Use an alternative mechanism to generate unique span ids.

PiperOrigin-RevId: 700828349
Change-Id: I194fc08d9c0d1887aab39b3b3197ee4156e60f15

tensorstore/internal/tracing/logged_trace_span.cc

@@ -14,14 +14,37 @@
 
 #include "tensorstore/internal/tracing/logged_trace_span.h"
 
+#include <stdint.h>
+
+#include <atomic>
 #include <ostream>
 #include <string_view>
 
 #include "absl/strings/str_format.h"
+#include "absl/time/clock.h"
+#include "absl/time/time.h"
 
 namespace tensorstore {
 namespace internal_tracing {
 
+/* static */
+uint64_t LoggedTraceSpan::random_id() {
+  static std::atomic<int64_t> base{absl::ToUnixNanos(absl::Now())};
+
+  thread_local uint64_t id =
+      static_cast<uint64_t>(base.fetch_add(1, std::memory_order_relaxed));
+
+  // Apply xorshift64, which has a period of 2^64-1, to the per-thread id
+  // to generate the next id.
+  uint64_t x = id;
+  do {
+    x ^= x << 13;
+    x ^= x >> 7;
+    x ^= x << 17;
+  } while (x == 0);
+  return id = x;
+}
+
 void LoggedTraceSpan::BeginLog(std::ostream& stream) {
   stream << absl::StreamFormat("%x: Start %s", id_, method());
 }

tensorstore/internal/tracing/logged_trace_span.h

@@ -26,8 +26,6 @@
 #include "absl/log/log_streamer.h"
 #include "absl/status/status.h"
 #include "absl/strings/str_format.h"
-#include "absl/time/clock.h"
-#include "absl/time/time.h"
 #include "tensorstore/internal/source_location.h"
 #include "tensorstore/internal/tracing/span_attribute.h"
 #include "tensorstore/internal/tracing/trace_span.h"
@@ -39,18 +37,7 @@ namespace internal_tracing {
 /// A TraceSpan which optionally includes scoped logging to ABSL INFO.
 class LoggedTraceSpan : public TraceSpan {
   // Generates a random ID for logging the Begin/End log messages.
-  inline uint64_t random_id() {
-    thread_local uint64_t id = absl::ToUnixNanos(absl::Now());
-    // Apply xorshift64, which has a period of 2^64-1, to the per-thread id
-    // to generate the next id.
-    uint64_t x = id;
-    do {
-      x ^= x << 13;
-      x ^= x >> 7;
-      x ^= x << 17;
-    } while (x == 0);
-    return id = x;
-  }
+  static uint64_t random_id();
 
  public:
   LoggedTraceSpan(std::string_view method, bool log,