Add support for thread local support on platforms that do not support it through emulation using a hash map.

This commit is contained in:
Rasmus Munk Larsen
2018-08-13 15:31:23 -07:00
parent 3ec60215df
commit 8278ae6313
5 changed files with 103 additions and 76 deletions

View File

@@ -12,56 +12,6 @@
namespace Eigen {
// Barrier is an object that allows one or more threads to wait until
// Notify has been called a specified number of times.
class Barrier {
public:
Barrier(unsigned int count) : state_(count << 1), notified_(false) {
eigen_assert(((count << 1) >> 1) == count);
}
~Barrier() {
eigen_assert((state_>>1) == 0);
}
void Notify() {
unsigned int v = state_.fetch_sub(2, std::memory_order_acq_rel) - 2;
if (v != 1) {
eigen_assert(((v + 2) & ~1) != 0);
return; // either count has not dropped to 0, or waiter is not waiting
}
std::unique_lock<std::mutex> l(mu_);
eigen_assert(!notified_);
notified_ = true;
cv_.notify_all();
}
void Wait() {
unsigned int v = state_.fetch_or(1, std::memory_order_acq_rel);
if ((v >> 1) == 0) return;
std::unique_lock<std::mutex> l(mu_);
while (!notified_) {
cv_.wait(l);
}
}
private:
std::mutex mu_;
std::condition_variable cv_;
std::atomic<unsigned int> state_; // low bit is waiter flag
bool notified_;
};
// Notification is an object that allows a user to to wait for another
// thread to signal a notification that an event has occurred.
//
// Multiple threads can wait on the same Notification object,
// but only one caller must call Notify() on the object.
struct Notification : Barrier {
Notification() : Barrier(1) {};
};
// Runs an arbitrary function and then calls Notify() on the passed in
// Notification.
template <typename Function, typename... Args> struct FunctionWrapperWithNotification