CI: run the tests using TSan

Author: vouillon

.github/workflows/main.yml

@@ -14,9 +14,14 @@ jobs:
         ocaml-compiler:
           - "4.14"
           - "5.2"
+        include:
+          - os: ubuntu-24.04-arm
+            ocaml-compiler: "ocaml-variants.5.2.1+options,ocaml-option-tsan"
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
+      - run: sudo apt update
+        if: ${{ matrix.os == 'ubuntu-24.04-arm' }}
       - uses: ocaml/setup-ocaml@v3
         with:
           ocaml-compiler: ${{ matrix.ocaml-compiler }}

lib_test/concurrency/dune

@@ -4,6 +4,10 @@
   (>= %{ocaml_version} 5.0))
  (action
   (pipe-outputs
-   (run %{test})
+   (setenv
+    TSAN_OPTIONS
+    suppressions=suppress.txt
+    (run %{test}))
    (run cat)))
+ (deps suppress.txt)
  (libraries re))

lib_test/concurrency/suppress.txt

@@ -0,0 +1,18 @@
+
+# Data race between Compile.State.follow_transition (inlined in Compile.next)
+# and Compile.State.set_transition
+race_top:^camlRe__Compile.next
+
+# Data race within Compile.find_initial_state (read/write re.initial_states)
+race_top:^camlRe__Compile.find_initial_state
+
+# Spurious data race due to the two-step initialization in Compile.State.make
+# (between Compile.State.get_info and Compile.State.set_info, both inlined)
+race_top:^camlRe__Compile.loop
+
+# Race within Automata.Desc.status and Automata.Desc.status_no_mutex
+# (read/write s.status)
+race_top:^camlRe__Automata.status
+
+# Race within Compile.final (not captured by this test)
+#race_top:^camlRe__Compile.final