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 @@
-7c43e683316530c0e9c46df4e670465b887f2a0c0774ee1dc67e4b0e1ca20a35  /usr/local/bin/tox-bootstrapd
+d225df25926c10a1f27a58db147316cd45fc577d20d6e5a4da4274f3f716512b  /usr/local/bin/tox-bootstrapd

toxcore/mono_time.c

@@ -165,7 +165,7 @@ Mono_Time *mono_time_new(mono_time_current_time_cb *current_time_callback, void
     // Maximum reproducibility. Never return time = 0.
     mono_time->base_time = 1;
 #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);
 #endif
 
     mono_time_update(mono_time);
@@ -190,14 +190,13 @@ 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->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->user_data);
 #ifdef OS_WIN32
     pthread_mutex_unlock(&mono_time->last_clock_lock);
 #endif
@@ -211,21 +210,22 @@ void mono_time_update(Mono_Time *mono_time)
 #endif
 }
 
-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
+#if !defined(ESP_PLATFORM) && !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
     // Fuzzing is only single thread for now, no locking needed */
-    return mono_time->cur_time;
-#else
-#ifndef ESP_PLATFORM
     pthread_rwlock_rdlock(mono_time->time_update_lock);
 #endif
     const uint64_t cur_time = mono_time->cur_time;
-#ifndef ESP_PLATFORM
+#if !defined(ESP_PLATFORM) && !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
     pthread_rwlock_unlock(mono_time->time_update_lock);
 #endif
     return cur_time;
-#endif
+}
+
+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)
@@ -245,9 +245,10 @@ 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

@@ -60,8 +60,16 @@ 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);
@@ -72,9 +80,10 @@ 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);