I am looking for an API to monitor the tasks running on a plain iPhone (no jailbreak). Those are about:
look for CPU usage (my main concern).
look for memory usage.
look for disk usage (how many read/write)
look for network usage (how many bytes sent and received by network: 3G, Wifi, GSM).
is it possible to rely on the IOS simulator running on a Mac (or should I test my application directly on the device)?
I think I can look into the system C libraries (sigint, etc.) but I am not sure to be able to retrieve this information except for the current applications running. I know some monitor applications run on the global usage but I would like to be able to find the information process by process.
If someone can provide some links or something useful, I will start a deeper investigation then.
CPU usage can be found by looking at the code from this related question:
iOS - Get CPU usage from application
Memory usage:
Available memory for iPhone OS app
And here are a couple threads that talk about how to find out about the applications or tasks currently running:
Can we retrieve the applications currently running in iPhone and iPad
How to get information about free memory and running processes in an App Store approved app? (Yes, there is one!)
How to get the active processes running in iOS
The answers to these questions may point you in the direction you'd like to head towards.
Good luck!
The Activity Monitor should get you what you're looking for. You should be able to observe RAM, CPU, and VRAM usage for each iOS process. This is a default tool installed with xCode. Very handy.
Related
I have stellaris LM4f232 evaluation borad. I have ported free rtos , sysbios to stellaris lm4f232 board and successfully developed an gps tracking application . But I always wanted to port uc linux for my board . my question are
i) is there any material to port uclinux to any controller
ii)what are necessary knowledge I required to do the same
I have googled a lot . I did n't get the right information, but I have seen posts that its difficult ,but I cant able to realise the same .any help????
iii) what is the road map to achieve it , what are the knowledge I should need to achieve this
Linux, even uCLinux requires considerable memory resources; you'd want to start with at least 2Mb for the boot device and 16Mb of RAM (although a minimal system can be booted in as little as 4Mb). On a microcontroller, this means that you must have external memory.
Another issue is that Cortex-M devices are optimised to run code from on-chip Flash memory, having separate buses for ROM and RAM so that data and instructions can be fetched simultaneously. uClinux must run from external RAM, which has a detrimental effect on the performance, and you will be unlikely to achieve the 1.25MIPS per MHz figure the CM4 is otherwise capable of. It is possible to arrange for time critical code to be placed in on-chip flash is necessary, but it is of course a limited resource.
Some good advice on the issues of deploying Linux on a Cortex-M device can be found here
I would suggest to have a look on buildroot which as far as I know can be build for this board.
adding to #Clifford , you can use u-boot (bootloader) ,already configured for many boards ,if your board is not on list you can edit it.,
I want to read how much data from 3G every app uses. Is this is possible in iOS 5.x ? And in iOS 4.x? My goal is for example:
Maps consumed 3 MB from your data plan
Mail consumed 420 kB from your data plan
etc, etc. Is this possible?
EDIT:
I just found app doing that: Data Man Pro
EDIT 2:
I'm starting a bounty. Extra points goes to the answer that make this clear. I know it is possible (screen from Data Man Pro) and i'm sure the solution is limited. But what is the solution and how to implement this.
These are just hints not a solution. I thought about this many times, but never really started implementing the whole thing.
first of all, you can calculate transferred bytes querying network interfaces, take a look to this SO answer for code and a nice explanation about network interfaces on iOS;
use sysctl or similar system functions to detect which apps are currently running (and for running I mean the process state is set to RUNNING, like the ps or top commands do on OSX. Never tried I just suppose this to be possible on iOS, hoping there are no problems with app running as unprivileged user) so you can deduce which apps are running and save the traffic stats for those apps. Obviously, given the possibility to have applications runnning in background it is hard to determine which app is transferring data.
It also could be possible to retrieve informations about network activity per process/app like nettop does on OSX Lion, unfortunately nettop uses the private framework NetworkStatistics.framework so you can't dig something out it's implementation;
take into account time;
My 2 cents
No, all applications in iOS are sandboxed, meaning you cannot access anything outside of the application. I do not believe this is possible. Neither do I believe data-traffic is saved on this level on the device, hence apple would have implemented it in either the network page or the usage page in Settings.app.
Besides that, not everybody has a "data-plan". E.g. in Sweden its common that data-traffic is free of charge without limit in either size or speed.
Given the multitasking function of iOS, will other applications that are currently sleeping affect my app (which is currently active) performance or memory consumption?
Absolutely. Any application that is running in the background (within the various parameters for when that's legal) will impact CPU availability. Apple apps can run in many more situations than 3rdparty apps, and they also will compete with you. I've particularly had trouble with Mail.app in the past.
Memory performance is a bit trickier, but yes, other applications are in memory at the same time and you can definitely generate memory warnings sooner with other applications in memory than you would otherwise. In principle, you should be able to get as much memory eventually as you would without other apps running, but that's not completely true. In particular, don't forget that Apple's apps don't always follow the same rules as 3rdparty apps, and if they're eating a lot of memory, they may or may not be killed.
The other performance consideration is network bandwidth, and this is most certainly a way that background apps may compete with you. I don't believe Apple is applying any bandwidth limiting on background apps, and downloading large files is a prime background activity. (There is some discussion that AppStore may decline apps that hit the network too hard while in the background, but I'm not aware of an official position on this. In any case, it it certainly legal to use some bandwidth in the background, and that's bandwidth not available to the foreground app.)
No they won't.
When the active app needs more memory being used by background apps, it automatically kills them off so the active app can use the resources.
Are there any "best practices" for writing a power-efficient background application in Symbian?
Specifically, is there any way (i.e. API) for a Symbian app to hint the OS regarding its current state in order to reduce battery consumption?
In Android, for instance, there is the notion of Wake Locks, which prevents the device from going into standby mode - Is there anything similar in Symbian?
EDIT:
Are there any implications when running code as a separate thread with the Open-C library, and not as "native" Symbian C++, using Active Objects etc.? (the Open-C code is blocking on IO most of the time).
You can check user (in-)activity with a RTimer::Inactivity() method. This way is described in Forum Nokia Wiki page. There it's also described how you can reset inactivity timer.
You can check whether device screen is turned on or off using HAL API. See classes HAL and HALData. You may use such a call:
TInt displayState;
HAL::Get(HALData::EDisplayState, displayState);
And the displayState will hold either 0 if display is turned off or 1 in other case.
With these APIs you will know whether user is active now, so you'll be able to change behavior of your background service to reduce its power consumption.
You can also use Nokia Energy Profiler application to record power consumption of handset, with different power saving options of your background service. Also please refer to Nokia's document describing best practices to save power of device. This document is quite straightforward, but useful nonetheless.
Hope this helps.
EDIT: About separate thread and Open C. As far as I know, Open C is just a plugin and deep down all the implementations are still "native Symbian". So, as far as you avoid periodic polling of some resource and just use usual blocking IO, your code is quite same economical on power as standard Symbian Active Objects techniques (which use Symbian-specific semaphores to block threads).
I have not come across anything special in Symbain to keep the device out of stand-by mode. Basically the "best practices" would be the same as all mobile devices:
Don't loop waiting for things, always use whatever signaling services avaialble on the platform, for Symbain ActiveObjects / User::WaitForXxx
Limit the number of background threads (currently all mobile devices are still only 1 CPU...)
Don't hang onto system services, close them ASAP (this is normally my main battery drain in my mobile applications, sometimes trying to find which system service causes the most battery drain can be a real pain, WinMo is very bad for this).
For me, I find that it mostly comes down to a tradeoff between battery life and performance / responsiveness for the application. Unfortunately power that be always seem to side with the performance / responsiveness side and damn the battery drain.....
Give your application low priority (see RProcess and RThread classes). Your approach will really depend on what your background application does. These things consume most battery: radio (GSM/3G/WIFI/BlueTooth), screen backlight, file accesses.
Symbian OS will always try to put your application to sleep, you don't need to tell it to do this. Just make sure your approach gives it the opportunity to put it to sleep.
Power management is an very most important issue while developing application.
In Symbian it depends on what you are using to run background activities .
Whether you are using Thread or ActiveX control.
For Eg. you are developing application browser that you want the browser to download something then that downloading activity should go in background and able activity starts and when to show progress and when it finishes it should again come to fore end.
It depends on how you are managing thread if you are using thread. You can do like which thread to pause when the long time taking activity starts and when to resume when background activity has finishes execution..
In fact this is the very good topic u have come across
There used to be an inactivity timer which could be reset by the application. This would prevent the screen from going into any screen saver mode.
If you use the various asynchronous function in Symbian, your app will run when appropriate.
One of these methods should work depending on your needs. If you describe what you want to achieve in more detail it would be easier to help you.
I have been tasked to write a device driver for an embedded device which will communicate with the micro controller via the SPI interface. Eventually, the USB interface will be used to download updated code externally and used during the verification phase.
My question is, does anyone know of a good reference design or documentation or online tutorial which covers the implementation/design of the USB protocol stack/device driver within an embedded system? I am just starting out and reading through the 650 page USB v2.0 spec is a little daunting at the moment.
Just as a FYI, the micro controller that I am using is a Freescale 9S12.
Mark
Based upon goldenmean's (-AD) comments I wanted to add the following info:
1) The embedded device uses a custom executive and makes no use of a COTS or RTOS.
2) The device will use interrupts to indicate data is ready to be retrieved from the device.
3) I have read through some of the docs regarding Linux, but since I am not at all familiar with Linux it isn't very helpful at the moment (though I am hoping it will be very quickly).
4) The design approach, for now at least, it to write a device driver for the USB device then a USB protocol layer (I/O) would reside on top of the device driver to interpret the data. I would assume this would be the best approach, though I could be wrong.
Edit - A year later
I just wanted to share a few items before they vanish from my mind in case I never work on a USB device again. I ran into a few obstacles when developing code and getting it up and running for the first.
The first problem I ran into was that when the USB device was connected to the Host (Windows in my case) was the host issues a Reset request. The USB device would reset and clear the interrupt enable flags. I didn't read the literature enough to know this was happening, thus I was never receiving the Set-Up Request Interrupt. It took me quite a while to figure this out.
The second problem I ran into was not handling the Set-Up Request for Set_Configuration properly. I was handling it, but I was not processing the request correctly in that the USB device was not sending an ACK when this Set-Up Request came in. I eventually found this out by using a hardware USB protocol analyzer.
There were other issues that I ran into, but these were the two biggest ones that took me quite a while to figure out. The other issue I had to worry about is big-endian and little-endian, Freescale 9S12 vs USB data format (Intel), respectively.
I ended up building the USB device driver similar to UART device drivers I had done in the past. I have posted the code to this at the following URL.
http://lordhog.wordpress.com/2010/12/13/usb-drive
I tend to use structures a lot, so people may not like them since they are not as portal as using #defines (e.g., MAX3420_SETUP_DATA_AVAIL_INT_REQR 0x20), but I like them since it makes the code more readable for me. If anyone has questions regarding it please feel free to e-mail and I can try to give some insight to it. The book "USB Complete: The Developer's Guide" was helpful, so long as you knew what areas to concentrate on. This was a simple application and only used low-speed USB.
While writing a device driver for any interface (USB, Parallel port, etc...) the code needed to be developed would depend upon whether there is any Operating System(OS), RTOS running on that Processor/Micro controller.
e.g. if thats going to run say WinCE - It will have its own Driver development Kit , and steps to be followed in the device driver development. Same for any other OS like Linux, symbian.
If its going to be a plain firmware code(No OS) which is going to control the processor/microcontroller, then it's a different situation altogether.
So based on either of the above situation u are in, one needs to read & understand:-
1.) The Hardware Specification of the processor/micro controller development board - Register files, ports, memory layout, etc.
2.) USB spec
3.) Couple of pointers i found quickly. Google shud be ur friend!
http://www.lrr.in.tum.de/Par/arch/usb/usbdoc/ - Linux USB device driver
http://www.microsoft.com/technet/archive/wce/support/usbce.mspx
-AD
I've used an earlier edition of USB Complete by Jan Axelson. Indeed very complete.
From the editorial review:
Now in its fourth edition, this developer's guide to the Universal Serial Bus (USB) interface covers all aspects of project development, such as hardware design, device firmware, and host application software.
I'm curious, why did you pick the 9S12? I used it at a previous job, and was not pleased.
It had lousy gcc support so we used Metrowerks
which may have been okay for C, but often generated buggy C++
had a lousy IDE with binary project files!
The 9s12 was also slow, a lot of instructions executed in 5 cycles.
Not very power efficient, either.
no barrel shifter, made operations that are common in embedded code slow
not that cheap.
About the only thing I dislike more is an 8051. I'm using an ARM CortexM3 at my current job, it's better than a 9S12 in every way (faster clock, more work done per clock, less power consumption, cheaper, good gcc support, 32-bit vs. 16-bit).
I don't know which hardware you're planning to use but assuming that's flexible, STMicro offers a line of microcontrollers with USB/SPI support and a library of C-code that can be used with their parts. -- I've used their ARM7 series micros for years with great success.
Here is an excellent site maintained by Jonathan Valvano, a professor at the University of Texas. He teaches four courses over there (three undergraduate, one graduate), all are about using a 9S12 microcontroller. His site contains all the lecture notes, lab manuals, and more importantly, starter files, that he uses for all his classes.
The website looks like it's from the 90's, but just dig around a bit and you should find everything you need.
users.ece.utexas.edu/~valvano/
Consider AVR for your next MCU project because of it's wonderful LUFA and V-USB libraries.
I'm working on a project using the Atmel V71. The processor is very powerful and among lot's of high end connectivity offered on chip is a USB engine that will do device or host modes for 480 Mhz or 48Mhz (not USB 3.0). The tools are free and come with a number of host and device USB example projects with all the USB stack code right there. It supports 10 end points and all the transfers are done via DMA so you have most of the processor horsepower available for other tasks. The Atmel USB stack works without needing an RTOS