how to initialize a sem_t variable

Question

I am getting a seg fault at sem_init. I am trying to create a unnamed sem. Thank you Appreciate some help on this.

sem_t *t;

int status = sem_init(t,1,1);

Offtopic: I really recommend to master basics of C++ before even attempting anything what is related to multiple threads. It will save you lots of time and frustration. Note also this is C API specific for Linux, C++ has own API for that. — Marek R, Dec 07 '22 at 12:39
https://sites.uclouvain.be/SystInfo/usr/include/bits/semaphore.h.html — jkafernando, Dec 07 '22 at 13:25

score 3 · Answer 1 · answered Dec 07 '22 at 12:34

sem_t t;

int status = sem_init(&t,1,1);

This is C API, so all functions use pointers, not references.

Furthermore there are no constructors, hence the existence of sem_init which is used to initialize a structure object t.

It doesn't allocate an object, double ptr would be needed for that.

See e.g. man 3 sem_wait for an example.

1 Answers1