1 // Copyright (C) 2023 The Android Open Source Project
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //     http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 //! Utilities to benchmark ATrace in Rust.
16 
17 use criterion::Criterion;
18 
19 // We could use bindgen to generate these bindings automatically but the signatures are simple and
20 // we don't expect them to change much (if at all). So we specify them manually and skip having an
21 // intermediate target.
22 extern "C" {
disable_app_atrace()23     fn disable_app_atrace();
enable_atrace_for_single_app(name: *const std::os::raw::c_char)24     fn enable_atrace_for_single_app(name: *const std::os::raw::c_char);
25 }
26 
27 /// Disables ATrace for all apps (ATRACE_TAG_APP).
turn_tracing_off()28 pub fn turn_tracing_off() {
29     // SAFETY: This call is always safe.
30     unsafe {
31         disable_app_atrace();
32     }
33 }
34 
35 /// Enables ATrace for this app.
turn_tracing_on()36 pub fn turn_tracing_on() {
37     // ATrace uses command line for per-process tracing control, so env::current_exe won't work.
38     let procname = std::ffi::CString::new(std::env::args().next().unwrap()).unwrap();
39     // SAFETY: `procname` is a valid C string and the function doesn't store it after it returns.
40     unsafe {
41         enable_atrace_for_single_app(procname.as_ptr());
42     }
43 }
44 
45 /// Creates a new configured instance of Criterion for benchmarking.
new_criterion() -> Criterion46 pub fn new_criterion() -> Criterion {
47     let path = "/data/local/tmp/criterion/benchmarks";
48     std::fs::create_dir_all(path).unwrap_or_else(|e| {
49         panic!("The criterion folder should be possible to create at {}: {}", path, e)
50     });
51     std::env::set_var("CRITERION_HOME", path);
52     Criterion::default()
53 }
54