intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 65 insertions, 0 deletions

diff --git a/library/cpp/actors/util/timerfd.h b/library/cpp/actors/util/timerfd.h
new file mode 100644
index 0000000000..3189e2a672
--- /dev/null
+++ b/library/cpp/actors/util/timerfd.h
@@ -0,0 +1,65 @@
+#pragma once
+
+#include "datetime.h"
+
+#include <util/generic/noncopyable.h>
+
+#ifdef _linux_
+
+#include <util/system/yassert.h>
+#include <errno.h>
+#include <sys/timerfd.h>
+
+struct TTimerFd: public TNonCopyable {
+    int Fd;
+
+    TTimerFd() {
+        Fd = timerfd_create(CLOCK_MONOTONIC, 0);
+        Y_VERIFY(Fd != -1, "timerfd_create(CLOCK_MONOTONIC, 0) -> -1; errno:%d: %s", int(errno), strerror(errno));
+    }
+
+    ~TTimerFd() {
+        close(Fd);
+    }
+
+    void Set(ui64 ts) {
+        ui64 now = GetCycleCountFast();
+        Arm(now >= ts? 1: NHPTimer::GetSeconds(ts - now) * 1e9);
+    }
+
+    void Reset() {
+        Arm(0); // disarm timer
+    }
+
+    void Wait() {
+        ui64 expirations;
+        ssize_t s = read(Fd, &expirations, sizeof(ui64));
+        Y_UNUSED(s); // Y_VERIFY(s == sizeof(ui64));
+    }
+
+    void Wake() {
+        Arm(1);
+    }
+private:
+    void Arm(ui64 ns) {
+        struct itimerspec spec;
+        spec.it_value.tv_sec = ns / 1'000'000'000;
+        spec.it_value.tv_nsec = ns % 1'000'000'000;
+        spec.it_interval.tv_sec = 0;
+        spec.it_interval.tv_nsec = 0;
+        int ret = timerfd_settime(Fd, 0, &spec, nullptr);
+        Y_VERIFY(ret != -1, "timerfd_settime(%d, 0, %" PRIu64 "ns, 0) -> %d; errno:%d: %s", Fd, ns, ret, int(errno), strerror(errno));
+    }
+};
+
+#else
+
+struct TTimerFd: public TNonCopyable {
+    int Fd = 0;
+    void Set(ui64) {}
+    void Reset() {}
+    void Wait() {}
+    void Wake() {}
+};
+
+#endif