I created my own thread library... Of course its a simple non-preemptive library in which the threads are executed in the order they are invoked. The brief out line of the program is as follows:
class Thread
{
static Thread sched;
/*called only once*/
static void init()
{
*create a context for sched thread*
static void schedule()
{
....
setcontext(current thread from the queue);
return if empty
}
Thread(function)
{
intializes the context via getcontext and sets the uc_link to the context of sched
and pushed into the queue and calls schedule function
}
Every thing seems to be fine with single thread. But when i initialize two thread objects only one of them is executing.
I doubt that when the first thread completes its job, it returns to the schedule function and when the schedule function sees the queue is empty... it also returns.
But I observe that the constructor is called only once for the first thread!! Why is that so?
If i don't call the schedule function from the constuctor, instead i define a function like
void start()
{
schedule();
}
and call it after all the threads are initialized it was executing correctly. But i dont want to use this method..
please explain me the path of execution and the solution to the above problem.
Here's the actual code for it
class thread
{
static queue<thread> Q;
ucontext_t con;
int u_p;
int c_p;
static void init()
{
flag=0;
getcontext(&schd.con);
//cout<<"fgh\n";
schd.con.uc_link=0;
schd.con.uc_stack.ss_sp=malloc(ST_S);
schd.con.uc_stack.ss_size=ST_S;
makecontext(&schd.con, schd.schedule, 0);
}
static thread main, schd;
static int flag;
public:
thread()
{ }
thread(int i){ init(); }
static void schedule()
{
//cout<<"ii\n";
if(Q.empty()){
flag=0;
return;
}
main=Q.front();
Q.pop();
setcontext(&main.con);
init();
//cout<<"yea\n";
}
thread(void (*fn)(), int u_p=15)
{
getcontext(&con);
con.uc_link=&schd.con;
con.uc_stack.ss_sp=malloc(ST_S);
con.uc_stack.ss_flags=0;
con.uc_stack.ss_size=ST_S;
makecontext(&con, fn, 0);
//cout<<"hjkl\n";
Q.push(*this);
if(flag==0){
flag=1;
schedule();
}
}
static void start(){ schedule(); }
};
queue<thread> thread::Q;
thread thread::main;
thread thread::schd;
int thread::flag;
Seems like this is happening:
you create a new thread
Thread::Thread() calls Thread::shedule()
Thread::shedule() calls setcontext()
control flow switches to function of new Thread object
this new thread executes, not switching back to its parent context, so another thread cannot be created
I think all thread libraries and OS API's I have seen either create threads suspended or provide a flag to create threads in suspended state. So it's a good way to go, otherwise you lose stop current thread at the moment of creating another one. Moreover, since you use lightweight threads, you're almost forced to create threads suspended without any flag in order to be able to create multiple threads from the main one.
Related
class ThreadOne {
public:
ThreadOne();
void RealThread();
void EnqueueJob(s_info job);
std::queue<s_info> q_jobs;
private:
H5::H5File* targetFile = new H5::H5File("file.h5", H5F_ACC_TRUNC);
std::condition_variable cv_condition;
std::mutex m_job_q_;
};
ThreadOne::ThreadOne() {
}
void ThreadOne::RealThread() {
while (true) {
std::unique_lock<std::mutex> lock(m_job_q_);
cv_condition.wait(lock, [this]() { return !this->q_jobs.empty(); });
s_info info = std::move(q_jobs.front());
q_jobs.pop();
lock.unlock();
//* DO THE JOB *//
}
}
void ThreadOne::EnqueueJob(s_info job) {
{
std::lock_guard<std::mutex> lock(m_job_q_);
q_jobs.push(std::move(job));
}
cv_condition.notify_one();
}
ThreadOne *tWrite = new ThreadOne();
I want to make a thread and send it a pointer of an array and its name as a struct(s_info), and then make the thread write it into a file. I think that it's better than creating a thread whenever writing is needed.
I could make a thread pool and allocate jobs to it, but it's not allowed to write the same file concurrently in my situation, I think that just making a thread will be enough and the program will still do CPU-bound jobs when writing job is in process.
To sum up, this class (hopefully) gets array pointers and their dataset names, puts them in q_jobs and RealThread writes the arrays into a file.
I referred to a C++ thread pool program and the program initiates threads like this:
std::vector<std::thread> vec_worker_threads;
vector_worker_threads.reserve(num_threads_);
vector_worker_threads.emplace_back([this]() { this->RealThread(); });
I'm new to C++ and I understand what the code above does, but I don't know how to initiate RealThread in my class without a vector. How can I make an instance of the class that has a thread(RealThread) that's already ready inside it?
From what I can gather, and as already discussed in the comments, you simply want a std::thread member for ThreadOne:
class ThreadOne {
std::thread thread;
public:
~ThreadOne();
//...
};
//...
ThreadOne::ThreadOne() {
thread = std::thread{RealThread, this};
}
ThreadOne::~ThreadOne() {
// (potentially) notify thread to finish first
if(thread.joinable())
thread.join();
}
//...
ThreadOne tWrite;
Note that I did not start the thread in the member-initializer-list of the constructor in order to avoid the thread accessing other members that have not been initialized yet. (The default constructor of std::thread does not start any thread.)
I also wrote a destructor which will wait for the thread to finish and join it. You must always join threads before destroying the std::thread object attached to it, otherwise your program will call std::terminate and abort.
Finally, I replaced tWrite from being a pointer to being a class type directly. There is probably no reason for you to use dynamic allocation there and even if you have a need for it, you should be using
auto tWrite = std::make_unique<ThreadOne>();
or equivalent, instead, so that you are not going to rely on manually deleteing the pointer at the correct place.
Also note that your current RealThread function seems to never finish. It must return at some point, probably after receiving a notification from the main thread, otherwise thread.join() will wait forever.
I'm trying to build a thread-safety layer on top of C++ 11's std::thread where each object is assigned to an owning thread, and certain calls can raise a hard error when they are used on the wrong thread. The owning thread is the only one that can transfer an object to another thread.
I have it all working, except that I can't find a way to get a thread's thread::id before it is actually running. And I need to attach the new thread's ID to the object before I hand it off.
If I use
std::thread newThread( [theObject]()
{
// use theObject here.
} );
The earliest point I can get the thread's ID is after the definition of the thread object, at which point the thread is already running.
I see there is a default constructor for std::thread, but I can't see a way to give it a function to run on the thread afterwards.
Is there a way to perform two-step construction on a thread, or control the thread's ID at time of creation?
Rather than getting the ID of the thread before it starts running, you could consider having the function the thread executes do some initial setup before taking off. For example, you could do something like this:
bool isReady = false;
bool wasReceived = false;
std::mutex mutex;
std::condition_variable condition;
std::thread newThread([theObject, &isReady, &mutex, &condition] {
/* Wait until we've been cleared to go. */
std::unique_lock<std::mutex> lock(isReady);
condition.wait(lock, [&isReady] { return isReady; });
/* Signal that we're done. */
wasReceived = true;
lock.unlock();
condition.notify_one();
/* Put code here to do whatever it is that the thread should do. */
});
/* Read the thread's ID. It's currently waiting for us. */
auto id = newThread.get_id();
/* Tell the thread that we're ready for it. */
std::unique_lock<std::mutex> lock(mutex);
isReady = true;
condition.notify_one();
/* Wait until the thread has confirmed that it's ready. */
condition.wait(lock, [&] { return wasReceived; });
This creates the thread and has it sit and wait until the creator has a chance to read its ID. Once that's happened, the creator then waits until the thread confirms that it's ready to go, and from there you can work with the thread ID however you'd like.
Beware of bugs in the above code - it's completely untested. :-)
No--as soon as you create a thread, it starts to run. If you want to get its ID before it does (much of) anything, you probably want to create a little wrapper, where you pass the thread (for example) a CV and a queue where it deposits its output.
Then when the thread starts up, it retrieves its own ID, deposits it in the output queue, and then waits on the CV. When the parent has retrieved the ID, and is ready for the child to start doing something, it signals the CV, and off it goes.
Start each thread inactived by passing a unique std::promise parameter, get the thread id first ( thread id is used as a pass by reference parameter for the purpose) afterwards let it wait for the promise to be set by the thread manager. This will also remove the hassle of using a conditional variable.
Edited Snippet
class smart_thread {
public:
smart_thread(std::function<void(void)> task)
{
thread_ = std::thread([=]() {
id_ = std::this_thread::get_id();
// wait here till activated
future_.get();
if(active_) task();
});
}
void activate() {
promise_.set_value();
active_ = true;
}
~smart_thread() {
if(!active_) promise_.set_value();
thread_.join();
}
private:
std::thread::id id_;
std::atomic<bool> active_ = false;
std::thread thread_;
std::promise<void> promise_;
std::future<void> future_ = promise_.get_future();
};
void main()
{
auto task = []() { std::cout << "Hello World\n"; };
smart_thread thread(task); // start thread inactive mode
thread.activate(); // activate thread
}
Would it be possible to create a template class that accepts the thread routine in the form of a std::function<void(T *object)>. This can easily be done with an anonymous closure if additional parameters need to be passed in.
template <class T>
class ThreadWrapper
{
public:
ThreadWrapper(std::function<void(T *object)> function, T *object) :
{
m_thread = std::thread(WrapFunction, function, object);
//optionally
m_thread.detach();
}
static void WrapFunction(ThreadWrapper *wrapper, std::function<void()> function, T *object)
{
// Get the thread id and save in the object
object->SetThreadId(get_id());
// Now actually invoke the thread routine, with the id already installed.
function(object);
}
}
// Cleanup is left as an exercise for the reader.
Beware of bugs in the above code - it's completely untested. :-) :-)
In a project we're creating multiple statemachines in a wrapper-class. Each wrapper runs in it's own thread. When the jobs is done, the wrapper-class destructor is being called, and in there we would like to stop the thread.
Though if we're using thread.join(), we get a deadlock (since it tries to join itself). We could somehow signal another thread, but that seems a bit messy.
Is there any way to properly terminate the thread in which a class is running in, upon object destruction?
thread.join() does not stop a thread. It waits for the thread to finish and then returns. In order to stop a thread you have to have some way of telling the thread to stop, and the thread has to check to see whether it's time to stop. One way to do that is with an atomic bool:
class my_thread {
public:
my_thread() : done(false) { }
~my_thread() { done = true; thr.join(); }
void run() { thread th(&my_thread::do_it, this); swap(th, thr); }
private:
void do_it() { while (!done) { /* ... */ } }
std::thread thr;
std::atomic<bool> done;
};
That's off the top of my head; not compiled, not tested.
After using threads for a while, I got into a situation where I needed a thread to run forever until a a function (or any sort of event) was called. To do this I created a bool value to control a while loop inside the function that was executed by the thread, but I quickly noticed that external variables are not updated after a thread starts running, causing the thread to never stop when it was asked to.
Heres some simple code to represent the issue:
#include <cstdio>
#include <thread>
#include <chrono>
class A {
public:
A();
void startThread();
void endThread();
private:
void threadCall();
bool active;
};
int main() {
A threadThing;
threadThing.startThread();
printf("[M] Thread Created\n");
std::this_thread::sleep_for(std::chrono::seconds(5));
threadThing.endThread();
printf("[M] Thread Killed\n");
std::this_thread::sleep_for(std::chrono::seconds(5));
return 0;
}
A::A() {
active = false;
}
void A::startThread() {
active = true;
std::thread AThread(&A::threadCall, *this);
AThread.detach();
}
void A::endThread() {
active = false;
}
void A::threadCall() {
printf("[T] Thread Started\n");
while (active) {
std::this_thread::sleep_for(std::chrono::seconds(2));
}
printf("[T] Thread Ended\n");
}
The expected result of this would be that the main function starts the thread, the thread says it started, then 4 seconds later the thread is killed and the thread says it ended, when in reality the thread never says it ends. Is there a way to let the thread access the 'active' variable, or is my approach to this problem incorrect altogether? (Side note, I did try to figure this out on my own but only got stuff like local thread storage which seems like its only for storage inside of threads, not access to the outside but I could be wrong)
The problem is with the constructor of std::thread, it copies/moves by default.
std::thread AThread(&A::threadCall, *this);
this copies the object into the new thread, so checking the active variable in the new object has no effect.
you can remove the *
std::thread AThread(&A::threadCall, this);
you pass the object pointer into the new thread, it will call like the method like this(*this).threadCall().
Edit: as the comments say, this is not guarantee to be thread safe, you need to use std::atomic<bool> to be safe.
What you need to do is pass an A class pointer as an argument to your function that is your thread.
void A::startThread()
{
active = true;
std::thread AThread(threadCall, this);
AThread.detach();
}
void A::threadCall(A *aClass)
{
printf("[T] Thread Started\n");
while (aClass->active)
{
std::this_thread::sleep_for(std::chrono::seconds(2));
}
printf("[T] Thread Ended\n");
}
Here is a skeleton of my thread class:
class MyThread {
public:
virutal ~MyThread();
// will start thread with svc() as thread entry point
void start() = 0;
// derive class will specialize what the thread should do
virtual void svc() = 0;
};
Somewhere in code I create an instance of MyThread and later I want to destroy it.
In this case MyThread~MyThread() is called. MyThread:svc() is still running and using the object's data members. So I need a way politely inform MyThread:svc() to stop spinning, before proceeding with the destructor.
What is the acceptable way to destroy the thread object?
Note: I'm looking for platform agnostic solution.
UPD: It's clear that the root of problem is that there's no relationship between C++ object representing thread and OS thread. So the question is: in context of object destuction, is there an acceptable way to make thread object behave like an ordinary C++ object or should it be treated as an unusual one (e.g. should we call join() before destoying it?
Considering your additional requirements posted as comment to Checkers' reply (which is the
most straightforward way to do that):
I agree that join in DTor is problematic for various reasons. But from that the lifetime of your thread object is unrelated to the lifetime of the OS thread object.
First, you need to separate the data the thread uses from the thread object itself. They are distinct entities with distinct lifetime requirements.
One approach is to make the data refcounted, and have any thread that wants to access it hold a strong reference to the data. This way, no thread will suddenly grab into the void, but the data will be destroyed as soon as noone touches it anymore.
Second, about the thread object being destroyed when the thread joins:
I am not sure if this is a good idea. The thread object is normally a way to query the state of a thread - but with a thread object that dies as soon as the thread finishes, noone can tell you wether the thread finished.
Generally, I'd completely decouple the lifetime of the thread object from the lifetime of the OS thread: Destroying your thread object should not affect the thread itself. I see two basic approaches to this:
Thread Handle Object - reference counted again, returned by thread creator, can be released as early as one likes without affecting the OS thread. It would expose methods such as Join, IsFinished, and can give access to the thread shared data.
(If the thread object holds relevant execution state, the threafFunc itself could hold a reference to it, thereby ensuring the instance won't be released before the thread ends)
Thin Wrapper - You simply create a temporary around an OS thread handle. You could not hold additional state for the thread easily, but it might be just enough to make it work: At any place, you can turn an OS thread handle into an thread object. The majority of communication - e.g. telling the thread to terminate - would be via the shared data.
For your code example, this means: separate the start() from the svc()
You'd roughly work with this API (XxxxPtr could be e.g. boost::shared_ptr):
class Thread
{
public:
bool IsFinished();
void Join();
bool TryJoin(long timeout);
WorkerPtr GetWorker();
static ThreadPtr Start(WorkerPtr worker); // creates the thread
};
class Worker
{
private:
virtual void Svc() = 0;
friend class Thread; // so thread can run Svc()
}
Worker could contain a ThreadPtr itself, giving you a guarantee that the thread object exists during execution of Svc(). If multiple threads are allowed to work on the same data, this would have to be a thread list. Otherwise, Thread::Start would have to reject Workers that are already associated with a thread.
Motivation: What to do with rogue threads that block?
Assuming a thread fails to terminate within time for one reason or another, even though you told it to. You simply have three choices:
Deadlock, your applicaiton hangs. That usually happens if you join in the destructor.
Violently terminate the thread. That's potentially a violent termination of the app.
Let the thread run to completion on it's own data - you can notify the user, who can safely save & exit. Or you simply let the rogue thread dance on it's own copy of the data (not reference by the main thread anymore) until it completes.
Usually any OS-specific threads API will allow you to "join" a thread. That is, to block indefinitely on a thread handle until the thread functions returns.
So,
Signal the thread function to return (e.g. by setting a flag in its loop to false).
Join the thread, to make sure the actual thread terminates before you try to delete the thread object.
Then you can proceed with destruction of the thread object (you may also join in the destructor, though some people object to blocking destructors.).
I've had a project before with a similar "thread worker" class and a corresponding "work item" class (a-la Java's Thread and Runnable, except thread does not terminate but waits for a new Runnable object to be executed).
In the end, there was no difference if you join in a separate "shutdown" function or in the destructor, except a separate function is a bit more clear.
If you join in a destructor and a thread blocks, you will wait indefinitely.
If you join in a separate function and a thread blocks, you will wait indefinitely.
If you detach the thread and let it finish on its own, it will usually block application from exiting, so you will wait indefinitely.
So there is no straightforward way to make a thread behave like a regular C++ object and ignore its OS thread semantics, unless you can guarantee that your thread code can terminate almost immediately when notified to do so.
You could havee somthing like this in your svc method
while (alive){ //loops}
//free resources after while.
In your destructor, you could set the alive member to false. Or, you could have a pleaseDie() method, that sets the alive member to false, and can be called from the outside requesting the Thread instance to stop processing.
void
Thread::pleaseDie()
{
this->alive = false;
}
You first need a way to communicate with the thread to tell it to shut down. The best mechanism to do this depends on what svc() is doing. If, for example, it is looping on a message queue, you could insert a "please stop" message in that queue. Otherwise, you could simply add a member bool variable (and synchronize access to it) that is periodically checked by the svc(), and set by the thread wanting to destroy the object. Your could add a pure virtual stop() function to your base class, giving the implementor a clear signal that it has to implement svc() to make its class "runnable", and to implement stop() to make it "stoppable".
After asking the thread to stop, you must wait for it to exit before destroying the object. Again, there are several ways to do this. One is to make the stop() function blocking. It could wait, for example, for a "ok, I'm really stopped now" condition variable to be set by the thread running svc(). Alternatively, the caller could "wait" on the thread running svc(). The way to "wait" is platform dependent.
Most thread systems allow you to send a signal to a thead.
Example: pthreads
pthread_kill(pthread_t thread, int sig);
This will send a signall to a thread.
You can use this to kill the thread. Though this can leave a few of the resources hanging in an undefined state.
A solution to the resource problem is to install a signall handler.
So that when the signal handler is called it throws an exception. This will cause the thread stack to unwind to the entry point where you can then get the thread to check a variable about weather it is sill alive.
NOTE: You should never allow an exception to propogate out of a thread (this is so undefined my eyes bleed thinking about it). Basically catch the exception at the thread entry point then check some state variable to see if the thread should really exit.
Meanwhile the thread that sends the signal should wait for the thread to die by doing a join.
The only issues are that when you throw out of signal handler function you need to be careful. You should not use a signal that is asynchronus (ie one that could have been generated by a signal in another thread). A good one to use is SIGSEGV. If this happens normally then you have accessed invalid memory any you thread should think about exiting anyway!
You may also need to specify an extra flag on some systems to cope.
See This article
A working example using pthreads:
#include <pthread.h>
#include <iostream>
extern "C" void* startThread(void*);
extern "C" void shouldIexit(int sig);
class Thread
{
public:
Thread();
virtual ~Thread();
private:
friend void* startThread(void*);
void start();
virtual void run() = 0;
bool running;
pthread_t thread;
};
// I have seen a lot of implementations use a static class method to do this.
// DON'T. It is not portable. This is because the C++ ABI is not defined.
//
// It currently works on several compilers but will break if these compilers
// change the ABI they use. To gurantee this to work you should use a
// function that is declared as extern "C" this guarantees that the ABI is
// correct for the callback. (Note this is true for all C callback functions)
void* startThread(void* data)
{
Thread* thread = reinterpret_cast<Thread*>(data);
thread->start();
}
void shouldIexit(int sig)
{
// You should not use std::cout in signal handler.
// This is for Demo purposes only.
std::cout << "Signal" << std::endl;
signal(sig,shouldIexit);
// The default handler would kill the thread.
// But by returning you can continue your code where you left off.
// Or by throwing you can cause the stack to unwind (if the exception is caught).
// If you do not catch the exception it is implementation defined weather the
// stack is unwound.
throw int(3); // use int for simplicity in demo
}
Thread::Thread()
:running(true)
{
// Note starting the thread in the constructor means that the thread may
// start before the derived classes constructor finishes. This may potentially
// be a problem. It is started here to make the code succinct and the derived
// class used has no constructor so it does not matter.
if (pthread_create(&thread,NULL,startThread,this) != 0)
{
throw int(5); // use int for simplicity in demo.
}
}
Thread::~Thread()
{
void* ignore;
running = false;
pthread_kill(thread,SIGSEGV); // Tell thread it may want to exit.
pthread_join(thread,&ignore); // Wait for it to finish.
// Do NOT leave before thread has exited.
std::cout << "Thread Object Destroyed" << std::endl;
}
void Thread::start()
{
while(running)
{
try
{
this->run();
}
catch(...)
{}
}
std::cout << "Thread exiting" << std::endl;
}
class MyTestThread:public Thread
{
public:
virtual void run()
{
// Unless the signal causes an exception
// this loop will never exit.
while(true)
{
sleep(5);
}
}
};
struct Info
{
Info() {std::cout << "Info" << std::endl;}
~Info() {std::cout << "Done: The thread Should have exited before this" << std::endl;}
};
int main()
{
signal(SIGSEGV,shouldIexit);
Info info;
MyTestThread test;
sleep(4);
std::cout << "Exiting About to Exit" << std::endl;
}
> ./a.exe
Info
Exiting About to Exit
Signal
Thread exiting
Thread Object Destroyed
Done: The thread Should have exited before this
>
You should add dedicated thread management class (i.e. MyThreadMngr), that handles this and other tasks, like book keeping, owning the thread handles etc. The Thread itself should somehow signal to the thread manager that its going to terminate and MyThreadMngr should i.e. have a loop like Tom proposed.
There will probably be more actions that suite into such a thread manager class.
I reckon the easiest way to do this is to wrap the thread execution code in a loop
while(isRunning())
{
... thread implementation ...
}
You can also stop your thread by doing specific calls, for instance when you're using a WIN32 thread you can call TerminateThread on the thread handle in the destructor.
i give a simple and clean design, no signal, no sync, no kill needed.
per your MyThread, i suggest renaming and adding as below:
class MyThread {
public:
virutal ~MyThread();
// will be called when starting a thread,
// could do some initial operations
virtual bool OnStart() = 0;
// will be called when stopping a thread, say calling join().
virtual bool OnStop() = 0;
// derive class will specialize what the thread should do,
// say the thread loop such as
// while (bRunning) {
// do the job.
// }
virtual int OnRun() = 0;
};
the thread interface user will control the lifetime of MyThread.
and actually the real thread object is as below:
class IThread
{
public:
virtual API ~IThread() {}
/* The real destructor. */
virtual void Destroy(void) = 0;
/* Starts this thread, it will call MyThread::OnStart()
* and then call MyThread::OnRun() just after created
* the thread. */
virtual bool Start(void) = 0;
/* Stops a thread. will call MyThread::OnStop(). */
virtual void Stop(void) = 0;
/* If Wait() called, thread won't call MyThread::OnStop().
* If could, it returns the value of MyThread::OnRun()
* returned */
virtual int Wait(void) = 0;
/* your staff */
virtual MyThread * Command(void) = 0;
};
/* The interface to create a thread */
extern IThread * ThrdCreate(MyThread *p);
See the complete interfaces
http://effoaddon.googlecode.com/svn/trunk/devel/effo/codebase/addons/thrd/include/thrd_i.h
Coding Examples
Case 1. Controlled thread loop
class ThreadLoop : public MyThread
{
private:
bool m_bRunning;
public:
virtual bool OnStart() { m_bRunning = true; }
virtual bool OnStop() { m_bRunning = false; }
virtual int OnRun()
{
while (m_bRunning) {
do your job;
}
}
};
int main(int argc, char **argv)
{
ThreadLoop oLoop;
IThread *pThread = ThrdCreate(&oLoop);
// Start the thread, it will call Loop::OnStart()
//and then call Loop::OnRun() internally.
pThread->Start();
do your things here. when it is time to stop the thread, call stop().
// Stop the thread, it will call Loop::OnStop(),
// so Loop::OnRun() will go to the end
pThread->Stop();
// done, destroy the thread
pThread->Destroy();
}
Case 2. Don't know when the thread will stop
class ThreadLoop : public MyThread
{
public:
virtual bool OnStart() { }
virtual bool OnStop() { }
virtual int OnRun()
{
do your job until finish.
}
};
int main(int argc, char **argv)
{
ThreadLoop oLoop;
IThread *pThread = ThrdCreate(&oLoop);
// Start the thread, it will call Loop::OnStart()
//and then call Loop::OnRun() internally.
pThread->Start();
do your things here. Since you don't know when the job will
finish in the thread loop. call wait().
// Wait the thread, it doesn't call Loop::OnStop()
pThread->Wait();
// done, destroy the thread
pThread->Destroy();
}
A complete IThread implementation:
see
http://effoaddon.googlecode.com/svn/trunk/devel/effo/codebase/addons/thrd/src/thrd/thrd.cpp