ngx_lua 中协程的应用

[jinhailang]

ngx_lua 中协程的应用

[jinhailang]

ngx_http_lua_run_thread 源码（ ngx.thread 调度部分）

ngx_http_lua_run_thread(lua_State *L, ngx_http_request_t *r,
952     ngx_http_lua_ctx_t *ctx, volatile int nrets)
953 {
954 ...
973     NGX_LUA_EXCEPTION_TRY {
974 ...
982         for ( ;; ) {
983 ...
997             orig_coctx = ctx->cur_co_ctx;
998 ...
1015             rv = lua_resume(orig_coctx->co, nrets);//通过lua_resume执行协程中的函数
1016 ...
1032             switch (rv) {//处理lua_resume的返回值
1033             case LUA_YIELD:
1034 ..
1047                 if (r->uri_changed) {
1048                     return ngx_http_lua_handle_rewrite_jump(L, r, ctx);
1049                 }
1050                 if (ctx->exited) {
1051                     return ngx_http_lua_handle_exit(L, r, ctx);
1052                 }
1053                 if (ctx->exec_uri.len) {
1054                     return ngx_http_lua_handle_exec(L, r, ctx);
1055                 }
1056                 switch(ctx->co_op) {
1057 ...
1167                 }
1168                 continue;
1169             case 0:
1170 ...
1295                 continue;
1296 ...
1313             default:
1314                 err = "unknown error";
1315                 break;
1316             }
1317 ...
1444         }
1445     } NGX_LUA_EXCEPTION_CATCH {
1446         dd("nginx execution restored");
1447     }
1448     return NGX_ERROR;
1449
1450 no_parent:
1451 ...
1465     return (r->header_sent || ctx->header_sent) ?
1466                 NGX_ERROR : NGX_HTTP_INTERNAL_SERVER_ERROR;
1467
1468 done:
1469 ...
1481     return NGX_OK;
1482 }```