Fix. Call multi callbacks with correct Lua state

.travis.yml

@@ -45,6 +45,8 @@ script:
   - lua -e "print(require 'cURL.utils'.find_ca_bundle())"
   - lunit.sh run.lua
   - lua test_pause02.c.lua
+  - lua test_multi_callback.lua
+  - lua test_multi_nested_callback.lua
   # - lunit.sh test_easy.lua
   # - lunit.sh test_safe.lua
   # - lunit.sh test_form.lua

appveyor.yml

@@ -56,6 +56,8 @@ test_script:
   - cd %APPVEYOR_BUILD_FOLDER%\test
   - lua run.lua
   - lua test_pause02.c.lua
+  - lua test_multi_callback.lua
+  - lua test_multi_nested_callback.lua
 
 after_test:
   - cd %APPVEYOR_BUILD_FOLDER%

examples/cURLv3/uvwget.lua

@@ -182,7 +182,7 @@ end
 
 on_curl_action = function(easy, fd, action)
   local ok, err = pcall(function()
-    trace("CURL::SOCKET", easy, s, ACTION_NAMES[action] or action)
+    trace("CURL::SOCKET", easy, fd, ACTION_NAMES[action] or action)
 
     local context = easy.data.context
 

lakefile

@@ -2,8 +2,9 @@ PROJECT = 'cURL'
 
 INITLAKEFILE()
 
-DEFINES = L{DEFINES, 
+DEFINES = L{DEFINES,
   IF(WINDOWS,  'DLL_EXPORT',  '');
+  IF(DEBUG, 'LCURL_RESET_NULL_LUA', '');
 }
 
 cURL = c.shared{'lcurl',
@@ -18,7 +19,7 @@ cURL = c.shared{'lcurl',
 target('build', cURL)
 
 install = target('install', {
-  file.group{odir=LIBDIR;              src = cURL                       };
+  file.group{odir=LIBDIR;              src = cURL                             };
   file.group{odir=LIBDIR;              src = J("src", "lua") ; recurse = true };
   file.group{odir=J(ROOT, 'examples'); src = 'examples';       recurse = true };
   file.group{odir=TESTDIR;             src = 'test';           recurse = true };
@@ -30,6 +31,8 @@ target('test', install, function()
   run_test('test_form.lua')
   run_test('test_pause02.c.lua')
   run_test('test_curl.lua')
+  run_test('test_multi_callback.lua')
+  run_test('test_multi_nested_callback.lua')
 
   if not test_summary() then
     quit("test fail")

src/lceasy.c

@@ -14,6 +14,7 @@
 #include "lcutils.h"
 #include "lchttppost.h"
 #include "lcshare.h"
+#include "lcmulti.h"
 #include <memory.h>
 
 static const char *LCURL_ERROR_TAG = "LCURL_ERROR_TAG";
@@ -27,6 +28,33 @@ static const char *LCURL_EASY = LCURL_EASY_NAME;
 #  define LCURL_E_UNKNOWN_OPTION CURLE_UNKNOWN_TELNET_OPTION
 #endif
 
+/* Before call curl_XXX function which can call any callback
+ * need set Curren Lua thread pointer in easy/multi contexts.
+ * But it also possible that we already in callback call.
+ * E.g. `curl_easy_pause` function may be called from write callback.
+ * and it even may be called in different thread.
+ * ```Lua
+ * multi:add_handle(easy)
+ * easy:setopt_writefunction(function(...)
+ *   coroutine.wrap(function() multi:add_handle(easy2) end)()
+ * end)
+ * ```
+ * So we have to restore previews Lua state in callback contexts.
+ * But if previews Lua state is NULL then we can just do not set it back.
+ * But set it to NULL make esier debug code.
+ */
+void lcurl__easy_assign_lua(lua_State *L, lcurl_easy_t *p, lua_State *value, int assign_multi){
+  if(p->multi && assign_multi){
+    lcurl__multi_assign_lua(L, p->multi, value, 1);
+  }
+  else{
+    p->L = value;
+    if(p->post){
+      p->post->L = value;
+    }
+  }
+}
+
 //{
 
 int lcurl_easy_create(lua_State *L, int error_mode){
@@ -45,6 +73,7 @@ int lcurl_easy_create(lua_State *L, int error_mode){
   p->magic       = LCURL_EASY_MAGIC;
   p->L           = NULL;
   p->post        = NULL;
+  p->multi       = NULL;
   p->storage     = lcurl_storage_init(L);
   p->wr.cb_ref   = p->wr.ud_ref = LUA_NOREF;
   p->rd.cb_ref   = p->rd.ud_ref = LUA_NOREF;
@@ -66,16 +95,38 @@ int lcurl_easy_create(lua_State *L, int error_mode){
 
 lcurl_easy_t *lcurl_geteasy_at(lua_State *L, int i){
   lcurl_easy_t *p = (lcurl_easy_t *)lutil_checkudatap (L, i, LCURL_EASY);
-  luaL_argcheck (L, p != NULL, 1, LCURL_EASY_NAME" expected");
+  luaL_argcheck (L, p != NULL, 1, LCURL_EASY_NAME" object expected");
   return p;
 }
 
+static int lcurl_easy_to_s(lua_State *L){
+  lcurl_easy_t *p = (lcurl_easy_t *)lutil_checkudatap (L, 1, LCURL_EASY);
+  lua_pushfstring(L, LCURL_EASY_NAME" (%p)", (void*)p);
+  return 1;
+}
+
 static int lcurl_easy_cleanup(lua_State *L){
   lcurl_easy_t *p = lcurl_geteasy(L);
   int i;
 
+  if(p->multi){
+    CURLMcode code = lcurl__multi_remove_handle(L, p->multi, p);
+
+    //! @todo what I can do if I can not remove it???
+  }
+
   if(p->curl){
+    lua_State *curL;
+
+    // In my tests when I cleanup some easy handle. 
+    // timerfunction called only for single multi handle.
+    curL = p->L; lcurl__easy_assign_lua(L, p, L, 1);
     curl_easy_cleanup(p->curl);
+#ifndef LCURL_RESET_NULL_LUA
+    if(curL != NULL)
+#endif
+    lcurl__easy_assign_lua(L, p, curL, 1);
+
     p->curl = NULL;
   }
 
@@ -113,18 +164,20 @@ static int lcurl_easy_cleanup(lua_State *L){
 static int lcurl_easy_perform(lua_State *L){
   lcurl_easy_t *p = lcurl_geteasy(L);
   CURLcode code;
+  lua_State *curL;
   int top = 1;
   lua_settop(L, top);
 
   assert(p->rbuffer.ref == LUA_NOREF);
 
   // store reference to current coroutine to callbacks
-  p->L = L;
-  if(p->post){
-    p->post->L = L;
-  }
-
+  // User should not call `perform` if handle assign to multi
+  curL = p->L; lcurl__easy_assign_lua(L, p, L, 0);
   code = curl_easy_perform(p->curl);
+#ifndef LCURL_RESET_NULL_LUA
+  if(curL != NULL)
+#endif
+  lcurl__easy_assign_lua(L, p, curL, 0);
 
   if(p->rbuffer.ref != LUA_NOREF){
     luaL_unref(L, LCURL_LUA_REGISTRY, p->rbuffer.ref);
@@ -730,6 +783,7 @@ static size_t lcurl_write_callback_(lua_State*L,
 
 static size_t lcurl_write_callback(char *ptr, size_t size, size_t nmemb, void *arg){
   lcurl_easy_t *p = arg;
+  assert(NULL != p->L);
   return lcurl_write_callback_(p->L, p, &p->wr, ptr, size, nmemb);
 }
 
@@ -833,11 +887,13 @@ static size_t lcurl_easy_read_callback(char *buffer, size_t size, size_t nitems,
   if(p->magic == LCURL_HPOST_STREAM_MAGIC){
     return lcurl_hpost_read_callback(buffer, size, nitems, arg);
   }
+  assert(NULL != p->L);
   return lcurl_read_callback(p->L, &p->rd, &p->rbuffer, buffer, size, nitems);
 }
 
 static size_t lcurl_hpost_read_callback(char *buffer, size_t size, size_t nitems, void *arg){
   lcurl_hpost_stream_t *p = arg;
+  assert(NULL != p->L);
   return lcurl_read_callback(*p->L, &p->rd, &p->rbuffer, buffer, size, nitems);
 }
 
@@ -855,6 +911,7 @@ static int lcurl_easy_set_READFUNCTION(lua_State *L){
 
 static size_t lcurl_header_callback(char *ptr, size_t size, size_t nmemb, void *arg){
   lcurl_easy_t *p = arg;
+  assert(NULL != p->L);
   return lcurl_write_callback_(p->L, p, &p->hd, ptr, size, nmemb);
 }
 
@@ -875,10 +932,12 @@ static int lcurl_xferinfo_callback(void *arg, curl_off_t dltotal, curl_off_t dln
 {
   lcurl_easy_t *p = arg;
   lua_State *L = p->L;
+  int n, top, ret = 0;
 
-  int ret = 0;
-  int top = lua_gettop(L);
-  int n   = lcurl_util_push_cb(L, &p->pr);
+  assert(NULL != p->L);
+
+  top = lua_gettop(L);
+  n   = lcurl_util_push_cb(L, &p->pr);
 
   lua_pushnumber( L, (lua_Number)dltotal );
   lua_pushnumber( L, (lua_Number)dlnow   );
@@ -1019,8 +1078,17 @@ static int lcurl_easy_getinfo(lua_State *L){
 
 static int lcurl_easy_pause(lua_State *L){
   lcurl_easy_t *p = lcurl_geteasy(L);
+  lua_State *curL;
   int mask = luaL_checkint(L, 2);
-  CURLcode code = curl_easy_pause(p->curl, mask);
+  CURLcode code;
+
+  curL = p->L; lcurl__easy_assign_lua(L, p, L, 1);
+  code = curl_easy_pause(p->curl, mask);
+#ifndef LCURL_RESET_NULL_LUA
+  if(curL != NULL)
+#endif
+  lcurl__easy_assign_lua(L, p, curL, 1);
+
   if(code != CURLE_OK){
     return lcurl_fail_ex(L, p->err_mode, LCURL_ERROR_EASY, code);
   }
@@ -1082,19 +1150,20 @@ static const struct luaL_Reg lcurl_easy_methods[] = {
   #include "lcinfoeasy.h"
 #undef OPT_ENTRY
 
-  { "pause",    lcurl_easy_pause          },
-  { "reset",    lcurl_easy_reset          },
-  { "setopt",   lcurl_easy_setopt         },
-  { "getinfo",  lcurl_easy_getinfo        },
-  { "unsetopt", lcurl_easy_unsetopt       },
-  { "escape",   lcurl_easy_escape         },
-  { "unescape", lcurl_easy_unescape       },
-  { "perform",  lcurl_easy_perform        },
-  { "close",    lcurl_easy_cleanup        },
-  { "__gc",     lcurl_easy_cleanup        },
-
-  { "setdata",  lcurl_easy_setdata        },
-  { "getdata",  lcurl_easy_getdata        },
+  { "pause",      lcurl_easy_pause          },
+  { "reset",      lcurl_easy_reset          },
+  { "setopt",     lcurl_easy_setopt         },
+  { "getinfo",    lcurl_easy_getinfo        },
+  { "unsetopt",   lcurl_easy_unsetopt       },
+  { "escape",     lcurl_easy_escape         },
+  { "unescape",   lcurl_easy_unescape       },
+  { "perform",    lcurl_easy_perform        },
+  { "close",      lcurl_easy_cleanup        },
+  { "__gc",       lcurl_easy_cleanup        },
+  { "__tostring", lcurl_easy_to_s           },
+
+  { "setdata",    lcurl_easy_setdata        },
+  { "getdata",    lcurl_easy_getdata        },
 
   {NULL,NULL}
 };

src/lceasy.h

@@ -35,6 +35,8 @@ enum {
 
 #define LCURL_EASY_MAGIC 0xEA
 
+typedef struct lcurl_multi_tag lcurl_multi_t;
+
 typedef struct lcurl_easy_tag{
   unsigned char magic;
 
@@ -44,6 +46,8 @@ typedef struct lcurl_easy_tag{
 
   lcurl_hpost_t *post;
 
+  lcurl_multi_t *multi;
+
   CURL *curl;
   int storage;
   int lists[LCURL_LIST_COUNT];
@@ -61,4 +65,6 @@ lcurl_easy_t *lcurl_geteasy_at(lua_State *L, int i);
 
 void lcurl_easy_initlib(lua_State *L, int nup);
 
+void lcurl__easy_assign_lua(lua_State *L, lcurl_easy_t *p, lua_State *value, int assign_multi);
+
 #endif

src/lchttppost.c

@@ -112,10 +112,16 @@ int lcurl_hpost_create(lua_State *L, int error_mode){
 
 lcurl_hpost_t *lcurl_gethpost_at(lua_State *L, int i){
   lcurl_hpost_t *p = (lcurl_hpost_t *)lutil_checkudatap (L, i, LCURL_HTTPPOST);
-  luaL_argcheck (L, p != NULL, 1, LCURL_PREFIX"HTTPPost object expected");
+  luaL_argcheck (L, p != NULL, 1, LCURL_HTTPPOST_NAME" object expected");
   return p;
 }
 
+static int lcurl_hpost_to_s(lua_State *L){
+  lcurl_hpost_t *p = (lcurl_hpost_t *)lutil_checkudatap (L, 1, LCURL_HTTPPOST);
+  lua_pushfstring(L, LCURL_HTTPPOST_NAME" (%p)", (void*)p);
+  return 1;
+}
+
 static int lcurl_hpost_add_content(lua_State *L){
   // add_buffer(name, data, [type,] [headers])
   lcurl_hpost_t *p = lcurl_gethpost(L);