close Warning: Can't synchronize with repository "(default)" (Unsupported version control system "svn": /usr/lib/python2.7/dist-packages/libsvn/_fs.so: failed to map segment from shared object: Cannot allocate memory). Look in the Trac log for more information.

Changes between Version 4 and Version 5 of wade/linuxProgramming


Ignore:
Timestamp:
Jan 10, 2009, 5:37:26 PM (17 years ago)
Author:
wade
Comment:

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  • wade/linuxProgramming

    v4 v5  
    3737
    3838== Pipe ==
    39  * FD[0] 負責 read pipe。FD[1] 負責 write pipe。
     39 * FD[0] 負責 read pipe。FD[1] 負責 write pipe。
     40   FD[1] → [PIPE] → FD[0]。
    4041 * read() 會被 block 住，所以不用擔心 parent 會比 child 先結束，而導致 child 也跟著結束 (因為 child process 是依附著 parent process 而存在，依存關係可透過 pstree 查詢)。
    41  * FD 也是分開，child 跟 parent 有各自的 FD[0]、FD[1]。
     42 * 先使用 pipe(FD[2])，再使用 fork() 時，FD[2] 也會同時複製兩份，child 跟 parent 有各自的 FD[0]、FD[1]，所以要記得關掉不必要的 FD ，兩個 processes 各自與 pipe 相接。
    4243 
    4344== Reference ==