Function PruneOldSwapChainData

PresentMon/OutputThread.cpp:247–286

}

static void PruneOldSwapChainData(
    PMTraceSession const& pmSession,
    uint64_t latestTimestamp)
{
    // sometimes we arrive here after skipping all frame events in the processing loop,
    // in which case we don't have a valid timestamp for the latest frame and should not
    // attempt to do any pruning during this pass
    if (latestTimestamp == 0) {
        return;
    }

    auto minTimestamp = latestTimestamp - pmSession.MilliSecondsDeltaToTimestamp(4000.0);

    for (auto& pair : gProcesses) {
        auto processInfo = &pair.second;

        // Check if this is DWM process
        const auto processNameLower = util::str::ToLower(processInfo->mModuleName);
        const bool isDwmProcess = (processNameLower.find(L"dwm.exe") != std::wstring::npos);

        for (auto ii = processInfo->mSwapChain.begin(), ie = processInfo->mSwapChain.end(); ii != ie; ) {
            auto swapChainAddress = ii->first;
            auto chain = &ii->second;

            // Don't prune DWM swap chains with address 0x0
            bool shouldSkipPruning = isDwmProcess && swapChainAddress == 0x0;
            bool shouldPrune = false;
            if (!shouldSkipPruning) {
                shouldPrune = chain->mUnifiedSwapChain.IsPrunableBefore(minTimestamp);
            }

            if (shouldPrune) {
                ii = processInfo->mSwapChain.erase(ii);
            }
            else {
                ++ii;
            }
        }
    }
}

static void QueryProcessName(uint32_t processId, ProcessInfo* info)
{