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8235741: Inappropriate uses of os::javaTimeMillis()

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Reviewed-by: rehn, kbarrett, egahlin, shade
This commit is contained in:
David Holmes 2020-01-17 00:52:10 -05:00
parent d517220df6
commit 7c27f9f5dd
22 changed files with 136 additions and 104 deletions
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39
src/hotspot/os/linux/os_perf_linux.cpp
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@ -1,5 +1,5 @@
/*
* Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2012, 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@ -431,19 +431,21 @@ static int get_boot_time(uint64_t* time) {
static int perf_context_switch_rate(double* rate) {
static pthread_mutex_t contextSwitchLock = PTHREAD_MUTEX_INITIALIZER;
static uint64_t lastTime;
static uint64_t bootTime;
static uint64_t lastTimeNanos;
static uint64_t lastSwitches;
static double lastRate;
uint64_t lt = 0;
uint64_t bt = 0;
int res = 0;
if (lastTime == 0) {
// First time through bootTime will be zero.
if (bootTime == 0) {
uint64_t tmp;
if (get_boot_time(&tmp) < 0) {
return OS_ERR;
}
lt = tmp * 1000;
bt = tmp * 1000;
}
res = OS_OK;
@ -454,20 +456,29 @@ static int perf_context_switch_rate(double* rate) {
uint64_t sw;
s8 t, d;
if (lastTime == 0) {
lastTime = lt;
if (bootTime == 0) {
// First interval is measured from boot time which is
// seconds since the epoch. Thereafter we measure the
// elapsed time using javaTimeNanos as it is monotonic-
// non-decreasing.
lastTimeNanos = os::javaTimeNanos();
t = os::javaTimeMillis();
d = t - bt;
// keep bootTime zero for now to use as a first-time-through flag
} else {
t = os::javaTimeNanos();
d = nanos_to_millis(t - lastTimeNanos);
}
t = os::javaTimeMillis();
d = t - lastTime;
if (d == 0) {
*rate = lastRate;
} else if (!get_noof_context_switches(&sw)) {
} else if (get_noof_context_switches(&sw) == 0) {
*rate = ( (double)(sw - lastSwitches) / d ) * 1000;
lastRate = *rate;
lastSwitches = sw;
lastTime = t;
if (bootTime != 0) {
lastTimeNanos = t;
}
} else {
*rate = 0;
res = OS_ERR;
@ -476,6 +487,10 @@ static int perf_context_switch_rate(double* rate) {
*rate = 0;
lastRate = 0;
}
if (bootTime == 0) {
bootTime = bt;
}
}
pthread_mutex_unlock(&contextSwitchLock);