panda3d/panda/src/pipeline/test_concurrency.cxx
2008-05-28 18:37:20 +00:00

119 lines
3.0 KiB
C++
Executable File

// Filename: test_concurrency.cxx
// Created by: drose (06Apr06)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) Carnegie Mellon University. All rights reserved.
//
// All use of this software is subject to the terms of the revised BSD
// license. You should have received a copy of this license along
// with this source code in a file named "LICENSE."
//
////////////////////////////////////////////////////////////////////
#include "pandabase.h"
#include "thread.h"
#include "pmutex.h"
#include "mutexHolder.h"
#include "pointerTo.h"
#include "trueClock.h"
// The number of iterations to spin within each thread, before
// printing output.
static const long long iterations_per_output = 100000000;
// The amount of time, in seconds, to wait between spawning threads.
static const double delay_between_threads = 2.0;
// The amount of time, in seconds, for each thread to run.
static const double thread_run_time = 15.0;
// The number of threads to spawn.
static const int number_of_threads = 4;
// Number of bytes to reserve between writable memory pointers.
static const int block_size = 64;
static Mutex _output_lock;
union MemBlock {
char _pad[block_size];
int _value;
};
volatile MemBlock memblock[number_of_threads];
#define OUTPUT(stuff) { \
MutexHolder holder(_output_lock); \
stuff; \
}
class MyThread : public Thread {
public:
MyThread(const string &name, int index) :
Thread(name, name),
_index(index)
{
}
virtual void thread_main() {
OUTPUT(nout << *this << " beginning.\n");
double total_seconds = 0.0;
TrueClock *clock = TrueClock::get_global_ptr();
volatile int snarf;
while (total_seconds < thread_run_time) {
double start_time = clock->get_short_time();
for (long long i = 0; i < iterations_per_output; ++i) {
memblock[_index]._value = snarf;
}
double end_time = clock->get_short_time();
double elapsed_seconds = end_time - start_time;
double iterations_per_second = iterations_per_output / elapsed_seconds;
OUTPUT(nout << *this << " achieving "
<< iterations_per_second / 1000000.0
<< " million iterations per second.\n");
total_seconds += elapsed_seconds;
}
OUTPUT(nout << *this << " exiting.\n");
}
int _index;
};
int
main(int argc, char *argv[]) {
OUTPUT(nout << "Making " << number_of_threads << " threads.\n");
typedef pvector< PT(MyThread) > Threads;
Threads threads;
PT(MyThread) thread = new MyThread("a", 0);
threads.push_back(thread);
thread->start(TP_normal, true);
for (int i = 1; i < number_of_threads; ++i) {
char name = 'a' + i;
Thread::sleep(delay_between_threads);
PT(MyThread) thread = new MyThread(string(1, name), i);
threads.push_back(thread);
thread->start(TP_normal, true);
}
// Now join all the threads.
Threads::iterator ti;
for (ti = threads.begin(); ti != threads.end(); ++ti) {
(*ti)->join();
}
Thread::prepare_for_exit();
return 0;
}