From fdddc814c7fc532a97c3cd5091971357234578d1 Mon Sep 17 00:00:00 2001
From: lizhao <lichao1@xiangyuyiliao.com>
Date: Mon, 8 Jun 2026 17:13:25 +0800
Subject: [PATCH] fitler buffer with lock

---
 Zmq/filterProcess.py | 79 ++++++++++++++++++++++----------------------
 1 file changed, 39 insertions(+), 40 deletions(-)

diff --git a/Zmq/filterProcess.py b/Zmq/filterProcess.py
index 5d25eb8..1486fa1 100644
--- a/Zmq/filterProcess.py
+++ b/Zmq/filterProcess.py
@@ -17,34 +17,39 @@ class FilterRingBuffer:
         """
         self.n_chan = n_chan
         self.n_points = n_points
-
         self.buffer = np.zeros((n_chan, n_points), dtype=np.float64)
-        self.current_ptr = 0  # 写入指针：指向下一个要写入的位置
-        self.total_samples = 0  # 已写入总点数
-        self.lock = threading.Lock()  # 线程安全锁
+        self.current_ptr = 0
+        self.total_samples = 0
+        self.lock = threading.Lock()  # 仅保护元数据
 
     def appendBuffer(self, data):
         """
         追加数据到缓存（与paradigmRingBuffer接口一致）
         :param data: 输入数据，shape=(n_chan, n_samples)
         """
+        n = data.shape[1]
+        if n == 0:
+            return
+        
+        # -------- 第一步：仅加锁读取/更新元数据（持锁极短）--------
         with self.lock:
-            n = data.shape[1]
-            if n == 0:
-                return
-
-            # 环形写入逻辑：指针到末尾则绕回
-            write_end = self.current_ptr + n
-            if write_end <= self.n_points:
-                self.buffer[:, self.current_ptr:write_end] = data
-            else:
-                split = self.n_points - self.current_ptr
-                self.buffer[:, self.current_ptr:] = data[:, :split]
-                self.buffer[:, :write_end - self.n_points] = data[:, split:]
-
-            # 更新指针（取模保证环形）和计数（不超过缓存总长度）
-            self.current_ptr = write_end % self.n_points
-            self.total_samples = min(self.total_samples + n, self.n_points)
+            old_ptr = self.current_ptr
+            new_ptr = (old_ptr + n) % self.n_points
+            new_total = min(self.total_samples + n, self.n_points)
+        
+        # -------- 第二步：数组写入（耗时操作，移出锁外）--------
+        write_end = old_ptr + n
+        if write_end <= self.n_points:
+            self.buffer[:, old_ptr:write_end] = data
+        else:
+            split = self.n_points - old_ptr
+            self.buffer[:, old_ptr:] = data[:, :split]
+            self.buffer[:, :write_end - self.n_points] = data[:, split:]
+        
+        # -------- 第三步：再次加锁更新最终元数据 --------
+        with self.lock:
+            self.current_ptr = new_ptr
+            self.total_samples = new_total
 
     def getData(self, count):
         """
@@ -53,39 +58,33 @@ class FilterRingBuffer:
         :param count: 读取点数
         :return: np.ndarray, shape=(n_chan, count)
         """
-        # with self.lock:
-        count = min(count, self.total_samples)
-        if count == 0:
-            return np.zeros((self.n_chan, 0))
+        # -------- 第一步：加锁获取最新元数据（持锁极短）--------
+        with self.lock:
+            count = min(count, self.total_samples)
+            if count == 0:
+                return np.zeros((self.n_chan, 0))
+            end = self.current_ptr
+            start = end - count
 
-        # 环形读取：end是当前写入指针（最新数据的下一位），start是end - count
-        end = self.current_ptr
-        start = end - count
         if start >= 0:
-            return self.buffer[:, start:end].copy()
+            res = self.buffer[:, start:end].copy()
         else:
-            # 跨环形边界：前半部分从缓存末尾取，后半部分从开头取
-            part1 = self.buffer[:, start:]  # start为负，等价于n_points + start
+            part1 = self.buffer[:, start:]
             part2 = self.buffer[:, :end]
-            return np.concatenate((part1, part2), axis=1)
+            res = np.concatenate((part1, part2), axis=1).copy()
+        return res
 
     def get_latest_n_points(self, n):
-        """
-        扩展方法：获取最新的n个点（不移动读指针，用于滑动窗口）
-        :param n: 点数
-        :return: np.ndarray, shape=(n_chan, n) | None（数据不足时）
-        """
-        if self.total_samples < n:
-            return None
+        with self.lock:
+            if self.total_samples < n:
+                return None
         return self.getData(n)
 
     def GetDataLenCount(self):
-        """获取当前缓存总点数（兼容原有接口）"""
         with self.lock:
             return self.total_samples
 
     def resetAllPara(self):
-        """重置所有缓存和指针（兼容原有接口）"""
         with self.lock:
             self.buffer.fill(0.0)
             self.current_ptr = 0