From dae17ce7e3b6a48d2e100757ebf25dd5bc431f03 Mon Sep 17 00:00:00 2001
From: Brian Gianforcaro <bgianf@serenityos.org>
Date: Sat, 14 Aug 2021 14:40:38 -0700
Subject: [PATCH] AK: Add Time::now_<clock_id> functions for obtaining the
 current time

In the quest of removing as timespec / timeval usage in the Userland as
possible, we need a way to conveniently retrieving the current clock
time from the kernel and storing it in `AK::Time` format.
---
 AK/Time.cpp | 32 ++++++++++++++++++++++++++++++++
 AK/Time.h   |  7 +++++++
 2 files changed, 39 insertions(+)

diff --git a/AK/Time.cpp b/AK/Time.cpp
index 170446b0a36..b7740371b67 100644
--- a/AK/Time.cpp
+++ b/AK/Time.cpp
@@ -14,6 +14,7 @@
 #    include <Kernel/UnixTypes.h>
 #else
 #    include <sys/time.h>
+#    include <time.h>
 #endif
 
 namespace AK {
@@ -288,4 +289,35 @@ Time Time::from_half_sanitized(i64 seconds, i32 extra_seconds, u32 nanoseconds)
     return Time { seconds + extra_seconds, nanoseconds };
 }
 
+#ifndef KERNEL
+namespace {
+static Time now_time_from_clock(clockid_t clock_id)
+{
+    timespec now_spec {};
+    ::clock_gettime(clock_id, &now_spec);
+    return Time::from_timespec(now_spec);
+}
+}
+Time Time::now_realtime()
+{
+    return now_time_from_clock(CLOCK_REALTIME);
+}
+
+Time Time::now_realtime_coarse()
+{
+    return now_time_from_clock(CLOCK_REALTIME_COARSE);
+}
+
+Time Time::now_monotonic()
+{
+    return now_time_from_clock(CLOCK_MONOTONIC);
+}
+
+Time Time::now_monotonic_coarse()
+{
+    return now_time_from_clock(CLOCK_MONOTONIC_COARSE);
+}
+
+#endif
+
 }
diff --git a/AK/Time.h b/AK/Time.h
index 8a754ab0ff7..585f676af53 100644
--- a/AK/Time.h
+++ b/AK/Time.h
@@ -143,6 +143,13 @@ public:
     constexpr static Time zero() { return Time(0, 0); };
     constexpr static Time max() { return Time(0x7fff'ffff'ffff'ffffLL, 999'999'999); };
 
+#ifndef KERNEL
+    [[nodiscard]] static Time now_realtime();
+    [[nodiscard]] static Time now_realtime_coarse();
+    [[nodiscard]] static Time now_monotonic();
+    [[nodiscard]] static Time now_monotonic_coarse();
+#endif
+
     // Truncates towards zero (2.8s to 2s, -2.8s to -2s).
     i64 to_truncated_seconds() const;
     i64 to_truncated_milliseconds() const;