solved paralel start bug. due to handshaking deficit in thread start

This commit is contained in:
Dhanya Maliakal 2016-08-17 10:29:47 +02:00
parent fb8f49985b
commit e0c45f4afd
3 changed files with 130 additions and 165 deletions

View File

@ -1608,36 +1608,7 @@ int* multiSlsDetector::startAndReadAll(){
int multiSlsDetector::startAndReadAllNoWait(){
/*
int i=0;
int ret=OK, ret1=OK;
for (i=0; i<thisMultiDetector->numberOfDetectors; i++) {
if (i!=thisMultiDetector->masterPosition)
if (detectors[i]) {
ret=detectors[i]->startAndReadAllNoWait();
if(detectors[i]->getErrorMask())
setErrorMask(getErrorMask()|(1<<i));
if (ret!=OK)
ret1=FAIL;
}
}
i=thisMultiDetector->masterPosition;
if (thisMultiDetector->masterPosition>=0) {
if (detectors[i]) {
ret=detectors[i]->startAndReadAllNoWait();
if(detectors[i]->getErrorMask())
setErrorMask(getErrorMask()|(1<<i));
if (ret!=OK)
ret1=FAIL;
}
}
return ret1;
*/
// hanging randomly around 4000-5000 frames at 1sec exptime (threads dont return)
int i=0;
int ret=OK;
int posmin=0, posmax=thisMultiDetector->numberOfDetectors;
@ -1653,10 +1624,9 @@ int multiSlsDetector::startAndReadAllNoWait(){
Task* task = new Task(new func0_t<int,slsDetector,int>(&slsDetector::startAndReadAllNoWait,
detectors[idet],iret[idet]));
threadpool->add_task(task);
cprintf(GREEN,"task addeD\n");
}
}cout<<"waiting for tasks to copmlete"<<endl;
threadpool->wait_for_tasks_to_complete();cout<<"returned!"<<endl;
}
threadpool->wait_for_tasks_to_complete();
for(int idet=posmin; idet<posmax; idet++){
if((idet!=thisMultiDetector->masterPosition) && (detectors[idet])){
if(iret[idet] != NULL){
@ -1673,7 +1643,7 @@ int multiSlsDetector::startAndReadAllNoWait(){
//master
int ret1=OK;
i=thisMultiDetector->masterPosition;
if (thisMultiDetector->masterPosition>=0) {cout<<"should never be here"<<endl;
if (thisMultiDetector->masterPosition>=0) {
if (detectors[i]) {
ret1=detectors[i]->startAndReadAllNoWait();
if(detectors[i]->getErrorMask())

View File

@ -1,178 +1,170 @@
#include "ThreadPool.h"
ThreadPool::ThreadPool(int pool_size) : m_pool_size(pool_size)
{
ThreadPool::ThreadPool(int pool_size) : m_pool_size(pool_size){
#ifdef VERBOSE
cout << "Constructed ThreadPool of size " << m_pool_size << endl;
cout << "Constructed ThreadPool of size " << m_pool_size << endl;
#endif
m_tasks_loaded = false;
thread_started = false;
current_thread_number = -1;
number_of_ongoing_tasks = 0;
m_tasks_loaded = false;
thread_started = false;
current_thread_number = -1;
number_of_ongoing_tasks = 0;
}
ThreadPool::~ThreadPool()
{
// Release resources
if (m_pool_state != STOPPED) {
destroy_threadpool();
}
ThreadPool::~ThreadPool(){
// Release resources
if (m_pool_state != STOPPED) {
destroy_threadpool();
}
}
// We can't pass a member function to pthread_create.
// So created the wrapper function that calls the member function
// we want to run in the thread.
extern "C"
void* start_thread(void* arg)
{
ThreadPool* tp = (ThreadPool*) arg;
tp->execute_thread();
return NULL;
ThreadPool* tp = (ThreadPool*) arg;
tp->execute_thread();
return NULL;
}
int ThreadPool::initialize_threadpool()
{
int ThreadPool::initialize_threadpool(){
if(m_pool_size == 1)
return m_pool_size;
// TODO: COnsider lazy loading threads instead of creating all at once
m_pool_state = STARTED;
int ret = -1;
for (int i = 0; i < m_pool_size; i++) {
pthread_t tid;
thread_started = false;
current_thread_number = i;
ret = pthread_create(&tid, NULL, start_thread, (void*) this);
if (ret != 0) {
cerr << "pthread_create() failed: " << ret << endl;
return 0;
}
m_threads.push_back(tid);
while(!thread_started);
}
m_pool_state = STARTED;
int ret = -1;
sem_init(&semStart,1,0);
for (int i = 0; i < m_pool_size; i++) {
pthread_t tid;
thread_started = false;
current_thread_number = i;
ret = pthread_create(&tid, NULL, start_thread, (void*) this);
if (ret != 0) {
cerr << "pthread_create() failed: " << ret << endl;
return 0;
}
m_threads.push_back(tid);
while(!thread_started);
}
#ifdef VERBOSE
cout << m_pool_size << " threads created by the thread pool" << endl;
cout << m_pool_size << " threads created by the thread pool" << endl;
#endif
return m_pool_size;
return m_pool_size;
}
int ThreadPool::destroy_threadpool()
{ if(m_pool_size == 1)
int ThreadPool::destroy_threadpool(){
if(m_pool_size == 1)
return 0;
//cout << "in destroying threadpool" << endl;
// Note: this is not for synchronization, its for thread communication!
// destroy_threadpool() will only be called from the main thread, yet
// the modified m_pool_state may not show up to other threads until its
// modified in a lock!
m_task_mutex.lock();
m_pool_state = STOPPED;
m_task_mutex.unlock();
/*cout << "Broadcasting STOP signal to all threads..." << endl;*/
m_task_cond_var.broadcast(); // notify all threads we are shttung down
/*cout << "in destroying threadpool" << endl;*/
// thread communication- modified m_pool_state may not show up
//to other threads until its modified in a lock!
m_task_mutex.lock();
m_pool_state = STOPPED;
m_task_mutex.unlock();
/*cout << "Broadcasting STOP signal to all threads..." << endl;*/
m_task_cond_var.broadcast(); // notify all threads we are shttung down
int ret = -1;
for (int i = 0; i < m_pool_size; i++) {
void* result;
ret = pthread_join(m_threads[i], &result);
/*cout << "pthread_join() returned " << ret << ": " << strerror(errno) << endl;*/
m_task_cond_var.broadcast(); // try waking up a bunch of threads that are still waiting
}
number_of_ongoing_tasks = 0;
/* cout << m_pool_size << " threads exited from the thread pool" << endl;*/
return 0;
int ret = -1;
for (int i = 0; i < m_pool_size; i++) {
void* result;
sem_post(&semStart);
ret = pthread_join(m_threads[i], &result);
/*cout << "pthread_join() returned " << ret << ": " << strerror(errno) << endl;*/
m_task_cond_var.broadcast(); // try waking up a bunch of threads that are still waiting
}
sem_destroy(&semStart);
number_of_ongoing_tasks = 0;
/* cout << m_pool_size << " threads exited from the thread pool" << endl;*/
return 0;
}
void* ThreadPool::execute_thread()
{
void* ThreadPool::execute_thread(){
int ithread = current_thread_number;
thread_started = true;
Task* task = NULL;
m_tasks_loaded = false;
/*cout << "Starting thread " << pthread_self() << endl;*/
while(true) {
// Try to pick a task
/*cout << "Locking: " << pthread_self() << endl;*/
m_task_mutex.lock();
// We need to put pthread_cond_wait in a loop for two reasons:
// 1. There can be spurious wakeups (due to signal/ENITR)
// 2. When mutex is released for waiting, another thread can be waken up
// from a signal/broadcast and that thread can mess up the condition.
// So when the current thread wakes up the condition may no longer be
// actually true!
while ((m_pool_state != STOPPED) && (m_tasks.empty())) {
// Wait until there is a task in the queue
// Unlock mutex while wait, then lock it back when signaled
/* cout << "Unlocking and waiting: " << pthread_self() << endl;*/
m_task_cond_var.wait(m_task_mutex.get_mutex_ptr());
/* cout << "Signaled and locking: " << pthread_self() << endl;*/
}
Task* task = NULL;
m_tasks_loaded = false;
/*cout << "Starting thread " << pthread_self() << endl;*/
while(true) {
// Try to pick a task
/*cout << "Locking: " << pthread_self() << endl;*/
m_task_mutex.lock();
// If the thread was woken up to notify process shutdown, return from here
if (m_pool_state == STOPPED) {
/* cout << "Unlocking and exiting: " << pthread_self() << endl;*/
m_task_mutex.unlock();
pthread_exit(NULL);
}
while ((m_pool_state != STOPPED) && (m_tasks.empty())) {
// Wait until there is a task in the queue
// Unlock mutex while wait, then lock it back when signaled
/* cout << "Unlocking and waiting: " << pthread_self() << endl;*/
m_task_cond_var.wait(m_task_mutex.get_mutex_ptr());
/* cout << "Signaled and locking: " << pthread_self() << endl;*/
}
task = m_tasks.front();
m_tasks.pop_front();
/*cout << "Unlocking: " << pthread_self() << endl;*/
m_task_mutex.unlock();
// If the thread was woken up to notify process shutdown, return from here
if (m_pool_state == STOPPED) {
/* cout << "Unlocking and exiting: " << pthread_self() << endl;*/
m_task_mutex.unlock();
pthread_exit(NULL);
}
cout << ithread <<" Executing thread " << pthread_self() << endl;
// execute the task
(*task)(); // could also do task->run(arg);
cout << ithread <<" Done executing thread " << pthread_self() << endl;
task = m_tasks.front();
m_tasks.pop_front();
/*cout << "Unlocking: " << pthread_self() << endl;*/
m_task_mutex.unlock();
m_all_tasks_mutex.lock();
number_of_ongoing_tasks--; cout<<ithread <<" number_of_ongoing_tasks:"<<number_of_ongoing_tasks<<endl;
m_all_tasks_mutex.unlock();
sem_wait(&semStart);
//if all required tasks done
if(!ithread && m_tasks_loaded && (m_tasks.empty())){cout<<ithread <<" waiting for all tasks to be done"<<endl;
while(number_of_ongoing_tasks)
usleep(5000);
cout<<ithread <<" all tasks done. gonna lock"<<endl;
m_all_tasks_mutex.lock(); cout<<ithread <<" all tasks done"<<endl;
m_tasks_loaded = false; cout<<ithread <<" task loaded set to false"<<endl;
m_all_tasks_cond_var.signal(); cout<<ithread <<" wake up signal sent"<<endl;// wake up thread that is waiting for all tasks to be complete
m_all_tasks_mutex.unlock();cout<<ithread <<" unlocked"<<endl;
}
/*cout << ithread <<" Executing thread " << pthread_self() << endl;*/
// execute the task
(*task)(); // could also do task->run(arg);
/*cout << ithread <<" Done executing thread " << pthread_self() << endl;*/
m_all_tasks_mutex.lock();
number_of_ongoing_tasks--;
m_all_tasks_mutex.unlock();
delete task;cout<<ithread <<" task deleted"<<endl;
}
return NULL;
//last task and check m_tasks_loaded to ensure done only once
if((!number_of_ongoing_tasks) && m_tasks_loaded){
/*cout << ithread << " all tasks done."<<endl;*/
m_all_tasks_mutex.lock();
m_tasks_loaded = false;
m_all_tasks_cond_var.signal();// wake up thread that is waiting for all tasks to be complete
m_all_tasks_mutex.unlock();
}
delete task;
/*cout << ithread << " task deleted" << endl;*/
}
return NULL;
}
int ThreadPool::add_task(Task* task)
{
int ThreadPool::add_task(Task* task){
if(m_pool_size == 1){
(*task)();
return 0;
(*task)();
return 0;
}
m_task_mutex.lock();
// TODO: put a limit on how many tasks can be added at most
m_tasks.push_back(task);
number_of_ongoing_tasks++;// cout<<"number_of_ongoing_tasks:"<<number_of_ongoing_tasks<<endl;
m_task_cond_var.signal(); // wake up one thread that is waiting for a task to be available
m_task_mutex.unlock();
return 0;
m_task_mutex.lock();
// TODO: put a limit on how many tasks can be added at most
m_tasks.push_back(task);
number_of_ongoing_tasks++;
m_task_cond_var.signal(); // wake up one thread that is waiting for a task to be available
m_task_mutex.unlock();
return 0;
}
void ThreadPool::wait_for_tasks_to_complete(){
if(m_pool_size == 1)
return;
m_all_tasks_mutex.lock();cout<<"waiting for tasks: locked. gonna wait" <<endl;
m_all_tasks_mutex.lock();
/*cout << "waiting for tasks: locked. gonna wait" << endl;*/
m_tasks_loaded = true;
while ((m_pool_state != STOPPED) && m_tasks_loaded) {cout<<"waiting for tasks: checking should be locked most likely, m_tasks_loaded:"<<m_tasks_loaded <<endl;
m_all_tasks_cond_var.wait(m_all_tasks_mutex.get_mutex_ptr());cout<<"waiting for tasks: out of the wait loop, m_tasks_loaded:"<< m_tasks_loaded<<endl;
}cout<<"waiting for tasks:totall out, must be locked again" <<endl;
m_all_tasks_mutex.unlock();cout<<"waiting for tasks: unlocked and done" <<endl;
//giving all threads permission to start as all tasks have been added
//using a different variable as number_of_ongoing_tasks is likely to change during the loop
int totalnumtasks = number_of_ongoing_tasks;
for(int i=0;i<totalnumtasks;i++)
sem_post(&semStart);
while ((m_pool_state != STOPPED) && m_tasks_loaded) {
m_all_tasks_cond_var.wait(m_all_tasks_mutex.get_mutex_ptr());
}
/*cout << "waiting for tasks:totall out, must be locked again" << endl;*/
m_all_tasks_mutex.unlock();
}

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@ -13,7 +13,7 @@
#include "Task.h"
#include "CondVar.h"
#include "Global.h"
#include <semaphore.h>
using namespace std;
@ -44,5 +44,8 @@ private:
//volatile uint64_t tasks_done_mask;
volatile int number_of_ongoing_tasks;
sem_t semStart;
};