Add Clock, implementing proper monotonic and wallclock time using Instant (sec + nsec), currentTimeMillis() is also monotonic now, reused by Platform. Dropped Platform.currentTimeMicros()

Clock and its implementation was copied from jaulibs, a spin-off from Direct-BT.

The implementation uses `clock_gettime(CLOCK_MONOTONIC, &t)` and is considered safe and high-performant
as it avoids a kernel call via VDSO (GNU/Linux).

2 files changed, 94 insertions, 25 deletions

diff --git a/src/native/common/Platforms.c b/src/native/common/Platforms.c
deleted file mode 100644
index f48d020..0000000
--- a/src/native/common/Platforms.c
+++ /dev/null
@@ -1,25 +0,0 @@
-
-#include <jni.h>
-
-#include <assert.h>
-
-#include <gluegen_stdint.h>
-
-#include "com_jogamp_common_os_Platform.h"
-
-#include <sys/time.h>
-
-JNIEXPORT jlong JNICALL 
-Java_com_jogamp_common_os_Platform_currentTimeMillis(JNIEnv *env, jclass _unused) {
-    struct timeval tv;
-    gettimeofday(&tv,NULL);
-    return (int64_t)tv.tv_sec * 1000 + tv.tv_usec / 1000;
-}
-
-JNIEXPORT jlong JNICALL 
-Java_com_jogamp_common_os_Platform_currentTimeMicros(JNIEnv *env, jclass _unused) {
-    struct timeval tv;
-    gettimeofday(&tv,NULL);
-    return (int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
-}
-
diff --git a/src/native/common/jau_sys_Clock.c b/src/native/common/jau_sys_Clock.c
new file mode 100644
index 0000000..27ee10b
--- /dev/null
+++ b/src/native/common/jau_sys_Clock.c
@@ -0,0 +1,94 @@
+/*
+ * Author: Sven Gothel <[email protected]>
+ * Copyright (c) 2020-2023 Gothel Software e.K.
+ * Copyright (c) 2020-2023 JogAmp Community.
+ * Copyright (c) 2020 ZAFENA AB
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <jni.h>
+
+#include <assert.h>
+
+#include <gluegen_stdint.h>
+
+#include "com_jogamp_common_os_Clock.h"
+
+// #include <sys/time.h>
+#include <time.h>
+
+static const int64_t NanoPerMilli = 1000000L;
+static const int64_t MilliPerOne = 1000L;
+
+JNIEXPORT void JNICALL
+Java_com_jogamp_common_os_Clock_getMonotonicTimeImpl(JNIEnv *env, jclass clazz, jlongArray jval) {
+    (void)clazz;
+    {
+        // Avoid GetPrimitiveArrayCritical(), which occasionally hangs on system call ::clock_gettime()
+        struct timespec t = { .tv_sec = 0, .tv_nsec = 0 };
+        clock_gettime(CLOCK_MONOTONIC, &t);
+        const jlong val[] = { (jlong)t.tv_sec, (jlong)t.tv_nsec };
+        (*env)->SetLongArrayRegion(env, jval, 0, 2, val);
+    }
+}
+
+JNIEXPORT void JNICALL
+Java_com_jogamp_common_os_Clock_getWallClockTimeImpl(JNIEnv *env, jclass clazz, jlongArray jval) {
+    (void)clazz;
+    {
+        // Avoid GetPrimitiveArrayCritical(), which occasionally hangs on system call ::clock_gettime()
+        struct timespec t = { .tv_sec = 0, .tv_nsec = 0 };
+        clock_gettime(CLOCK_REALTIME, &t);
+        const jlong val[] = { (jlong)t.tv_sec, (jlong)t.tv_nsec };
+        (*env)->SetLongArrayRegion(env, jval, 0, 2, val);
+    }
+}
+
+/**
+ * See <http://man7.org/linux/man-pages/man2/clock_gettime.2.html>
+ * <p>
+ * Regarding avoiding kernel via VDSO,
+ * see <http://man7.org/linux/man-pages/man7/vdso.7.html>,
+ * clock_gettime seems to be well supported at least on kernel >= 4.4.
+ * Only bfin and sh are missing, while ia64 seems to be complicated.
+ */
+JNIEXPORT jlong JNICALL
+Java_com_jogamp_common_os_Clock_currentTimeMillis(JNIEnv *env, jclass clazz) {
+    (void)env;
+    (void)clazz;
+
+    struct timespec t = { .tv_sec = 0, .tv_nsec = 0 };
+    clock_gettime(CLOCK_MONOTONIC, &t);
+    int64_t res = (int64_t)( t.tv_sec ) * MilliPerOne +
+                  (int64_t)( t.tv_nsec ) / NanoPerMilli;
+    return (jlong)res;
+}
+
+JNIEXPORT jlong JNICALL
+Java_com_jogamp_common_os_Clock_wallClockSeconds(JNIEnv *env, jclass clazz) {
+    (void)env;
+    (void)clazz;
+
+    struct timespec t = { .tv_sec = 0, .tv_nsec = 0 };
+    clock_gettime(CLOCK_REALTIME, &t);
+    return (jlong)( (int64_t)( t.tv_sec ) );
+}
+