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

@@ -4354,6 +4354,9 @@ 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 +201,75 @@ 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) {
+        return luaL_error(L, "attempt to wait on a coroutine that is "
+                          "not a user thread");
+    }
+
+    if (sub_coctx->parent_co_ctx != coctx) {
+        return luaL_error(L, "only the parent coroutine can wait on the "
+                          "thread");
+    }
+
+    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]
 

t/127-uthread-kill.t

@@ -0,0 +1,254 @@
+# vim:set ft= ts=4 sw=4 et fdm=marker:
+
+use lib 'lib';
+use Test::Nginx::Socket::Lua;
+use t::StapThread;
+
+our $GCScript = $t::StapThread::GCScript;
+our $StapScript = $t::StapThread::StapScript;
+
+repeat_each(2);
+
+plan tests => repeat_each() * (blocks() * 5 + 2);
+
+$ENV{TEST_NGINX_RESOLVER} ||= '8.8.8.8';
+$ENV{TEST_NGINX_MEMCACHED_PORT} ||= '11211';
+
+#no_shuffle();
+no_long_string();
+run_tests();
+
+__DATA__
+
+=== TEST 1: kill pending sleep
+--- config
+    location /lua {
+        content_by_lua '
+            function f()
+                ngx.say("hello from f()")
+                ngx.sleep(1)
+            end
+
+            local t, err = ngx.thread.spawn(f)
+            if not t then
+                ngx.say("failed to spawn thread: ", err)
+                return
+            end
+
+            ngx.say("thread created: ", coroutine.status(t))
+
+            collectgarbage()
+
+            local ok, err = ngx.thread.kill(t)
+            if not ok then
+                ngx.say("failed to kill thread: ", err)
+                return
+            end
+
+            ngx.say("killed")
+
+            local ok, err = ngx.thread.kill(t)
+            if not ok then
+                ngx.say("failed to kill thread: ", err)
+                return
+            end
+        ';
+    }
+--- request
+GET /lua
+--- stap2 eval: $::StapScript
+--- stap eval: $::GCScript
+--- stap_out
+create 2 in 1
+spawn user thread 2 in 1
+delete thread 2
+terminate 1: ok
+delete thread 1
+
+--- response_body
+hello from f()
+thread created: running
+killed
+failed to kill thread: already waited or killed
+
+--- no_error_log
+[error]
+--- error_log
+lua clean up the timer for pending ngx.sleep
+
+
+
+=== TEST 2: already waited
+--- config
+    location /lua {
+        content_by_lua '
+            function f()
+                ngx.say("hello from f()")
+                ngx.sleep(0.001)
+                return 32
+            end
+
+            local t, err = ngx.thread.spawn(f)
+            if not t then
+                ngx.say("failed to spawn thread: ", err)
+                return
+            end
+
+            ngx.say("thread created: ", coroutine.status(t))
+
+            collectgarbage()
+
+            local ok, res = ngx.thread.wait(t)
+            if not ok then
+                ngx.say("failed to kill thread: ", res)
+                return
+            end
+
+            ngx.say("waited: ", res)
+
+            local ok, err = ngx.thread.kill(t)
+            if not ok then
+                ngx.say("failed to kill thread: ", err)
+                return
+            end
+        ';
+    }
+--- request
+GET /lua
+--- stap2 eval: $::StapScript
+--- stap eval: $::GCScript
+--- stap_out
+create 2 in 1
+spawn user thread 2 in 1
+terminate 2: ok
+delete thread 2
+terminate 1: ok
+delete thread 1
+
+--- response_body
+hello from f()
+thread created: running
+waited: 32
+failed to kill thread: already waited or killed
+
+--- no_error_log
+[error]
+lua clean up the timer for pending ngx.sleep
+
+
+
+=== TEST 3: kill pending resolver
+--- config
+    resolver agentzh.org:12345;
+    location /lua {
+        content_by_lua '
+            function f()
+                local sock = ngx.socket.tcp()
+                sock:connect("some.agentzh.org", 12345)
+            end
+
+            local t, err = ngx.thread.spawn(f)
+            if not t then
+                ngx.say("failed to spawn thread: ", err)
+                return
+            end
+
+            ngx.say("thread created: ", coroutine.status(t))
+
+            collectgarbage()
+
+            local ok, err = ngx.thread.kill(t)
+            if not ok then
+                ngx.say("failed to kill thread: ", err)
+                return
+            end
+
+            ngx.say("killed")
+        ';
+    }
+--- request
+GET /lua
+--- stap2 eval: $::StapScript
+--- stap eval: $::GCScript
+--- stap_out
+create 2 in 1
+spawn user thread 2 in 1
+delete thread 2
+terminate 1: ok
+delete thread 1
+
+--- response_body
+thread created: running
+killed
+
+--- no_error_log
+[error]
+--- error_log
+lua tcp socket abort resolver
+resolve name done: -2
+
+
+
+=== TEST 4: kill pending connect
+--- config
+    resolver $TEST_NGINX_RESOLVER;
+    location /lua {
+        content_by_lua '
+            local ready = false
+            function f()
+                local sock = ngx.socket.tcp()
+                sock:connect("agentzh.org", 80)
+                sock:close()
+                ready = true
+                sock:settimeout(10000)
+                sock:connect("agentzh.org", 12345)
+            end
+
+            local t, err = ngx.thread.spawn(f)
+            if not t then
+                ngx.say("failed to spawn thread: ", err)
+                return
+            end
+
+            ngx.say("thread created: ", coroutine.status(t))
+
+            collectgarbage()
+
+            while not ready do
+                ngx.sleep(0.001)
+            end
+
+            local ok, err = ngx.thread.kill(t)
+            if not ok then
+                ngx.say("failed to kill thread: ", err)
+                return
+            end
+
+            ngx.say("killed")
+        ';
+    }
+--- request
+GET /lua
+--- stap2 eval: $::StapScript
+--- stap eval: $::GCScript
+--- stap_out
+create 2 in 1
+spawn user thread 2 in 1
+delete thread 2
+terminate 1: ok
+delete thread 1
+
+--- response_body
+thread created: running
+killed
+
+--- no_error_log
+[error]
+lua tcp socket abort resolver
+--- grep_error_log: lua finalize socket
+--- grep_error_log_out
+lua finalize socket
+lua finalize socket
+
+--- error_log
+