uhd: fix for dealing with negative wrapping in time_spec

2 files changed, 29 insertions, 20 deletions

diff --git a/host/lib/types/time_spec.cpp b/host/lib/types/time_spec.cpp
index a785332c2..0224fb6c2 100644
--- a/host/lib/types/time_spec.cpp
+++ b/host/lib/types/time_spec.cpp
@@ -83,25 +83,26 @@ time_spec_t time_spec_t::get_system_time(void){
 /***********************************************************************
  * Time spec constructors
  **********************************************************************/
-time_spec_t::time_spec_t(double secs):
-    _full_secs(0),
-    _frac_secs(secs)
-{
-    /* NOP */
+#define time_spec_init(full, frac) { \
+    _full_secs = full + time_t(frac); \
+    _frac_secs = frac - time_t(frac); \
+    if (_frac_secs < 0) {\
+        _full_secs -= 1; \
+        _frac_secs += 1; \
+    } \
 }
 
-time_spec_t::time_spec_t(time_t full_secs, double frac_secs):
-    _full_secs(full_secs),
-    _frac_secs(frac_secs)
-{
-    /* NOP */
+time_spec_t::time_spec_t(double secs){
+    time_spec_init(0, secs);
 }
 
-time_spec_t::time_spec_t(time_t full_secs, long tick_count, double tick_rate):
-    _full_secs(full_secs),
-    _frac_secs(tick_count/tick_rate)
-{
-    /* NOP */
+time_spec_t::time_spec_t(time_t full_secs, double frac_secs){
+    time_spec_init(full_secs, frac_secs);
+}
+
+time_spec_t::time_spec_t(time_t full_secs, long tick_count, double tick_rate){
+    const double frac_secs = tick_count/tick_rate;
+    time_spec_init(full_secs, frac_secs);
 }
 
 /***********************************************************************
@@ -116,11 +117,11 @@ double time_spec_t::get_real_secs(void) const{
 }
 
 time_t time_spec_t::get_full_secs(void) const{
-    return this->_full_secs + time_t(this->_frac_secs);
+    return this->_full_secs;
 }
 
 double time_spec_t::get_frac_secs(void) const{
-    return this->_frac_secs - time_t(this->_frac_secs);
+    return this->_frac_secs;
 }
 
 /***********************************************************************
diff --git a/host/tests/time_spec_test.cpp b/host/tests/time_spec_test.cpp
index e57bbced1..97e0dec21 100644
--- a/host/tests/time_spec_test.cpp
+++ b/host/tests/time_spec_test.cpp
@@ -56,9 +56,9 @@ BOOST_AUTO_TEST_CASE(test_time_spec_parts){
     BOOST_CHECK_CLOSE(uhd::time_spec_t(1.1).get_frac_secs(), 0.1, 0.001);
     BOOST_CHECK_EQUAL(uhd::time_spec_t(1.1).get_tick_count(100), 10);
 
-    BOOST_CHECK_EQUAL(uhd::time_spec_t(-1.1).get_full_secs(), -1);
-    BOOST_CHECK_CLOSE(uhd::time_spec_t(-1.1).get_frac_secs(), -0.1, 0.001);
-    BOOST_CHECK_EQUAL(uhd::time_spec_t(-1.1).get_tick_count(100), -10);
+    BOOST_CHECK_EQUAL(uhd::time_spec_t(-1.1).get_full_secs(), -2);
+    BOOST_CHECK_CLOSE(uhd::time_spec_t(-1.1).get_frac_secs(), 0.9, 0.001);
+    BOOST_CHECK_EQUAL(uhd::time_spec_t(-1.1).get_tick_count(100), 90);
 }
 
 BOOST_AUTO_TEST_CASE(test_time_spec_get_system_time){
@@ -78,3 +78,11 @@ BOOST_AUTO_TEST_CASE(test_time_spec_get_system_time){
     BOOST_CHECK(diff.get_real_secs() > 0); //assert positive
     BOOST_CHECK(diff.get_real_secs() < 1.0); //assert under 1s
 }
+
+BOOST_AUTO_TEST_CASE(test_time_spec_neg_values){
+    uhd::time_spec_t ts1(0.3);
+    uhd::time_spec_t ts2(1, -0.9);
+    std::cout << "ts1 " << ts1.get_real_secs() << std::endl;
+    std::cout << "ts2 " << ts2.get_real_secs() << std::endl;
+    BOOST_CHECK(ts1 > ts2);
+}