pintool
Using TLS
sonysame
2018. 9. 28. 19:53
#include <iostream>
#include <fstream>
#include <map>
#include "pin.H"
KNOB<string> KnobOutputFile(KNOB_MODE_WRITEONCE, "pintool",
"o", "", "specify output file name");
INT32 numThreads = 0;
ostream* OutFile = NULL;
// Force each thread's data to be in its own data cache line so that
// multiple threads do not contend for the same data cache line.
// This avoids the false sharing problem.
#define PADSIZE 56 // 64 byte line size: 64-8
// a running count of the instructions
class thread_data_t
{
public:
thread_data_t() : _count(0) {}
UINT64 _count;
UINT8 _pad[PADSIZE];
};
// key for accessing TLS storage in the threads. initialized once in main()
static TLS_KEY tls_key = INVALID_TLS_KEY;
// A map to store the data attached for each thread, and a lock to protect the map
std::map<THREADID, thread_data_t*> threads_data;
PIN_LOCK lock;
// function to access thread-specific data
thread_data_t* get_tls(THREADID threadid)
{
thread_data_t* tdata = static_cast<thread_data_t*>(PIN_GetThreadData(tls_key, threadid));
if (tdata == NULL)
{
cerr << "PIN_GetThreadData(" << tls_key << "," << threadid << ") Failed" << endl;
PIN_ExitProcess(1);
}
PIN_GetLock(&lock, threadid);
std::map<THREADID, thread_data_t*>::const_iterator it = threads_data.find(threadid);
if ((it == threads_data.end()) || (it->second != tdata))
{
cerr << "PIN_GetThreadData(" << tls_key << "," << threadid << ") returned the wrong thread data" << endl;
PIN_ExitProcess(1);
}
PIN_ReleaseLock(&lock);
return tdata;
}
// This function is called before every block
VOID PIN_FAST_ANALYSIS_CALL docount(UINT32 c, THREADID threadid)
{
thread_data_t* tdata = get_tls(threadid);
tdata->_count += c;
}
// This function tests operations with illegal TLS keys.
VOID TestIllegalTLSOPerations(THREADID threadid)
{
static bool tested = false;
if (tested)
return;
tested = true;
// start with an invalid key
TLS_KEY temp_tls_key = INVALID_TLS_KEY;
// Try to get thread data - expected to fail
if (PIN_GetThreadData(temp_tls_key, threadid) != NULL)
{
cerr << "PIN_GetThreadData(" << tls_key << "," << threadid << ") should have failed" << endl;
PIN_ExitProcess(1);
}
// Create a key
temp_tls_key = PIN_CreateThreadDataKey(NULL);
if (temp_tls_key == INVALID_TLS_KEY)
{
cerr << "number of already allocated keys reached the MAX_CLIENT_TLS_KEYS limit" << endl;
PIN_ExitProcess(1);
}
// Delete the key
if (PIN_DeleteThreadDataKey(temp_tls_key) == FALSE)
{
cerr << "PIN_DeleteThreadDataKey failed" << endl;
PIN_ExitProcess(1);
}
// Delete it again - expected to fail
if (PIN_DeleteThreadDataKey(temp_tls_key) == TRUE)
{
cerr << "PIN_DeleteThreadDataKey should have failed" << endl;
PIN_ExitProcess(1);
}
// Try to use the deleted key - expected to fail
if (PIN_SetThreadData(temp_tls_key, new thread_data_t, threadid) != FALSE)
{
cerr << "PIN_SetThreadData should have failed" << endl;
PIN_ExitProcess(1);
}
}
VOID ThreadStart(THREADID threadid, CONTEXT *ctxt, INT32 flags, VOID *v)
{
numThreads++;
thread_data_t* tdata = new thread_data_t;
if (PIN_SetThreadData(tls_key, tdata, threadid) == FALSE)
{
cerr << "PIN_SetThreadData failed" << endl;
PIN_ExitProcess(1);
}
PIN_GetLock(&lock, threadid+1);
threads_data.insert(std::make_pair(threadid, tdata));
PIN_ReleaseLock(&lock);
TestIllegalTLSOPerations(threadid);
}
// Pin calls this function every time a new basic block is encountered.
// It inserts a call to docount.
VOID Trace(TRACE trace, VOID *v)
{
// Visit every basic block in the trace
for (BBL bbl = TRACE_BblHead(trace); BBL_Valid(bbl); bbl = BBL_Next(bbl))
{
// Insert a call to docount for every bbl, passing the number of instructions.
BBL_InsertCall(bbl, IPOINT_ANYWHERE, (AFUNPTR)docount, IARG_FAST_ANALYSIS_CALL,
IARG_UINT32, BBL_NumIns(bbl), IARG_THREAD_ID, IARG_END);
}
}
// This function is called when the thread exits
VOID ThreadFini(THREADID threadIndex, const CONTEXT *ctxt, INT32 code, VOID *v)
{
thread_data_t* tdata = get_tls(threadIndex);
*OutFile << "Count[" << decstr(threadIndex) << "] = " << tdata->_count << endl;
}
// This function is called when the application exits
VOID Fini(INT32 code, VOID *v)
{
*OutFile << "Total number of threads = " << numThreads << endl;
}
/* ===================================================================== */
/* Print Help Message */
/* ===================================================================== */
INT32 Usage()
{
cerr << "This tool counts the number of dynamic instructions executed" << endl;
cerr << endl << KNOB_BASE::StringKnobSummary() << endl;
return 1;
}
/* ===================================================================== */
/* Main */
/* ===================================================================== */
int main(int argc, char * argv[])
{
// Initialize pin
PIN_InitSymbols();
if (PIN_Init(argc, argv))
return Usage();
OutFile = KnobOutputFile.Value().empty() ? &cout : new std::ofstream(KnobOutputFile.Value().c_str());
// Initialize the pin lock
PIN_InitLock(&lock);
// Obtain a key for TLS storage.
tls_key = PIN_CreateThreadDataKey(NULL);
if (tls_key == INVALID_TLS_KEY)
{
cerr << "number of already allocated keys reached the MAX_CLIENT_TLS_KEYS limit" << endl;
PIN_ExitProcess(1);
}
// Register ThreadStart to be called when a thread starts.
PIN_AddThreadStartFunction(ThreadStart, NULL);
// Register Fini to be called when thread exits.
PIN_AddThreadFiniFunction(ThreadFini, NULL);
// Register Fini to be called when the application exits.
PIN_AddFiniFunction(Fini, NULL);
// Register Instruction to be called to instrument instructions.
TRACE_AddInstrumentFunction(Trace, NULL);
// Start the program, never returns
PIN_StartProgram();
return 1;
}
Pin provides efficient thread local storage(TLS) APIs. These APIs allow a tool to create thread-specific data.
------main함수------
1. PIN_InitLock();
2. PIN_CreateThreadDataKey();->obtain a key for TLS storage
3. PIN_AddThreadStartFunction(ThreadStart, );
4. PIN_AddThreadFiniFunction(ThreadFini, );
5. PIN_AddFiniFunction(Fini, );
6. TRACE_AddInstrumentFunction(Trace, );
------ThreadStart------
1. PIN_SetThreadData();->store specified value in the specified TLS slot of the thread
2. PIN_GetLock();
3. PIN_ReleaseLock();
thread_data_t * tdata=get_tls(threadid) 로 thread의 data를 가져온다!
이 예제는 TLS를 사용하는 것을 나타내는데,
ThreadStart에서 PIN_SetThreadData()로 TLS에 데이터를 저장한다.
PIN_GetLock->threads_data.insert(threadid,tdata)->PIN_ReleaseLock
Trace에서 각 BBL의 instruction 수를 tdata->_count에 저장한다.
ThreadFini에서 tdata->_count 출력
그 결과 각각의 쓰레드의 instruction 숫자가 출력된다.
이렇게 함으로써, 각각의 thread는 서로 다른 data cache line을 사용한다.