mirror of
https://github.com/scylladb/scylladb.git
synced 2026-06-02 21:17:01 +00:00
54 lines
1.7 KiB
C++
54 lines
1.7 KiB
C++
/*
|
|
* Copyright (C) 2021-present ScyllaDB
|
|
*/
|
|
|
|
/*
|
|
* This file is part of Scylla.
|
|
*
|
|
* Scylla is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Affero General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* Scylla is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "wasm_engine.hh"
|
|
|
|
namespace wasm {
|
|
|
|
#ifdef SCYLLA_ENABLE_WASMTIME
|
|
|
|
seastar::future<> init_sharded_engine(seastar::sharded<engine>& e) {
|
|
// Fuel defines more or less how many bytecode instructions
|
|
// can be performed at once. Empirically, 20k units
|
|
// allow for considerably less than 0.5ms of preemption-free execution time.
|
|
// TODO: investigate other configuration variables.
|
|
// We're particularly interested in limiting resource usage
|
|
// and yielding in the middle of execution - which is possible
|
|
// in the original wasmtime implementation for Rust and tightly
|
|
// bound with its native async support, but not yet possible
|
|
// in wasmtime.hh binding at the time of this writing.
|
|
// It's highly probable that a more generic support for yielding
|
|
// can be contributed to wasmtime.
|
|
const uint64_t initial_fuel_amount = 20*1024;
|
|
return e.start(initial_fuel_amount);
|
|
}
|
|
|
|
#else
|
|
|
|
seastar::future<> init_sharded_engine(seastar::sharded<engine>& e) {
|
|
return e.start();
|
|
}
|
|
|
|
|
|
#endif
|
|
|
|
} // namespace wasm
|