class.Define a subclass author to inherit the parent class person, as follows:function Author (name,books) { Author.superClass.constructor.call (this, name); this. book=books; } Extend (Author,person); Author.prototype.getBooks=function () { returnthis. Book; }Here the constructor of the parent class is called through its superclass property in the constructor of the subclass, and the call method is used to transform this point of the method invocation, so that the
frame where the lock was obtained3. Re-entry lock Reentrantlockjava.util.concurrent.lockThe framework in a Lock lock is an abstraction that allows the implementation of a lock to be implemented as a Java class, rather than as a language feature.This leaves space for a variety of Lock implementations that may have different scheduling algorithms, performance characteristics, or locking semantics.ReentrantLockClass is implemented Lock , it has the synchronized same concurrency and memory semantic
/wKioL1j4bnriIV-wAADc6VwWjjE827.png-wh_500x0-wm_ 3-wmp_4-s_1758970625.png "title=" screenshot from 2017-04-18 21-06-17.png "alt=" Wkiol1j4bnriiv-waadc6vwwjje827.png-wh_50 "/>ACL Mask and inheritanceA file with an ACL "has a mask" that can limit the maximum permissions for the group that owns the file, and can limit the maximum permissions that the supplemental users and groups in the ACL haveSetfacl-m M:rwxfileThe "directory can have default ACL" entr
following characters, a group of three, each of which is a combination of three parameters, is "rwx". where [R] stands for readable (read), [W] stands for writable (write), [x] stands for executable (execute). Note that the location of the three permissions does not change, and if there is no permission, a minus sign [-] is present. The properties of each file are determined by the 10 characters of the first part of the left (for example).0-9 of these numbers are used to indicate from left to r
that currently owns Sk_buff.Tail: Point to the current end address of the protocol data. As with the data pointer, the value of the pointer changes depending on the protocol layer that currently owns the Sk_buff.End: Points to the end of the in-memory data area. As with the head pointer, the value of the pointer is fixed when the Sk_buff is assigned.Sk_buff's two length fields, Len and truesize, describe t
0, Mutual exclusion amountMutex under Windowsis a kernel object that checks whether the current thread ID and the thread ID that owns the mutex are consistent each time WaitForSingleObject and ReleaseMutex.When multiple wait** is required to correspond to multiple ReleaseMutex, when ReleaseMutex too many times if you find that the current possessive mutex thread ID and the current call ReleaseMutex the thread ID is inconsistent, only return flase, Get
processes.
Characteristics
A Core object
If the thread that owns the mutex ends, a "abandoned" error message is generated
You can use wait ... () waits for one or more mutexes
Can be named so that it can be opened by another process
Can only be freed by the thread that owns it.
related functions
).
In the following characters, a group of three, each of which is a combination of three parameters, is "rwx". where [R] stands for readable (read), [W] stands for writable (write), [x] stands for executable (execute). Note that the location of the three permissions does not change, and if there is no permission, a minus sign [-] is present.The properties of each file are determined by the 10 characters of the first part of the left (for example).0-9 of these numbers are used to indicate f
thread synchronization. Just use the CCriticalSection class member function lock () and unlock () in the thread function to demarcate the protected code fragment. The resources used by the Lock () are automatically considered to be protected in the critical zone. These resources can be accessed by other threads after unlock. Mutex (mutex) mutex is similar to the critical section, only the line friend that owns the mutex has permission to access the r
Windows 8, the birth of this system confirms the Microsoft software giant's turn, but this turned Hua not gorgeous, depending on Win8 's new ecology can not be as prosperous as the previous desktop platform, that is, Win8 apps system can bring a new round of revolution.
From the beginning until now, for software vendors, especially the system has always been who owns the ecosystem who owns the world, looki
say that an element "owns layout" or "gets layout", or that an element "has layout", we mean that its Microsoft proprietary attribute Haslayout is set to true. A "layout element" can be an element that has a layout by default or an element that gets layout by setting some CSS properties. If an HTML element has a Haslayout attribute, then the haslayout value of the element must be true,haslayout only if the read-only property is triggered, it is irrev
permissions and file types)
If there is information output, it should be carefully considered, is deleted, reinstall, or fix the problem.
(6) Several examples of RPM applications
A. If you accidentally delete some files, but not sure which files are deleted. If you want to verify the entire system and see what files are missing, you can type: Rpm–va
B. If some files are missing or damaged, you can reinstall them or uninstall them before installing the package. If you encounter a file that y
processes. Let's take a look at its basic process.
After the ① user initiates the shutdown instruction, The program that initiates the shutdown instruction notifies the Windows subsystem that the Csrss.exe,csrss.exe will make a data exchange with Winlogon.EXE, followed by Winlogon.EXE to notify CSRSS.EXE to begin shutting down the system process.
②csrss.exe receives Winlogon.EXE notification, sequentially queries the user process that owns the top-
Group members-A: Adding a user to a group-D: Delete a user member from within a group-M: Defines a list of group members, separated by commasEnquiry Account InformationID Command Query user identityThe groups command queries the group to which the user belongsUsers, W, who commands query for user information that is logged on to the hostPermissions and attribution of files/directoriesAccess rightsRead R:4 allows viewing of file contents, displaying directory listingsWrite W:2 allows you to modi
create a soft linkThe 9 letters after the 1th character indicate the permission bit for the file or directory.R table is read (read), W for write (write), X for Execute (EXECUTE)The first three represent the permissions of the file owner, and the middle three represents the permissions that the file group owns, and the last three represent the permissions that other users have.Like what:-rw-r--r--1 root root 762 07-29 18:19 exitIndicates that the own
(one-time reading device).
In the following characters, a group of three, each of which is a combination of three parameters, is "rwx". where [R] stands for readable (read), [W] stands for writable (write), [x] stands for executable (execute). Note that the location of the three permissions does not change, and if there is no permission, a minus sign [-] is present.The properties of each file are determined by the 10 characters of the first part of the left (for example).0-9 of these numbe
permissions see book notes)Chmod-r representing cascading change propertiesAnother way to change the permissions of a directory or fileUser owner referred to as U group name g other users abbreviation o all users short Achmod u=rwx,og=rx file or directory namechmod u-x file or directory name//reduce execution rights to the user who owns the file or directory nameThe CHGRP command is used to change the user group to which the file or directory belongs
Access rights:READ: Allow viewing of content-readWrite: Allow content to be modified-writeExecutable: Allow to run and switch-excute(The above three points rwx together determine the final authority)Attribution Relationship:Owner: The user who owns this file/directory-userOwning group: The group that owns this file/directory-groupOther users: Users other than the owner, the owning group-otherAll users: The
)?The lock framework in Java.util.concurrent.lock is an abstraction of locking, which allows the implementation of a lock to be implemented as a Java class, rather than as a language feature.This leaves space for the various implementations of lock, which may have different scheduling algorithms, performance characteristics, or locking semantics. The Reentrantlock class implements lock, which has the same concurrency and memory semantics as synchronized, but adds features like lock polling, time
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