core: initialize random udp package id using nanosecond timestamp (#1270

)

ecal/core/src/io/snd_raw_buffer.cpp

@@ -21,6 +21,8 @@
  * @brief raw message buffer handling
 **/
 
+#include <chrono>
+#include <mutex>
 #include <thread>
 
 #include "ecal_process.h"
@@ -129,8 +131,18 @@ namespace eCAL
  msg_header.type = msg_type_header;
  {
  // create random number for message id
- static unsigned long x = 123456789, y = 362436069, z = 521288629;
- msg_header.id = xorshf96(x, y, z);
+ {
+ static std::mutex xorshf96_mtx;
+ const std::lock_guard<std::mutex> lock(xorshf96_mtx);
+
+ static unsigned long x = static_cast<unsigned long>(std::chrono::duration_cast<std::chrono::nanoseconds>(
+ std::chrono::high_resolution_clock::now().time_since_epoch()).count()
+ );
+ static unsigned long y = 362436069;
+ static unsigned long z = 521288629;
+
+ msg_header.id = xorshf96(x, y, z);
+ }
  }
  msg_header.num = total_packet_num;
  msg_header.len = int32_t(buf_len_);