[gpsd-dev] [PATCH 4/6] Replaces deprecated usleep() with nanosleep()-based alternative.

[Fred Wright]

This creates a new gps_usleep() function, which is a drop-in
replacement for usleep().  Although it now uses nanosleep()
unconditionally, this single function could be switched back
to usleep() if needed for any targets.

This change only fixes the main gpsd components, leaving the
contrib/ fixes for a followup.

TESTED:
Ran "scons build-all check" under OSX.  This change is not expected
to be OS-dependent as it stands.
---
 SConstruct      |  1 +
 driver_garmin.c |  2 +-
 drivers.c       |  4 ++--
 gps_usleep.c    | 23 +++++++++++++++++++++++
 gpsctl.c        |  2 +-
 gpsd.c          |  2 +-
 gpsd.h-tail     |  3 +++
 gpsmon.c        |  4 ++--
 libgps.h        |  3 +++
 ntpshmmon.c     |  4 +++-
 serial.c        |  2 +-
 11 files changed, 41 insertions(+), 9 deletions(-)
 create mode 100644 gps_usleep.c

diff --git a/SConstruct b/SConstruct
index a5be834..1a5c1cf 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1068,6 +1068,7 @@ libgps_sources = [
     "gpsutils.c",
     "gpsdclient.c",
     "gps_maskdump.c",
+    "gps_usleep.c",
     "hex.c",
     "json.c",
     "libgps_core.c",
diff --git a/driver_garmin.c b/driver_garmin.c
index c80b842..9f1788a 100644
--- a/driver_garmin.c
+++ b/driver_garmin.c
@@ -1158,7 +1158,7 @@ gps_mask_t garmin_ser_parse(struct gps_device_t *session)
 
     // sending ACK too soon might hang the session
     // so send ACK last, after a pause
-    (void)usleep(300);
+    (void)gps_usleep(300);
     Send_ACK();
     gpsd_log(&session->context->errout, LOG_DATA,
             "Garmin: garmin_ser_parse( )\n");
diff --git a/drivers.c b/drivers.c
index 85b12a9..eaafe63 100644
--- a/drivers.c
+++ b/drivers.c
@@ -290,7 +290,7 @@ static void garmin_mode_switch(struct gps_device_t 
*session, int mode)
     if (mode == MODE_BINARY) {
        (void)nmea_send(session, "$PGRMC1,1,2,1,,,,2,W,N");
        (void)nmea_send(session, "$PGRMI,,,,,,,R");
-       (void)usleep(333);      /* standard Garmin settling time */
+       (void)gps_usleep(333);  /* standard Garmin settling time */
     }
 }
 #endif /* RECONFIGURE_ENABLE */
@@ -607,7 +607,7 @@ static void earthmate_event_hook(struct gps_device_t 
*session, event_t event)
        return;
     if (event == event_triggermatch) {
        (void)gpsd_write(session, "EARTHA\r\n", 8);
-       (void)usleep(10000);
+       (void)gps_usleep(10000);
        (void)gpsd_switch_driver(session, "Zodiac");
     }
 }
diff --git a/gps_usleep.c b/gps_usleep.c
new file mode 100644
index 0000000..fd526d2
--- /dev/null
+++ b/gps_usleep.c
@@ -0,0 +1,23 @@
+/*
+ * Replacement for deprecated usleep()
+ *
+ * This file is Copyright (c) 2016 by the GPSD project
+ * BSD terms apply: see the file COPYING in the distribution root for details.
+ */
+
+#include <time.h>
+
+#include "libgps.h"  /* For prototype */
+
+/*
+ * Note that this is the only place that would need to be modified to go
+ * back to using usleep() if needed.
+ */
+
+int gps_usleep(unsigned int useconds)
+{
+    struct timespec delay = { .tv_sec = useconds / 1000000,
+                              .tv_nsec = useconds % 1000000 * 1000};
+
+    return nanosleep(&delay, NULL);
+}
diff --git a/gpsctl.c b/gpsctl.c
index e3835bd..34d2e56 100644
--- a/gpsctl.c
+++ b/gpsctl.c
@@ -47,7 +47,7 @@ static void settle(struct gps_device_t *session)
      * See the 'deep black magic' comment in serial.c:set_serial().
      */
     (void)tcdrain(session->gpsdata.gps_fd);
-    (void)usleep(50000);
+    (void)gps_usleep(50000);
     (void)tcdrain(session->gpsdata.gps_fd);
 }
 #endif /* defined(RECONFIGURE_ENABLE) || defined(CONTROLSEND_ENABLE) */
diff --git a/gpsd.c b/gpsd.c
index 726cba4..626ab64 100644
--- a/gpsd.c
+++ b/gpsd.c
@@ -1042,7 +1042,7 @@ static void set_serial(struct gps_device_t *device,
             * across any given type of UART.
             */
            (void)tcdrain(device->gpsdata.gps_fd);
-           (void)usleep(50000);
+           (void)gps_usleep(50000);
            gpsd_set_speed(device, speed, parity, stopbits);
        }
     }
diff --git a/gpsd.h-tail b/gpsd.h-tail
index d1fb5ea..e075cf1 100644
--- a/gpsd.h-tail
+++ b/gpsd.h-tail
@@ -980,6 +980,9 @@ void cfmakeraw(struct termios *);
 
 #define DEVICEHOOKPATH "/"SYSCONFDIR"/gpsd/device-hook"
 
+/* System call helpers */
+extern int gps_usleep(unsigned int useconds);
+
 # ifdef __cplusplus
 }
 # endif
diff --git a/gpsmon.c b/gpsmon.c
index ee4aaeb..7e469db 100644
--- a/gpsmon.c
+++ b/gpsmon.c
@@ -963,7 +963,7 @@ static bool do_command(const char *line)
                switcher->mode_switcher(&session, (int)v);
                context.readonly = true;
                (void)tcdrain(session.gpsdata.gps_fd);
-               (void)usleep(50000);
+               (void)gps_usleep(50000);
                /*
                 * Session device change will be set to NMEA when
                 * gpsmon resyncs.  So stash the current type to
@@ -1035,7 +1035,7 @@ static bool do_command(const char *line)
                     * buffer.
                     */
                    (void)tcdrain(session.gpsdata.gps_fd);
-                   (void)usleep(50000);
+                   (void)gps_usleep(50000);
                    (void)gpsd_set_speed(&session, speed,
                                         parity, stopbits);
                } else
diff --git a/libgps.h b/libgps.h
index 70d4b7d..610bbab 100644
--- a/libgps.h
+++ b/libgps.h
@@ -41,6 +41,9 @@ extern int gps_dbus_mainloop(struct gps_data_t *, int,
 extern int json_ais_read(const char *, char *, size_t, struct ais_t *,
                         const char **);
 
+/* System call helpers */
+extern int gps_usleep(unsigned int useconds);
+
 /* debugging apparatus for the client library */
 #ifdef CLIENTDEBUG_ENABLE
 #define LIBGPS_DEBUG
diff --git a/ntpshmmon.c b/ntpshmmon.c
index 8706f41..1bdf2d2 100644
--- a/ntpshmmon.c
+++ b/ntpshmmon.c
@@ -17,6 +17,8 @@
 #include "revision.h"
 #include "timespec.h"
 
+extern int gps_usleep(unsigned int useconds);
+
 #define NTPSEGMENTS    256     /* NTPx for x any byte */
 
 static struct shmTime *segments[NTPSEGMENTS + 1];
@@ -173,7 +175,7 @@ int main(int argc, char **argv)
                break;
            }
        }
-       (void)usleep((useconds_t)1000);
+       (void)gps_usleep((useconds_t)1000);
     } while ( 0 < nsamples );
 
     exit(EXIT_SUCCESS);
diff --git a/serial.c b/serial.c
index 0a17007..5883930 100644
--- a/serial.c
+++ b/serial.c
@@ -383,7 +383,7 @@ void gpsd_set_speed(struct gps_device_t *session,
         * occasional failure to lock.
         */
        (void)tcflush(session->gpsdata.gps_fd, TCIOFLUSH);
-       (void)usleep(200000);
+       (void)gps_usleep(200000);
        (void)tcflush(session->gpsdata.gps_fd, TCIOFLUSH);
     }
     gpsd_log(&session->context->errout, LOG_INF,
-- 
2.9.3