read lock

Read lock: Read is not mutually exclusiveWrite lock: exclusive ReadwritelockSynchronized is exclusive. 1. In the Java concurrent library, reetrantreadwritelock implements the readwritelock interface and adds the reentrant feature.2.

FCNTL system CallExample 1: Status flags for a fileMyfcntl_access.c#include #include#include#include#include#include#include#defineERROR (flag)if(flag) {printf ("%d:", __line__); Fflush (stdout); Perror ("Error");

Tag:perl   home    Read    blog   shared   write  gray    read lock    family    technology sharing     Java Concurrency Programming: Concurrent lock mechanism parsing table of Contents 1. Lock 2. Reentrantlock 3. Readwritelock 4

1. The difference between synchronized and lockThere are some drawbacks to synchronizing blocks that are implemented using the SYNCHRONIZED keyword:(1) There is only one type of lock(2) thread gets locked or blocked(3) lock is implemented in the

The Cache-blockingcache can be blockedIn the previous section we mentioned the issue of displaying the use of Ehcache locks, in fact we can also implicitly use the Ehcache lock, that is, through the Blockingcache. Blockingcache is a wrapper class

Display lockPrior to java5.0, there were only synchronized and volatile mechanisms available to coordinate shared object access. Java5.0 adds a new mechanism: Reentrantlock. Reentrantlock is not an alternative to built-in locks, but is an optional

1. Define Readwritelock maintains a pair of related locks, one for read-only operations and another for write operations. As long as there is no writer, the read lock can be persisted by multiple reader threads at the same time. The write lock is

Start transaction, commit and rollback syntaxStart Transaction | Begin [Work]commit [Work] [and [No] chain] [[No] release]rollback [work] [and [No] chain] [[No] release]set autocommit = { 0 | The 1}start transaction or BEGIN statement can begin a

Usually the lock is divided into pessimistic lock and optimistic lock, so-called pessimistic lock is always wary of its people to operate, for fear of others and their own resources, so one up on the lock; and optimistic lock is the usual optimist

MySQL master-slave Replication Principle IntroductionFirst, the principle of replicationMySQL replication tracks all changes to the database (updates, deletions, and so on) based on the primary server in the binary log. Each slave server receives a

Table level: Engine MyISAM, understood to lock the entire table, during the lock, other processes cannot write to the table, if it is a read lock, other processes can read at the same time, if it is a write lock, then other processes are not allowed

MySQL's database has the following high-availability architectures: Clustering, read-write separation, and master preparation. And two of the following are done by copying. The following is a brief introduction to the principles and configuration of

One: OverviewCompared with other databases, MySQL's locking mechanism is relatively simple, and its most notable feature is that different storage engines support different locking mechanisms. For example, the MyISAM and memory storage engines use

I. OverviewMySQL's lock mechanism is relatively simple, and its most notable feature is that different storage engines support different locking mechanisms. For example, the MyISAM and memory storage engines use table-level locks (table-level

Original link: http://www.jb51.net/article/50047.htmPage level: Engine BDB.Table level: Engine MyISAM, understood to lock the entire table, can read at the same time, write NoRow level: Engine INNODB, single row of records plus lockTable level,

Page level: Engine BDB.Table level: Engine MyISAM, understood to lock the entire table, can read at the same time, write NoRow level: Engine INNODB, single row of records plus lockTable level, which locks the entire table directly, and other

What locks are in Java This problem after I read After all can't answer, explain oneself to the concept of the lock not understand enough. So again looked at the contents of the book, suddenly a bit open the feeling of the forehead. It seems that

Http://www.cnblogs.com/lidabnu/p/4495785.html First, you need to define the concept of the transaction: a set of atomic SQL queries that, if the database engine succeeds in applying all the statements of the group query to the database, executes the

Read-Write Spin lock (Rwlock) is a spin lock mechanism with smaller spin-lock granularity, which retains the concept of "spin". However, in the write operation, there can be only one write process, in terms of reading, can have more than one

Objective Locks are used to control how multiple threads access a shared resource. Before the lock interface appears, the Java program relies on the Synchronized keyword to implement the lock function, although lock is more explicitly acquired and