{"id":125054,"date":"2020-06-27T02:57:28","date_gmt":"2020-06-26T18:57:28","guid":{"rendered":"http:\/\/4563.org\/?p=125054"},"modified":"2020-06-27T02:57:28","modified_gmt":"2020-06-26T18:57:28","slug":"%e6%b1%82%e5%90%84%e4%bd%8d%e6%8c%87%e7%82%b9%e4%b8%80%e4%b8%8b%e8%bf%99%e9%87%8c-python-lock-%e7%9a%84%e7%94%a8%e6%b3%95%ef%bc%8c%e6%88%91%e6%83%b3%e4%ba%86%e5%be%88%e4%b9%85%e8%bf%98%e6%98%af","status":"publish","type":"post","link":"http:\/\/4563.org\/?p=125054","title":{"rendered":"\u6c42\u5404\u4f4d\u6307\u70b9\u4e00\u4e0b\u8fd9\u91cc Python lock \u7684\u7528\u6cd5\uff0c\u6211\u60f3\u4e86\u5f88\u4e45\u8fd8\u662f\u4e0d\u7406\u89e3\u3002"},"content":{"rendered":"
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\u6c42\u5404\u4f4d\u6307\u70b9\u4e00\u4e0b\u8fd9\u91cc Python lock \u7684\u7528\u6cd5\uff0c\u6211\u60f3\u4e86\u5f88\u4e45\u8fd8\u662f\u4e0d\u7406\u89e3\u3002 <\/h1>\n

<\/p>\n

\n
\u8cc7\u6df1\u5927\u4f6c : oooolongtea <\/span> <\/i> 7<\/span> <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
\u8fd9\u662f\u4e00\u9053 leetcode \u9898\u76ee\u7684\u7b54\u6848\uff1a https:\/\/leetcode.com\/problems\/print-foobar-alternately\/discuss\/603570\/python3%3A-40ms-86.64-Faster-100-Less-memory-using-threading.Lock<\/p>\n

\u7528\u4e24\u4e2a lock \u53bb\u63a7\u5236 def foo()\u548c def bar()\u8fd0\u884c\u7684\u987a\u5e8f\u3002
\u6211\u4e0d\u7406\u89e3\u7684\u5730\u65b9\u662f\uff1a
\u5728__init__\u91cc\u9762\uff0cself.bar_lock.acquire()\u5df2\u7ecf\u628a self.bar_lock \u7ed9\u9501\u4e0a\u4e86\u3002
\u8fd0\u884c\u7684\u65f6\u5019\uff0cfoo()\u548c bar()\u4f1a\u540c\u65f6\u8fdb\u884c\uff0c\u4f46\u662f\u56e0\u4e3a\u5728 bar()\u91cc\u9762\uff0c\u6709\u4e00\u4e2a self.bar_lock.acquire()\uff0c\u8fd9\u884c\u4ee3\u7801\u4e4b\u524d\u5df2\u7ecf\u8fd0\u884c\u8fc7\u4e86\uff0c\u56e0\u6b64\u5728\u8fd9\u91cc\u53c8\u518d\u4e00\u6b21\u628a self.bar_lock \u7ed9 acquire \u4f4f\u4e86\uff0c\u7b49\u4e8e\u662f self.bar_lock \u88ab acquire \u4e86\u4e24\u6b21\u3002
\u6211\u4e0a\u7f51\u67e5\u4e86\u4e00\u4e0b\uff0c\u9047\u5230\u8fd9\u4e2a\u60c5\u51b5\uff0c\u7b2c\u4e8c\u6b21 acquire \u7684\u65f6\u5019\uff0c\u5982\u679c\u53d1\u73b0\u8fd9\u4e2a self.bar_lock \u4e4b\u524d\u5df2\u7ecf\u88ab acquire\uff0c\u90a3\u4e48\u8fd9\u4e2a\u7b2c\u4e8c\u6b21\u7684 acquire \u5c31\u4f1a\u505c\u5728\u8fd9\u91cc\uff0c\u7b49\u5230 self.bar_lock \u88ab release \u3002
\u90a3\u4e48\u6211\u7684\u95ee\u9898\u6765\u4e86\uff0c\u5982\u679c\u88ab acquire \u4e86\u4e24\u6b21\u7684\u8bdd\uff0c\u6211\u4eec\u9700\u8981\u4e0d\u8981 release \u4e24\u6b21\uff1f \u770b\u4ee3\u7801\uff0c\u6211\u4eec\u4e0d\u9700\u8981 release \u4e24\u6b21\u3002 <\/div>\n

\u5927\u4f6c\u6709\u8a71\u8aaa<\/b> (6<\/span>) <\/div>\n
<\/div>\n<\/p><\/div>\n<\/p><\/div>\n
    \n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : noqwerty <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5efa\u8bae\u8bfb\u4e00\u4e0b\u6587\u6863\uff1a https:\/\/docs.python.org\/3\/library\/threading.html#threading.Lock.acquire<\/p>\n

    \u53e6\u5916\u4e5f\u53ef\u4ee5\u4ece\u8bed\u4e49\u4e0a\u53bb\u7406\u89e3\uff0c\u9501 (Lock) \u53ea\u6709\u4e0a\u9501\u548c\u89e3\u9501\u4e24\u79cd\u72b6\u6001\uff0c\u4e0d\u5b58\u5728\u4f60\u8bf4\u7684\u5f00\u4e24\u6b21\u9501\u7684\u60c5\u51b5\u3002 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : cigarzh <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u4f60\u8bf4\u7684\u90a3\u73a9\u610f\u662f threading.RLock() <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : js8510 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u54c7\u3002leetcode \u90fd\u6709\u4e00\u5343\u591a\u9898\u4e86\u5440\u3002\u6211\u8fd8\u771f\u5728 \u5728\u751f\u4ea7\u73af\u5883\u89c1\u8fc7\u7c7b\u4f3c\u7684\u60c5\u51b5\u3002\u4f46\u662f\u5b9e\u73b0\u548c\u4f60\u53d1\u7684\u8fd9\u4e2a\u6709\u4e0d\u540c<\/p>\n

    \u4f5c\u8005\u7684\u610f\u56fe\u5e94\u8be5\u662f\u8fd9\u6837\uff0c
    \u00b7\u00b7\u00b7
    from threading import Lock<\/p>\n

    class FooBar:
    def __init__(self, n):
    self.n = n
    self.foo_lock = Lock()
    self.bar_lock = Lock()
    self.bar_lock.acquire() # <—- 1<\/p>\n

    def foo(self, printFoo: ‘Callable[[], None]’) -> None:
    for i in range(self.n):
    self.foo_lock.acquire() # <—- 2 | # <—- 5, blocked here and wait for foo_lock
    # printFoo() outputs “foo”. Do not change or remove this line.
    printFoo() # <—- 3
    self.bar_lock.release() # <—- 4<\/p>\n

    def bar(self, printBar: ‘Callable[[], None]’) -> None:
    for i in range(self.n):
    self.bar_lock.acquire() # <—- 2 and blocked here and wait for bar_lock
    # printBar() outputs “bar”. Do not change or remove this line.
    printBar() # <—- 5
    self.foo_lock.release() # <—- 6
    \u00b7\u00b7\u00b7 <\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : lpts007 <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    “`python
    from threading import Lock<\/p>\n

    “` <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : gzfrankie <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u56e0\u4e3a\u90a3\u6bb5\u4ee3\u7801\uff0cfoo_lock \u548c bar_lock \u662f\u4e24\u4e2a\u4e0d\u540c\u7684 lock \u3002
    \u6d41\u7a0b\uff1a
    1. \u5728__INIT__\u91cc\u9501\u4e86 bar_lock
    2.\u8fd9\u65f6\u5019\u4e24\u4e2a\u8fdb\u7a0b\u540c\u65f6\u5f00\u59cb\uff0cbar \u9501\u5728 self.bar_lock.acquire()\u90a3\u91cc\u4e0d\u52a8\u4e86
    3.foo \u6b63\u5e38\u8fd0\u884c\uff0c\u8fd0\u884c\u7ed3\u675f\u4e86\u4e4b\u540e self.bar_lock.release()\u89e3\u9501 bar_lock \uff1b\u8fd0\u884c\u5230\u7b2c\u4e8c\u6b21 foo_lock.acquire()\uff0c\u9501\u4f4f\u4e0d\u52a8
    4.bar_lock \u88ab\u89e3\u9501\uff0cbar \u7ee7\u7eed\u8fd0\u884c\uff0c\u5230\u6700\u540e\u89e3\u9501 foo_lock
    5.foo_lock \u88ab\u89e3\u9501\uff0cfoo \u7ee7\u7eed\u8fd0\u884c<\/p>\n

    \u6240\u4ee5\u662f\u4e24\u4e2a lock\uff0c\u5728 foo \u91cc\u89e3 bar_lock\uff0c\u5728 bar \u91cc\u89e3 foo_lock\uff0c\u4e0d\u5b58\u5728\u540c\u4e00\u4e2a threadacquire \u4e86\u4e24\u6b21\u540c\u4e00\u4e2a lock \u7684\u60c5\u51b5 <\/p><\/div>\n<\/p><\/div>\n<\/li>\n

  • \n
    \n
    \n
    \u8cc7\u6df1\u5927\u4f6c : gzfrankie <\/span> <\/div>\n
    <\/i> <\/span> <\/div>\n<\/p><\/div>\n
    \u5728\u770b\u4e86\u4e00\u4e0b\u4f60\u7684\u7591\u95ee\uff0c\u8865\u5145\u4e00\u4e0b:
    “\u90a3\u4e48\u6211\u7684\u95ee\u9898\u6765\u4e86\uff0c\u5982\u679c\u88ab acquire \u4e86\u4e24\u6b21\u7684\u8bdd\uff0c\u6211\u4eec\u9700\u8981\u4e0d\u8981 release \u4e24\u6b21\uff1f \u770b\u4ee3\u7801\uff0c\u6211\u4eec\u4e0d\u9700\u8981 release \u4e24\u6b21\u3002”
    \u4e0d\u9700\u8981 release \u4e24\u6b21\uff0c\u56e0\u4e3a
    1. \u5982\u679c\u7b2c\u4e00\u6b21 acquire()\u6210\u529f,acquire()\u8fd4\u56de True,\u7a0b\u5e8f\u8fd0\u884c
    2.\u7b2c\u4e8c\u6b21 acquire()\uff0c\u7531\u4e8e lock \u5e76\u6ca1\u6709\u88ab release\uff0c\u7a0b\u5e8f\u88ab\u505c\u5728 acquire \u90a3\u884c\uff1b\u60f3\u8ba9\u7a0b\u5e8f\u7ee7\u7eed\u8fd0\u884c\uff0c\u9700\u8981\u5728\u522b\u7684\u5730\u65b9\u628a\u8fd9\u4e2a lock release \u6389\u3002
    3.release \u4e00\u4e2a\u5df2\u88ab\u89e3\u9501\u7684 lock\uff0cpython \u4f1a throw RuntimeError <\/div>\n<\/p><\/div>\n<\/li>\n
  • \n","protected":false},"excerpt":{"rendered":"

    \u6c42\u5404\u4f4d\u6307\u70b9\u4e00\u4e0b\u8fd9\u91cc Python …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[],"tags":[],"_links":{"self":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/125054"}],"collection":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=125054"}],"version-history":[{"count":0,"href":"http:\/\/4563.org\/index.php?rest_route=\/wp\/v2\/posts\/125054\/revisions"}],"wp:attachment":[{"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=125054"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=125054"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/4563.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=125054"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}