Added a thread killing API

src/ngx_http_lua_uthread.c

@@ -24,7 +24,7 @@
 
 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)
@@ -38,6 +38,9 @@ ngx_http_lua_inject_uthread_api(ngx_log_t *log, lua_State *L)
     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");
 }
 
@@ -196,4 +199,84 @@ ngx_http_lua_uthread_wait(lua_State *L)
     return lua_yield(L, 0);
 }
 
+
+static int
+ngx_http_lua_uthread_kill(lua_State *L)
+{
+    int                          i, nargs;
+    int                          killed;
+    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;
+
+    nargs = lua_gettop(L);
+
+    killed = 0;
+    for (i = 1; i <= nargs; i++) {
+        sub_co = lua_tothread(L, i);
+
+        luaL_argcheck(L, sub_co, i, "lua thread expected");
+
+        sub_coctx = ngx_http_lua_get_co_ctx(sub_co, ctx);
+        if (sub_coctx == NULL
+            || sub_coctx->co_status == NGX_HTTP_LUA_CO_DEAD)
+        {
+            /* XXX The thread is dead, consider it a success and continue. */
+            ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
+                          "attempt to kill an already dead thread");
+            killed++;
+            continue;
+        }
+
+        if (!sub_coctx->is_uthread) {
+            return luaL_error(L, "attempt to kill a coroutine that is "
+                              "not a user thread");
+        }
+
+        if (sub_coctx->parent_co_ctx != coctx) {
+            return luaL_error(L, "only the parent coroutine can kill the "
+                              "thread");
+        }
+
+        if (sub_coctx->nsubreqs) {
+            /* XXX Don't kill threads with pending subrequests. */
+            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                          "attempt to kill thread with pending subrequests");
+            continue;
+        }
+
+        if (sub_coctx->cleanup) {
+            sub_coctx->cleanup(sub_coctx);
+            sub_coctx->cleanup = NULL;
+        }
+
+        if (ngx_http_lua_del_thread(r, L, ctx, sub_coctx) == NGX_OK) {
+            killed++;
+            ctx->uthreads--;
+        }
+
+    }
+
+    lua_pushinteger(L, killed);
+    return 1;
+}
+
 /* vi:set ft=c ts=4 sw=4 et fdm=marker: */

src/ngx_http_lua_util.c

@@ -344,12 +344,12 @@ ngx_http_lua_new_thread(ngx_http_request_t *r, lua_State *L, int *ref)
 }
 
 
-void
+ngx_int_t
 ngx_http_lua_del_thread(ngx_http_request_t *r, lua_State *L,
     ngx_http_lua_ctx_t *ctx, ngx_http_lua_co_ctx_t *coctx)
 {
     if (coctx->co_ref == LUA_NOREF) {
-        return;
+        return NGX_DECLINED;
     }
 
     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
@@ -365,6 +365,8 @@ ngx_http_lua_del_thread(ngx_http_request_t *r, lua_State *L,
     coctx->co_status = NGX_HTTP_LUA_CO_DEAD;
 
     lua_pop(L, 1);
+
+    return NGX_OK;
 }
 
 

src/ngx_http_lua_util.h

@@ -192,7 +192,7 @@ ngx_int_t ngx_http_lua_run_posted_threads(ngx_connection_t *c, lua_State *L,
 ngx_int_t ngx_http_lua_post_thread(ngx_http_request_t *r,
     ngx_http_lua_ctx_t *ctx, ngx_http_lua_co_ctx_t *coctx);
 
-void ngx_http_lua_del_thread(ngx_http_request_t *r, lua_State *L,
+ngx_int_t ngx_http_lua_del_thread(ngx_http_request_t *r, lua_State *L,
     ngx_http_lua_ctx_t *ctx, ngx_http_lua_co_ctx_t *coctx);
 
 void ngx_http_lua_rd_check_broken_connection(ngx_http_request_t *r);