Expose CancellAllBackgroundWork to C api (#6832)

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6832

Reviewed By: cheng-chang

Differential Revision: D21498186

Pulled By: riversand963

fbshipit-source-id: 66bb0d7c06af2bf0df3c6a09b61bca2fb81f2dd3

db/c.cc

@@ -4456,6 +4456,10 @@ void rocksdb_approximate_memory_usage_destroy(rocksdb_memory_usage_t* usage) {
   delete usage;
 }
 
+void rocksdb_cancel_all_background_work(rocksdb_t* db, unsigned char wait) {
+  CancelAllBackgroundWork(db->rep, wait);
+}
+
 }  // end extern "C"
 
 #endif  // !ROCKSDB_LITE

db/c_test.c

@@ -1840,6 +1840,9 @@ int main(int argc, char** argv) {
     CheckNoError(err);
   }
 
+  StartPhase("cancel_all_background_work");
+  rocksdb_cancel_all_background_work(db, 1);
+
   StartPhase("cleanup");
   rocksdb_close(db);
   rocksdb_options_destroy(options);

include/rocksdb/c.h

@@ -1803,6 +1803,9 @@ extern ROCKSDB_LIBRARY_API void
 rocksdb_options_set_memtable_whole_key_filtering(rocksdb_options_t*,
                                                  unsigned char);
 
+extern ROCKSDB_LIBRARY_API void rocksdb_cancel_all_background_work(
+    rocksdb_t* db, unsigned char wait);
+
 #ifdef __cplusplus
 }  /* end extern "C" */
 #endif