[Openmp-commits] [PATCH] D60729: Fixed memory leak reported in https://bugs.llvm.org/show_bug.cgi?id=41494

[Andrey Churbanov via Phabricator via Openmp-commits]

AndreyChurbanov created this revision.
AndreyChurbanov added reviewers: tlwilmar, jlpeyton, hbae.
AndreyChurbanov added a project: OpenMP.
Herald added subscribers: openmp-commits, jdoerfert.

Might be a bit too verbose (not sure if we need to check that the number of threads reduced to 0), but it fixes the memory leak(s) for me.  Multiple leaks were possible in case of multiple foreign threads registered into the library.


Repository:
  rOMP OpenMP

https://reviews.llvm.org/D60729

Files:
  runtime/src/kmp_runtime.cpp


Index: runtime/src/kmp_runtime.cpp
===================================================================
--- runtime/src/kmp_runtime.cpp
+++ runtime/src/kmp_runtime.cpp
@@ -3982,12 +3982,18 @@
 
   TCW_4(__kmp_nth,
         __kmp_nth - 1); // __kmp_reap_thread will decrement __kmp_all_nth.
-  root->r.r_uber_thread->th.th_cg_roots->cg_nthreads--;
+  i = root->r.r_uber_thread->th.th_cg_roots->cg_nthreads--;
   KA_TRACE(100, ("__kmp_reset_root: Thread %p decrement cg_nthreads on node %p"
                  " to %d\n",
                  root->r.r_uber_thread, root->r.r_uber_thread->th.th_cg_roots,
                  root->r.r_uber_thread->th.th_cg_roots->cg_nthreads));
-
+  if (i == 1) {
+    // need to free contention group structure
+    KMP_DEBUG_ASSERT(root->r.r_uber_thread == root->r.r_uber_thread->th.th_cg_roots->cg_root);
+    KMP_DEBUG_ASSERT(root->r.r_uber_thread->th.th_cg_roots->up == NULL);
+    __kmp_free(root->r.r_uber_thread->th.th_cg_roots);
+    root->r.r_uber_thread->th.th_cg_roots = NULL;
+  }
   __kmp_reap_thread(root->r.r_uber_thread, 1);
 
   // We canot put root thread to __kmp_thread_pool, so we have to reap it istead


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