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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <csignal>
#include <cerrno>
#include <pthread.h>
#include <mozilla/Sprintf.h>
#include <mozilla/Atomics.h>
#include "audio_thread_priority.h"
#include "nsDebug.h"
namespace mozilla {
Atomic<bool, MemoryOrdering::ReleaseAcquire> gRealtimeLimitReached;
void UnderrunHandler(int signum) { gRealtimeLimitReached = true; }
bool SoftRealTimeLimitReached() { return gRealtimeLimitReached; }
void InstallSoftRealTimeLimitHandler() {
struct sigaction action, previous;
action.sa_handler = UnderrunHandler;
sigemptyset(&action.sa_mask);
action.sa_flags = 0;
int rv = sigaction(SIGXCPU, &action, &previous);
if (rv != 0) {
char buf[256];
SprintfLiteral(buf, "sigaction(SIGXCPU, ...): %s", strerror(errno));
NS_WARNING(buf);
return;
}
void* previous_handler = previous.sa_flags == SA_SIGINFO
? reinterpret_cast<void*>(previous.sa_sigaction)
: reinterpret_cast<void*>(previous.sa_handler);
MOZ_ASSERT(previous_handler != UnderrunHandler,
"Only install the SIGXCPU handler once per process.");
if (previous_handler != SIG_DFL && previous_handler != UnderrunHandler) {
NS_WARNING(
"SIGXCPU handler was already set by something else, dropping real-time "
"priority.");
rv = sigaction(SIGXCPU, &previous, nullptr);
if (rv != 0) {
NS_WARNING("Could not restore previous handler for SIGXCPU.");
}
gRealtimeLimitReached = true;
return;
}
gRealtimeLimitReached = false;
}
void DemoteThreadFromRealTime() {
atp_thread_info* info = atp_get_current_thread_info();
if (!info) {
NS_WARNING("Could not get current thread info when demoting thread.");
return;
}
int rv = atp_demote_thread_from_real_time(info);
if (rv) {
NS_WARNING("Could not demote thread from real-time.");
return;
}
rv = atp_free_thread_info(info);
if (rv) {
NS_WARNING("Could not free atp_thread_info struct");
}
gRealtimeLimitReached = false;
}
} // namespace mozilla