Hello!My question addressed to Firebird developers and developers of UDF
who had same problem.
I'm writing UDF (C++, Linux), that uses POSIX-sockets for TCP-connection
and POSIX-signals (SIGALRM) to implement timeouts for this connection.
See sample code under this text.As you can see, I try to terminate
connection using SIGALRM. And it works correctly when function called
from my own application (using dlopen/dlsym that also used for
udf-calling in Firebird, isn't it?)But when I call this function from
Firebird i have problem. Signal-handler still called, but connect()
doesn't terminate. So, that's my question: what I did uncorrectly and
what can I do to implement this connection timeout?Thanks,Ivan
Zelenskyy.
Code:#include <stdlib.h>#include <unistd.h>#include
<sys/socket.h>#include <netinet/in.h>#include <sys/time.h>#include
<signal.h>#include <arpa/inet.h>#include <errno.h>
static void timer_handler(int signo){ return;}
extern "C" int fbconnectiontest(int i){ struct sigaction sa, sa_old;
sa.sa_handler = timer_handler; sigemptyset(&sa.sa_mask); sa.sa_flags =
SA_INTERRUPT; if (sigaction(SIGALRM, &sa, &sa_old) == -1) return -1;
//can't set sigaction
struct itimerval timerstruct; timerstruct.it_interval.tv_sec=0;
timerstruct.it_interval.tv_usec=0; timerstruct.it_value.tv_sec=0;
timerstruct.it_value.tv_usec=200000;
struct sockaddr_in addr; addr.sin_family = AF_INET; addr.sin_port =
htons(80); bool all_ok = inet_aton("8.8.8.8", &(addr.sin_addr)) != 0;
int sock = socket(PF_INET,SOCK_STREAM,0); if (sock==-1) return -2;
//can't create socket
if(setitimer(ITIMER_REAL,&timerstruct,NULL)!=0) return -3; //can't set
timer; if(connect(sock, (struct sockaddr*)&addr, sizeof(addr))!=0)
return errno;
close(sock); return 0; //all ok!}



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