refactor: Store time in Mono_Time in milliseconds.

Conversion to seconds happens in `mono_time_get`, and a new function
`mono_time_get_ms` allows code to retrieve monotonic time in
milliseconds.

other/bootstrap_daemon/docker/tox-bootstrapd.sha256

@@ -1 +1 @@
-cfa2c61f92df59419af678ef9d6fcd4f5609a505235d77a54c1a4ec66f1c10af  /usr/local/bin/tox-bootstrapd
+46107403fe7f6d00b8371d17797ee48d8cc2fd67ffc13f28728bc2cb0df3d3f3  /usr/local/bin/tox-bootstrapd

toxcore/mono_time.c

@@ -161,9 +161,9 @@ Mono_Time *mono_time_new(void)
     // had a chance to set the callback.
     // TODO(iphydf): Put mono time callback into Tox_Options with accessors only
     // in tox_private.h.
-    mono_time->base_time = 0;
+    mono_time->base_time = 1;  // Never return time = 0.
 #else
-    mono_time->base_time = (uint64_t)time(nullptr) - (current_time_monotonic(mono_time) / 1000ULL);
+    mono_time->base_time = (uint64_t)time(nullptr) * 1000ULL - current_time_monotonic(mono_time);
     mono_time_update(mono_time);
 #endif
 
@@ -185,14 +185,13 @@ void mono_time_free(Mono_Time *mono_time)
 
 void mono_time_update(Mono_Time *mono_time)
 {
-    uint64_t cur_time = 0;
 #ifdef OS_WIN32
     /* we actually want to update the overflow state of mono_time here */
     pthread_mutex_lock(&mono_time->last_clock_lock);
     mono_time->last_clock_update = true;
 #endif
-    cur_time = mono_time->current_time_callback(mono_time, mono_time->user_data) / 1000ULL;
-    cur_time += mono_time->base_time;
+    const uint64_t cur_time =
+        mono_time->base_time + mono_time->current_time_callback(mono_time, mono_time->user_data);
 #ifdef OS_WIN32
     pthread_mutex_unlock(&mono_time->last_clock_lock);
 #endif
@@ -202,17 +201,22 @@ void mono_time_update(Mono_Time *mono_time)
     pthread_rwlock_unlock(mono_time->time_update_lock);
 }
 
-uint64_t mono_time_get(const Mono_Time *mono_time)
+uint64_t mono_time_get_ms(const Mono_Time *mono_time)
 {
-#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
     // Fuzzing is only single thread for now, no locking needed */
-    return mono_time->cur_time;
-#else
     pthread_rwlock_rdlock(mono_time->time_update_lock);
+#endif
     const uint64_t cur_time = mono_time->cur_time;
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
     pthread_rwlock_unlock(mono_time->time_update_lock);
-    return cur_time;
 #endif
+    return cur_time;
+}
+
+uint64_t mono_time_get(const Mono_Time *mono_time)
+{
+    return mono_time_get_ms(mono_time) / 1000ULL;
 }
 
 bool mono_time_is_timeout(const Mono_Time *mono_time, uint64_t timestamp, uint64_t timeout)
@@ -232,9 +236,10 @@ void mono_time_set_current_time_callback(Mono_Time *mono_time,
     }
 }
 
-/**
- * Return current monotonic time in milliseconds (ms). The starting point is
- * unspecified.
+/** @brief Return current monotonic time in milliseconds (ms).
+ *
+ * The starting point is unspecified and in particular is likely not comparable
+ * to the return value of `mono_time_get_ms()`.
  */
 uint64_t current_time_monotonic(Mono_Time *mono_time)
 {

toxcore/mono_time.h

@@ -57,8 +57,16 @@ void mono_time_free(Mono_Time *mono_time);
 non_null()
 void mono_time_update(Mono_Time *mono_time);
 
-/**
- * Return unix time since epoch in seconds.
+/** @brief Return current monotonic time in milliseconds (ms).
+ *
+ * The starting point is UNIX epoch as measured by `time()` in `mono_time_new()`.
+ */
+non_null()
+uint64_t mono_time_get_ms(const Mono_Time *mono_time);
+
+/** @brief Return a monotonically increasing time in seconds.
+ *
+ * The starting point is UNIX epoch as measured by `time()` in `mono_time_new()`.
  */
 non_null()
 uint64_t mono_time_get(const Mono_Time *mono_time);
@@ -69,9 +77,10 @@ uint64_t mono_time_get(const Mono_Time *mono_time);
 non_null()
 bool mono_time_is_timeout(const Mono_Time *mono_time, uint64_t timestamp, uint64_t timeout);
 
-/**
- * Return current monotonic time in milliseconds (ms). The starting point is
- * unspecified.
+/** @brief Return current monotonic time in milliseconds (ms).
+ *
+ * The starting point is unspecified and in particular is likely not comparable
+ * to the return value of `mono_time_get_ms()`.
  */
 non_null()
 uint64_t current_time_monotonic(Mono_Time *mono_time);