From 2ac6eadbbe9b9097d998eb2e917d63dc5cc481b3 Mon Sep 17 00:00:00 2001
From: Avery Pennarun <apenwarr@gmail.com>
Date: Sat, 5 Apr 2014 03:08:36 -0400
Subject: [PATCH 2/2] Add support for clock_gettime(CLOCK_MONOTONIC_RAW) as a
 clock type.

clockspeed only supports rdtsc (x86-only) and gethrtime() (solaris-only) out
of the box.  clock_gettime() is the modern posix standard for this.
---
 Makefile     |  9 ++++++++-
 clockspeed.c |  2 ++
 monotime.h   | 21 +++++++++++++++++++++
 sntpclock.c  |  1 +
 timing.h     | 11 +++++++++++
 trymono.c    |  7 +++++++
 6 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 monotime.h
 create mode 100644 trymono.c

diff --git a/Makefile b/Makefile
index fd4a071..2a65dba 100644
--- a/Makefile
+++ b/Makefile
@@ -74,7 +74,7 @@ clockspeed.1
 
 clockspeed.o: \
 compile clockspeed.c readwrite.h exit.h select.h scan.h fmt.h str.h \
-fifo.h open.h error.h auto_home.h timing.h hasrdtsc.h hasgethr.h
+fifo.h open.h error.h auto_home.h timing.h hasrdtsc.h hasgethr.h hasmono.h
 	./compile clockspeed.c
 
 clockview: \
@@ -151,6 +151,13 @@ trymkffo.c compile load
 	&& echo \#define HASMKFIFO 1 || exit 0 ) > hasmkffo.h
 	rm -f trymkffo.o trymkffo
 
+hasmono.h: \
+trymono.c compile load
+	( ( ./compile trymono.c && ./load trymono ) >/dev/null \
+	2>&1 \
+	&& echo \#define HASMONOTIME 1 || exit 0 ) > hasmono.h
+	rm -f trymono.o trymono
+
 hasrdtsc.h: \
 tryrdtsc.c compile load
 	( ( ./compile tryrdtsc.c && ./load tryrdtsc && ./tryrdtsc \
diff --git a/clockspeed.c b/clockspeed.c
index c915256..efaab98 100644
--- a/clockspeed.c
+++ b/clockspeed.c
@@ -15,11 +15,13 @@
 
 #ifndef HASRDTSC
 #ifndef HASGETHRTIME
+#ifndef HASMONOTIME
 
   Error! Need an unadjusted hardware clock.
 
 #endif
 #endif
+#endif
 
 struct point {
   timing lowlevel;
diff --git a/monotime.h b/monotime.h
new file mode 100644
index 0000000..b4f8393
--- /dev/null
+++ b/monotime.h
@@ -0,0 +1,21 @@
+#ifndef MONOTIME_H
+#define MONOTIME_H
+
+#include <time.h>
+#include "error.h"
+
+#ifndef CLOCK_MONOTONIC_RAW
+#define CLOCK_MONOTONIC_RAW 4
+#endif
+
+static long long monotime()
+{
+  struct timespec ts;
+  if (clock_gettime(CLOCK_MONOTONIC_RAW, &ts) < 0) {
+    perror("clock_gettime");
+    _exit(1);
+  }
+  return ts.tv_sec * 1000000000LL + ts.tv_nsec;
+}
+
+#endif
diff --git a/sntpclock.c b/sntpclock.c
index d1e334e..9b3a0df 100644
--- a/sntpclock.c
+++ b/sntpclock.c
@@ -3,6 +3,7 @@
 #include <sys/param.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <unistd.h>
 #include "strerr.h"
 #include "ip.h"
 #include "str.h"
diff --git a/timing.h b/timing.h
index f1d537e..45bc3df 100644
--- a/timing.h
+++ b/timing.h
@@ -3,6 +3,7 @@
 
 #include "hasrdtsc.h"
 #include "hasgethr.h"
+#include "hasmono.h"
 #include <sys/types.h>
 #include <sys/time.h>
 
@@ -25,6 +26,15 @@ typedef struct { hrtime_t t; } timing;
 #define timing_diff(x,y) ((double) ((x)->t - (y)->t))
 
 #else
+#ifdef HASMONOTIME
+
+#include "monotime.h"
+
+typedef struct { long long t; } timing;
+#define timing_now(x) ((x)->t = monotime())
+#define timing_diff(x,y) ((double) ((x)->t - (y)->t))
+
+#else
 
 #define timing timing_basic
 #define timing_now timing_basic_now
@@ -32,5 +42,6 @@ typedef struct { hrtime_t t; } timing;
 
 #endif
 #endif
+#endif
 
 #endif
diff --git a/trymono.c b/trymono.c
new file mode 100644
index 0000000..0461af5
--- /dev/null
+++ b/trymono.c
@@ -0,0 +1,7 @@
+#include <time.h>
+#include "monotime.h"
+
+main()
+{
+  long long x = monotime();
+}
-- 
1.9.1.423.g4596e3a