer");
+        }
+        FD_SET(fd, &readfds);
+        if (fd+1 > nfds) nfds = fd+1;
+      }
+    }
+  }
+  if (!lua_isnoneornil(L, 2)) {
+    luaL_checktype(L, 2, LUA_TTABLE);
+    for (lua_pushnil(L); lua_next(L, 2); lua_pop(L, 1)) {
+      if (lua_toboolean(L, -1)) {
+        handle = luaL_testudata(L, -2, MOONBR_IO_HANDLE_MT_REGKEY);
+        if (handle) {
+          fd = handle->fd;
+          if (fd < 0) luaL_error(L, "Handle in illegal state");
+        } else {
+          fd = lua_tointegerx(L, -2, &isnum);
+          if (!isnum) luaL_error(L, "File descriptor is not an integer");
+        }
+        FD_SET(fd, &writefds);
+        if (fd+1 > nfds) nfds = fd+1;
+      }
+    }
+  }
+  if (!lua_isnoneornil(L, 3)) {
+    lua_Number n;
+    n = lua_tonumberx(L, 3, &isnum);
+    if (isnum && n>=0 && n<100000000) {
+      timeout.tv_sec = n;
+      timeout.tv_usec = 1e6 * (n - timeout.tv_sec);
+    } else {
+      luaL_argcheck(L, 0, 3, "not a valid timeout");
+    }
+    status = select(nfds, &readfds, &writefds, &exceptfds, &timeout);
+  } else {
+    status = select(nfds, &readfds, &writefds, &exceptfds, NULL);
+  }
+  if (status == -1) {
+    if (errno == EINTR) {
+      lua_pushboolean(L, 0);
+      lua_pushliteral(L, "Signal received while polling file descriptors");
+      return 2;
+    } else {
+      moonbr_io_errmsg();
+      return luaL_error(L, "Unexpected error during \"select\" system call: %s", errmsg);
+    }
+  } else if (status == 0) {
+    lua_pushboolean(L, 0);
+    lua_pushliteral(L, "Timeout while polling file descriptors");
+    return 2;
+  } else {
+    lua_pushboolean(L, 1);
+    return 1;
+  }
+}
+
 static const struct luaL_Reg moonbr_io_handle_methods[] = {
   {"read", moonbr_io_read},
   {"read_nb", moonbr_io_read_nb},
@@ -616,6 +692,7 @@
 static const struct luaL_Reg moonbr_io_module_funcs[] = {
   {"tcpconnect", moonbr_io_tcpconnect},
   {"tcpconnect_nb", moonbr_io_tcpconnect_nb},
+  {"poll", moonbr_io_poll},
   {NULL, NULL}
 };
 
diff -r 11d03470ef19 -r 8fce76ef321f reference.txt
--- a/reference.txt	Wed Apr 08 19:37:09 2015 +0200
+++ b/reference.txt	Wed Apr 08 20:38:18 2015 +0200
@@ -236,6 +236,19 @@
 library to support blocking as well as nonblocking I/O operations.
 
 
+### moonbridge_io.poll(input_set, output_set, timeout)
+
+This function waits for at least one of the given file descriptors and/or
+I/O handles to be ready for input or output. The two sets of file descriptors
+and/or handles must contain the file descriptor or handle as a key, and a value
+which does evaluate to true. If a set is nil, it is treated as being empty.
+
+Returns true when at least one file descriptor or handle is ready for reading
+or writing respectively. Returns false (as first return value) plus a status
+message (as second return value) in case of timeout or when a signal was
+received.
+
+
 ### moonbridge_io.tcpconnect(hostname, port)
 
 Tries to open a TCP connection with the given host and TCP port number. Returns