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| author | Eric S. Raymond <esr@thyrsus.com> | 2015-01-31 15:16:55 -0500 |
|---|---|---|
| committer | Eric S. Raymond <esr@thyrsus.com> | 2015-01-31 15:16:55 -0500 |
| commit | 6ee9556f2fea231303a488f07a8b0e0a9f552dc4 (patch) | |
| tree | 0427b34e9b53f0317b3c575ef5cd507bae92be35 /libgpsd_core.c | |
| parent | 2bab8b2a7f810a4a430def430cbae80d74c572c6 (diff) | |
| download | gpsd-6ee9556f2fea231303a488f07a8b0e0a9f552dc4.tar.gz | |
Back out the attempt to use VTIME.
According to Matthias Drochner at
http://lists.lysator.liu.se/pipermail/lsh-bugs/2003q4/000151.html:
I thought I'd give lsh a try, just to see how it compares to openssh...
The client didn't work well on NetBSD, got a message like "unexpected
EWOULDBLOCK" on each keystroke.
Looked a bit deeper and found that stdin is set to O_NONBLOCK and
a raw tty mode with c_cc[VMIN] > 1 and c_cc[VTIME] > 0.
I'll append a little test program which does the same. I've tried
it on 3 operating systems (Linux, NetBSD, Digital UNIX), and it
behaves differently on each:
-on Linux, if a key is pressed, the read returns immediately with
that one character
-on NetBSD, the read returns with no data but EWOULDBLOCK
-on D'UNIX, the poll() doesn't teturn before 4 keypresses are done;
the read() returns these 4 characters
Indeed, in SUSv2's termios page is a sentence which says that if
both O_NONBLOCK and VTIME>0 are set, the behaviour is more or less
undefined.
I've solved my immediate problems by setting VMIN to 1 instead of 4
in unix_interact.c:do_make_raw(), but VTIME is still pointless,
so I wouldn't call this a clean solution.
All regression tests pass.
Diffstat (limited to 'libgpsd_core.c')
| -rw-r--r-- | libgpsd_core.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/libgpsd_core.c b/libgpsd_core.c index 579d32e1..b9868bfa 100644 --- a/libgpsd_core.c +++ b/libgpsd_core.c @@ -248,9 +248,6 @@ int gpsd_switch_driver(struct gps_device_t *session, char *type_name) "selecting %s driver...\n", (*dp)->type_name); gpsd_assert_sync(session); - gpsd_optimize_io(session, - (*dp)->minlength, - TEXTUAL_PACKET_TYPE((*dp)->packet_type)); /*@i@*/ session->device_type = *dp; session->driver_index = i; #ifdef RECONFIGURE_ENABLE |