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Is a LINQ statement faster than a 'foreach' loop?
...cts generally is going to add some marginal overheads (multiple iterators, etc). It still has to do the loops, and has delegate invokes, and will generally have to do some extra dereferencing to get at captured variables etc. In most code this will be virtually undetectable, and more than afforded b...
What exactly are “spin-locks”?
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When you use regular locks (mutexes, critical sections etc), operating system puts your thread in the WAIT state and preempts it by scheduling other threads on the same core. This has a performance penalty if the wait time is really short, because your thread now has to wait for ...
What's the difference between compiled and interpreted language?
...g machine's machine code. So how's that different from a VM (python or JVM etc.) doing the same in case of an interpreted language?
– qre0ct
Jun 23 at 10:28
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SQL SELECT speed int vs varchar
...ver see it. Depending upon CPU, implementation (client/server, web/script, etc) you probably will not see it until you hit few hundred comparisons on the DB server (maybe even a couple thousand comparisons before it is noticeable).
To void the incorrect dispute about hash comparisons. Most hashing...
一次「Too many open files」故障 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...务不可用故障，于是我惯性的判断应该还是 ES_HEAP_SIZE 的问题，不过登录服务器后发现日志里显示大量的「Too many open files」错误信息。
那么 ElasticSearch 设置的最大文件数到底是多少呢？可以通过 proc 确认：
shell> cat /proc/<PID>/l...
What is compiler, linker, loader?
...telligent than an assembler. It checks all kinds of limits, ranges, errors etc. But its program run time is more and occupies a larger part of the memory. It has slow speed. Because a compiler goes through the entire program and then translates the entire program into machine codes. If a compiler ru...
Android AsyncTask threads limits?
... the phone. For all those operations (updates, retrieving data from db and etc.) I use async tasks. As up till now I didn't see why I shouldn't use them, but recently I experienced that if I do some operations some of my async tasks simply stop on pre-execute and don't jump to doInBackground. That w...
Timer function to provide time in nano seconds using C++
...u are measuring code involving sleep, mutex lock, condition_variable wait, etc, the rdtsc clock is likely to have inaccurate conversions to other units. It is a good idea to set your measurements up so that you can easily change and compare clocks (as shown in this answer).
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Once upon a time, when > was faster than < … Wait, what?
...ntions that we can perform custom depth tests, such as GL_LESS, GL_ALWAYS, etc. He also explains that the actual meaning of depth values (which is top and which isn't) can also be customized. I understand so far. And then the author says something unbelievable:
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Linux日志管理Rsyslog入门 - C/C++ - 清泛网 - 专注IT技能提升
...性能上更为出色，至于孰优孰劣是个仁者见仁智者见智的问题，鉴于多数Linux发行版均选择了Rsyslog，姑且让我随波逐流一次。
如果说Rsyslog有哪些缺点的话，那么兼容性无疑是很显眼的一个，不同版本之间的差异比较大，使用时...