Fix. Init socket callback with nil.

Fix. `multi.setopt` supports socket callback.
Change. `socket_acttion` without args means timeout action.
Change. cURLv3 multi supports options in callback.
Add. `multi-uv` example.

examples/cURLv3/multi-uv.lua

@@ -0,0 +1,162 @@
+local curl = require "cURL"
+local uv   = require "lluv"
+
+local fprintf = function(f, ...) f:write((string.format(...))) end
+local printf  = function(...) fprintf(io.stdout, ...) end
+
+local stderr = io.stderr
+
+local timeout, curl_handle
+
+local ACTION_NAMES = {
+  [curl.POLL_IN     ] = "POLL_IN";
+  [curl.POLL_INOUT  ] = "POLL_INOUT";
+  [curl.POLL_OUT    ] = "POLL_OUT";
+  [curl.POLL_NONE   ] = "POLL_NONE";
+  [curl.POLL_REMOVE ] = "POLL_REMOVE";
+}
+local EVENT_NAMES = {
+  [ uv.READABLE ] = "READABLE";
+  [ uv.WRITABLE ] = "WRITABLE";
+  [ uv.READABLE + uv.WRITABLE ] = "READABLE + WRITABLE";
+}
+local FLAGS = {
+  [ uv.READABLE ]               = curl.CSELECT_IN;
+  [ uv.WRITABLE ]               = curl.CSELECT_OUT;
+  [ uv.READABLE + uv.WRITABLE ] = curl.CSELECT_IN + curl.CSELECT_OUT;
+
+}
+
+local trace = function() end or print
+
+local FILES, CONTEXT = {}, {}
+
+function create_curl_context(sockfd)
+  local context = {
+    sockfd      = sockfd;
+    poll_handle = uv.poll_socket(sockfd);
+  }
+  context.poll_handle.data = context
+  
+  return context
+end
+
+function destroy_curl_context(context)
+  context.poll_handle:close()
+end 
+
+function add_download(url, num)
+  local filename = tostring(num) ..  ".download"
+  local file = io.open(filename, "w")
+  if not file then
+    fprintf(stderr, "Error opening %s\n", filename)
+    return
+  end
+
+  local handle = curl.easy{
+    url           = url;
+    writefunction = file;
+  }
+
+  FILES[handle] = file
+
+  curl_handle:add_handle(handle)
+  fprintf(stderr, "Added download %s -> %s\n", url, filename);
+end
+
+function check_multi_info()
+  while true do
+    local easy, ok, err = curl_handle:info_read()
+    if not easy then curl_handle:close() error(err) end
+    if easy == 0 then break end
+
+    local context = CONTEXT[e]
+    if context then destroy_curl_context(context) end
+    local file = FILES[easy]
+    if file then FILES[easy] = nil, file:close() end
+    local done_url = easy:getinfo_effective_url()
+    easy:close()
+    if ok then
+      printf("%s DONE\n", done_url);
+    elseif data == "error" then
+      printf("%s ERROR - %s\n", done_url, tostring(err));
+    end
+  end
+end
+
+function curl_perform(handle, err, events)
+  -- calls by libuv --
+  trace("UV::POLL", handle, err, EVENT_NAMES[events] or events)
+
+  local flags = assert(FLAGS[events], ("unknown event:" .. events))
+
+  context = handle.data
+
+  curl_handle:socket_action(context.sockfd, flags)
+
+  check_multi_info()
+end
+
+function on_timeout(timer)
+  -- calls by libuv --
+  trace("UV::TIMEOUT", timer)
+
+  local running_handles, err = curl_handle:socket_action()
+
+  check_multi_info()
+end
+
+function start_timeout(timeout_ms)
+  -- calls by curl --
+  trace("CURL::TIMEOUT", timeout_ms)
+
+  -- 0 means directly call socket_action, but we'll do it in a bit
+  if timeout_ms <= 0 then timeout_ms = 1 end
+
+  timeout:stop():start(timeout_ms, 0, on_timeout)
+end
+
+local handle_socket = function(...)
+  local ok, err = pcall(handle_socket_impl, ...)
+  if not ok then uv.defer(function() error(err) end) end
+end
+
+function handle_socket_impl(easy, s, action)
+  -- calls by curl --
+
+  trace("CURL::SOCKET", easy, s, ACTION_NAMES[action] or action)
+
+  local curl_context = CONTEXT[easy] or create_curl_context(s)
+  CONTEXT[easy] = curl_context
+
+  assert(curl_context.sockfd == s)
+
+  if action == curl.POLL_IN then
+    curl_context.poll_handle:start(uv.READABLE, curl_perform)
+  elseif action == curl.POLL_OUT then
+    curl_context.poll_handle:start(uv.WRITABLE, curl_perform)
+  elseif action == curl.POLL_REMOVE then
+    CONTEXT[easy] = nil
+    destroy_curl_context(curl_context)
+  end
+end
+
+timeout = uv.timer()
+
+curl_handle = curl.multi{
+  socketfunction = handle_socket;
+  timerfunction  = start_timeout;
+}
+
+curl_handle = curl.multi{
+  socketfunction = handle_socket;
+  timerfunction  = start_timeout;
+}
+
+for i = 1, math.huge do
+  local url = arg[i]
+  if not url then break end
+  add_download(url, i)
+end
+
+uv.run(loop, UV_RUN_DEFAULT)

src/lcmulti.c

@@ -43,6 +43,7 @@ int lcurl_multi_create(lua_State *L, int error_mode){
   lcurl_util_new_weak_table(L, "v");
   p->h_ref = luaL_ref(L, LCURL_LUA_REGISTRY);
   p->tm.cb_ref = p->tm.ud_ref = LUA_NOREF;
+  p->sc.cb_ref = p->sc.ud_ref = LUA_NOREF;
 
   if(lua_type(L, 1) == LUA_TTABLE){
     int ret = lcurl_utils_apply_options(L, 1, 2, 1, p->err_mode, LCURL_ERROR_MULTI, CURLM_UNKNOWN_OPTION);
@@ -228,9 +229,11 @@ static int lcurl_multi_timeout(lua_State *L){
 
 static int lcurl_multi_socket_action(lua_State *L){
   lcurl_multi_t *p = lcurl_getmulti(L);
-  curl_socket_t s  = lutil_checkint64(L, 2);
-  int n, mask      = lutil_checkint64(L, 3);
-  CURLMcode code   = curl_multi_socket_action(p->curl, s, mask, &n);
+  curl_socket_t s  = lutil_optint64(L, 2, CURL_SOCKET_TIMEOUT);
+  CURLMcode code; int n, mask;
+  if(s == CURL_SOCKET_TIMEOUT) mask = 0;
+  else mask = lutil_checkint64(L, 3);
+  code = curl_multi_socket_action(p->curl, s, mask, &n);
   if(code != CURLM_OK){
     lcurl_fail_ex(L, p->err_mode, LCURL_ERROR_MULTI, code);
   }
@@ -427,7 +430,8 @@ static int lcurl_multi_setopt(lua_State *L){
 #define OPT_ENTRY(l, N, T, S) case CURLMOPT_##N: return lcurl_multi_set_##N(L);
   switch(opt){
     #include "lcoptmulti.h"
-    OPT_ENTRY(timerfunction, TIMERFUNCTION, TTT, 0)
+    OPT_ENTRY(timerfunction,  TIMERFUNCTION,  TTT, 0)
+    OPT_ENTRY(socketfunction, SOCKETFUNCTION, TTT, 0)
   }
 #undef OPT_ENTRY
 

src/lua/cURL/impl/cURL.lua

@@ -520,8 +520,9 @@ local Multi = class(curl.multi) do
 local add_handle    = wrap_function("add_handle")
 local remove_handle = wrap_function("remove_handle")
 
-function Multi:__init()
+function Multi:__init(opt)
   self._easy = {n = 0}
+  if opt then self:setopt(opt) end
   return self
 end