thread.C

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#include "bcsignals.h"
#include <sys/wait.h>
#include <sched.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include "thread.h"


Thread::Thread(int synchronous, int realtime, int autodelete)
{
        this->synchronous = synchronous;
        this->realtime = realtime;
        this->autodelete = autodelete;
        tid = (pthread_t)-1;
        tid_valid = 0;
        thread_running = 0;
        cancel_enabled = 0;
}

Thread::~Thread()
{
}

void* Thread::entrypoint(void *parameters)
{
        Thread *thread = (Thread*)parameters;

// allow thread to be cancelled at any point during a region where it is enabled.
        pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, 0);
// Disable cancellation by default.
        pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0);
        thread->cancel_enabled = 0;

// Set realtime here seince it doesn't work in start
        if(thread->realtime && getuid() == 0)
        {
                struct sched_param param = 
                {
                        sched_priority : 1
                };
                if(pthread_setschedparam(thread->tid, SCHED_RR, &param) < 0)
                        perror("Thread::entrypoint pthread_attr_setschedpolicy");
        }

        thread->run();

        thread->thread_running = 0;

        if(thread->autodelete && !thread->synchronous) delete thread;
        return NULL;
}

void Thread::start()
{
        pthread_attr_t  attr;
        struct sched_param param;

        pthread_attr_init(&attr);

        thread_running = 1;

// Inherit realtime from current thread the easy way.
        if(!realtime) realtime = calculate_realtime();


        if(!synchronous) pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

        if(realtime && getuid() == 0)
        {
                if(pthread_attr_setschedpolicy(&attr, SCHED_RR) < 0)
                        perror("Thread::start pthread_attr_setschedpolicy");
                param.sched_priority = 50;
                if(pthread_attr_setschedparam(&attr, &param) < 0)
                        perror("Thread::start pthread_attr_setschedparam");
        }
        else
        {
                if(pthread_attr_setinheritsched(&attr, PTHREAD_INHERIT_SCHED) < 0)
                        perror("Thread::start pthread_attr_setinheritsched");
        }

        pthread_create(&tid, &attr, Thread::entrypoint, this);
        tid_valid = 1;
}

int Thread::end(pthread_t tid)           // need to join after this if synchronous
{
        if(tid_valid)
        {
                pthread_cancel(tid);
        }
        return 0;
}

int Thread::end()           // need to join after this if synchronous
{
        cancel();
        return 0;
}

int Thread::cancel()
{
        if(tid_valid) pthread_cancel(tid);
        if(!synchronous)
        {
                tid = (pthread_t)-1;
                tid_valid = 0;
        }
        return 0;
}

int Thread::join()   // join this thread
{
        int result = 0;
        if(tid_valid)
        {
                result = pthread_join(tid, 0);
        }

        tid = (pthread_t)-1;
        tid_valid = 0;

// Don't execute anything after this.
        if(autodelete && synchronous) delete this;
        return 0;
}

int Thread::enable_cancel()
{
        cancel_enabled = 1;
        pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
        return 0;
}

int Thread::disable_cancel()
{
        pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
        cancel_enabled = 0;
        return 0;
}

int Thread::get_cancel_enabled()
{
        return cancel_enabled;
}

int Thread::exit_thread()
{
        pthread_exit(0);
        if(!synchronous)
        {
                tid = (pthread_t)-1;
                tid_valid = 0;
        }
        return 0;
}


int Thread::suspend_thread()
{
        if(tid_valid) pthread_kill(tid, SIGSTOP);
        return 0;
}

int Thread::continue_thread()
{
        if(tid_valid) pthread_kill(tid, SIGCONT);
        return 0;
}

int Thread::running()
{
        return thread_running;
}

int Thread::set_synchronous(int value)
{
        this->synchronous = value;
        return 0;
}

int Thread::set_realtime(int value)
{
        this->realtime = value;
        return 0;
}

int Thread::set_autodelete(int value)
{
        this->autodelete = value;
        return 0;
}

int Thread::get_autodelete()
{
        return autodelete;
}

int Thread::get_synchronous()
{
        return synchronous;
}

int Thread::calculate_realtime()
{
//printf("Thread::calculate_realtime %d %d\n", getpid(), sched_getscheduler(0));
        return (sched_getscheduler(0) == SCHED_RR ||
                sched_getscheduler(0) == SCHED_FIFO);
}

int Thread::get_realtime()
{
        return realtime;
}

int Thread::get_tid()
{
        return tid;
}

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