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xpipe: introduce (saves ~170 bytes)

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udhcp/signalpipe.c: use pipe instead of socketpair.
This commit is contained in:
Denis Vlasenko
2007-05-26 16:44:20 +00:00
parent 6239b1f50a
commit 5a6aeddfa7
9 changed files with 35 additions and 36 deletions
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13
networking/udhcp/signalpipe.c
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@@ -27,7 +27,8 @@ static int signal_pipe[2];
static void signal_handler(int sig)
{
if (send(signal_pipe[1], &sig, sizeof(sig), MSG_DONTWAIT) < 0)
unsigned char ch = sig; /* use char, avoid dealing with partial writes */
if (write(signal_pipe[1], &ch, 1) != 1)
bb_perror_msg("cannot send signal");
}
@@ -36,11 +37,11 @@ static void signal_handler(int sig)
* and installs the signal handler */
void udhcp_sp_setup(void)
{
// BTW, why socketpair and not just pipe?
if (socketpair(AF_UNIX, SOCK_STREAM, 0, signal_pipe))
bb_perror_msg_and_die("socketpair");
/* was socketpair, but it needs AF_UNIX in kernel */
xpipe(signal_pipe);
fcntl(signal_pipe[0], F_SETFD, FD_CLOEXEC);
fcntl(signal_pipe[1], F_SETFD, FD_CLOEXEC);
fcntl(signal_pipe[1], F_SETFL, O_NONBLOCK);
signal(SIGUSR1, signal_handler);
signal(SIGUSR2, signal_handler);
signal(SIGTERM, signal_handler);
@@ -67,12 +68,12 @@ int udhcp_sp_fd_set(fd_set *rfds, int extra_fd)
* your signal on success */
int udhcp_sp_read(fd_set *rfds)
{
int sig;
unsigned char sig;
if (!FD_ISSET(signal_pipe[0], rfds))
return 0;
if (read(signal_pipe[0], &sig, sizeof(sig)) < 0)
if (read(signal_pipe[0], &sig, 1) != 1)
return -1;
return sig;