Merge pull request #460 from weiyanhua100/master

add communication.

Author: geekcomputers

communication/file.py

@@ -0,0 +1,41 @@
+#!/usr/bin/python
+# coding: utf-8
+ 
+import os
+import sys
+import math
+ 
+ 
+def slice(mink, maxk):
+    s = 0.0
+    for k in range(mink, maxk):
+        s += 1.0/(2*k+1)/(2*k+1)
+    return s
+ 
+ 
+def pi(n):
+    pids = []
+    unit = n / 10
+    for i in range(10):  # 分10个子进程
+        mink = unit * i
+        maxk = mink + unit
+        pid = os.fork()
+        if pid > 0:
+            pids.append(pid)
+        else:
+            s = slice(mink, maxk)  # 子进程开始计算
+            with open("%d" % os.getpid(), "w") as f:
+                f.write(str(s))
+            sys.exit(0)  # 子进程结束
+    sums = []
+    for pid in pids:
+        os.waitpid(pid, 0)  # 等待子进程结束
+        with open("%d" % pid, "r") as f:
+            sums.append(float(f.read()))
+        os.remove("%d" % pid)  # 删除通信的文件
+    return math.sqrt(sum(sums) * 8)
+ 
+if __name__ == '__main__': 
+    print "start"
+    print pi(10000000)
+

communication/pipe.py

@@ -0,0 +1,42 @@
+# coding: utf-8
+ 
+import os
+import sys
+import math
+ 
+ 
+def slice(mink, maxk):
+    s = 0.0
+    for k in range(mink, maxk):
+        s += 1.0/(2*k+1)/(2*k+1)
+    return s
+ 
+ 
+def pi(n):
+    childs = {}
+    unit = n / 10
+    for i in range(10):  # 分10个子进程
+        mink = unit * i
+        maxk = mink + unit
+        r, w = os.pipe()
+        pid = os.fork()
+        if pid > 0:
+            childs[pid] = r  # 将子进程的pid和读描述符存起来
+            os.close(w)  # 父进程关闭写描述符，只读
+        else:
+            os.close(r)  # 子进程关闭读描述符，只写
+            s = slice(mink, maxk)  # 子进程开始计算
+            os.write(w, str(s))
+            os.close(w)  # 写完了，关闭写描述符
+            sys.exit(0)  # 子进程结束
+    sums = []
+
+    for pid, r in childs.items():
+        sums.append(float(os.read(r, 1024)))
+        os.close(r)  # 读完了，关闭读描述符
+        os.waitpid(pid, 0)  # 等待子进程结束
+    return math.sqrt(sum(sums) * 8)
+ 
+ 
+print pi(10000000)
+

communication/socket_conn.py

@@ -0,0 +1,39 @@
+# coding: utf-8
+ 
+import os
+import sys
+import math
+import socket
+ 
+def slice(mink, maxk):
+    s = 0.0
+    for k in range(mink, maxk):
+        s += 1.0/(2*k+1)/(2*k+1)
+    return s
+ 
+def pi(n):
+    childs = {}
+    unit = n / 10
+    for i in range(10):  # 分10个子进程
+        mink = unit * i
+        maxk = mink + unit
+        rsock, wsock = socket.socketpair()
+        pid = os.fork()
+        if pid > 0:
+            childs[pid] = rsock
+            wsock.close()
+        else:
+            rsock.close()
+            s = slice(mink, maxk)  # 子进程开始计算
+            wsock.send(str(s))
+            wsock.close()
+            sys.exit(0)  # 子进程结束
+    sums = []
+    for pid, rsock in childs.items():
+        sums.append(float(rsock.recv(1024)))
+        rsock.close()
+        os.waitpid(pid, 0)  # 等待子进程结束
+    return math.sqrt(sum(sums) * 8)
+ 
+ 
+print pi(10000000)