namespace base {
namespace {
+
int ThreadNiceValue(ThreadPriority priority) {
switch (priority) {
case kThreadPriority_RealtimeAudio:
return 0;
}
}
-} // namespace
+
+} // namespace
// static
void PlatformThread::SetName(const char* name) {
ThreadPriority priority) {
#if !defined(OS_NACL)
if (priority == kThreadPriority_RealtimeAudio) {
- const struct sched_param kRealTimePrio = { 8 };
+ const struct sched_param kRealTimePrio = {8};
if (pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio) == 0) {
// Got real time priority, no need to set nice level.
return;
}
}
- // setpriority(2) will set a thread's priority if it is passed a tid as
- // the 'process identifier', not affecting the rest of the threads in the
- // process. Setting this priority will only succeed if the user has been
- // granted permission to adjust nice values on the system.
+ // setpriority(2) should change the whole thread group's (i.e. process)
+ // priority. however, on linux it will only change the target thread's
+ // priority. see the bugs section in
+ // http://man7.org/linux/man-pages/man2/getpriority.2.html.
+ // we prefer using 0 rather than the current thread id since they are
+ // equivalent but it makes sandboxing easier (https://crbug.com/399473).
DCHECK_NE(handle.id_, kInvalidThreadId);
const int kNiceSetting = ThreadNiceValue(priority);
- if (setpriority(PRIO_PROCESS, handle.id_, kNiceSetting)) {
- DVPLOG(1) << "Failed to set nice value of thread ("
- << handle.id_ << ") to " << kNiceSetting;
+ const PlatformThreadId current_id = PlatformThread::CurrentId();
+ if (setpriority(PRIO_PROCESS,
+ handle.id_ == current_id ? 0 : handle.id_,
+ kNiceSetting)) {
+ DVPLOG(1) << "Failed to set nice value of thread (" << handle.id_ << ") to "
+ << kNiceSetting;
}
#endif // !defined(OS_NACL)
}