When I do
UErrorCode status = U_ZERO_ERROR;
icu::Transliterator* myTrans = Transliterator::createInstance("Latin-Greek", UTRANS_FORWARD, status);
myTrans->transliterate(...);
and have no further use for myTrans, AddressSanitizer tells me it's leaking memory. I don't see methods like close or free in https://unicode-org.github.io/icu-docs/apidoc/released/icu4c/classicu_1_1Transliterator.html. There is unregister but it will mean I can't create the same transliterator again, right?
A workaround which works in my particular case: declare
class AutoDeletedTransliterator {
public:
AutoDeletedTransliterator(const icu::UnicodeString& id, UErrorCode& status)
: transliterator_(icu::Transliterator::createInstance(
id, UTRANS_FORWARD, status)) {}
~AutoDeletedTransliterator() {
icu::Transliterator::unregister(transliterator_->getID());
}
void transliterate(icu::UnicodeString& string) {
transliterator_->transliterate(string);
}
private:
icu::Transliterator* transliterator_;
};
and use it in a static variable, so the destructor runs at the end of the program.
Related
I'm writing a class Thread_Guard as explained in the book Concurrency in Action at Listing 2.3 - Using RAII to wait for a thread to complete.
Below is the class
class Thread_Guard
{
thread& gThread;
public:
Thread_Guard() : gThread(NULL) {};
explicit Thread_Guard(thread& t1) : gThread(t1)
{
}
~Thread_Guard()
{
if (gThread.joinable())
gThread.join();
}
Thread_Guard(const Thread_Guard& gT1) = delete;
Thread_Guard& operator=(const Thread_Guard& gT1) = delete;
};
What is the value to be initialized for the reference to std::thread in the default constructor? I will be calling it from main like below. Where MyInt is a sample class I have written.
int main()
{
int a = 100;
MyInt customInt(a);
thread worker(customInt);
Thread_Guard(worker);
return 0;
}
The original version of thread_guard does not contain a default constructor; probably by design. It would be interesting to see the use-case motivating your question (perhaps there's an alternative?).
However, if you do want to do this, you could simply store a thread * in the class object, make the default constructor set it to nullptr, and have the destructor check this first:
class Thread_Guard
{
thread *gThread;
public:
Thread_Guard() : gThread(nullptr) {};
explicit Thread_Guard(thread& t1) : gThread(&t1)
{
}
~Thread_Guard()
{
if (gThread && gThread->joinable())
gThread->join();
}
Thread_Guard(const Thread_Guard& gT1) = delete;
Thread_Guard& operator=(const Thread_Guard& gT1) = delete;
};
I am getting started with Haxe and OpenFl, and have some experience with Javascript and Lua.
It was going pretty well, till I got to a point where I needed a function similar to wait() in Lua, etc, which stops the script until the number of seconds you set is over.
How would I go about doing this?
EDIT: To clarify, I am building to Flash.
Although this is old, I wanted to add another point for reference. The OP mentioned in a comment this was for a game. One method I often use is (and could probably be put in a library):
var timerCount:Float = 0;
var maxTimerCounter:Float = 5;
function update () {
timerCounter += elapsedTime;
if (timerCounter > maxTimerCounter){
onTimerComplete();
timerCount = 0;
}
}
In SYS you are looking for:
static function sleep( seconds : Float ) : Void
Suspend the current execution for the given time (in seconds).
Example: Sys.sleep(.5);
http://haxe.org/api/sys/
Edit: User is porting to flash.
So the suggestion is to use Timer
http://haxe.org/api/haxe/timer
In Timer the suggestion is to use
static function delay( f : Void -> Void, time_ms : Int ) : Timer
Someone on stack overflow has an example that looks like this: haxe.Timer.delay(callback(someFunction,"abc"), 10); located here... Pass arguments to a delayed function with Haxe
For the Flash compile target, the best you can do is use a timer, and something like this setTimeout() function.
This means slicing your function into two - everything before the setTimeout(), and everything after that, which is in a separate function that the timeout can call.
so somethine like, eg:
tooltipTimerId = GlobalTimer.setTimeout(
Tooltip.TOOLTIP_DELAY_MS,
handleTooltipAppear,
tootipParams
);
[...]
class GlobalTimer {
private static var timerList:Array<Timer>;
public static function setTimeout(milliseconds:Int, func:Dynamic, args:Array<Dynamic>=null):Int {
var timer:Timer = new Timer(milliseconds);
var id = addTimer(timer, timerList);
timer.run = function() {
Reflect.callMethod(null, func, args);
clearTimeout(id);
}
return id;
}
private static function addTimer(timer:Timer, arr:Array<Timer>):Int {
for (i in 0...arr.length) {
if (null == arr[i]) {
arr[i] = timer;
return i;
}
}
arr.push(timer);
return arr.length -1;
}
public static function clearTimeout(id:Int) {
var timers:Array<Timer> = GlobalTimer.getInstance().timerList;
try {
timers[id].stop();
timers[id] = null;
} catch(e:Error) {/* Nothing we can do if it fails, really. */}
}
}
Hi i am trying to grab a value from my threading but it seem work not so find to me course i found that my code structure are unstable enough..here is my code i name my thread class as "clsThreadCount" and below is my implementation
public volatile bool Grab = false;
public volatile int count = 0;
public void Initialization(int i)
{
count = i;
}
public void Play()
{
Grab = false;
_shouldStop = false;
ThreadTest();
}
public void Stop()
{
_shouldStop = true;
workerThread.Join(1);
workerThread.Abort();
}
private void ThreadTest()
{
workerThread = new Thread(DoWork);
workerThread.Start();
while (!workerThread.IsAlive) ;
}
private void DoWork()
{
try
{
while (!_shouldStop)
{
if (Grab)
{
count++;
Grab = false;
}
}
}
catch (Exception)
{
Play();
}
finally
{
}
}
when my program(main menu) are starting to run i will trigger the initialize function at pass the parameter as 7
ObjThreadCount.Initialization(7); // count = 7
ObjThreadCount.Play(); // the thread are running
ObjThreadCount.Grab = true; // the grab equal to true, count++ are trigger
Thread.Sleep(100); // wait awhile
lblResult.Text = ObjThreadCount.count.ToString(); // sometime i can get count++ result (e.g. 8)
ObjThreadCount.Stop(); // thread stop
sometime my program can able to get a right counting from the thread but sometime are not.
i realize at my while loop implementation there are something are missing..
something like waitone or waitautoevent..can i ignore Thread.Sleep(100) ?? what are the suitable code should i add in the while loop ?
Please help me~ :S
** sorry in the first upload i forgot to write down "volatile" into the variable
thank you..
If C# (and C and java, and probably C++), you need to declare _shouldStop and Grab as volatile.
Consider the following struct:
public struct vip
{
string email;
string name;
int category;
public vip(string email, int category, string name = "")
{
this.email = email;
this.name = name;
this.category = category;
}
}
Is there a performance difference between the following two calls?
var e = new vip(email: "foo", name: "bar", category: 32);
var e = new vip("foo", 32, "bar");
Is there a difference if there are no optional parameters defined?
I believe none. It's only a language/compiler feature, call it syntactic sugar if you like. The generated CLR code should be the same.
There's a compile-time cost, but not a runtime one...and the compile time is very, very minute.
Like extension methods or auto-implemented properties, this is just magic the compiler does, but in reality generates the same IL we're all familiar with and have been using for years.
Think about it this way, if you're using all the parameters, the compiler would call the method using all of them, if not, it would generate something like this behind the scenes:
var e = new vip(email: "foo", category: 32); //calling
//generated, this is what it's actually saving you from writing
public vip(string email, int category) : this(email, category, "bar") { }
No it is a compile-time feature only. If you inspect the generated IL you'll see no sign of the named parameters. Likewise, optional parameters is also a compile-time feature.
One thing to keep in mind regarding named parameters is that the names are now part of the signature for calling a method (if used obviously) at compile time. I.e. if names change the calling code must be changed as well if you recompile. A deployed assembly, on the other hand, will not be affected until recompiled, as the names are not present in the IL.
There shouldn't be any. Basically, named parameters and optional parameters are syntactic sugar; the compiler writes the actual values or the default values directly into the call site.
EDIT: Note that because they are a compiler feature, this means that changes to the parameters only get updated if you recompile the "clients". So if you change the default value of an optional parameter, for example, you will need to recompile all "clients", or else they will use the old default value.
Actually, there is cost at x64 CLR
Look at here http://www.dotnetperls.com/named-parameters
I am able to reproduce the result: named call takes 4.43 ns, and normal call takes 3.48 ns
(program runs in x64)
However, in x86, both take around 0.32 ns
The code is attached below, compile and run it yourself to see the difference.
Note that in VS2012 the default targat is AnyCPU x86 prefered, you have to switch to x64 to see the difference.
using System;
using System.Diagnostics;
class Program
{
const int _max = 100000000;
static void Main()
{
Method1();
Method2();
var s1 = Stopwatch.StartNew();
for (int i = 0; i < _max; i++)
{
Method1();
}
s1.Stop();
var s2 = Stopwatch.StartNew();
for (int i = 0; i < _max; i++)
{
Method2();
}
s2.Stop();
Console.WriteLine(((double)(s1.Elapsed.TotalMilliseconds * 1000 * 1000) /
_max).ToString("0.00 ns"));
Console.WriteLine(((double)(s2.Elapsed.TotalMilliseconds * 1000 * 1000) /
_max).ToString("0.00 ns"));
Console.Read();
}
static void Method1()
{
Method3(flag: true, size: 1, name: "Perl");
}
static void Method2()
{
Method3(1, "Perl", true);
}
static void Method3(int size, string name, bool flag)
{
if (!flag && size != -1 && name != null)
{
throw new Exception();
}
}
}
As every Haxe developer knows, you could use haxe.Timer.delayed() to delay function call for some time. But this function doesn't exist for Neko at all. Is there a way to achieve the same results?
Have to check it first but
function delayed(f, time) {
neko.vm.Thread.create(function() {
neko.Sys.sleep(time);
f();
});
}
might be the closest thing possible. The only cons is that application becomes multi threaded which could lead to serious problems.
I thought about your issue and I think the best way is to create your own Timer class for Neko. I made a Timer class for you:
NekoTimer.hx
package;
import neko.Sys;
class NekoTimer
{
private static var threadActive:Bool = false;
private static var timersList:Array<TimerInfo> = new Array<TimerInfo>();
private static var timerInterval:Float = 0.1;
public static function addTimer(interval:Int, callMethod:Void->Void):Int
{
//setup timer thread if not yet active
if (!threadActive) setupTimerThread();
//add the given timer
return timersList.push(new TimerInfo(interval, callMethod, Sys.time() * 1000)) - 1;
}
public static function delTimer(id:Int):Void
{
timersList.splice(id, 1);
}
private static function setupTimerThread():Void
{
threadActive = true;
neko.vm.Thread.create(function() {
while (true) {
Sys.sleep(timerInterval);
for (timer in timersList) {
if (Sys.time() * 1000 - timer.lastCallTimestamp >= timer.interval) {
timer.callMethod();
timer.lastCallTimestamp = Sys.time() * 1000;
}
}
}
});
}
}
private class TimerInfo
{
public var interval:Int;
public var callMethod:Void->Void;
public var lastCallTimestamp:Float;
public function new(interval:Int, callMethod:Void->Void, lastCallTimestamp:Float) {
this.interval = interval;
this.callMethod = callMethod;
this.lastCallTimestamp = lastCallTimestamp;
}
}
Call it like this:
package ;
import neko.Lib;
class Main
{
private var timerId:Int;
public function new()
{
trace("setting up timer...");
timerId = NekoTimer.addTimer(5000, timerCallback);
trace(timerId);
//idle main app
while (true) { }
}
private function timerCallback():Void
{
trace("it's now 5 seconds later");
NekoTimer.delTimer(timerId);
trace("removed timer");
}
//neko constructor
static function main()
{
new Main();
}
}
Hope that helps.
Note: this one has an accuracy of 100ms. You can increase this by decreasing the timerInterval setting.
I used the class as well, and I found one issue. Because is not completely realtime, it sleeps the interval, calls the function, and sleeps the interval again. So, depending on how long the function you are running takes, it ticks slower or faster.
I've solved it by replacing line 39 like so:
//timer.lastCallTimestamp = Sys.time() * 1000;
timer.lastCallTimestamp = timer.lastCallTimestamp + timer.interval;
Yes I don't know anything except for what you mention in your first answer. On Linux you can use SIGALARM - but this doesn't look trivial, 100% pure C code, and needs to be handled with great care to avoid crashing the VM.