/*
 * Copyright 2002-2019 Intel Corporation.
 * 
 * This software is provided to you as Sample Source Code as defined in the accompanying
 * End User License Agreement for the Intel(R) Software Development Products ("Agreement")
 * section 1.L.
 * 
 * This software and the related documents are provided as is, with no express or implied
 * warranties, other than those that are expressly stated in the License.
 */

#include <assert.h>
#include <stdio.h>
#include <dlfcn.h>
#include <signal.h>
#include <sys/types.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <string>
#include <list>
#include "../Utils/threadlib.h"
using std::list;
using std::string;



/* 
 * The total number of threads that should run in this process
 * The number may be changed in command line with -th_num
 */
unsigned int numOfSecondaryThreads = 4;

/*
 * An write-read function for secondary threads
 */
extern "C" int ThreadsReady(unsigned int numOfThreads)
{
	assert(numOfThreads == numOfSecondaryThreads+1);
	return 0;
}
	

void * ThreadEndlessLoopFunc(void * arg)
{
	pthread_mutex_t *mutex = (pthread_mutex_t *)arg;
	
	while (!ThreadsReady(numOfSecondaryThreads+1))
	{
		pthread_mutex_lock(mutex);
		sched_yield();
		pthread_mutex_unlock(mutex);
	}
	fprintf(stderr, "Thread %u leaving the loop\n", GetTid());

    return 0;
}

#define DECSTR(buf, num) { buf = (char *)malloc(10); sprintf(buf, "%d", num); }

inline void PrintArguments(char **inArgv)
{
    fprintf(stderr, "Going to run: ");
    for(unsigned int i=0; inArgv[i] != 0; ++i)
    {
        fprintf(stderr, "%s ", inArgv[i]);
    }
    fprintf(stderr, "\n");
}


/* AttachAndInstrument()
 * a special routine that runs $PIN
 */
void AttachAndInstrument(list <string > * pinArgs)
{
    list <string >::iterator pinArgIt = pinArgs->begin();

    string pinBinary = *pinArgIt;
    pinArgIt++;

    pid_t parent_pid = getpid();
    
    pid_t child = fork();

    if (child) 
    {
		fprintf(stderr, "Pin injector pid %d\n", child);
        // inside parent
        return;  
    }
    else
    {
        // inside child

        char **inArgv = new char*[pinArgs->size()+10];

        unsigned int idx = 0;
        inArgv[idx++] = (char *)pinBinary.c_str(); 
        inArgv[idx++] = (char*)"-pid"; 
        inArgv[idx] = (char *)malloc(10);
        sprintf(inArgv[idx++], "%d", parent_pid);

        for (; pinArgIt != pinArgs->end(); pinArgIt++)
        {
            inArgv[idx++]= (char *)pinArgIt->c_str();
        }
        inArgv[idx] = 0;
        
        PrintArguments(inArgv);

        execvp(inArgv[0], inArgv);
        fprintf(stderr, "ERROR: execv %s failed\n", inArgv[0]);
		kill(parent_pid, 9);
        return;
    }
}


/*
 * Expected command line: <this exe> [-th_num NUM] -pin $PIN -pinarg <pin args > -t tool <tool args>
 */

void ParseCommandLine(int argc, char *argv[], list < string>* pinArgs)
{
    string pinBinary;
    for (int i=1; i<argc; i++)
    {
        string arg = string(argv[i]);
        if (arg == "-pin")
        {
            pinBinary = argv[++i];
        }
        else if (arg == "-pinarg")
        {
            for (int parg = ++i; parg < argc; parg++)
            {
                pinArgs->push_back(string(argv[parg]));
                ++i;
            }
        }
    }
    assert(!pinBinary.empty());
    pinArgs->push_front(pinBinary);
}

pthread_t *thHandle;

int main(int argc, char *argv[])
{
    list <string> pinArgs;
    ParseCommandLine(argc, argv, &pinArgs);
    
    thHandle = new pthread_t[numOfSecondaryThreads];

    pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
    // start all secondary threads
    for (unsigned int i = 0; i < numOfSecondaryThreads; i++)
    {
        pthread_create(&thHandle[i], 0, ThreadEndlessLoopFunc, (void *)&mutex);
    }

    AttachAndInstrument(&pinArgs);

    for (unsigned int i = 0; i < numOfSecondaryThreads; i++)
    {
        pthread_join(thHandle[i], 0);
    }   

    return 0;
}