/*
 * 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.
 */

/*
   Test the scenario where Pin tries to reattach to an application, using PIN_AttachProbed API,
   when the main thread of the application is a zombie thread.
   Pin wouldn't attach to the application in this scenario. 
   Instead, Pin will give a message to the user notifying why Pin didn't attach to the application and the
   application will continue to run natively
*/

#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <fstream>
#include <sstream>
#include "zombie_utils.h"
#include <string.h>
#define MAX_COMMAND_LINE_SIZE 15    // the size for the array of arguments to execv (this value is arbitrary)

EXPORT_SYM bool AfterAttach1();

pid_t zombieThreadPid;

const char * fileName;

const char *imageToLoad;

bool AfterAttach1()
{
    // Pin sets an analysis function here to notify the application when Pin attaches to it.
    return false;
}

// This function is invoked when the secondary thread starts execution.
void* SecondaryThreadMain(void* v)
{
    // Wait until Pin notifies the application that it can't reattach to it since
    // the main thread of the application is a zombie thread.
    while(!NotifyUserPinUnableToAttach(fileName)) sleep(1);
    pthread_exit(0);
    return NULL;
}

// Expected argv arguments:
// [1] pin executable
// [2] Pin flags (e.g. -slow_asserts)
//     >> zero or more flags possible
// [3] "-t"
// [4] tool
// [5] imageName
// [6] output file
int main(int argc, char** argv)
{
    if(argc < 6)
    {
       fprintf(stderr, "Not enough arguments\n" );
       fflush(stderr);
       exit(RES_INVALID_ARGS);
    }
    if (argc > MAX_COMMAND_LINE_SIZE - 3){      // added: -probe -pid attachPid -o NULL, omitted: argv[0], imageName
        fprintf(stderr, "Too many arguments\n" );
        fflush(stderr);
        exit(RES_INVALID_ARGS);
    }
    imageToLoad = argv[argc-2];     // argv[argc-2] is imageName
    fileName = argv[argc-1];        // argv[argc-1] is output file
    zombieThreadPid = getpid();
    pid_t child = fork();
    if (child < 0)
    {
        perror("Fork failed while creating application process");
        exit(RES_FORK_FAILED);
    }

    if (child)
    { 
        // Pin sets an analysis function here to notify the application
        // when Pin attaches to it in the first attach session.
        while(!AfterAttach1())
        {
            sleep(1);
        }

        NotifyTestType(TEST_TYPE_MAIN_THREAD_ZOMBIE_IN_REATTACH);

        NotifyZombiePid(zombieThreadPid);

        pthread_t tid;
        pthread_create(&tid, NULL, SecondaryThreadMain, NULL);

        // When the image is loaded into the memory,
        // the tool instructs Pin to detach from the application.
        void *handle = dlopen(imageToLoad, RTLD_LAZY);
        if (!handle)
        {
            fprintf(stderr, " Failed to load: %s because: %s\n", imageToLoad, dlerror());
            fflush(stderr);
            exit(RES_LOAD_FAILED);
        }  

        // After calling to thread_exit(0) function, the main thread is going to become a zombie thread.
        // Pin should not attach to the application.
        // Instead, Pin should give a message to the user notifying why Pin didn't attach to the application.
        pthread_exit(0);
    }

    if (child == 0)
    {
        // Inside child 1
        pid_t second_child_pid = fork ();
        
        if (second_child_pid < 0)
        {
            perror("Fork failed while creating application process");
            exit(RES_FORK_FAILED);
        }

        if (second_child_pid > 0)
        {
            // Inside parent 2
            waitpid(second_child_pid, 0, 0); // wait until Pin is injected to the application process.
            exit(RES_SUCCESS);
        }
        else
        {
            //Inside child 2
            char attachPid[MAX_SIZE];
            snprintf(attachPid, MAX_SIZE , "%d", zombieThreadPid);

            char* args[MAX_COMMAND_LINE_SIZE] = {NULL};  // arguments for execv command
            int args_count = 0;
            int argv_count = 1;                          // to start from argv[1]...
            args[args_count++] = argv[argv_count++];     // by convention, first arg is the filename of the executed file (pin)
            args[args_count++] = (char*)"-probe";
            args[args_count++] = (char*)"-pid";
            args[args_count++] = attachPid;
            while (strcmp(argv[argv_count], "-t") != 0){   // additional Pin flags (optional)
                args[args_count++] = argv[argv_count++];
            }
            args[args_count++] = argv[argv_count++];     // "-t"
            args[args_count++] = argv[argv_count++];     // tool
            args[args_count++] = (char*)"-o";
            argv_count++;                                // skip the imageName, not needed for the execv command
            args[args_count++] = argv[argv_count++];     // output file
            args[args_count++] = NULL;                   // end
            // Pin  attaches to the application.
            execv(argv[1], (char * const *)args);        // never returns
            perror("execv failed while trying to attach Pin to the application\n");
            exit(RES_EXEC_FAILED);
        }
    }

    return RES_SUCCESS;
}