原创 reentrant & thread safe with examples
Wiki says, In computing, a computer program or subroutine is called reentrant if multiple invocations can safely run co
2020-06-26 21:04:49
原创 How to access physical addresses from user space in Linux?
see stackoverflow. Will need dig more to see the details.
2020-06-26 21:04:49
原创 c struct with array of zero length (1 length or empty length in C99)
details see stackoverflow. /* C99 */ struct s { int n; double d[]; }; int m = /* some value */; struct s *p =
2020-06-26 21:04:49
原创 makefile default target
How does “make” app know default target to build if no target is specified? $ make which target to build? By default, i
2020-06-26 21:04:38
原创 Design a stack that supports getMin()/push/pop in O(1) time
See blog. will figure out why later.
2020-06-26 21:04:38
原创 _Generic keyword in C
A major drawback of Macro in C/C++ is that the arguments are strongly typed checked i.e. a macro can operate on differe
2020-04-27 11:36:16
原创 Squash commits into one with Git
Step 1: choose your starting commit git rebase --interactive [commit-hash] Where [commit-hash] is the hash of the commi
2020-04-27 11:36:16
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原创 ubuntu: How to Copy selection to clipboard automatically like putty?
ubuntu中設置鼠標選中即複製的功能。（不太好用，設置之後vs code中也變成了鼠標選中即複製……寫代碼的時候不行，還是設置個快捷鍵吧） 主要命令和設置： it's possible. sudo apt-get install pa
2020-04-24 09:46:17
原创 max(a, b) and more
Summary from link1 and link2. The “maximum” function is commonly defined as a macro in standard C as follows: #define
2020-04-03 07:43:02
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原创 offsetof()
Add comments to offsetof() wiki to understand its implementation. The "traditional" implementation of the macro relied
2020-04-03 07:43:02
3
原创 size_t
According to the 1999 ISO C standard (C99), size_t is an unsigned integer type of at least 16 bit (see sections 7.17 an
2020-03-29 14:54:29
原创 How time is updated when tick interrupts are disabled
In Understanding the Linux Kernel, there is paragram pasted below. It states why jiffies_64 is correct in long run even
2020-03-14 03:47:16
原创 process switch in interrupt handler or sleep in interrupt handler
ULK: The price to pay for allowing nested kernel control paths is that an interrupt handler must never block, that is,
2020-03-11 08:56:27
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