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| author | Adam Ierymenko <adam.ierymenko@gmail.com> | 2017-08-23 18:52:32 -0700 |
|---|---|---|
| committer | Adam Ierymenko <adam.ierymenko@gmail.com> | 2017-08-23 18:52:32 -0700 |
| commit | 49fa30d495c0524a15ba86668f4fee12b9715089 (patch) | |
| tree | 739056815cee56bf39cd440c128578fc8485bfe2 /node | |
| parent | dd8b03a5c55baf7349ce075c8f4cad1d59cbe988 (diff) | |
| download | infinitytier-49fa30d495c0524a15ba86668f4fee12b9715089.tar.gz infinitytier-49fa30d495c0524a15ba86668f4fee12b9715089.zip | |
Ticket lock for x64/gcc/clang platforms.
Diffstat (limited to 'node')
| -rw-r--r-- | node/Mutex.hpp | 84 |
1 files changed, 63 insertions, 21 deletions
diff --git a/node/Mutex.hpp b/node/Mutex.hpp index 854f321a..b16f53f7 100644 --- a/node/Mutex.hpp +++ b/node/Mutex.hpp @@ -32,32 +32,84 @@ #ifdef __UNIX_LIKE__
+#include <stdint.h>
#include <stdlib.h>
#include <pthread.h>
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 : NonCopyable
{
public:
- Mutex()
+ Mutex() :
+ nextTicket(0),
+ nowServing(0)
{
- pthread_mutex_init(&_mh,(const pthread_mutexattr_t *)0);
}
- ~Mutex()
+ inline void lock() const
{
- pthread_mutex_destroy(&_mh);
+ 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 lock()
+ inline void unlock() const
{
- pthread_mutex_lock(&_mh);
+ ++(const_cast<Mutex *>(this)->nowServing);
}
- inline void unlock()
+ /**
+ * Uses C++ contexts and constructor/destructor to lock/unlock automatically
+ */
+ class Lock : NonCopyable
{
- pthread_mutex_unlock(&_mh);
+ 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:
+ uint16_t nextTicket;
+ uint16_t nowServing;
+};
+
+#else
+
+// libpthread based mutex lock
+class Mutex : NonCopyable
+{
+public:
+ Mutex()
+ {
+ pthread_mutex_init(&_mh,(const pthread_mutexattr_t *)0);
+ }
+
+ ~Mutex()
+ {
+ pthread_mutex_destroy(&_mh);
}
inline void lock() const
@@ -70,9 +122,6 @@ public: (const_cast <Mutex *> (this))->unlock();
}
- /**
- * Uses C++ contexts and constructor/destructor to lock/unlock automatically
- */
class Lock : NonCopyable
{
public:
@@ -101,6 +150,8 @@ private: pthread_mutex_t _mh;
};
+#endif
+
} // namespace ZeroTier
#endif // Apple / Linux
@@ -112,6 +163,7 @@ private: namespace ZeroTier {
+// Windows critical section based lock
class Mutex : NonCopyable
{
public:
@@ -125,16 +177,6 @@ public: DeleteCriticalSection(&_cs);
}
- inline void lock()
- {
- EnterCriticalSection(&_cs);
- }
-
- inline void unlock()
- {
- LeaveCriticalSection(&_cs);
- }
-
inline void lock() const
{
(const_cast <Mutex *> (this))->lock();
|