在longjmp和setjmp的联机帮助页中，有这一行：
如果调用
setjmp()的函数在longjmp()之前返回 这个行为是未定义的。
这是否意味着我实际上必须在调用longjmp的函数或嵌套函数中的某处调用setjmp？或者根本不打电话可以吗？
答案 0 :(得分：11)
你读错了。
如果在调用longjmp（）之前调用setjmp（）的函数返回，则行为未定义。
如果您在设置I solved this issue , even i was facing same issue , If you dont use local model you will not face issue or if you define your model in controller you will not face the issue.
sap.ui.define([
"sap/ui/core/mvc/Controller",
"sap/ui/model/json/JSONModel"
], function(Controller,JSONModel) {
"use strict";
return Controller.extend("SmartPurchaseReq.controller.Home", {
/**
* Called when a controller is instantiated and its View controls (if available) are already created.
* Can be used to modify the View before it is displayed, to bind event handlers and do other one-time initialization.
* @memberOf SmartPurchaseReq.view.Home
*/
onInit: function() {
var that = this;
var data = {
"TileCollection" : [
{
"icon" : "sap-icon://hint",
"type" : "Monitor",
"title" : "Tiles: a modern UI design pattern for overview & navigation."
},
{
"icon" : "sap-icon://inbox",
"number" : "89",
"title" : "Approve Leave Requests",
"info" : "Overdue",
"infoState" : "Error"
},
{
"type" : "Create",
"title" : "Create Leave Requests",
"info" : "28 Days Left",
"infoState" : "Success"
},
{
"icon" : "sap-icon://travel-expense-report",
"number" : "281",
"numberUnit" : "euro",
"title" : "Travel Reimbursement",
"info" : "1 day ago"
},
{
"icon" : "sap-icon://loan",
"number" : "2380",
"numberUnit" : "euro",
"title" : "My Salary",
"info" : "8 days ago"
},
{
"icon" : "sap-icon:`enter code here`//lab",
"number" : "1",
"numberUnit" : "Invention",
"title" : "Test Lab Reports",
"info" : "8 Days Ago"
},
{
"icon" : "sap-icon://inbox",
"type" : "Monitor",
"title" : "Leave Request History"
},
{
"type" : "Create",
"title" : "Create Purchase Order",
"info" : "890€ Open Budget",
"infoState" : "Success"
},
{
"icon" : "sap-icon://stethoscope",
"number" : "3",
"title" : "Yearly Health Check",
"info" : "3 year overdue",
"infoState" : "Error"
},
{
"icon" : "sap-icon://meal",
"type" : "Monitor",
"title" : "Meal Schedule"
}
]
};
var DummyModel = new JSONModel();
DummyModel.setData(data);
// var sPath = jQuery.sap.getModulePath("model", "/Dummy.json");
// var DummyModel = new JSONModel(sPath);
that.getView().byId("container").setModel(DummyModel);
},
OnTilePress: function(evt) {
var idj = evt.getSource();
var d =5;
}
/**
* Similar to onAfterRendering, but this hook is invoked before the controller's View is re-rendered
* (NOT before the first rendering! onInit() is used for that one!).
* @memberOf SmartPurchaseReq.view.Home
*/
// onBeforeRendering: function() {
//
// },
/**
* Called when the View has been rendered (so its HTML is part of the document). Post-rendering manipulations of the HTML could be done here.
* This hook is the same one that SAPUI5 controls get after being rendered.
* @memberOf SmartPurchaseReq.view.Home
*/
// onAfterRendering: function() {
//
// },
/**
* Called when the Controller is destroyed. Use this one to free resources and finalize activities.
* @memberOf SmartPurchaseReq.view.Home
*/
// onExit: function() {
//
// }
});
});
的函数返回后调用，则longjmp的行为未定义。但完全可以不来调用setjmp。
Wikipedia更清楚：
如果调用setjmp的函数返回，则不再可能安全地将longjmp与相应的jmp_buf对象一起使用。
这是因为函数返回时堆栈帧无效。调用longjmp会恢复堆栈指针，因为返回的函数会指向不存在且可能被覆盖或损坏的堆栈帧。
这些函数通常用于处理异常机制。如果没有发生异常，您不想拨打longjmp，因为没有理由“回滚”您的程序。