paper4—Multi-MPE_Trigger_Algorithm—temp



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  1. Description: when SMD start, this algorithm will run as a deamon, two roles: Master, Slave. When the SMD is elected as a Master role, then, the MPE will be the master MPE accessed by other SMD, and related process data will backup to other SMD (Slave MPE).

  3. ctrl: Master or Slave, this value is set by batman-adv;
  4.   ctrl=0, SMD is Slave role;
  5.   ctrl=1, SMD is elected as a Master role;

  7. changed: Master or Slave, this value is set by batman-adv;
  8.   changed=0, Master SMD is not changed, so, do not need to create thread in MAIN again for data synchronization;
  9.   changed=1, Master SMD is changed, so, need to create thread in MAIN again for data synchronization;

  11. changed=0;
  12. is_me=-1;
  13. prev_state=-1; //0:Slave; 1:Master;

  15. //READ_CTRL, set URL of application system. Access master_ip in browser.
  16. PROCEDURE: READ_CTRL
  17. prev_ip=0.0.0.0;
  18. while true do
  19.   read the value of ctrl set by batman-adv;
  20.   read master_ip of Master SMD;
  21.   if master_ip==me_ip and is_me!=-1 then
  22.     prev_state=is_me;
  23.     is_me=1;
  24.   else if master_ip!=me_ip and is_me!=-1 then
  25.     prev_state=is_me;
  26.     is_me=0;
  27.   end if
  28.   if master_ip!=prev_ip then
  29.     changed=1;
  30.     prev_ip=master_ip;
  31.     add (or update) "master_ip mpe.localhost" in /etc/hosts;
  32.   end if
  33.   sleep 1s;
  34. done
  35. END PROCEDURE READ_CTRL

  37. //****************************** MAIN Thread
  38. PROCEDURE: MAIN
  39. pthread_create(READ_CTRL);
  40. sleep 1s; //waiting for READ_CTRL to read the value of ctrl and master_ip of Master SMD
  41. start=1; //set initial state
  42. while true do
  43.   if start==1 and ctrl==1 then
  44.     start=0;
  45.     is_me=1;
  46.     pthread_create(Master);
  47.     pthread_join(Master);
  48.   else if start==1 and ctrl==0 then
  49.     start=0;
  50.     is_me=0;
  51.     pthread_create(Slave);
  52.     pthread_join(Slave);
  53.   else if start==0 and changed==1 and ctrl==1 then
  54.     pthread_create(Master);
  55.     pthread_join(Master);
  56.   else if start==0 and changed==1 and ctrl==0 then
  57.     sleep(2);    //waiting master initialize
  58.     pthread_create(Master);
  59.     pthread_join(Master);
  60.   else //start==0 and changed==0
  61.     continue;
  62.   end if
  63. done
  64. END PROCEDURE MAIN

  66. //****************************** Master Thread
  67. PROCEDURE: Master
  68. socket();
  69. bind();
  70. listen();
  71. while true do
  72.   accept(); //waiting for connect from Slave
  73.   pthread_create(M_THREAD);
  74. done
  75. END PROCEDURE Master

  77. //****************************** M_THREAD Thread
  78. PROCEDURE: M_THREAD
  79. while true do //communication between Master & Slave
  80.   if database updating then
  81.     send synchronous data to Slave;
  82.   end if
  83. done
  84. END PROCEDURE M_THREAD

  86. //****************************** Slave Thread
  87. PROCEDURE: Slave
  88. socket();
  89. connect();
  90. while true do
  91.   if receive synchronous data from Master then
  92.     update database;
  93.   end if
  94. done
  95. END PROCEDURE Slave





posted @ 2016-02-01 00:00  张同光  阅读(72)  评论(0)  编辑  收藏  举报