diff options
| author | Eric S. Raymond <esr@thyrsus.com> | 2005-06-28 11:00:35 +0000 |
|---|---|---|
| committer | Eric S. Raymond <esr@thyrsus.com> | 2005-06-28 11:00:35 +0000 |
| commit | 07fb877e0a7eb9d87482b68bb45e839fdaf851d8 (patch) | |
| tree | 8c7a7af071fcd1e16f87417fcf6515fd917925fa | |
| parent | f5a180ff4be1599ffc8dae38d97a42242979f809 (diff) | |
| download | gpsd-07fb877e0a7eb9d87482b68bb45e839fdaf851d8.tar.gz | |
Document that the low-level interface uses no dynamic allocation.
| -rw-r--r-- | HACKING | 10 | ||||
| -rw-r--r-- | gpsd.spec.in | 3 | ||||
| -rw-r--r-- | libgpsd.xml | 11 |
3 files changed, 18 insertions, 6 deletions
@@ -315,6 +315,16 @@ enough to manage that, consider whether your feature control might be implemented with an extension to the gpsd protocol or the control-socket command set. +** Don't use malloc! + +The best way to avoid having dynamic-memory allocation problems is +not to use malloc/free at all. The gpsd daemon doesn't (though the +client-side code does). Thus, even the longest-running instance +can't have memory leaks. The only cost for this turned out to be +embedding a PATH_MAX-sized buffer in the gpsd.h structure. + +Don't undo this by using malloc/free in a driver or anywhere else. + ** Error modeling To estimate errors (which we must do if the GPS isn't nice like a diff --git a/gpsd.spec.in b/gpsd.spec.in index 38189fcc..5f78b84b 100644 --- a/gpsd.spec.in +++ b/gpsd.spec.in @@ -132,7 +132,8 @@ cp gps.py gpsfake.py "$RPM_BUILD_ROOT"%{_libdir}/python${PYVERSION}/site-package some minor bugs found by valgrind audit, including (1) a slow memory leak, (2) a possible but unconfirmed file-descriptor leak, and (3) a subtle error in the channel-assignment logic that only - showed up with multiple sessions active. + showed up with multiple sessions active. In fact, the daemon code + no longer uses dynamic-memory allocation at all. * Wed Jun 22 2005 Eric S. Raymond <esr@snark.thyrsus.com> - 2.26 - Time DOP and total DOP are now passed on from GPSes that report diff --git a/libgpsd.xml b/libgpsd.xml index 05fff9be..42026372 100644 --- a/libgpsd.xml +++ b/libgpsd.xml @@ -144,12 +144,13 @@ ends the session, implicitly performing a The library will use this to issue ordinary status messages. Use first argument of 0 for errors, 1 for ordinary status messages, and 2 or higher for debugging messages.</para> -</refsect1> -<!-- para>These functions do not allocate or free any dynamic storage. -(This isn't true yet. The use of dynamic storage in the Garmin driver -needs to be fixed.) -</para --> +<para>The low-level functions do not allocate or free any dynamic +storage. They can thus be used in a long-running application (such as +<citerefentry><refentrytitle>gpsd</refentrytitle><manvolnum>8</manvolnum></citerefentry> +itself) with a guarantee that thwy won't cause memory leaks.</para> + +</refsect1> <refsect1 id='bugs'><title>BUGS</title> |