Meat plays a vital role in human’s evolution. Millions of years ago,human’s ancestors ate only leaves, fruits and cereals. Their brains are much smaller and it takes them hours daily to chew and digest such raw food. …

[Vipassana meditators only] Introduction By mid 2021, I unconsciously practiced Vipassana mechanically. Misery started appearing. In my case, it was misery that the health getting worse and worse. To the deepest days, I almost could not eat anything. That, on the other, may also be the turning days of my…

Initial idea of crash : Multi global thread access to one variable (val) at the same time : Write (newVal). Then read : Check if val == newVal. Each thread initially sleeps for a random time to create the multiple access randomly. Hopefully, crash comes. But still. Everything works well…

Inspired by Signal’ promise source code, I now build a simple version of “Promise” with main point : Provide a clean interface for running a task on a specific queue, and work with multiple completion handlers. Running block on a specific queue, it’s just this simple : Here, we handle…

Migrate db into a new one, we normally need a new class for the entity object, and so entirely all new properties. It seems unavoidable to miss some cases where a new object accesses properties of the old one. So how to avoid crashing ? Working for Zalo, an app…

The girl is a gentle one. At work, she has no such ambitions of promotions, no cravings of earning money. In daily life, she easily adapts to outside situations. Staying in her home or her boyfriend’s or her sister’s, it’s all ok. In a relationship, the girl even easily forgives…

Inspired by Mike Ash’s let’s build series, I write this article as my initial self-build in a simple version. Firstly, what dispatch_group_t is ? It is easy to read Apple’s code and figure out, it is just an NSObject object , confronting OS_dispatch_group_protocol. Then what should my dispatch_group (mn_dispatch_group) be…

One had been an “extreme person”, doing everything with limitless attempt. Also one has some stomach issues. For reasons, from days to days, years to years, one’s situation went from bad to worse. Till a day, physically, one can barely eat. Mentally, one in the cycle that, should I think…

Atomic and mutex in C Atomic According to definition: “Atomic types are types that encapsulate a value whose access is guaranteed to not cause data races and can be used to synchronize memory accesses among different threads.” Firstly, we should understand “data races”. When an evaluation of an expression writes…