8027294: Prepare hotspot for non TOD based uptime counter
Summary: Use HR timer when available for os::elapsed_counter() on linux/bsd. Add a new counter for the JVM uptime.
Reviewed-by: dholmes, sla
--- a/hotspot/src/os/bsd/vm/os_bsd.cpp Thu Oct 24 22:19:48 2013 -0700
+++ b/hotspot/src/os/bsd/vm/os_bsd.cpp Fri Oct 25 09:07:58 2013 +0200
@@ -945,17 +945,15 @@
// Used by VMSelfDestructTimer and the MemProfiler.
double os::elapsedTime() {
- return (double)(os::elapsed_counter()) * 0.000001;
+ return ((double)os::elapsed_counter()) / os::elapsed_frequency();
}
jlong os::elapsed_counter() {
- timeval time;
- int status = gettimeofday(&time, NULL);
- return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
+ return javaTimeNanos() - initial_time_count;
}
jlong os::elapsed_frequency() {
- return (1000 * 1000);
+ return NANOSECS_PER_SEC; // nanosecond resolution
}
bool os::supports_vtime() { return true; }
@@ -3582,7 +3580,7 @@
Bsd::_main_thread = pthread_self();
Bsd::clock_init();
- initial_time_count = os::elapsed_counter();
+ initial_time_count = javaTimeNanos();
#ifdef __APPLE__
// XXXDARWIN
--- a/hotspot/src/os/linux/vm/os_linux.cpp Thu Oct 24 22:19:48 2013 -0700
+++ b/hotspot/src/os/linux/vm/os_linux.cpp Fri Oct 25 09:07:58 2013 +0200
@@ -1333,17 +1333,15 @@
// Used by VMSelfDestructTimer and the MemProfiler.
double os::elapsedTime() {
- return (double)(os::elapsed_counter()) * 0.000001;
+ return ((double)os::elapsed_counter()) / os::elapsed_frequency(); // nanosecond resolution
}
jlong os::elapsed_counter() {
- timeval time;
- int status = gettimeofday(&time, NULL);
- return jlong(time.tv_sec) * 1000 * 1000 + jlong(time.tv_usec) - initial_time_count;
+ return javaTimeNanos() - initial_time_count;
}
jlong os::elapsed_frequency() {
- return (1000 * 1000);
+ return NANOSECS_PER_SEC; // nanosecond resolution
}
bool os::supports_vtime() { return true; }
@@ -4750,7 +4748,7 @@
Linux::_main_thread = pthread_self();
Linux::clock_init();
- initial_time_count = os::elapsed_counter();
+ initial_time_count = javaTimeNanos();
// pthread_condattr initialization for monotonic clock
int status;
--- a/hotspot/src/share/vm/services/jmm.h Thu Oct 24 22:19:48 2013 -0700
+++ b/hotspot/src/share/vm/services/jmm.h Fri Oct 25 09:07:58 2013 +0200
@@ -78,6 +78,7 @@
JMM_COMPILE_TOTAL_TIME_MS = 8, /* Total accumulated time spent in compilation */
JMM_GC_TIME_MS = 9, /* Total accumulated time spent in collection */
JMM_GC_COUNT = 10, /* Total number of collections */
+ JMM_JVM_UPTIME_MS = 11, /* The JVM uptime in milliseconds */
JMM_INTERNAL_ATTRIBUTE_INDEX = 100,
JMM_CLASS_LOADED_BYTES = 101, /* Number of bytes loaded instance classes */
--- a/hotspot/src/share/vm/services/management.cpp Thu Oct 24 22:19:48 2013 -0700
+++ b/hotspot/src/share/vm/services/management.cpp Fri Oct 25 09:07:58 2013 +0200
@@ -1032,6 +1032,9 @@
case JMM_JVM_INIT_DONE_TIME_MS:
return Management::vm_init_done_time();
+ case JMM_JVM_UPTIME_MS:
+ return Management::ticks_to_ms(os::elapsed_counter());
+
case JMM_COMPILE_TOTAL_TIME_MS:
return Management::ticks_to_ms(CompileBroker::total_compilation_ticks());