diff --git a/a8/stringlist.cc b/a8/stringlist.cc
index e290781..14f7459 100644
--- a/a8/stringlist.cc
+++ b/a8/stringlist.cc
@@ -69,6 +69,11 @@ namespace a8
             }
             p2++;
         }
+        #if 0
+        if (p2 > p1) {
+            Add(p2 > p1 ? std::string(p1, p2 - p1) : "");
+        }
+        #endif
     }
 
     std::string StringList::Text()
diff --git a/a8/sysutils.cc b/a8/sysutils.cc
index bfca194..e293166 100644
--- a/a8/sysutils.cc
+++ b/a8/sysutils.cc
@@ -209,4 +209,10 @@ namespace a8
         return (int)(int64_val >> 32);
     }
 
+    float RandAngle()
+    {
+        float angle = 0.00001f + ((float)rand() / RAND_MAX) * 2.0f;
+        return angle;
+    }
+
 }
diff --git a/a8/sysutils.h b/a8/sysutils.h
index 0e04df2..72befc2 100644
--- a/a8/sysutils.h
+++ b/a8/sysutils.h
@@ -42,6 +42,18 @@ namespace a8
         return t.back();
     }
 
+    template <typename T>
+    const T& Clamp(const T& v, const T& lo, const T& hi)
+    {
+        return v < hi ? (v > lo ? v : lo) : hi;
+    }
+
+    template <typename T>
+    float LengthSqr(const T& v)
+    {
+        return v.x * v.x + v.y * v.y;
+    }
+
     template <typename T>
     void SetToVector(std::set<T>& set_v, std::vector<T>& vector_v)
     {
@@ -73,6 +85,7 @@ namespace a8
     int Low32(long long int64_val);
     int High32(long long int64_val);
 
+    float RandAngle();
 }
 
 #endif
diff --git a/a8/timer.cc b/a8/timer.cc
index 232369a..4753894 100644
--- a/a8/timer.cc
+++ b/a8/timer.cc
@@ -148,6 +148,9 @@ namespace a8
 
     void Timer::UnInit()
     {
+        Clear();
+        delete base_;
+        base_ = nullptr;
     }
 
     void Timer::Update()
@@ -227,7 +230,7 @@ namespace a8
         if (!list_empty(&timer->attach_entry)) {
             list_del_init(&timer->attach_entry);
         }
-         AddToFreeList(timer);
+        AddToFreeList(timer);
     }
 
     timer_list* Timer::GetTimerByAttach(list_head* attach_entry)
@@ -332,6 +335,33 @@ namespace a8
         base_->free_timer_num++;
     }
 
+    void Timer::Clear()
+    {
+        auto free_timers =
+            [] (list_head* head)
+            {
+                while (!list_empty(head)) {
+                    struct timer_list *timer;
+                    timer = list_first_entry(head, struct timer_list,entry);
+                    DetachTimer(timer);
+                    if (!list_empty(&timer->attach_entry)) {
+                        list_del_init(&timer->attach_entry);
+                    }
+                    delete timer;
+                }
+            };
+        for (int j = 0; j < TVN_SIZE; j++) {
+            free_timers(base_->tv5.vec + j);
+            free_timers(base_->tv4.vec + j);
+            free_timers(base_->tv3.vec + j);
+            free_timers(base_->tv2.vec + j);
+        }
+        for (int j = 0; j < TVR_SIZE; j++) {
+            free_timers(base_->tv1.vec + j);
+        }
+        free_timers(&base_->free_timer);
+    }
+
     void Timer::GC_TimerFunc(const a8::XParams& param)
     {
         Timer* timer = (Timer*)param.sender.GetUserData();
diff --git a/a8/timer.h b/a8/timer.h
index 14c41b9..9695f2b 100644
--- a/a8/timer.h
+++ b/a8/timer.h
@@ -47,6 +47,7 @@ namespace a8
         void UpdateTimer();
         timer_list* NewTimerList();
         void AddToFreeList(timer_list* timer);
+        void Clear();
         static void GC_TimerFunc(const a8::XParams& param);
 
     private:
diff --git a/a8/xobject.cc b/a8/xobject.cc
index fe6db94..1341313 100644
--- a/a8/xobject.cc
+++ b/a8/xobject.cc
@@ -298,6 +298,33 @@ namespace a8
         return ReadFromJsonString(sl.Text());
     }
 
+    bool XObject::ReadFromJsonFile(const std::string& filename)
+    {
+        std::string json_data;
+        {
+            FILE *fp = fopen(filename.c_str(), "rb");
+            if (!fp) {
+                return false;
+            }
+            fseek(fp, 0, SEEK_END);
+            int fileSize = ftell(fp);
+            if(fileSize){
+                char *p = (char*)malloc(fileSize + 1);
+                if(p){
+                    *(p + fileSize) = '\0';
+                    fseek(fp, 0, SEEK_SET);
+                    fread(p, 1, fileSize, fp);
+                    if (fileSize > 0) {
+                        json_data.append(p, fileSize);
+                    }
+                    free(p);
+                }
+            }
+            fclose(fp);
+        }
+        return ReadFromJsonString(json_data);
+    }
+
     bool XObject::ReadFromJsonString(const std::string& json_data)
     {
         Json::Reader reader;
diff --git a/a8/xobject.h b/a8/xobject.h
index 6b17e4e..1214d11 100644
--- a/a8/xobject.h
+++ b/a8/xobject.h
@@ -44,6 +44,7 @@ namespace a8
         a8::XObject& Move(a8::XObject& a);
 
         bool ReadFromFile(const std::string& filename);
+        bool ReadFromJsonFile(const std::string& filename);
         bool ReadFromJsonString(const std::string& jsondata);
         bool ReadFromXmlFile(const std::string& filename);
         bool ReadFromXmlString(const std::string& xmldata);
diff --git a/a8/xtimer.cc b/a8/xtimer.cc
new file mode 100644
index 0000000..824cc82
--- /dev/null
+++ b/a8/xtimer.cc
@@ -0,0 +1,352 @@
+#include <a8/a8.h>
+
+#include <a8/xtimer.h>
+
+#define CONFIG_BASE_SMALL 0
+#define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6)
+#define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8)
+#define TVN_SIZE (1 << TVN_BITS)
+#define TVR_SIZE (1 << TVR_BITS)
+#define TVN_MASK (TVN_SIZE - 1)
+#define TVR_MASK (TVR_SIZE - 1)
+#define INDEX(N) ((base->timer_tick >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK)
+
+struct xtvec {
+    struct list_head vec[TVN_SIZE];
+};
+
+struct xtvec_root {
+    struct list_head vec[TVR_SIZE];
+};
+
+struct xtvec_base {
+    struct xtimer_list *running_timer;
+    long long timer_tick;
+    list_head free_timer;
+    int free_timer_num;
+    struct xtvec_root tv1;
+    struct xtvec tv2;
+    struct xtvec tv3;
+    struct xtvec tv4;
+    struct xtvec tv5;
+};
+
+struct xtimer_list {
+    struct list_head entry;
+    struct list_head attach_entry;
+    int timer_type; // 0:deadline 1: repeattimer 2:fixedtimer outher:deadline
+    long long expires;
+    int expire_time;
+    int fixed_timer_execute_times;
+    struct xtvec_base *base;
+
+    a8::XTimerFunc timer_func;
+    a8::XTimerAfterFunc timer_after_func;
+    a8::XParams param;
+};
+
+static void InternalAddXTimer(struct xtvec_base *base, struct xtimer_list *timer)
+{
+    long long expires = timer->expires;
+    long long idx = expires - base->timer_tick;
+    struct list_head *vec;
+
+    if (idx < 0) {
+        vec = base->tv1.vec + (base->timer_tick & TVR_MASK);
+    }else if (idx < TVR_SIZE) {
+        int i = expires & TVR_MASK;
+        vec = base->tv1.vec + i;
+    } else if (idx < 1 << (TVR_BITS + TVN_BITS)) {
+        int i = (expires >> TVR_BITS) & TVN_MASK;
+        vec = base->tv2.vec + i;
+    } else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) {
+        int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK;
+        vec = base->tv3.vec + i;
+    } else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) {
+        int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK;
+        vec = base->tv4.vec + i;
+    } else {
+        int i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK;
+        vec = base->tv5.vec + i;
+    }
+    list_add_tail(&timer->entry, vec);
+}
+
+static int Cascade(struct xtvec_base *base, struct xtvec *tv, int index)
+{
+    /* cascade all the timers from tv up one level */
+    struct xtimer_list *timer, *tmp;
+    struct list_head tv_list;
+
+    // 将tv数组中以index为下标的定时器队列取出，准备搬移
+    list_replace_init(tv->vec + index, &tv_list);
+
+    // 根据超时时间，将队列中的定时器重新排队。定时器往上一级时间轮排队的过程就          // 在这里发生。
+    list_for_each_entry_safe(timer, tmp, &tv_list, entry) {
+        InternalAddXTimer(base, timer);
+    }
+    return index;
+}
+
+static inline int DetachTimer(struct xtimer_list *timer)
+{
+    if (!list_empty(&timer->entry)) {
+        list_del_init(&timer->entry);
+    }
+    return 1;
+}
+
+static inline void InitTimerList(xtvec_base* base, xtimer_list* timer, int timer_type,
+                                 long long expires, int expire_time, a8::XParams& param,
+                                 a8::XTimerFunc timer_func, a8::XTimerAfterFunc timer_after_func)
+{
+    INIT_LIST_HEAD(&timer->entry);
+    INIT_LIST_HEAD(&timer->attach_entry);
+    timer->timer_type = timer_type;
+    timer->expires = expires;
+    timer->expire_time = expire_time;
+    timer->fixed_timer_execute_times = 0;
+    timer->base = base;
+    timer->timer_func = timer_func;
+    timer->timer_after_func = timer_after_func;
+    timer->param = param;
+}
+
+namespace a8
+{
+
+    XTimer::XTimer()
+    {
+        base_ = new xtvec_base();
+        base_->running_timer = nullptr;
+        base_->timer_tick = get_tick_count_func_(context_);
+        INIT_LIST_HEAD(&base_->free_timer);
+        base_->free_timer_num = 0;
+        for (int j = 0; j < TVN_SIZE; j++) {
+            INIT_LIST_HEAD(base_->tv5.vec + j);
+            INIT_LIST_HEAD(base_->tv4.vec + j);
+            INIT_LIST_HEAD(base_->tv3.vec + j);
+            INIT_LIST_HEAD(base_->tv2.vec + j);
+        }
+        for (int j = 0; j < TVR_SIZE; j++) {
+            INIT_LIST_HEAD(base_->tv1.vec + j);
+        }
+    }
+
+    XTimer::~XTimer()
+    {
+        Clear();
+        delete base_;
+        base_ = nullptr;
+    }
+
+    void XTimer::Init(XGetTickCountFunc func, void* context, int gc_time, int cache_timer_num)
+    {
+        get_tick_count_func_ = func;
+        context_ = context_;
+        gc_time_ = gc_time;
+        cache_timer_num_ = cache_timer_num;
+        AddRepeatTimer(gc_time_,
+                       a8::XParams().SetSender(this),
+                       &XTimer::GC_XTimerFunc);
+    }
+
+    void XTimer::Update()
+    {
+        if (get_tick_count_func_(context_) >= base_->timer_tick) {
+            UpdateTimer();
+        }
+    }
+
+    xtimer_list* XTimer::AddDeadLineTimer(int expire_time, a8::XParams param, a8::XTimerFunc timer_func,
+                                        a8::XTimerAfterFunc timer_after_func)
+    {
+        xtimer_list *timer = NewTimerList();
+        InitTimerList(base_,
+                      timer,
+                      0,
+                      get_tick_count_func_(context_) + expire_time,
+                      expire_time,
+                      param,
+                      timer_func,
+                      timer_after_func);
+        ModifyTimer(timer, expire_time);
+        return timer;
+    }
+
+    xtimer_list* XTimer::AddDeadLineTimerAndAttach(int expire_time, a8::XParams param, a8::XTimerFunc timer_func,
+                                                 list_head* attach_list, a8::XTimerAfterFunc timer_after_func)
+    {
+        xtimer_list* timer = AddDeadLineTimer(expire_time, param, timer_func, timer_after_func);
+        list_add_tail(&timer->attach_entry, attach_list);
+        return timer;
+    }
+
+    xtimer_list* XTimer::AddRepeatTimer(int expire_time, a8::XParams param, a8::XTimerFunc timer_func)
+    {
+        xtimer_list *timer = NewTimerList();
+        InitTimerList(base_,
+                      timer,
+                      1,
+                      get_tick_count_func_(context_) + expire_time,
+                      expire_time,
+                      param,
+                      timer_func,
+                      nullptr);
+        ModifyTimer(timer, expire_time);
+        return timer;
+    }
+
+    void XTimer::ModifyTimer(xtimer_list* timer, int expire_time)
+    {
+        DetachTimer(timer);
+        timer->expire_time = expire_time;
+        if (timer->timer_type == 2) {
+            long long tick = get_tick_count_func_(context_);
+            long long today_passed_seconds = time(nullptr) - a8::GetDaySeconds(time(nullptr), 0);
+            timer->expires = (tick - today_passed_seconds * 1000) + expire_time;
+            if (timer->fixed_timer_execute_times > 0) {
+                if (timer->expires <= tick) { //已过期
+                    timer->expires += 1000 * 3600 * 24;
+                }
+            }
+        }else {
+            timer->expires = get_tick_count_func_(context_) + expire_time;
+        }
+        InternalAddXTimer(base_, timer);
+    }
+
+    void XTimer::DeleteTimer(xtimer_list* timer)
+    {
+        if (timer->timer_after_func) {
+            timer->timer_after_func(timer->param);
+        }
+        DetachTimer(timer);
+        if (!list_empty(&timer->attach_entry)) {
+            list_del_init(&timer->attach_entry);
+        }
+        AddToFreeList(timer);
+    }
+
+    xtimer_list* XTimer::GetTimerByAttach(list_head* attach_entry)
+    {
+        if (attach_entry) {
+            xtimer_list* timer = list_entry(attach_entry, struct xtimer_list, attach_entry);
+            return timer;
+        } else {
+            return nullptr;
+        }
+    }
+
+    void XTimer::UpdateTimer()
+    {
+        struct xtvec_base *base = base_;
+        while (get_tick_count_func_(context_) >= base->timer_tick) {
+            struct list_head work_list;
+            struct list_head *head = &work_list;
+            int index = base->timer_tick & TVR_MASK;
+
+            if (!index &&
+                (!Cascade(base, &base->tv2, INDEX(0))) &&
+                (!Cascade(base, &base->tv3, INDEX(1))) &&
+                !Cascade(base, &base->tv4, INDEX(2))) {
+                Cascade(base, &base->tv5, INDEX(3));
+            }
+            ++base->timer_tick;
+            list_replace_init(base->tv1.vec + index, &work_list);
+            while (!list_empty(head)) {
+                struct xtimer_list *timer;
+                timer = list_first_entry(head, struct xtimer_list,entry);
+                base->running_timer = timer;
+                if (timer->timer_func) {
+                    timer->timer_func(timer->param);
+                }
+                if (timer->timer_after_func) {
+                    timer->timer_after_func(timer->param);
+                }
+                switch (timer->timer_type) {
+                case 1:
+                case 2: //循环类定时 fixed timer也是循环定时器
+                    {
+                        if (timer->timer_type == 2) {
+                            timer->fixed_timer_execute_times++;
+                        }
+                        ModifyTimer(timer, timer->expire_time);
+                    }
+                    break;
+                default: //deadline timer
+                    {
+                        DetachTimer(timer);
+                        if (!list_empty(&timer->attach_entry)) {
+                            list_del_init(&timer->attach_entry);
+                        }
+                        AddToFreeList(timer);
+                    }
+                    break;
+                }
+            }
+        }
+        base->running_timer = nullptr;
+    }
+
+    xtimer_list* XTimer::NewTimerList()
+    {
+        if (!list_empty(&base_->free_timer)) {
+            xtimer_list* timer = list_first_entry(&base_->free_timer, struct xtimer_list,entry);
+            list_del_init(&timer->entry);
+            base_->free_timer_num--;
+            return timer;
+        } else {
+            return new xtimer_list();
+        }
+    }
+
+    void XTimer::AddToFreeList(xtimer_list* timer)
+    {
+        list_add_tail(&timer->entry, &base_->free_timer);
+        base_->free_timer_num++;
+    }
+
+    void XTimer::Clear()
+    {
+        auto free_timers =
+            [] (list_head* head)
+            {
+                while (!list_empty(head)) {
+                    struct xtimer_list *timer;
+                    timer = list_first_entry(head, struct xtimer_list,entry);
+                    DetachTimer(timer);
+                    if (!list_empty(&timer->attach_entry)) {
+                        list_del_init(&timer->attach_entry);
+                    }
+                    delete timer;
+                }
+            };
+        for (int j = 0; j < TVN_SIZE; j++) {
+            free_timers(base_->tv5.vec + j);
+            free_timers(base_->tv4.vec + j);
+            free_timers(base_->tv3.vec + j);
+            free_timers(base_->tv2.vec + j);
+        }
+        for (int j = 0; j < TVR_SIZE; j++) {
+            free_timers(base_->tv1.vec + j);
+        }
+        free_timers(&base_->free_timer);
+    }
+
+    void XTimer::GC_XTimerFunc(const a8::XParams& param)
+    {
+        XTimer* timer = (XTimer*)param.sender.GetUserData();
+        int i = 0;
+        while (!list_empty(&timer->base_->free_timer) &&
+               timer->base_->free_timer_num > timer->cache_timer_num_ && i < 1000) {
+            xtimer_list* timer1 = list_first_entry(&timer->base_->free_timer, struct xtimer_list, entry);
+            list_del_init(&timer1->entry);
+            delete timer1;
+
+            timer->base_->free_timer_num--;
+            i++;
+        }
+    }
+
+}
diff --git a/a8/xtimer.h b/a8/xtimer.h
new file mode 100644
index 0000000..f398f74
--- /dev/null
+++ b/a8/xtimer.h
@@ -0,0 +1,60 @@
+/*
+ * 仿照linux2.6内核定时器实现
+ */
+#ifndef A8_XTIMER_H
+#define A8_XTIMER_H
+
+struct xtimer_list;
+struct xtvec_base;
+
+namespace a8
+{
+    typedef void (*XTimerFunc)(const a8::XParams& param);
+    typedef void (*XTimerAfterFunc)(const a8::XParams& param);
+    typedef long long (*XGetTickCountFunc)(void*);
+
+    class XTimer
+    {
+    private:
+        XTimer();
+        ~XTimer();
+
+    public:
+        void Init(XGetTickCountFunc func, void* context, int gc_time, int cache_timer_num);
+
+        void Update();
+
+        //添加截止时间定时器(一次性定时器)
+        xtimer_list* AddDeadLineTimer(int expire_time, a8::XParams param, a8::XTimerFunc timer_func,
+                                     a8::XTimerAfterFunc timer_after_func = nullptr);
+        xtimer_list* AddDeadLineTimerAndAttach(int expire_time, a8::XParams,
+                                               a8::XTimerFunc timer_func,
+                                               list_head* attach_list,
+                                               a8::XTimerAfterFunc timer_after_func = nullptr);
+        //添加重复执行定时器(周期性定时器)
+        xtimer_list* AddRepeatTimer(int expire_time, a8::XParams param, a8::XTimerFunc timer_func);
+        //修改定时器参数
+        void  ModifyTimer(xtimer_list* timer, int expire_time);
+        //删除定时器
+        void DeleteTimer(xtimer_list* timer);
+        //通过关联的list_head获取定时器对象
+        xtimer_list* GetTimerByAttach(list_head* attach_entry);
+
+    private:
+        void UpdateTimer();
+        xtimer_list* NewTimerList();
+        void AddToFreeList(xtimer_list* timer);
+        void Clear();
+        static void GC_XTimerFunc(const a8::XParams& param);
+
+    private:
+        xtvec_base* base_ = nullptr;
+        XGetTickCountFunc get_tick_count_func_ = nullptr;
+        void* context_ = nullptr;
+        int gc_time_ = 10;
+        int cache_timer_num_ = 100;
+    };
+
+}
+
+#endif