Hi, On Sat, Dec 20, 2025 at 01:24:55PM +0000, a1ex@dismail.de wrote:
Hmm, I don't think I'm catching all possible errors from that socket. Maybe this patch can help:
---8<--- diff --git a/src/IO/control.c b/src/IO/control.c index 6f677e52..c6cd15bf 100644 --- a/src/IO/control.c +++ b/src/IO/control.c @@ -110,7 +110,7 @@ static void Control_read_cb(int fd, void *data) r = read(new_fd, buf, 1); _MSG("read = %zd\n", r); if (r < 0) { - if (errno == EINTR) { + if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK) { continue; } else { MSG_ERR("Control_read_cb %s\n", dStrerror(errno)); ---8<---
Let me know if that makes it work.
Looks to be working now! Thanks for this very cool new feature, BTW!
I took a closer look and it seems that this patch doesn't address the actual problem. The problem is that BSD inherits the non-blocking behavior while Linux doesn't (POSIX doesn't seem to indicate what should be done). We want the new_fd to work in blocking mode, so this patch should fix it for BSD and Linux (otherwise let me know): ---8<--- diff --git a/src/IO/control.c b/src/IO/control.c index 6f677e52..0d11187e 100644 --- a/src/IO/control.c +++ b/src/IO/control.c @@ -95,12 +95,30 @@ static void Control_read_cb(int fd, void *data) int new_fd = accept(control_fd, NULL, NULL); if (new_fd < 0) { - if (errno != EWOULDBLOCK) { - MSG("accept failed: %s\n", strerror(errno)); + if (errno == EAGAIN || errno == EWOULDBLOCK) { + /* Nothing? */ + return; + } else { + MSG_ERR("accept failed: %s\n", strerror(errno)); exit(1); } - /* Nothing? */ - return; + } + + /* From accept(2) man page: + * + * On Linux, the new socket returned by accept() does not inherit + * file status flags such as O_NONBLOCK and O_ASYNC from the + * listening socket. This behavior differs from the canonical BSD + * sockets implementation. Portable programs should not rely on + * inheritance or noninheritance of file status flags and always + * explicitly set all required flags on the socket returned from + * accept(). + * + * So, disable O_NONBLOCK flag explicitly. + */ + if (fcntl(new_fd, F_SETFL, 0) == -1) { + MSG_ERR("control socket fcntl failed: %s\n", strerror(errno)); + exit(1); } ssize_t r; ---8<--- Best, Rodrigo.