int main(int argc, char** argv)
{
std::thread t1([&]{
std::cout << "Sample" << std::endl;
printSample();
});
t1.join();
return 0;
}
int CAPerfCfg::readMmapBuffers()
{
CAPerfMmap *mmapBuffer;
struct perf_event_mmap_page *mmapMetaData; // first page in mmapBuffer
unsigned int dataHead;
unsigned int dataTail;
unsigned char *dataBuf;
void *data;
// Iterate over all the mmaps and read them..
for (int i = 0; i < m_nbrMmaps; i++) {
mmapBuffer = &m_mmap[i];
if (mmapBuffer->m_base != NULL) {
mmapMetaData = (struct perf_event_mmap_page*)mmapBuffer->m_base;
dataHead = mmapMetaData->data_head;
dataTail = mmapMetaData->data_tail;
rmb();
dataBuf = (unsigned char*)mmapMetaData + m_pageSize;
CA_DBG_PRINTF(3, "dataHead(%u), prevHead(%u)\n",
dataHead, mmapBuffer->m_prev);
if (dataHead == dataTail) {
CA_DBG_PRINTF(3, "No Samples collected so far..dataHead(%d),"
" dataTail(%d)\n", dataHead, dataTail);
}
unsigned int prevHead = mmapBuffer->m_prev;
if ( (dataHead - prevHead) <= 0) {
CA_DBG_PRINTF(3, "Invalid data.. Current Head(%u), Prev Head(%u).\n",
dataHead, prevHead);
// dataHead = prevHead;
continue;
}
unsigned long dataSize = dataHead - prevHead;
unsigned long tmp = 0;
if ( ((prevHead & mmapBuffer->m_mask) + dataSize)
!= (dataHead & mmapBuffer->m_mask))
{
data = &dataBuf[prevHead & mmapBuffer->m_mask];
dataSize = mmapBuffer->m_mask + 1 - (prevHead & mmapBuffer->m_mask);
prevHead += dataSize;
errno = 0;
memcpy(m_pData, data, dataSize);
CA_DBG_PRINTF(3, "memcpy.. errno(%d).\n", errno);
CA_DBG_PRINTF(3, "1 - dataSize(%u), prevHead(%u)\n",
dataSize, prevHead);
tmp = dataSize;
// printSample(data);
}
data = &dataBuf[prevHead & mmapBuffer->m_mask];
dataSize = dataHead - prevHead;
prevHead += dataSize;
CA_DBG_PRINTF(3, "2 - dataSize(%u), prevHead(%u)\n",
dataSize, prevHead);
errno = 0;
memcpy((void*)((uintptr_t)m_pData+tmp), data, dataSize);
CA_DBG_PRINTF(3, "memcpy.. errno(%d).\n", errno);
m_dataWriter.writePMUSampleData(m_pData, tmp+dataSize);
// printSample(data);
printSample(m_pData);
mmapBuffer->m_prev = prevHead;
// TODO:
// when the mapping is PROT_WRITE, the data_tail value should be
// writen by userspace to reflect the last read data. In this case
// the kernel will not overwrite unread data.
#if 0
if (! overwrite) {
mmapMetaData->data_tail = prevHead;
}
#endif // 0
}
}
return S_OK;
}
