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Spinlock removed, causes long standing issues on single core machines.

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Adam Ierymenko 2021-11-12 16:44:54 -05:00
parent 272fb2ca96
commit 1ef385b685
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GPG Key ID: C8877CF2D7A5D7F3
1 changed files with 1 additions and 66 deletions
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67
node/Mutex.hpp
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@ -24,69 +24,6 @@
namespace ZeroTier {
#if defined(__GNUC__) && (defined(__amd64) || defined(__amd64__) || defined(__x86_64) || defined(__x86_64__) || defined(__AMD64) || defined(__AMD64__) || defined(_M_X64))
// Inline ticket lock on x64 systems with GCC and CLANG (Mac, Linux) -- this is really fast as long as locking durations are very short
class Mutex
{
public:
Mutex() :
nextTicket(0),
nowServing(0)
{
}
inline void lock() const
{
const uint16_t myTicket = __sync_fetch_and_add(&(const_cast<Mutex *>(this)->nextTicket),1);
while (nowServing != myTicket) {
__asm__ __volatile__("rep;nop"::);
__asm__ __volatile__("":::"memory");
}
}
inline void unlock() const
{
++(const_cast<Mutex *>(this)->nowServing);
}
/**
* Uses C++ contexts and constructor/destructor to lock/unlock automatically
*/
class Lock
{
public:
Lock(Mutex &m) :
_m(&m)
{
m.lock();
}
Lock(const Mutex &m) :
_m(const_cast<Mutex *>(&m))
{
_m->lock();
}
~Lock()
{
_m->unlock();
}
private:
Mutex *const _m;
};
private:
Mutex(const Mutex &) {}
const Mutex &operator=(const Mutex &) { return *this; }
uint16_t nextTicket;
uint16_t nowServing;
};
#else
// libpthread based mutex lock
class Mutex
{
@ -142,11 +79,9 @@ private:
pthread_mutex_t _mh;
};
#endif
} // namespace ZeroTier
#endif // Apple / Linux
#endif
#ifdef __WINDOWS__