Experimental Physics and
Industrial Control System

Hi,
I have a bunch of unit tests for support modules that spawn epicsThreads
and tear them down after a very short time. I noticed that although I'm
waiting for the thread to shut down cleanly tests are not reproducible.
In the attached simple code snipped I sometimes see the thread function
running:

$ time ./a.out
myThread::myThread() begin
myThread::myThread() end
myThread::~myThread() begin
myThread::run() begin
myThread::run() end
myThread::~myThread() end

real    0m8.044s
user    0m0.025s
sys     0m0.024s

However, sometimes the destructor gets called so fast that the thread
function doesn't run:

$ time ./a.out
myThread::myThread() begin
myThread::myThread() end
myThread::~myThread() begin
myThread::~myThread() end

real    0m5.041s
user    0m0.014s
sys     0m0.031s

I'm wondering if there is a way I can ensure run() always runs. I'm
wondering if making the constructor wait until run() actually starts
executing.

Thanks,

Martin

-- 
Martin Konrad
High Performance Controls Team Leader
Facility for Rare Isotope Beams
Michigan State University
640 South Shaw Lane
East Lansing, MI 48824-1321, USA
Tel. 517-908-7253
Email: [email protected]

// compile with g++ -I /usr/lib/epics/include -I /usr/lib/epics/include/os/Linux/ -I /usr/lib/epics/include/compiler/gcc/ -L /usr/lib/epics/lib/linux-x86_64 epicsThread.cpp -lCom

#include <iostream>
#include <epicsThread.h>

class myThread: public epicsThreadRunable {
public:
  myThread(int arg,const char *name);
  virtual ~myThread();
  virtual void run();
  epicsThread thread;
};

myThread::myThread(int arg,const char *name) : thread(*this,name,epicsThreadGetStackSize(epicsThreadStackSmall),50)
{
  std::cerr << "myThread::myThread() begin\n";
  thread.start();
  std::cerr << "myThread::myThread() end\n";
}

myThread::~myThread() {
  std::cerr << "myThread::~myThread() begin\n";
  thread.exitWait();
  std::cerr << "myThread::~myThread() end\n";
}

void myThread::run()
{
  std::cerr << "myThread::run() begin\n";
  epicsThreadSleep(3);
  std::cerr << "myThread::run() end\n";
}

int main() {
  {
    myThread t1(0, "foo");
  }
  epicsThreadSleep(5);
}

Replies:

Re: How to ensure epicsThread function is running in short-lived environment? Dirk Zimoch via Core-talk

Re: How to ensure epicsThread function is running in short-lived environment? Michael Davidsaver via Core-talk

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