/dpt/ - Daily Programming Thread

Reposting:
Let's say I want to transpile an statically-linked x86 binaries to arm. Can I write the software to do that from scratch without going insane?
How much harder would doing the same thing for dynamically linked software be?

is this victim to a race condition? if so, how do you fix that?

access(mutex){
  if (mutex->lock == UNLOCKED){
    mutex->lock = LOCKED;
    return UNLOCKED;
  }
  else return LOCKED;
}

i'm thinking of two threads running this at the same time
thread one would run the first line, immediately followed by thread 2 doing that first line. both of them read the mutex is unlocked. then thread 1 sets the mutex to locked, as well as thread 2 doing that right after. then both of them get unlocked returned from this function. how would you avoid that? or does that not happen?

>>62168024
Does "access" protect the mutex in any way? If not, then yes that will be a race condition

>>62168024
Afaik it isn't possible to correctly implement a mutex in plain C. You need help from assembly to ensure certain operations are synchronized.

File: I THOUGHT THIS WAS AMERICA.png (5KB, 465x73px) Image search: [Google]

5KB, 465x73px

>>62167573
Will I be in pretty good shape if I work through this entire book? I'm not new to programming, but I feel like i'm stuck at whatever is between complete beginner and intermediate.

File: orly.png (177KB, 415x583px) Image search: [Google]

177KB, 415x583px

>>62168951
Sorry, forgot link:

https://repo.zenk-security.com/Programmation/O%20Reilly%20-%20Practical%20C%20Programming,%203rd%20Edition.pdf

>>62168024
You need to use the CMPXCHG instruction if you are using x86. But you should use your operating system's mutex implementation as it will abstract it away for you.

>>62167573
pic saved

thanks op

File: reflexivesymmetric.png (4KB, 339x34px) Image search: [Google]

4KB, 339x34px

I need to write a relation which is both reflexive and symmetric, but not transitive. does pic related satisfy this?

>>62169935
No. D(a,b) is always equal to |a - b|

>>62170416
What? That's the point...

>>62170467
SO it's transitive.

>>62170533
Do you understand what transitive means?

We already have a thread though >>62167566

>>62170555
aRb -> bRc -> aRc

File: book.jpg (416KB, 1512x2016px) Image search: [Google]

416KB, 1512x2016px

Bought this off of ebay, is this the same as the second edition with the white cover that I often see?

>>62171895
Must be, see if recursion in the alphabet index has the same page number as recursion does.

>>62171958
It does, thanks.