fix missing task in task based hlu

Author: PierreMarchand20

CHANGELOG.md

@@ -38,6 +38,7 @@ All notable changes to this project will be documented in this file.
 ### Fixed
 
 - Fix uninitialized values in `Partitioning_N`.
+- Fix bug in task-based HLU, PR#81 thanks to @ABoisneault.
 
 ## [1.0.2] - 2026-02-14
 

include/htool/hmatrix/linalg/task_based_factorization.hpp

@@ -93,7 +93,15 @@ void task_based_lu_factorization(HMatrix<CoefficientPrecision, CoordinatePrecisi
             }
         }
     } else if (hmatrix.is_dense()) {
-        lu_factorization(*hmatrix.get_dense_data());
+#if defined(_OPENMP) && !defined(HTOOL_WITH_PYTHON_INTERFACE)
+#    pragma omp task default(none) \
+        shared(hmatrix)            \
+        depend(inout : hmatrix)
+
+#endif
+        {
+            lu_factorization(*hmatrix.get_dense_data());
+        }
     } else {
         htool::Logger::get_instance().log(LogLevel::ERROR, "Operation is not implemented for task_based_lu_factorization (hmatrix is low-rank)"); // LCOV_EXCL_LINE
     }
@@ -185,7 +193,16 @@ void task_based_cholesky_factorization(char UPLO, HMatrix<CoefficientPrecision,
             }
         }
     } else if (hmatrix.is_dense()) {
-        cholesky_factorization(UPLO, *hmatrix.get_dense_data());
+#if defined(_OPENMP) && !defined(HTOOL_WITH_PYTHON_INTERFACE)
+#    pragma omp task default(none) \
+        firstprivate(UPLO)         \
+        shared(hmatrix)            \
+        depend(inout : hmatrix)
+
+#endif
+        {
+            cholesky_factorization(UPLO, *hmatrix.get_dense_data());
+        }
     } else {
         htool::Logger::get_instance().log(LogLevel::ERROR, "Operation is not implemented for task_based_cholesky_factorization (hmatrix is low-rank)"); // LCOV_EXCL_LINE
     }

tests/functional_tests/hmatrix/hmatrix_factorization/test_task_based_hmatrix_factorization_double.cpp

@@ -11,21 +11,21 @@ int main(int, char *[]) {
 
     bool is_error = false;
 
-    const int n1 = 1100;
     const int n2 = 1000;
+    for (auto n1 : {10, 1100}) { // 10 to deal with trival case
+        for (auto epsilon : {1e-4, 1e-8}) {
+            for (auto trans : {'N', 'T'}) {
 
-    for (auto epsilon : {1e-4, 1e-8}) {
-        for (auto trans : {'N', 'T'}) {
+                std::cout << "task based LU factorization test case: " << "epsilon = " << epsilon << ", n1 = " << n1 << ", n2 = " << n2 << ", trans = " << trans << "\n";
 
-            std::cout << "task based LU factorization test case: " << "epsilon = " << epsilon << ", n1 = " << n1 << ", n2 = " << n2 << ", trans = " << trans << "\n";
+                is_error = is_error || test_task_based_lu_factorization<double, GeneratorTestDoubleSymmetric>(trans, n1, n2, epsilon);
+            }
 
-            is_error = is_error || test_task_based_lu_factorization<double, GeneratorTestDoubleSymmetric>(trans, n1, n2, epsilon);
-        }
-
-        for (auto UPLO : {'L', 'U'}) {
-            std::cout << "task based Cholesky factorization test case: " << "epsilon = " << epsilon << ", n1 = " << n1 << ", n2 = " << n2 << ", UPLO = " << UPLO << "\n";
+            for (auto UPLO : {'L', 'U'}) {
+                std::cout << "task based Cholesky factorization test case: " << "epsilon = " << epsilon << ", n1 = " << n1 << ", n2 = " << n2 << ", UPLO = " << UPLO << "\n";
 
-            is_error = is_error || test_task_based_cholesky_factorization<double, GeneratorTestDoubleSymmetric>(UPLO, n1, n2, epsilon);
+                is_error = is_error || test_task_based_cholesky_factorization<double, GeneratorTestDoubleSymmetric>(UPLO, n1, n2, epsilon);
+            }
         }
     }