/*
 * 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 <stdio.h>
#include <set>
#include "pin.H"

using std::set;
using std::string;

KNOB<string> KnobOutputFile(KNOB_MODE_WRITEONCE, "pintool", "o", "thread_count.out", "Output file");

FILE * out;
PIN_LOCK pinLock;
INT32 threadCreated = 0;
INT32 threadEnded = 0;

THREADID myThread = INVALID_THREADID;
set<THREADID> appThreads;

static VOID AppThreadStart(THREADID threadIndex)
{
    PIN_GetLock(&pinLock, PIN_GetTid());
    threadCreated++;
    appThreads.insert(threadIndex);
    PIN_ReleaseLock(&pinLock);
}

VOID ThreadStart(THREADID threadid, CONTEXT *ctxt, INT32 flags, VOID *v)
{
    if (myThread == INVALID_THREADID)
    {
        // We will execute this code only once, and we are assuming that this is for the main thread or
        // at least NOT one of the threads that the application created with CreateThread().
        // We are registering this additional thread because ThreadFini is called for all threads including the main thread.
        myThread = threadid;
        AppThreadStart(threadid);
    }
}

VOID ThreadFini(THREADID threadid, const CONTEXT *ctxt, INT32 code, VOID *v)
{
    // Use the Pin lock to protect writes to appThreads between this callback function and the analysis routine AppThreadStart
    PIN_GetLock(&pinLock, PIN_GetTid());
    set<THREADID>::iterator it = appThreads.find(threadid);
    if (it != appThreads.end())
    {
        threadEnded++;
        appThreads.erase(it);
    }
    PIN_ReleaseLock(&pinLock);
}

VOID Fini(INT32 code, VOID *v)
{
    fprintf(out, "Number of threads created  - %d\n", (int)threadCreated);
    fprintf(out, "Number of threads terminated  - %d\n", (int)threadEnded);
    fclose(out);
}

static VOID InstrumentImg(IMG img, VOID *)
{
    if (IMG_IsMainExecutable(img))
    {
        RTN rtn = RTN_FindByName(img, "ThreadRoutine");
        if (RTN_Valid(rtn))
        {
            RTN_Open(rtn);
            RTN_InsertCall(rtn, IPOINT_BEFORE, AFUNPTR(AppThreadStart), IARG_THREAD_ID, IARG_END);
            RTN_Close(rtn);
        }
    }
}

int main(INT32 argc, CHAR **argv)
{
    PIN_Init(argc, argv);
    PIN_InitLock(&pinLock);

    out = fopen(KnobOutputFile.Value().c_str(), "w");

    PIN_InitSymbols();

    IMG_AddInstrumentFunction(InstrumentImg, NULL);
    PIN_AddThreadStartFunction(ThreadStart, NULL);
    PIN_AddThreadFiniFunction(ThreadFini, NULL);
    PIN_AddFiniFunction(Fini, NULL);

    // Never returns
    PIN_StartProgram();

    return 0;
}