In GNU/Linux I use Intel&#39;s PCM to monitor CPU utilization. I&#39;m not sure if this works fine on OSX, but as far as I know the source-code is including the MacMSRDriver directory. I have no any OSX device, never test it anyway.

In case this source compiled on your device, Just run: 

`pcm.x -r -- your_program your_program_parameter`

or if you want advanced profiling, use `pcm-core.x` instead or you can build your own code based on `pcm-core.cpp`

Can any Java 8 + JDBC expert tell me if something&#39;s wrong in the following reasoning? And, if in the secrets of Gods, why this hasn&#39;t been done?

A `java.sql.Date` is currently the type used by JDBC to map to the DATE SQL type, which represents a date without time, and without timezone. But this class is awfully designed, since it&#39;s in fact a subclass of `java.util.Date`, which stores a precise instant in time, up to the millisecond.

To represent the date 2015-09-13 in database, we&#39;re thus forced to choose a timezone, parse the string &quot;2015-09-13T00:00:00.000&quot; in that timezone as a java.util.Date to get a millisecond value, then construct a `java.sql.Date` from this millisecond value, and finally call `setDate()` on the prepared statement, passing a Calendar holding the timezone chosen in order for the JDBC driver to be able to correctly recompute the date 2015-09-13 from this millisecond value. This process is made a bit simpler by using the default timezone everywhere, and not passing a Calendar.

Java 8 introduces a LocalDate class, which is a much better fit for the DATE database type, since it&#39;s not a precise moment in time, and is thus not dependent on the timezone. And Java 8 also introduces default methods, which would allow to make backward-compatible changes to the PreparedStatement and ResultSet interfaces.

So, haven&#39;t we missed a huge opportunity to clean up the mess in JDBC while still maintaining backward compatibility? Java 8 could simply have added those default methods to PreparedStatement and ResultSet:

    default public void setLocalDate(int parameterIndex, LocalDate localDate) {
        if (localDate == null) {
            setDate(parameterIndex, null);
        }
        else {
            ZoneId utc = ZoneId.of(&quot;UTC&quot;);
            java.util.Date utilDate = java.util.Date.from(localDate.atStartOfDay(utc).toInstant());
            Date sqlDate = new Date(utilDate.getTime());
            setDate(parameterIndex, sqlDate, Calendar.getInstance(TimeZone.getTimeZone(utc)));
        }
    }

    default LocalDate getLocalDate(int parameterIndex) {
        ZoneId utc = ZoneId.of(&quot;UTC&quot;);
        Date sqlDate = getDate(parameterIndex, Calendar.getInstance(TimeZone.getTimeZone(utc)));
        if (sqlDate == null) {
            return null;
        }

        java.util.Date utilDate = new java.util.Date(sqlDate.getTime());
        return utilDate.toInstant().atZone(utc).toLocalDate();
    }

Of course, the same reasoning applies to the support of Instant for the TIMESTAMP type, and the support of LocalTime for the TIME type.

Missed opportunity to fix JDBC date handling in Java 8?

I am a developer of two alarm clock apps on Google Play.  I am trying to get them to work with Android 6.0.  However, Doze mode makes it so they do not ring.  I put them on the white list, I put a foreground notification icon up, I&#39;m not sure what else I can do - when in Doze mode, the the Alarm Manager alarms are still ignored.  The Clock app (which is a Google Play rather than AOSP app), however, is different.  When the alarm is enabled on the Clock app, &quot;adb deviceidle step&quot; will always read &quot;active&quot; and never &quot;idle&quot;, &quot;idle_pending&quot; or anything else.

Is Android cheating here, giving its own app more power, aka. &quot;pulling an apple&quot;?  Are all alarm clock apps on Google Play about to become non-functional?  Kind of worried here, these are quality apps that each took a year of part-time development time, and are big income sources for me.  Any clues on how I could get these to work would be a huge help.

Setting the AlarmManager intent:

    		Intent intent = new Intent(context, ReceiverAlarm.class);
			if (android.os.Build.VERSION.SDK_INT &gt;= 16) {
				intent.addFlags(Intent.FLAG_RECEIVER_FOREGROUND);
			}
			amSender = PendingIntent.getBroadcast(context, 1, intent, PendingIntent.FLAG_CANCEL_CURRENT); //FLAG_CANCEL_CURRENT seems to be required to prevent a bug where the intent doesn&#39;t fire after app reinstall in KitKat
			am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
			am.set(AlarmManager.RTC_WAKEUP, scheduleToTime+1, amSender);

and the ReceiverAlarm class:

    public class ReceiverAlarm extends BroadcastReceiver{

	@Override
	public void onReceive(Context context, Intent intent) {
    	if (wakeLock == null) {
	        PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
	        wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, Theme.appTitle);
	        wakeLock.acquire();
        }
		X.alarmMaster.startRingingAlarm(true);
	}


and the relevant parts of the X.alarmMaster.startRingingAlarm() method:

        if (wakeLock == null) {
	        PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
	        wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, Theme.appTitle);
	        wakeLock.acquire();
        }

        if (screenWakeLock == null) {
            PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
            screenWakeLock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP | PowerManager.ON_AFTER_RELEASE, Theme.appTitle+&quot; scr&quot;);
            screenWakeLock.acquire();
        }

        Intent alarmIntent = new Intent(Intent.ACTION_VIEW);
		alarmIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        alarmIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        alarmIntent.setClass(context, ActivityAlarmAlarm.class);

        context.startActivity(alarmIntent);

Some of the methods have been pasted inline for easier readability.

How to make Alarm Manager work when Android 6.0 in Doze mode?

In Xcode&#39;s Instruments, there is a tool called [Counters][1] that exposes low-level counter information provided by the CPU, such as the number of instructions executed or number of cache misses:

[![screenshot of Counters tool in Instruments][2]][1]

This is similar to the Linux syscall [`perf_event_open`](http://man7.org/linux/man-pages/man2/perf_event_open.2.html) introduced in Linux 2.6.32. On Linux, I can use `perf_event_open` then start/stop profiling around the section of my code I&#39;m interested in. I&#39;d like to record the same type of stats on OS X: counting the instructions (etc.) that a certain piece of code takes, and getting the result in an automated fashion. (I don&#39;t want to use the Instruments GUI to analyze the data.)

Are there any APIs that allow this (ex: using dtrace or similar)? From some searching it sounds like the private AppleProfileFamily.framework might have the necessary hooks, but it&#39;s unclear how to go about linking to or using it.


  [1]: https://developer.apple.com/library/mac/documentation/AnalysisTools/Reference/Instruments_User_Reference/CountersInstrument/CountersInstrument.html
  [2]: http://i.stack.imgur.com/lG4K1.png

Record values of Performance Monitor Counters (PM events) on OS X without Instruments

In Xcode's Instruments, there is a tool called <a href="https://developer.apple.com/library/mac/documentation/AnalysisTools/Reference/Instruments_User_Reference/CountersInstrument/CountersInstrument.html" target="_blank" rel="noopener noreferrer">Counters</a> that exposes low-level counter information provided by the CPU, such as the number of instructions executed or number of cache misses:
<a href="https://developer.apple.com/library/mac/documentation/AnalysisTools/Reference/Instruments_User_Reference/CountersInstrument/CountersInstrument.html" target="_blank" rel="noopener noreferrer"><img src="http://i.stack.imgur.com/lG4K1.png" alt="screenshot of Counters tool in Instruments"></a>
This is similar to the Linux syscall <a href="http://man7.org/linux/man-pages/man2/perf_event_open.2.html" target="_blank" rel="noopener noreferrer"><code>perf_event_open</code></a> introduced in Linux 2.6.32. On Linux, I can use <code>perf_event_open</code> then start/stop profiling around the section of my code I'm interested in. I'd like to record the same type of stats on OS X: counting the instructions (etc.) that a certain piece of code takes, and getting the result in an automated fashion. (I don't want to use the Instruments GUI to analyze the data.)
Are there any APIs that allow this (ex: using dtrace or similar)? From some searching it sounds like the private AppleProfileFamily.framework might have the necessary hooks, but it's unclear how to go about linking to or using it.

I&#39;m trying to get a Mono install running on a mac (OS X version 10.10.5), and while the install states that it&#39;s completed successfully, I&#39;m not able to call mono from the terminal.

To install it, I ran uninstallMono.sh as root to ensure we didn&#39;t have any leftover cruft, then ran MonoFramework-MDK-4.0.4.1.macos10.xamarin.x86.pkg. The installer appeared to complete successfully, but an attempt to call mono returns

&gt; -bash: mono: command not found

The mono framework does appear to be installed:

    Lees-Mac-Pro:Downloads kevinmack$ cd /Volumes/Macintosh\ HD/Library/Frameworks/
    Lees-Mac-Pro:Frameworks kevinmack$ ls -l
    total 32
    lrwxr-xr-x  1 root  wheel   71 Jan 20  2015 AEProfiling.framework -&gt; ../../Applications/Motion.app/Contents/Frameworks/AEProfiling.framework
    lrwxr-xr-x  1 root  wheel   74 Jan 20  2015 AERegistration.framework -&gt; ../../Applications/Motion.app/Contents/Frameworks/AERegistration.framework
    lrwxr-xr-x  1 root  wheel   74 Jan 20  2015 AudioMixEngine.framework -&gt; ../../Applications/Motion.app/Contents/Frameworks/AudioMixEngine.framework
    drwxr-xr-x  8 root  admin  272 Sep 12 11:24 Mono.framework
    lrwxr-xr-x  1 root  wheel   60 Sep  9 22:16 NyxAudioAnalysis.framework -&gt; /System/Library/PrivateFrameworks/NyxAudioAnalysis.framework
    drwxr-xr-x  5 root  wheel  170 Jan 20  2015 PluginManager.framework
    drwxr-xr-x  8 root  wheel  272 Sep  9 22:19 iTunesLibrary.framework

...but it isn&#39;t present in `/usr/bin` and attempting to find its executable using `which mono` returns nothing.


How to install Mono on macOS so mono works in terminal?

Where are the docker images located once they are downloaded from docker hub in Mac OSX. For example if I run a command like:
    
    docker run hello-world

the image is downloaded and the container is run but where is that image located on my system? 

Note: https://stackoverflow.com/questions/19234831/where-are-docker-images-stored-on-the-host-machine This question has answers related to linux machine, mainly. The answers for Mac OS X are considering that boot2docker is being used alongside docker installation, which is not the case for me. 

Location of docker images downloaded by Docker (1.9.1) on Mac OS X

I am trying to move something to **/usr/bin** on OS X El Capitan. I have disabled rootless using the following commands: `sudo nvram boot-args=&quot;rootless=0&quot;; sudo reboot`,  but I keep getting the same error:

    MacBook-Air:~ Mark$ sudo cp class-dump /usr/bin
    Password:
    cp: /usr/bin/class-dump: Operation not permitted
    MacBook-Air:~ Mark$ sudo mv class-dump /usr/bin
    mv: rename class-dump to /usr/bin/class-dump: Operation not permitted


Operation Not Permitted when on root - El Capitan (rootless disabled)

I get this error in Android Studio:

&gt; Can&#39;t start Git: /usr/bin/git
&gt;            Probably the path to Git executable is not valid.

It gives me an option to fix it, where it takes me to the area in Android Studio to set the path to git. I see it is set to 

&gt; /usr/bin/git

And I check that path, and that path is indeed the path to the git executable. Why is Android Studio unable to start git?

**EDIT: When I try to use git commands in the Android Studio terminal it says:**

&gt; Agreeing to the Xcode/iOS license requires admin privileges, please
&gt; re-run as root via sudo.



OS X - Can&#39;t start Git: /usr/bin/git Probably the path to Git executable is not valid

I am trying to automate setting up a developer environment on Mac. Part of that setup is installing the [Docker Toolbox](https://www.docker.com/toolbox). I cannot find any documentation on how do to this via command line. How can I automate this installation (must be triggered via command line)?  

---
**Update:** As pointed out in a commend by [Dennis](https://stackoverflow.com/questions/32744780/install-docker-toolbox-on-a-mac-via-command-line?noredirect=1#comment71074157_32744780) 
&gt; [Docker for Mac](https://docs.docker.com/docker-for-mac/) now exists, which is an alternative to Docker Toolbox. You can get it via the homebrew cask: `brew cask install docker; open /Applications/Docker.app`

Install Docker Toolbox on a Mac via command line

I have a config with around 100 rules, and running eslint on my project with all these rules takes around 10 seconds. I&#39;d like to identify the slowest rules and eliminate some of them. How do I do this? Is there any profiler tool for eslint?

Which eslint rules in my config are slow?

I am profiling a python script `main.py` using cProfile with the following command:

    python -m cProfile -s tottime main.py

The output I get is (only copy-pasted the top lines of the output):

    10184337 function calls (10181667 primitive calls) in 13.597 seconds

    Ordered by: internal time

    ncalls  tottime  percall  cumtime  percall filename:lineno(function)
        1    4.674    4.674   13.598   13.598 main.py:2(&lt;module&gt;)
     2142    2.964    0.001    4.663    0.002 load_aerdat3.py:61(getPacket)
      459    2.381    0.005    2.381    0.005 {waitKey}
    1667989    1.170    0.000    1.170    0.000 {numpy.core.multiarray.array}
    
    ...

How can the `tottime` (4.674) be different from the `cumtime` (13.598) for `main.py`, since this function (ie. the whole script) is only called once? 

What is the difference between tottime and cumtime on cProfile output?

How do I diagnose the cause of Docker on MacOS, specifically `com.docker.hyperkit` using 100% of CPU?

[![docker CPU usage][1]][1]

### Docker stats

Docker stats shows all the running containers have low CPU, memory, net IO and block IO.


[![docker stats output][2]][2]

### iosnoop

iosnoop shows that `com.docker.hyperkit` performs about 50 writes per second totaling 500KB per second to the file `Docker.qcow2`.  According to https://stackoverflow.com/questions/49887747/what-is-docker-qcow2, `Docker.qcow2` is a sparse file that&#39;s the persistent storage for all Docker containers.

In my case the file isn&#39;t that sparse. The physical size matches the logical size.

[![docker.qcow actual size][3]][3]


### dtrace (dtruss)

dtruss `sudo dtruss -p $DOCKER_PID` shows a large number of `psynch_cvsignal` and `psynch_cvwait` calls.

```
psynch_cvsignal(0x7F9946002408, 0x4EA701004EA70200, 0x4EA70100)          = 257 0
psynch_mutexdrop(0x7F9946002318, 0x5554700, 0x5554700)           = 0 0
psynch_mutexwait(0x7F9946002318, 0x5554702, 0x5554600)           = 89474819 0
psynch_cvsignal(0x10BF7B470, 0x4C8095004C809600, 0x4C809300)             = 257 0
psynch_cvwait(0x10BF7B470, 0x4C8095014C809600, 0x4C809300)               = 0 0
psynch_cvwait(0x10BF7B470, 0x4C8096014C809700, 0x4C809600)               = -1 Err#316
psynch_cvsignal(0x7F9946002408, 0x4EA702004EA70300, 0x4EA70200)          = 257 0
psynch_cvwait(0x7F9946002408, 0x4EA702014EA70300, 0x4EA70200)            = 0 0
psynch_cvsignal(0x10BF7B470, 0x4C8097004C809800, 0x4C809600)             = 257 0
psynch_cvwait(0x10BF7B470, 0x4C8097014C809800, 0x4C809600)               = 0 0
psynch_cvwait(0x10BF7B470, 0x4C8098014C809900, 0x4C809800)               = -1 Err#316
```

### Update: `top` on Docker host

From https://stackoverflow.com/a/58293240/30900:

```
docker run -it --rm --pid host busybox top
```

The CPU usage on docker embedded host is ~3%.  CPU usage on my MacBook was ~100%.  So, the docker embedded host isn&#39;t causing the CPU usage spike.

[![docker host top][4]][4]

### Update: running dtrace scripts of most common stack traces

Stack traces from the dtrace scripts in the answer below: https://stackoverflow.com/a/58293035/30900.

These kernel stack traces look innocuous.

```
              AppleIntelLpssGspi`AppleIntelLpssGspi::regRead(unsigned int)+0x1f
              AppleIntelLpssGspi`AppleIntelLpssGspi::transferMmioDuplexMulti(void*, void*, unsigned long long, unsigned int)+0x91
              AppleIntelLpssSpiController`AppleIntelLpssSpiController::transferDataMmioDuplexMulti(void*, void*, unsigned int, unsigned int)+0xb2
              AppleIntelLpssSpiController`AppleIntelLpssSpiController::_transferDataSubr(AppleInfoLpssSpiControllerTransferDataRequest*)+0x5bc
              AppleIntelLpssSpiController`AppleIntelLpssSpiController::_transferData(AppleInfoLpssSpiControllerTransferDataRequest*)+0x24f
              kernel`IOCommandGate::runAction(int (*)(OSObject*, void*, void*, void*, void*), void*, void*, void*, void*)+0x138
              AppleIntelLpssSpiController`AppleIntelLpssSpiDevice::transferData(IOMemoryDescriptor*, void*, unsigned long long, unsigned long long, IOMemoryDescriptor*, void*, unsigned long long, unsigned long long, unsigned int, AppleIntelSPICompletion*)+0x151
              AppleHSSPISupport`AppleHSSPIController::transferData(IOMemoryDescriptor*, void*, unsigned long long, unsigned long long, IOMemoryDescriptor*, void*, unsigned long long, unsigned long long, unsigned int, AppleIntelSPICompletion*)+0xcc
              AppleHSSPISupport`AppleHSSPIController::doSPITransfer(bool, AppleHSSPITransferRetryReason*)+0x97
              AppleHSSPISupport`AppleHSSPIController::InterruptOccurred(IOInterruptEventSource*, int)+0xf8
              kernel`IOInterruptEventSource::checkForWork()+0x13c
              kernel`IOWorkLoop::runEventSources()+0x1e2
              kernel`IOWorkLoop::threadMain()+0x2c
              kernel`call_continuation+0x2e
               53

              kernel`waitq_wakeup64_thread+0xa7
              pthread`__psynch_cvsignal+0x495
              pthread`_psynch_cvsignal+0x28
              kernel`psynch_cvsignal+0x38
              kernel`unix_syscall64+0x27d
              kernel`hndl_unix_scall64+0x16
               60

              kernel`hndl_mdep_scall64+0x4
              113

              kernel`ml_set_interrupts_enabled+0x19
              524

              kernel`ml_set_interrupts_enabled+0x19
              kernel`hndl_mdep_scall64+0x10
             5890

              kernel`machine_idle+0x2f8
              kernel`call_continuation+0x2e
            43395
```

The most common stack traces in user space over 17 seconds clearly implicate com.docker.hyperkit.  There 1365 stack traces in 17 seconds in which `com.docker.hyperkit` created threads which averages to 80 threads per second.

```
              com.docker.hyperkit`0x000000010cbd20db+0x19f9
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
               19

              Hypervisor`hv_vmx_vcpu_read_vmcs+0x1
              com.docker.hyperkit`0x000000010cbd4c4f+0x2a
              com.docker.hyperkit`0x000000010cbd20db+0x174a
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
               22

              Hypervisor`hv_vmx_vcpu_read_vmcs
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
               34

              com.docker.hyperkit`0x000000010cbd878d+0x36
              com.docker.hyperkit`0x000000010cbd20db+0x42f
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
               47

              Hypervisor`hv_vcpu_run+0xd
              com.docker.hyperkit`0x000000010cbd20db+0x6b6
              com.docker.hyperkit`0x000000010cbdb98c+0x157
              com.docker.hyperkit`0x000000010cbf6c2d+0x4bd
              libsystem_pthread.dylib`_pthread_body+0x7e
              libsystem_pthread.dylib`_pthread_start+0x42
              libsystem_pthread.dylib`thread_start+0xd
              135
```

### Related issues

Github - docker/for-mac: [com.docker.hyperkit 100% cpu usage is back again #3499
][5].  One comment suggests adding volume caching described here: https://www.docker.com/blog/user-guided-caching-in-docker-for-mac/.  I tried this and got a small ~10% reduction in CPU usage.


  [1]: https://i.stack.imgur.com/N0ftg.png
  [2]: https://i.stack.imgur.com/YhAui.png
  [3]: https://i.stack.imgur.com/aixXT.png
  [4]: https://i.stack.imgur.com/vkbdV.jpg
  [5]: https://github.com/docker/for-mac/issues/3499

Diagnosing high CPU usage on Docker for Mac

I recently update my Xcode to version 9.3, so is instruments. After that, time profiler won&#39;t work anymore, it usually works fine before.

I tried to run it via Xcode, and I tried to run it manually. Doesn&#39;t work.
The life cycle row stuck in initializing, and I got a bunch of warnings complain about **the data volume is too high for a recording mode of &quot;immediate&quot; and some data had to be dropped to move forward**. 

Then I switch to delay mode, still got nothing. Then I create a simple new project, which should have &quot;little data volume&quot;, still got nothing.

I checked help, I googled, seems like no one has encountered this before. Does anyone have any clue about this?

![enter image description here][1]

  [1]: https://i.stack.imgur.com/gyGGq.png

Time profiler in instruments is not working

We&#39;re using React Native `0.59.10` and React-Redux `5.0.7`, and are experiencing a CPU-bound performance issue, in which our Redux actions are taking ~0.25s to complete.

We&#39;ve profiled using the Time Profiler configuration in Instruments, but none of our JS code is symbolicated.

Remotely debugging in Chrome seems to just debug the &quot;remote inspector&quot; page, which is entirely unhelpful.

Is there a way to build/attach a source map, or symbolicate the memory addresses seen below, to the JS function names/calls?

[![Instruments Callstack][1]][1]


  [1]: https://i.stack.imgur.com/HW82V.png

Content Type	Original Author	Original Content on Stackoverflow
Question	Sophie Alpert	View Question on Stackoverflow
Solution 1 - Macos	Max Rafiandy	View Answer on Stackoverflow

Record values of Performance Monitor Counters (PM events) on OS X without Instruments

Macos Problem Overview

Macos Solutions

Solution 1 - Macos

How to make Alarm Manager work when Android 6.0 in Doze mode?

Missed opportunity to fix JDBC date handling in Java 8?

Attributions