add _mi_stats_init to initialize the process start time

Author: daanx

include/mimalloc/internal.h

@@ -237,6 +237,7 @@ bool          _mi_heap_area_visit_blocks(const mi_heap_area_t* area, mi_page_t*
 void          _mi_heap_page_reclaim(mi_heap_t* heap, mi_page_t* page);
 
 // "stats.c"
+void          _mi_stats_init(void);
 void          _mi_stats_done(mi_stats_t* stats);
 void          _mi_stats_merge_thread(mi_tld_t* tld);
 void          _mi_stats_merge_from(mi_stats_t* to, mi_stats_t* from);

src/init.c

@@ -709,6 +709,7 @@ void mi_process_init(void) mi_attr_noexcept {
   _mi_verbose_message("process init: 0x%zx\n", _mi_thread_id());
 
   mi_detect_cpu_features();
+  _mi_stats_init();
   _mi_os_init();
   _mi_page_map_init();
   mi_heap_main_init();

src/stats.c

@@ -386,6 +386,12 @@ static void _mi_stats_print(mi_stats_t* stats, mi_output_fun* out0, void* arg0)
 
 static mi_msecs_t mi_process_start; // = 0
 
+// called on process init
+void _mi_stats_init(void) {
+  if (mi_process_start == 0) { mi_process_start = _mi_clock_start(); };
+}
+
+
 // return thread local stats
 static mi_stats_t* mi_get_tld_stats(void) {
   return &_mi_thread_tld()->stats;
@@ -396,9 +402,10 @@ void mi_stats_reset(void) mi_attr_noexcept {
   mi_subproc_t* subproc = _mi_subproc();
   if (stats != &subproc->stats) { _mi_memzero(stats, sizeof(mi_stats_t)); }
   _mi_memzero(&subproc->stats, sizeof(mi_stats_t));
-  if (mi_process_start == 0) { mi_process_start = _mi_clock_start(); };
+  _mi_stats_init();
 }
 
+
 void _mi_stats_merge_from(mi_stats_t* to, mi_stats_t* from) {
   mi_assert_internal(to != NULL && from != NULL);
   if (to != from) {