About the return value of pthread_mutex_init ()

Introduction

I checked the return value of the library function pthread_mutex_init ().

background

At work, I was looking at the code written by BP (Business Partner). Then check the return value of pthead_mutex_init ()

hoge.c


   if (r == -1)
   {
      //Error handling
   }

Was written.

I "... -1 !?"

Result of investigation

It varies depending on the page, but it was roughly the following three.

-Pthread_mutex_init () always returns 0. or -Pthread_mutex_init () returns 0 when normal and -1 when abnormal. or -Pthread_mutex_init () returns 0 when normal and nonzero when abnormal.

Is it environment-dependent?

Finally

For the time being, regarding the check of the return value

hoge.c


   if (r != 0)
   {
      //Error handling
   }

I wonder if it should be non-zero.

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