From 7a6363189efb1872e577f8ba3eafa47d1bc32253 Mon Sep 17 00:00:00 2001
From: Steven Hahn <hahnse@ornl.gov>
Date: Thu, 27 Apr 2017 16:38:13 -0400
Subject: [PATCH] Use compare_exchange_weak instead of a critical section.
---
Framework/MDAlgorithms/src/MDNormSCD.cpp | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/Framework/MDAlgorithms/src/MDNormSCD.cpp b/Framework/MDAlgorithms/src/MDNormSCD.cpp
index 866d15d23ab..ed8155a2690 100644
--- a/Framework/MDAlgorithms/src/MDNormSCD.cpp
+++ b/Framework/MDAlgorithms/src/MDNormSCD.cpp
@@ -363,6 +363,16 @@ void MDNormSCD::cacheDimensionXValues() {
}
}
+namespace {
+template <typename T, typename BinaryOp>
+void AtomicOp(std::atomic<T> &f, T d, BinaryOp _Op) {
+ T old = f.load();
+ T desired = _Op(old, d);
+ while (!f.compare_exchange_weak(old, desired))
+ desired = _Op(old, d);
+}
+} // namespace
+
/**
* Computed the normalization for the input workspace. Results are stored in
* m_normWS
@@ -402,6 +412,8 @@ void MDNormSCD::calculateNormalization(
const detid2index_map solidAngDetToIdx =
solidAngleWS->getDetectorIDToWorkspaceIndexMap();
+ std::vector<std::atomic<signal_t>> signalArray(m_normWS->getNPoints());
+
auto prog = make_unique<API::Progress>(this, 0.3, 1.0, ndets);
PARALLEL_FOR_IF(Kernel::threadSafe(*integrFlux))
for (int64_t i = 0; i < ndets; i++) {
@@ -474,18 +486,16 @@ void MDNormSCD::calculateNormalization(
// index of the current intersection
size_t k = static_cast<size_t>(std::distance(intersectionsBegin, it));
// signal = integral between two consecutive intersections
- double signal = (yValues[k] - yValues[k - 1]) * solid;
-
- PARALLEL_CRITICAL(updateMD) {
- signal += m_normWS->getSignalAt(linIndex);
- m_normWS->setSignalAt(linIndex, signal);
- }
+ signal_t signal = (yValues[k] - yValues[k - 1]) * solid;
+ AtomicOp(signalArray[linIndex], signal, std::plus<signal_t>());
}
prog->report();
PARALLEL_END_INTERUPT_REGION
}
PARALLEL_CHECK_INTERUPT_REGION
+ std::copy(signalArray.cbegin(), signalArray.cend(),
+ m_normWS->getSignalArray());
}
/**
--
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