feature: added new API function ngx.thread.kill() for killing a user "light thread". thanks aviramc for the original patch in #288.

Author: agentzh

src/ngx_http_lua_socket_tcp.c

@@ -4344,6 +4344,9 @@ ngx_http_lua_tcp_resolve_cleanup(void *data)
     ngx_http_lua_socket_tcp_upstream_t      *u;
     ngx_http_lua_co_ctx_t                   *coctx = data;
 
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0,
+                   "lua tcp socket abort resolver");
+
     u = coctx->data;
     if (u == NULL) {
         return;

src/ngx_http_lua_uthread.c

@@ -24,20 +24,24 @@
 
 static int ngx_http_lua_uthread_spawn(lua_State *L);
 static int ngx_http_lua_uthread_wait(lua_State *L);
+static int ngx_http_lua_uthread_kill(lua_State *L);
 
 
 void
 ngx_http_lua_inject_uthread_api(ngx_log_t *log, lua_State *L)
 {
     /* new thread table */
-    lua_createtable(L, 0 /* narr */, 2 /* nrec */);
+    lua_createtable(L, 0 /* narr */, 3 /* nrec */);
 
     lua_pushcfunction(L, ngx_http_lua_uthread_spawn);
     lua_setfield(L, -2, "spawn");
 
     lua_pushcfunction(L, ngx_http_lua_uthread_wait);
     lua_setfield(L, -2, "wait");
 
+    lua_pushcfunction(L, ngx_http_lua_uthread_kill);
+    lua_setfield(L, -2, "kill");
+
     lua_setfield(L, -2, "thread");
 }
 
@@ -181,7 +185,7 @@ ngx_http_lua_uthread_wait(lua_State *L)
 
             /* being the last one */
             lua_pushnil(L);
-            lua_pushliteral(L, "already waited");
+            lua_pushliteral(L, "already waited or killed");
             return 2;
 
         default:
@@ -197,4 +201,83 @@ ngx_http_lua_uthread_wait(lua_State *L)
     return lua_yield(L, 0);
 }
 
+
+static int
+ngx_http_lua_uthread_kill(lua_State *L)
+{
+    lua_State                   *sub_co;
+    ngx_http_request_t          *r;
+    ngx_http_lua_ctx_t          *ctx;
+    ngx_http_lua_co_ctx_t       *coctx, *sub_coctx;
+
+    r = ngx_http_lua_get_req(L);
+    if (r == NULL) {
+        return luaL_error(L, "no request found");
+    }
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
+    if (ctx == NULL) {
+        return luaL_error(L, "no request ctx found");
+    }
+
+    ngx_http_lua_check_context(L, ctx, NGX_HTTP_LUA_CONTEXT_REWRITE
+                               | NGX_HTTP_LUA_CONTEXT_ACCESS
+                               | NGX_HTTP_LUA_CONTEXT_CONTENT
+                               | NGX_HTTP_LUA_CONTEXT_TIMER);
+
+    coctx = ctx->cur_co_ctx;
+
+    sub_co = lua_tothread(L, 1);
+    luaL_argcheck(L, sub_co, 1, "lua thread expected");
+
+    sub_coctx = ngx_http_lua_get_co_ctx(sub_co, ctx);
+
+    if (sub_coctx == NULL) {
+        return luaL_error(L, "no co ctx found");
+    }
+
+    if (!sub_coctx->is_uthread) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "not user thread");
+        return 2;
+    }
+
+    if (sub_coctx->parent_co_ctx != coctx) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "killer not parent");
+        return 2;
+    }
+
+    if (sub_coctx->pending_subreqs > 0) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "pending subrequests");
+        return 2;
+    }
+
+    switch (sub_coctx->co_status) {
+    case NGX_HTTP_LUA_CO_ZOMBIE:
+        ngx_http_lua_del_thread(r, L, ctx, sub_coctx);
+        ctx->uthreads--;
+
+        lua_pushnil(L);
+        lua_pushliteral(L, "already terminated");
+        return 2;
+
+    case NGX_HTTP_LUA_CO_DEAD:
+        lua_pushnil(L);
+        lua_pushliteral(L, "already waited or killed");
+        return 2;
+
+    default:
+        ngx_http_lua_cleanup_pending_operation(sub_coctx);
+        ngx_http_lua_del_thread(r, L, ctx, sub_coctx);
+        ctx->uthreads--;
+
+        lua_pushinteger(L, 1);
+        return 1;
+    }
+
+    /* not reacheable */
+}
+
 /* vi:set ft=c ts=4 sw=4 et fdm=marker: */

t/062-count.t

@@ -414,7 +414,7 @@ probe process("$LIBLUA_PATH").function("rehashtab") {
 }
 --- stap_out2
 --- response_body
-thread: 2
+thread: 3
 --- no_error_log
 [error]
 

t/098-uthread-wait.t

@@ -1274,7 +1274,7 @@ delete thread 1
 --- response_body
 hello in thread
 thread created: zombie
-failed to run thread: already waited
+failed to run thread: already waited or killed
 --- no_error_log
 [error]