Stacktrace improvements.

GitOrigin-RevId: 99dd952cff5c9e5edce575b84e365def24a59441

tdutils/td/utils/port/signals.cpp

@@ -306,6 +306,7 @@ static void block_stdin() {
 }
 
 static void default_failure_signal_handler(int sig) {
+  Stacktrace::init();
   signal_safe_write_signal_number(sig);
 
   Stacktrace::PrintOptions options;

tdutils/td/utils/port/stacktrace.cpp

@@ -114,4 +114,11 @@ void Stacktrace::print_to_stderr(const PrintOptions &options) {
   print_backtrace();
 }
 
+void Stacktrace::init() {
+#if __GLIBC__
+  void *buffer[1];
+  backtrace(buffer, 1);
+#endif
+}
+
 }  // namespace td

tdutils/td/utils/port/stacktrace.h

@@ -16,6 +16,8 @@ class Stacktrace {
     }
   };
   static void print_to_stderr(const PrintOptions &options = PrintOptions());
+  // backtrace needs to be called once to ensure that next calls are async-signal-safe
+  static void init();
 };
 
 }  // namespace td