makecontext producing void value?

Question

My issue concerns this line:

    int f = makecontext( &threadList[ numThreads ].context

My program compiles without error without the assignment operation, but does not work at all. The line appears to do nothing. When I add "int f =" the compiler gives me the error:

my_pthread.c:41:10: error: void value not ignored as it ought to be

I don't understand how this is happening, since ucontext should always return 0 or -1.

Any help is appreciated.

score 2 · Accepted Answer · answered Feb 23 '19 at 03:23

2

The makecontext function is declared as:

void makecontext(ucontext_t *ucp, void (*func)(), int argc, ...);

It returns no value, so you can't assign the result of the function to anything.

answered Feb 23 '19 at 03:23

dbush

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I just realized I was reading the docs for swapcontext. Thank you, I feel like an idiot now. – Aperson123 Feb 23 '19 at 03:25

makecontext producing void value?

1 Answers1