memory

问题 The Info I recently launched an app on the AppStore. After testing on the simulator thousands of times, and actual devices hundreds of times we finally released our app. The Problem Reviews started popping up about app crashes when the user launches the app. We figured that the app crashes on launch on iOS devices with less than (or equal to) 256 Mb of RAM . The following devices are devices our app supports with less than 256: iPod Touch 4G iPhone 3GS iPad 1 The app doesn't always crash.

问题 Is there a way to know how much memory is consumed by each Eclipse plugin separately? 回答1: Take a heap dump and analyse it with e.g. the Eclipse Memory Analyser. For more information, see Analyzing Equinox Bundle Dependencies with Memory Analyzer 回答2: I would be quite surprised if this were possible, because you would have to have an unambiguous way of determining which plugin "owned" a particular object on the heap. 回答3: Eclipse 3.1 has a built-in Memory Monitor (aka Heap Status) Plugin,

问题 Is there a way to know how much memory is consumed by each Eclipse plugin separately? 回答1: Take a heap dump and analyse it with e.g. the Eclipse Memory Analyser. For more information, see Analyzing Equinox Bundle Dependencies with Memory Analyzer 回答2: I would be quite surprised if this were possible, because you would have to have an unambiguous way of determining which plugin "owned" a particular object on the heap. 回答3: Eclipse 3.1 has a built-in Memory Monitor (aka Heap Status) Plugin,

问题 So I've extended TextView to use a custom font (as described here), i.e., public class CustomTextView extends TextView { public static final int CUSTOM_TEXT_NORMAL = 1; public static final int CUSTOM_TEXT_BOLD = 2; public CustomTextView(Context context, AttributeSet attrs) { super(context, attrs); initCustomTextView(context, attrs); } private void initCustomTextView(Context context, AttributeSet attrs) { TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.CustomTextView, 0, 0

问题 So I've extended TextView to use a custom font (as described here), i.e., public class CustomTextView extends TextView { public static final int CUSTOM_TEXT_NORMAL = 1; public static final int CUSTOM_TEXT_BOLD = 2; public CustomTextView(Context context, AttributeSet attrs) { super(context, attrs); initCustomTextView(context, attrs); } private void initCustomTextView(Context context, AttributeSet attrs) { TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.CustomTextView, 0, 0

问题 Are machine word size (or smaller) writes serialized? Only one native opcode is needed to copy register content to RAM. 回答1: Writing data to RAM is atomic. If two CPUs try to write to the same location at the same time, the memory controller will decide on some order for the writes. While one CPU is writing to memory, the other CPU will stall for as many cycles as necessary until the first write is completed; then it will overwrite its value. This is what's known as a race condition. Writes

问题 The type of each member of the structure usually has a default alignment i.e.each structure member is aligned on a pre-determined boundary. For this reason the padding is performed in the following wiki example: struct MixedData { char Data1; short Data2; int Data3; char Data4; }; struct MixedData /* After compilation in 32-bit x86 machine */ { char Data1; /* 1 byte */ /* 1 byte for the following 'short' to be aligned on a 2 byte boundary assuming that the address where structure begins is an

问题 I would like to know if there is for linux a way of retrieving the protection of the memory. Like, I want to restore the protection that existed after changing it with mprotect. 回答1: Based on the answer by davidg, here's the function unsigned int read_mprotection(void* addr) : re_mprot.c, re_mprot.h from the reDroid project at github (the code works on Android, it should be portable to other linuxes). 回答2: The file /proc/self/maps on Linux contains information about the current layout of

问题 A long time ago I learned about filling unused / uninitialized memory with 0xDEADBEEF so that in a debugger or a crash report if I ever see that value I know I'm looking at uninitialized memory. I saw from a crash report iOS uses 0xBBADBEEF . What other creative values have people used? Do any particular values have any kind of specific benefit? The most obvious benefit of values that turn into words is that, at least of most people, if the words are in their language they stick out easily

问题 I am trying to process > 10000 xts objects saved on disk each being around 0.2 GB when loaded into R. I would like to use foreach to process these in parallel. My code works for something like 100 xts objects which I pre-load in memory, export etc. but after > 100 xts objects I hit memory limits on my machine. Example of what I am trying to do: require(TTR) require(doMPI) require(foreach) test.data <- runif(n=250*10*60*24) xts.1 <- xts(test.data, order.by=as.Date(1:length(test.data))) xts.1 <