Implement POSIX clock_gettime(3) for systems that lack it (like Mac OS X).

On Mac OS X it will get proper nanosecond precision; elsewhere, only
microseconds.  Hides the conformance failure from the rest of the code.

All regression tests pass.

8 files changed, 58 insertions, 37 deletions

diff --git a/SConstruct b/SConstruct
index 7b2f6cf7..e82857d5 100644
--- a/SConstruct
+++ b/SConstruct
@@ -751,6 +751,14 @@ pid_t getsid(pid_t pid);
 }
 # endif
 #endif
+#ifndef HAVE_CLOCK_GETTIME
+# ifdef __cplusplus
+extern "C" {
+typedef int clockid_t;
+#define CLOCK_REALTIME	0
+int clock_gettime(clockid_t, struct timespec *);
+# endif
+#endif
 
 
 #define GPSD_CONFIG_H
@@ -823,6 +831,7 @@ libgpsd_version = "%d.%d.%d" %(libgpsd_version_soname, libgpsd_version_age, libg
 libgps_sources = [
     "ais_json.c",
     "bits.c",
+    "clock_gettime.c",
     "daemon.c",
     "gpsutils.c",
     "gpsdclient.c",
diff --git a/clock_gettime.c b/clock_gettime.c
new file mode 100644
index 00000000..b6b7dff1
--- /dev/null
+++ b/clock_gettime.c
@@ -0,0 +1,47 @@
+/*
+ * Simulate ANSI/POSIX conformance on platforms that don't have it
+ *
+ * This file is Copyright (c) 2010 by the GPSD project
+ * BSD terms apply: see the file COPYING in the distribution root for details.
+ */
+#include <time.h>
+#include <sys/time.h>
+
+#include "compiler.h"
+
+#ifdef __MACH__
+#include <mach/clock.h>
+#include <mach/mach.h>
+#endif
+
+#ifndef HAVE_CLOCK_GETTIME
+int clock_gettime(clockid_t clk_id UNUSED, struct timespec *tp)
+{
+#ifdef __MACH__ // OS X does not have clock_gettime, use clock_get_time
+    clock_serv_t cclock;
+    mach_timespec_t mts;
+    host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &cclock);
+    clock_get_time(cclock, &mts);
+    mach_port_deallocate(mach_task_self(), cclock);
+    ts.tv_sec = mts.tv_sec;
+    ts.tv_nsec = mts.tv_nsec;
+#else
+    struct timeval tv;
+    if (gettimeofday(&tv, NULL) < 0)
+	return -1;
+    tp->ts_sec = tv.tv_sec;
+    tp->ts_nsec = tv.tv_usec * 1000;
+    /* paranoid programming */
+    if (1000000 <= (tv)->tv_usec) {
+	(tv)->tv_usec -= 1000000;
+	(tv)->tv_sec++;
+    } else if (0 > (tv)->tv_usec) {
+	(tv)->tv_usec += 1000000;
+	(tv)->tv_sec--;
+    }
+    return 0;
+#endif /* __MACH__ */
+}
+#endif /* HAVE_CLOCK_GETTIME */
+
+/* end */
diff --git a/gpsutils.c b/gpsutils.c
index fa15bc49..e7000f70 100644
--- a/gpsutils.c
+++ b/gpsutils.c
@@ -299,15 +299,9 @@ void gps_merge_fix( /*@ out @*/ struct gps_fix_t *to,
  * near microSec.  Do not use near PPS which is nanoSec precise */
 timestamp_t timestamp(void)
 {
-#ifdef HAVE_CLOCK_GETTIME
      struct timespec ts;
      /*@i2@*/(void)clock_gettime(CLOCK_REALTIME, &ts);
      /*@i3@*/return (timestamp_t)(ts.tv_sec + ts.tv_nsec * 1e-9);
-#else
-    struct timeval tv;
-    (void)gettimeofday(&tv, NULL);
-    return (timestamp_t)(tv.tv_sec + tv.tv_usec * 1e-6);
-#endif
 }
 
 time_t mkgmtime(register struct tm * t)
diff --git a/libgps.h b/libgps.h
index 914c4df2..9ef0ae37 100644
--- a/libgps.h
+++ b/libgps.h
@@ -10,6 +10,8 @@
 #define SHM_PSEUDO_FD	-1
 #define DBUS_PSEUDO_FD	-2
 
+#include "compiler.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/libgps_dbus.c b/libgps_dbus.c
index 092e0bdf..826f12d4 100644
--- a/libgps_dbus.c
+++ b/libgps_dbus.c
@@ -14,7 +14,6 @@
 
 #include "gps.h"
 #include "gpsd_config.h"
-#include "compiler.h"
 #include "libgps.h"
 
 #if defined(DBUS_EXPORT_ENABLE) && !defined(S_SPLINT_S)
diff --git a/libgpsd_core.c b/libgpsd_core.c
index 210aa596..a1a1a44e 100644
--- a/libgpsd_core.c
+++ b/libgpsd_core.c
@@ -1658,13 +1658,7 @@ void ntp_latch(struct gps_device_t *device, struct timedelta_t /*@out@*/*td)
     /* this should be an invariant of the way this function is called */
     assert(isnan(device->newdata.time)==0);
 
-#ifdef HAVE_CLOCK_GETTIME
     /*@i2@*/(void)clock_gettime(CLOCK_REALTIME, &td->clock);
-#else
-    struct timeval clock_tv;
-    (void)gettimeofday(&clock_tv, NULL);
-    TVTOTS(&td->clock, &clock_tv);
-#endif /* HAVE_CLOCK_GETTIME */
     fix_time = device->newdata.time;
 
 #ifdef TIMEHINT_ENABLE
diff --git a/ntpshmread.c b/ntpshmread.c
index 092e6e95..7a9206e3 100644
--- a/ntpshmread.c
+++ b/ntpshmread.c
@@ -74,16 +74,7 @@ enum segstat_t shm_query(/*@null@*/struct shmTime *shm_in, /*@out@*/struct shm_s
     /*@-type@*//* splint is confused about struct timespec */
     shm_stat->tvc.tv_sec = shm_stat->tvc.tv_nsec = 0;
 
-#ifdef HAVE_CLOCK_GETTIME
     clock_gettime(CLOCK_REALTIME, &shm_stat->tvc);
-#else
-    {
-	struct timeval tv;
-	(void)gettimeofday(&tv, NULL);
-	shm_stat->tvc.tv_sec = tv.tv_sec;
-	shm_stat->tvc.tv_nsec = tv.tv_usec * 1000;
-    }
-#endif
 
     /* relying on word access to be atomic here */
     if (shm->valid == 0) {
diff --git a/ppsthread.c b/ppsthread.c
index ad8750a4..b8a716c7 100644
--- a/ppsthread.c
+++ b/ppsthread.c
@@ -269,9 +269,6 @@ static /*@null@*/ void *gpsd_ppsmonitor(void *arg)
     /* the system clock ime, to the nSec, when the last fix received */
     /* using a double would cause loss of precision */
     struct timespec last_fixtime_clock = {0, 0};
-#ifndef HAVE_CLOCK_GETTIME
-    struct timeval  clock_tv = {0, 0};
-#endif /* HAVE_CLOCK_GETTIME */
     struct timespec clock_ts = {0, 0};
     time_t last_second_used = 0;
 #if defined(TIOCMIWAIT)
@@ -359,24 +356,12 @@ static /*@null@*/ void *gpsd_ppsmonitor(void *arg)
 
 /*@-noeffect@*/
         /* get the time after we just woke up */
-#ifdef HAVE_CLOCK_GETTIME
-	/* using  clock_gettime() here, that is nSec,
-	 * not uSec like gettimeofday */
 	if ( 0 > clock_gettime(CLOCK_REALTIME, &clock_ts) ) {
 	    /* uh, oh, can not get time! */
 	    gpsd_report(&session->context->errout, LOG_ERROR,
 			"PPS clock_gettime() failed\n");
 	    break;
 	}
-#else
-	if ( 0 > gettimeofday(&clock_tv, NULL) ) {
-	    /* uh, oh, can not get time! */
-	    gpsd_report(&session->context->errout, LOG_ERROR,
-			"PPS gettimeofday() failed\n");
-	    break;
-	}
-	TVTOTS( &clock_ts, &clock_tv);
-#endif /* HAVE_CLOCK_GETTIME */
 /*@+noeffect@*/
      
         /* got the edge, got the time just after the edge, now quickly