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fix a race-condition in JobSystem

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mThreadMap needs to be protected as it's accessed from multiple threads.
This commit is contained in:
Pixelflinger
2020-04-03 16:51:05 -07:00
committed by Mathias Agopian
parent 2ad932f345
commit fb0e89d969
2 changed files with 10 additions and 0 deletions
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9
libs/utils/src/JobSystem.cpp
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@@ -223,6 +223,7 @@ void JobSystem::wake() noexcept {
}
inline JobSystem::ThreadState& JobSystem::getState() noexcept {
std::lock_guard<utils::SpinLock> lock(mThreadMapLock);
auto iter = mThreadMap.find(std::this_thread::get_id());
ASSERT_PRECONDITION(iter != mThreadMap.end(), "This thread has not been adopted.");
return *iter->second;
@@ -301,7 +302,9 @@ void JobSystem::loop(ThreadState* state) noexcept {
setThreadAffinityById(state->id);
// record our work queue
mThreadMapLock.lock();
bool inserted = mThreadMap.emplace(std::this_thread::get_id(), state).second;
mThreadMapLock.unlock();
ASSERT_PRECONDITION(inserted, "This thread is already in a loop.");
// run our main loop...
@@ -469,8 +472,12 @@ void JobSystem::runAndWait(JobSystem::Job*& job) noexcept {
void JobSystem::adopt() {
const auto tid = std::this_thread::get_id();
std::unique_lock<utils::SpinLock> lock(mThreadMapLock);
auto iter = mThreadMap.find(tid);
ThreadState* const state = iter == mThreadMap.end() ? nullptr : iter->second;
lock.unlock();
if (state) {
// we're already part of a JobSystem, do nothing.
ASSERT_PRECONDITION(this == state->js,
@@ -493,11 +500,13 @@ void JobSystem::adopt() {
// however, it's not a problem since mThreadState is pre-initialized and valid
// (e.g.: the queue is empty).
lock.lock();
mThreadMap[tid] = &mThreadStates[index];
}
void JobSystem::emancipate() {
const auto tid = std::this_thread::get_id();
std::lock_guard<utils::SpinLock> lock(mThreadMapLock);
auto iter = mThreadMap.find(tid);
ThreadState* const state = iter == mThreadMap.end() ? nullptr : iter->second;
ASSERT_PRECONDITION(state, "this thread is not an adopted thread");