ClangPchManager: Protect fetchPchSources

It was not protected by a transaction so it was not thread save.

Change-Id: Ib4529d0e94942d3cbafb46705a0256812908c8c6
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

2 files changed, 38 insertions, 1 deletions

diff --git a/src/tools/clangpchmanagerbackend/source/builddependenciesstorage.h b/src/tools/clangpchmanagerbackend/source/builddependenciesstorage.h
index 00bb429dba..f75d83b572 100644
--- a/src/tools/clangpchmanagerbackend/source/builddependenciesstorage.h
+++ b/src/tools/clangpchmanagerbackend/source/builddependenciesstorage.h
@@ -68,7 +68,18 @@ public:
 
     FilePathIds fetchPchSources(ProjectPartId projectPartId) const override
     {
-        return fetchPchSourcesStatement.template values<FilePathId>(1024, projectPartId.projectPathId);
+        try {
+            Sqlite::DeferredTransaction transaction{database};
+
+            FilePathIds values = fetchPchSourcesStatement
+                                     .template values<FilePathId>(1024, projectPartId.projectPathId);
+
+            transaction.commit();
+
+            return values;
+        } catch (const Sqlite::StatementIsBusy &) {
+            return fetchPchSources(projectPartId);
+        }
     }
 
     FilePathIds fetchSources(ProjectPartId projectPartId) const override
diff --git a/tests/unit/unittest/builddependenciesstorage-test.cpp b/tests/unit/unittest/builddependenciesstorage-test.cpp
index 56f8b42ac5..b542fd3082 100644
--- a/tests/unit/unittest/builddependenciesstorage-test.cpp
+++ b/tests/unit/unittest/builddependenciesstorage-test.cpp
@@ -251,6 +251,32 @@ TEST_F(BuildDependenciesStorage, FetchPchSources)
     ASSERT_THAT(sources, result);
 }
 
+TEST_F(BuildDependenciesStorage, FetchPchSourcesCalls)
+{
+    InSequence s;
+
+    EXPECT_CALL(mockDatabase, deferredBegin());
+    EXPECT_CALL(fetchPchSourcesStatement, valuesReturnFilePathIds(_, 22));
+    EXPECT_CALL(mockDatabase, commit());
+
+    auto sources = storage.fetchPchSources(22);
+}
+
+TEST_F(BuildDependenciesStorage, FetchPchSourcesCallsIsBusy)
+{
+    InSequence s;
+
+    EXPECT_CALL(mockDatabase, deferredBegin());
+    EXPECT_CALL(fetchPchSourcesStatement, valuesReturnFilePathIds(_, 22))
+        .WillOnce(Throw(Sqlite::StatementIsBusy{""}));
+    EXPECT_CALL(mockDatabase, rollback());
+    EXPECT_CALL(mockDatabase, deferredBegin());
+    EXPECT_CALL(fetchPchSourcesStatement, valuesReturnFilePathIds(_, 22));
+    EXPECT_CALL(mockDatabase, commit());
+
+    auto sources = storage.fetchPchSources(22);
+}
+
 TEST_F(BuildDependenciesStorage, FetchSources)
 {
     ClangBackEnd::FilePathIds result{3, 5, 7};