Support for monotime

Provide `monotime` function with at least 1 millisecond resolution.

3 files changed, 124 insertions, 8 deletions

diff --git a/src/Makefile b/src/Makefile
index 25f468d..10fc31a 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -4,13 +4,28 @@
 # environment.
 #
 
-# PLAT: linux macosx win32 mingw
+# PLAT: linux macosx win32 mingw freebsd
 # platform to build for
+ifeq ($(origin PLAT),undefined)
+UNAME_S:=$(shell uname -s)
+ifeq ($(UNAME_S),Linux)
+    PLAT=linux
+endif
+ifeq ($(UNAME_S),Darwin)
+    PLAT=macosx
+endif
+ifeq ($(UNAME_S),FreeBSD)
+    PLAT=freebsd
+endif
+ifeq ($(patsubst MINGW%,MINGW,$(UNAME_S)),MINGW)
+    PLAT=mingw
+endif
+endif
 PLAT?=linux
 
 # LUA_VERSION: 5.1 5.2 5.3
 # lua version to build against
-LUA_VERSION?=5.1
+LUA_VERSION?=$(basename $(word 2,$(shell lua -v)))
 
 # MYCFLAGS: to be set by user if needed
 MYCFLAGS=
@@ -130,7 +145,7 @@ CC_linux=gcc
 DEF_linux=
 CFLAGS_linux= -I$(LUAINC) $(DEF) -Wall -Wshadow -Wextra \
         -Wimplicit -O2 -ggdb3 -fpic -fvisibility=hidden
-LDFLAGS_linux=-O -shared -fpic -o
+LDFLAGS_linux=-lrt -O -shared -fpic -o
 LD_linux=gcc
 
 #------
@@ -151,7 +166,7 @@ LD_freebsd=gcc
 SO_mingw=dll
 O_mingw=o
 CC_mingw=gcc
-DEF_mingw=-DWINVER=0x0501
+DEF_mingw=-DWINVER=0x0600 -D_WIN32_WINNT=0x0600
 CFLAGS_mingw= -I$(LUAINC) $(DEF) -Wall -O2 -fno-common \
         -fvisibility=hidden
 LDFLAGS_mingw= $(LUALIB) -shared -Wl,-s -o
@@ -165,7 +180,8 @@ SO_win32=dll
 O_win32=obj
 CC_win32=cl
 DEF_win32= //D "WIN32" //D "NDEBUG" //D "_WINDOWS" //D "_USRDLL" \
-     //D "_CRT_SECURE_NO_WARNINGS" //D "_WINDLL"
+     //D "_CRT_SECURE_NO_WARNINGS" //D "_WINDLL" \
+     //D"WINVER=0x0600" //D"_WIN32_WINNT=0x0600"
 CFLAGS_win32=//I "$(LUAINC)" $(DEF) //O2 //Ot //MD //W3 //nologo
 LDFLAGS_win32= //nologo //link //NOLOGO //DLL //INCREMENTAL:NO \
     //MANIFEST //MANIFESTFILE:"intermediate.manifest" \
diff --git a/src/time.c b/src/time.c
index 43d0e35..353f259 100644
--- a/src/time.c
+++ b/src/time.c
@@ -10,6 +10,10 @@
 #include <sys/time.h>
 #endif
 
+#ifdef __APPLE__
+#include "time_osx.h"
+#endif
+
 #include "compat.h"
 
 /*-------------------------------------------------------------------------
@@ -23,7 +27,7 @@ static double time_gettime(void) {
     double t;
     GetSystemTimeAsFileTime(&ft);
     /* Windows file time (time since January 1, 1601 (UTC)) */
-    t  = ft.dwLowDateTime/1.0e7 + ft.dwHighDateTime*(4294967296.0/1.0e7);
+    t  = ft.dwLowDateTime*1.0e-7 + ft.dwHighDateTime*(4294967296.0*1.0e-7);
     /* convert to Unix Epoch time (time since January 1, 1970 (UTC)) */
     return (t - 11644473600.0);
 }
@@ -32,12 +36,32 @@ static double time_gettime(void) {
     struct timeval v;
     gettimeofday(&v, (struct timezone *) NULL);
     /* Unix Epoch time (time since January 1, 1970 (UTC)) */
-    return v.tv_sec + v.tv_usec/1.0e6;
+    return v.tv_sec + v.tv_usec*1.0e-6;
 }
 #endif
 
 /*-------------------------------------------------------------------------
- * Returns the time the system has been up, in secconds.
+ * Gets monotonic time in s
+ * Returns
+ *   time in s.
+ *-------------------------------------------------------------------------*/
+#ifdef _WIN32
+WINBASEAPI ULONGLONG WINAPI GetTickCount64(VOID);
+
+static double time_monotime(void) {
+    ULONGLONG ms = GetTickCount64();
+    return ms*1.0e-3;
+}
+#else
+static double time_monotime(void) {
+    struct timespec ts;
+    clock_gettime(CLOCK_MONOTONIC, &ts);
+    return ts.tv_sec + ts.tv_nsec*1.0e-9;
+}
+#endif
+
+/*-------------------------------------------------------------------------
+ * Returns the current system time, 1970 (UTC), in secconds.
  *-------------------------------------------------------------------------*/
 static int time_lua_gettime(lua_State *L)
 {
@@ -46,6 +70,15 @@ static int time_lua_gettime(lua_State *L)
 }
 
 /*-------------------------------------------------------------------------
+ * Returns the monotonic time the system has been up, in secconds.
+ *-------------------------------------------------------------------------*/
+static int time_lua_monotime(lua_State *L)
+{
+    lua_pushnumber(L, time_monotime());
+    return 1;
+}
+
+/*-------------------------------------------------------------------------
  * Sleep for n seconds.
  *-------------------------------------------------------------------------*/
 #ifdef _WIN32
@@ -79,6 +112,7 @@ static int time_lua_sleep(lua_State *L)
 
 static luaL_Reg func[] = {
     { "gettime", time_lua_gettime },
+    { "monotime", time_lua_monotime },
     { "sleep", time_lua_sleep },
     { NULL, NULL }
 };
diff --git a/src/time_osx.h b/src/time_osx.h
new file mode 100644
index 0000000..3308318
--- /dev/null
+++ b/src/time_osx.h
@@ -0,0 +1,66 @@
+#ifndef TIME_OSX_H
+#define TIME_OSX_H
+
+/*
+ * clock_gettime()
+ *
+ * OS X doesn't implement the clock_gettime() POSIX interface, but does
+ * provide a monotonic clock through mach_absolute_time(). On i386 and
+ * x86_64 architectures this clock is in nanosecond units, but not so on
+ * other devices. mach_timebase_info() provides the conversion parameters.
+ *
+ */
+
+#include <time.h>            /* struct timespec */
+#include <errno.h>           /* errno EINVAL */
+#include <sys/time.h>        /* TIMEVAL_TO_TIMESPEC struct timeval gettimeofday(3) */
+#include <mach/mach_time.h>  /* mach_timebase_info_data_t mach_timebase_info() mach_absolute_time() */
+
+
+#define CLOCK_REALTIME  0
+#define CLOCK_VIRTUAL   1
+#define CLOCK_PROF      2
+#define CLOCK_MONOTONIC 3
+
+static mach_timebase_info_data_t clock_timebase = {
+    .numer = 1, .denom = 1,
+}; /* clock_timebase */
+
+void clock_gettime_init(void) __attribute__((constructor));
+
+void clock_gettime_init(void) {
+    if (mach_timebase_info(&clock_timebase) != KERN_SUCCESS)
+        __builtin_abort();
+} /* clock_gettime_init() */
+
+static int clock_gettime(int clockid, struct timespec *ts) {
+    switch (clockid) {
+    case CLOCK_REALTIME: {
+        struct timeval tv;
+
+        if (0 != gettimeofday(&tv, 0))
+        return -1;
+
+        TIMEVAL_TO_TIMESPEC(&tv, ts);
+
+        return 0;
+    }
+    case CLOCK_MONOTONIC: {
+        unsigned long long abt;
+
+        abt = mach_absolute_time();
+        abt = abt * clock_timebase.numer / clock_timebase.denom;
+
+        ts->tv_sec = abt / 1000000000UL;
+        ts->tv_nsec = abt % 1000000000UL;
+
+        return 0;
+    }
+    default:
+        errno = EINVAL;
+
+        return -1;
+    } /* switch() */
+} /* clock_gettime() */
+
+#endif /* TIME_OSX_H */