xref: /aosp_15_r20/external/perfetto/src/trace_redaction/merge_threads.cc (revision 6dbdd20afdafa5e3ca9b8809fa73465d530080dc)
1 /*
2  * Copyright (C) 2024 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "src/trace_redaction/merge_threads.h"
18 
19 namespace perfetto::trace_redaction {
20 
Modify(const Context & context,uint64_t ts,int32_t cpu,int32_t * pid,std::string * comm) const21 void MergeThreadsPids::Modify(const Context& context,
22                               uint64_t ts,
23                               int32_t cpu,
24                               int32_t* pid,
25                               std::string* comm) const {
26   // When Modify() is used with RedactFtraceEvents, comm will be null.
27   PERFETTO_DCHECK(pid);
28 
29   // Avoid re-mapping system threads (pid 0). These pids have special uses (e.g.
30   // cpu_idle) and if re-mapped, important structures break (e.g. remapping
31   // cpu_idle's pid breaks scheduling).
32 
33   if (*pid == 0) {
34     return;
35   }
36 
37   if (context.timeline->PidConnectsToUid(ts, *pid, *context.package_uid)) {
38     return;
39   }
40 
41   *pid = context.synthetic_process->RunningOn(cpu);
42 
43   if (comm) {
44     comm->clear();
45   }
46 }
47 
48 }  // namespace perfetto::trace_redaction
49