Support monotonic boot time with suspend awareness

1 files changed, 60 insertions, 15 deletions

diff --git a/library/cpp/time_provider/monotonic.cpp b/library/cpp/time_provider/monotonic.cpp
index 99126080e2..ee0f29e498 100644
--- a/library/cpp/time_provider/monotonic.cpp
+++ b/library/cpp/time_provider/monotonic.cpp
@@ -1,31 +1,76 @@
 #include "monotonic.h"
 
 #include <chrono>
+#include <optional>
+#include <util/system/platform.h>
+
+#ifdef _linux
+    #include <time.h>
+    #include <string.h>
+#endif
 
 namespace NMonotonic {
 
-namespace {
-// Unfortunately time_since_epoch() is sometimes negative on wine
-// Remember initial time point at program start and use offsets from that
-std::chrono::steady_clock::time_point MonotonicOffset = std::chrono::steady_clock::now();
-}
+    namespace {
+        // Unfortunately time_since_epoch() is sometimes negative on wine
+        // Remember initial time point at program start and use offsets from that
+        std::chrono::steady_clock::time_point MonotonicOffset = std::chrono::steady_clock::now();
+    }
 
-ui64 GetMonotonicMicroSeconds() {
-    auto microseconds = std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::steady_clock::now() - MonotonicOffset).count();
-    // Steady clock is supposed to never jump backwards, but it's better to be safe in case of buggy implementations
-    if (Y_UNLIKELY(microseconds < 0)) {
-        microseconds = 0;
+    ui64 GetMonotonicMicroSeconds() {
+        auto microseconds = std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::steady_clock::now() - MonotonicOffset).count();
+        // Steady clock is supposed to never jump backwards, but it's better to be safe in case of buggy implementations
+        if (Y_UNLIKELY(microseconds < 0)) {
+            microseconds = 0;
+        }
+        // Add one so we never return zero
+        return microseconds + 1;
     }
-    // Add one so we never return zero
-    return microseconds + 1;
-}
 
-} // namespace TMonotonic
+#ifdef _linux_
+    namespace {
+        std::optional<ui64> GetClockBootTimeMicroSeconds() {
+            struct timespec t;
+            std::optional<ui64> r;
+            if (0 == ::clock_gettime(CLOCK_BOOTTIME, &t)) {
+                r.emplace(t.tv_nsec / 1000ULL + t.tv_sec * 1000000ULL);
+            }
+            return r;
+        }
+
+        // We want time relative to process start
+        std::optional<ui64> BootTimeOffset = GetClockBootTimeMicroSeconds();
+    }
+
+    ui64 GetBootTimeMicroSeconds() {
+        if (Y_UNLIKELY(!BootTimeOffset)) {
+            return GetMonotonicMicroSeconds();
+        }
+
+        auto r = GetClockBootTimeMicroSeconds();
+        Y_VERIFY(r, "Unexpected clock_gettime(CLOCK_BOOTTIME) failure: %s", strerror(errno));
+        return *r - *BootTimeOffset + 1;
+    }
+#else
+    ui64 GetBootTimeMicroSeconds() {
+        return GetMonotonicMicroSeconds();
+    }
+#endif
+
+}
 
-template<>
+template <>
 void Out<NMonotonic::TMonotonic>(
     IOutputStream& o,
     NMonotonic::TMonotonic t)
 {
     o << t - NMonotonic::TMonotonic::Zero();
 }
+
+template <>
+void Out<NMonotonic::TBootTime>(
+    IOutputStream& o,
+    NMonotonic::TBootTime t)
+{
+    o << t - NMonotonic::TBootTime::Zero();
+}