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C++ Lock-free Hazard Pointer（冒险指针） - C/C++ - 清泛网 - 专注C/C++及内核技术
...每次读取都需要修改引用计数，高并发场景下这样的原子操作也会成为性能瓶颈，毕竟原子加对应的 CPU 指令 lock add 也可以看成是微型锁。
Linux 内核中提供了 RCU 方法，笔者目前对此还没有太多的了解。本文主要介绍 Hazard Pointe...
Regular expression for letters, numbers and - _
...et to show how you can use this pattern:
<?php
$arr = array(
'screen123.css',
'screen-new-file.css',
'screen_new.js',
'screen new file.css'
);
foreach ($arr as $s) {
if (preg_match('/^[\w.-]*$/', $s)) {
print "$s is a match\n";
} else {
print "$s is NO match!!!\n";
};
}
...
MySQL一次主从数据不一致的问题解决过程 - 数据库(内核) - 清泛网 - 专注C/...
...原理
用pt-table-sync修复不一致的数据 描述了工具原理
操作过程
只把过程和用到的东西解释了下，有些参数选项等还需要查阅文档。两台机器都是centos6.5 mysql版本都是5.6 , 由于是线上环境，这里ip和密码等敏感信息修改了下。...
Code Golf: Collatz Conjecture
...ut by passing a number to it on the command line:
;
; >> $ ./collatz 123
; >> 123 --> 370 --> 185 --> 556 --> 278 --> 139 --> 418 --> 209 --> 628 --> 314
; >> --> 157 --> 472 --> 236 --> 118 --> 59 --> 178 --> 89 --> 268 --> 134...
Convert Rows to columns using 'Pivot' in SQL Server
..., 212),
(105, 2, 78),
(109, 2, 97),
(105, 3, 60),
(102, 3, 123),
(101, 3, 220),
(109, 3, 87);
If your values are known, then you will hard-code the query:
select *
from
(
select store, week, xCount
from yt
) src
pivot
(
sum(xcount)
for week in ([1], [2], [3])
) pi...
怎么往SetTimer的回调函数传递参数 - C/C++ - 清泛网 - 专注C/C++及内核技术
...息，然后处理之，这个过程有两个参与者，一 个是windows系统，它主要负责投递消息，收不收是用户线程的事，另一个就是用户线程，它主要负责取出消息并处理消息，即使用户线程因为睡眠或者根本 就没有设定消息循环，系统...
How to use hex color values
...
How would you handle 123ABC? The compiler is burking at it not being a digit.
– Islam Q.
Mar 2 '16 at 6:28
1
...
Understanding :source option of has_one/has_many through of Rails
...'ve chosen to namespace the Dog::Breed, because we want to access Dog.find(123).breeds as a nice and convenient association.
Now, if we now want to create a has_many :dog_breeds, :through => :dogs association on Pet, we suddenly have a problem. Rails won't be able to find a :dog_breeds associati...
How do I create a unique constraint that also allows nulls?
...et_AllowNull
UNIQUE (TicketID, TicketUnique);
If IssueID 1 has ticket 123, the UNIQUE constraint will be on values (123, NULL). If IssueID 2 has no ticket, it will be on (NULL, 2). Some thought will show that this constraint cannot be duplicated for any row in the table, and still allows multip...
REDHAT 6.4 X64下ORACLE 11GR2静默安装 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
...at pacakage.txt )
输入y 后开始安装。
7 、创建所需要的操作系统用户和组
具体命令
#groupadd -g 5000 oinstall
#groupadd -g 5001 dba
# useradd -m -g oinstall -G dba oracle
# passwd oracle
7、配置oracle 用户的环境变量
其实安装的时候...