c - Interrupt a accept() that is waiting, just changing a global variable value -

i'm doing project university, chat system server , multiple clients.

in specification document there written:

the main thread controlled loop on global var go, , @ each cycle waits connection request user

and also:

server stops sigterm or sigint. when signal received, global var go set zero, , threads exit loop cycle

so, thread main create socket, bind port , @ every new connection accept() , create thread worker takes care of communication client.

my problem exiting thread main changing global var. in thread main if do

while (go && accept(params)) {} 

it doesn't enter in while loop.

so @ moment code

while (go) {     accept(params);     // stuff } 

and, well, when set go 0 waits on accept, have create new connection, accepts connection , exit thread 'cause go becomes zero.

same problem thread worker

while (go && read(socket_id, buffer, sizeof(char)) > 0) {} 

it waits char socket exit loop.

i don't see way exit loops using go var. think i've close socket, or find way, wrong?

i'm not interested in other ways exit threads, know if it's possible exit loops changing go var

thanks!

assuming setup signal handler sigint , sigterm toggle go !=0 want unset sa_restart flag handler(s), make accept() return -1 on signal's reception.

to setup signal handler using sigaction(). struct sigaction pass in not set member sa_flags hold sa_restart.

for detailed description system call influenced sa_restart flag see section "interruption of system calls , library functions signal handlers" of man 7 signal.

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independendly make sure go defined sig_atomic_t.