Merge pull request #1146 from zevv/os-clock

Add  clock sources to os/clock (:realtime, :monotonic, :cputime)

src/core/os.c

@@ -1278,14 +1278,32 @@ JANET_CORE_FN(os_time,
 }
 
 JANET_CORE_FN(os_clock,
-              "(os/clock)",
-              "Return the number of whole + fractional seconds since some fixed point in time. The clock "
-              "is guaranteed to be non-decreasing in real time.") {
+              "(os/clock &opt source)",
+              "Return the number of whole + fractional seconds of the requested clock source.\n\n"
+              "The `source` argument selects the clock source to use, when not specified the default "
+              "is `:realtime`:\n"
+              "- :realtime: Return the real (i.e., wall-clock) time. This clock is affected by discontinuous "
+              "  jumps in the system time\n"
+              "- :monotonic: Return the number of whole + fractional seconds since some fixed point in "
+              "  time. The clock is guaranteed to be non-decreasing in real time.\n"
+              "- :cputime: Return the CPU time consumed by this process  (i.e. all threads in the process)\n") {
     janet_sandbox_assert(JANET_SANDBOX_HRTIME);
-    janet_fixarity(argc, 0);
-    (void) argv;
+    janet_arity(argc, 0, 1);
+    enum JanetTimeSource source = JANET_TIME_REALTIME;
+    if (argc == 1) {
+        JanetKeyword sourcestr = janet_getkeyword(argv, 0);
+        if (janet_cstrcmp(sourcestr, "realtime") == 0) {
+            source = JANET_TIME_REALTIME;
+        } else if (janet_cstrcmp(sourcestr, "monotonic") == 0) {
+            source = JANET_TIME_MONOTONIC;
+        } else if (janet_cstrcmp(sourcestr, "cputime") == 0) {
+            source = JANET_TIME_CPUTIME;
+        } else {
+            janet_panicf("expected :realtime, :monotonic, or :cputime, got %v", argv[0]);
+        }
+    }
     struct timespec tv;
-    if (janet_gettime(&tv)) janet_panic("could not get time");
+    if (janet_gettime(&tv, source)) janet_panic("could not get time");
     double dtime = tv.tv_sec + (tv.tv_nsec / 1E9);
     return janet_wrap_number(dtime);
 }

src/core/util.c

@@ -875,7 +875,9 @@ int32_t janet_sorted_keys(const JanetKV *dict, int32_t cap, int32_t *index_buffe
 /* Clock shims for various platforms */
 #ifdef JANET_GETTIME
 #ifdef JANET_WINDOWS
-int janet_gettime(struct timespec *spec) {
+#include <profileapi.h>
+int janet_gettime(struct timespec *spec, enum JanetTimeSource source) {
+    if (source == JANET_TIME_REALTIME) {
         FILETIME ftime;
         GetSystemTimeAsFileTime(&ftime);
         int64_t wintime = (int64_t)(ftime.dwLowDateTime) | ((int64_t)(ftime.dwHighDateTime) << 32);
@@ -884,13 +886,28 @@ int janet_gettime(struct timespec *spec) {
         spec->tv_sec  = wintime / 10000000LL;
         /* Resolution is 100 nanoseconds. */
         spec->tv_nsec = wintime % 10000000LL * 100;
+    } else if (source == JANET_TIME_MONOTONIC) {
+        LARGE_INTEGER count;
+        LARGE_INTEGER perf_freq;
+        QueryPerformanceCounter(&count);
+        QueryPerformanceFrequency(&perf_freq);
+        spec->tv_sec = count.QuadPart / perf_freq.QuadPart;
+        spec->tv_nsec = (long)((count.QuadPart % perf_freq.QuadPart) * 1000000000 / perf_freq.QuadPart);
+    } else if (source == JANET_TIME_CPUTIME) {
+        FILETIME creationTime, exitTime, kernelTime, userTime;
+        GetProcessTimes(GetCurrentProcess(), &creationTime, &exitTime, &kernelTime, &userTime);
+        int64_t tmp = ((int64_t)userTime.dwHighDateTime << 32) + userTime.dwLowDateTime;
+        spec->tv_sec = tmp / 10000000LL;
+        spec->tv_nsec = tmp % 10000000LL * 100;
+    }
     return 0;
 }
 /* clock_gettime() wasn't available on Mac until 10.12. */
 #elif defined(JANET_APPLE) && !defined(MAC_OS_X_VERSION_10_12)
 #include <mach/clock.h>
 #include <mach/mach.h>
-int janet_gettime(struct timespec *spec) {
+int janet_gettime(struct timespec *spec, enum JanetTimeSource source) {
+    if (source == JANET_TIME_REALTIME) {
         clock_serv_t cclock;
         mach_timespec_t mts;
         host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &cclock);
@@ -898,11 +915,33 @@ int janet_gettime(struct timespec *spec) {
         mach_port_deallocate(mach_task_self(), cclock);
         spec->tv_sec = mts.tv_sec;
         spec->tv_nsec = mts.tv_nsec;
+    } else if (source == JANET_TIME_MONOTONIC) {
+        clock_serv_t cclock;
+        int nsecs;
+        mach_msg_type_number_t count;
+        host_get_clock_service(mach_host_self(), clock, &cclock);
+        clock_get_attributes(cclock, CLOCK_GET_TIME_RES, (clock_attr_t)&nsecs, &count);
+        mach_port_deallocate(mach_task_self(), cclock);
+        clock_getres(CLOCK_MONOTONIC, spec);
+    }
+    if (source == JANET_TIME_CPUTIME) {
+        clock_t tmp = clock();
+        spec->tv_sec = tmp;
+        spec->tv_nsec = (tmp - spec->tv_sec) * 1.0e9;
+    }
     return 0;
 }
 #else
-int janet_gettime(struct timespec *spec) {
-    return clock_gettime(CLOCK_REALTIME, spec);
+int janet_gettime(struct timespec *spec, enum JanetTimeSource source) {
+    clockid_t cid = JANET_TIME_REALTIME;
+    if (source == JANET_TIME_REALTIME) {
+        cid = CLOCK_REALTIME;
+    } else if (source == JANET_TIME_MONOTONIC) {
+        cid = CLOCK_MONOTONIC;
+    } else if (source == JANET_TIME_CPUTIME) {
+        cid = CLOCK_PROCESS_CPUTIME_ID;
+    }
+    return clock_gettime(cid, spec);
 }
 #endif
 #endif

src/core/util.h

@@ -126,7 +126,12 @@ void janet_core_cfuns_ext(JanetTable *env, const char *regprefix, const JanetReg
 
 /* Clock gettime */
 #ifdef JANET_GETTIME
-int janet_gettime(struct timespec *spec);
+enum JanetTimeSource {
+    JANET_TIME_REALTIME,
+    JANET_TIME_MONOTONIC,
+    JANET_TIME_CPUTIME
+};
+int janet_gettime(struct timespec *spec, enum JanetTimeSource source);
 #endif
 
 /* strdup */

test/suite0007.janet

@@ -333,4 +333,29 @@
 
 (assert (pos? (length (gensym))) "gensym not empty, regression #753")
 
+
+# os/clock. These tests might prove fragile under CI because they
+# rely on measured time. We'll see.
+
+(defmacro measure-time [clocks & body]
+  (def [t1 t2] [(gensym) (gensym)])
+  ~(do
+    (def ,t1 (map |(os/clock $) ,clocks))
+    ,;body
+    (def ,t2 (map |(os/clock $) ,clocks))
+    (zipcoll ,clocks (map |(- ;$) (map tuple ,t2 ,t1))))
+)
+
+# Spin for 0.1 seconds
+(def dt (measure-time [:realtime :monotonic :cputime]
+  (def t1 (os/clock :monotonic))
+  (while (< (- (os/clock :monotonic) t1) 0.1) true)))
+(assert (> (dt :monotonic) 0.10))
+(assert (> (dt :cputime) 0.05))
+
+# Sleep for 0.1 seconds
+(def dt (measure-time [:realtime :monotonic :cputime] (os/sleep 0.1)))
+(assert (> (dt :monotonic) 0.10))
+(assert (< (dt :cputime) 0.05))
+
 (end-suite)