can I reuse a rocksdb writebatch by calling rocksdb_writebatch_clear?

[979357361]

Hi friends,
I use rocksdb by C API (V8.6.7). Sometimes I need to write a batch of KV, calling rocksdb_writebatch_create() everytime seems expensive, so I use a mempool to buffer about 1024 writebatch struct and alloc one when I need, I use rocksdb_writebatch_clear to wipe away old data before writing to it, but I got stucked when I call rocksdb_writebatch_clear, it seems it never ends at empty() func. thanks for your time~

void WriteBatch::Clear() {
rep_.clear();
rep_.resize(WriteBatchInternal::kHeader);

content_flags_.store(0, std::memory_order_relaxed);

if (save_points_ != nullptr) {
while (!save_points_->stack.empty()) {
save_points_->stack.pop();
}
}

if (prot_info_ != nullptr) {
prot_info_->entries_.clear();
}
wal_term_point_.clear();
default_cf_ts_sz_ = 0;
}

#0 size (this=0x2046f5594c10, this=0x2046f5594c10) at /opt/rh/devtoolset-7/root/usr/include/c++/7/bits/stl_vector.h:671
#1 size (this=) at ./util/autovector.h:188
#2 empty (this=) at ./util/autovector.h:210
#3 empty (this=) at /opt/rh/devtoolset-7/root/usr/include/c++/7/bits/stl_stack.h:186
#4 rocksdb::WriteBatch::Clear (this=0x2046f5594b58) at db/write_batch.cc:252
#5 0x00000000008be2e5 in rocksdb_writebatch_clear (b=) at db/c.cc:1947