portable thread local storage class (#2229)

src/platform.h.in

@@ -60,30 +60,7 @@ private:
     // NOTE SRWLock is available from windows vista
     SRWLOCK srwlock;
 };
-#else // _WIN32
-class Mutex
-{
-public:
-    Mutex() { pthread_mutex_init(&mutex, 0); }
-    ~Mutex() { pthread_mutex_destroy(&mutex); }
-    void lock() { pthread_mutex_lock(&mutex); }
-    void unlock() { pthread_mutex_unlock(&mutex); }
-private:
-    friend class ConditionVariable;
-    pthread_mutex_t mutex;
-};
-#endif // _WIN32
-
-class MutexLockGuard
-{
-public:
-    MutexLockGuard(Mutex& _mutex) : mutex(_mutex) { mutex.lock(); }
-    ~MutexLockGuard() { mutex.unlock(); }
-private:
-    Mutex& mutex;
-};
 
-#if (defined _WIN32 && !(defined __MINGW32__))
 class ConditionVariable
 {
 public:
@@ -95,21 +72,7 @@ public:
 private:
     CONDITION_VARIABLE condvar;
 };
-#else // _WIN32
-class ConditionVariable
-{
-public:
-    ConditionVariable() { pthread_cond_init(&cond, 0); }
-    ~ConditionVariable() { pthread_cond_destroy(&cond); }
-    void wait(Mutex& mutex) { pthread_cond_wait(&cond, &mutex.mutex); }
-    void broadcast() { pthread_cond_broadcast(&cond); }
-    void signal() { pthread_cond_signal(&cond); }
-private:
-    pthread_cond_t cond;
-};
-#endif // _WIN32
 
-#if (defined _WIN32 && !(defined __MINGW32__))
 static unsigned __stdcall start_wrapper(void* args);
 class Thread
 {
@@ -129,7 +92,41 @@ private:
     void* _args;
 };
 
-#else // _WIN32
+class ThreadLocalStorage
+{
+public:
+    ThreadLocalStorage() { key = TlsAlloc(); }
+    ~ThreadLocalStorage() { TlsFree(key); }
+    void set(void* value) { TlsSetValue(key, (LPVOID)value); }
+    void* get() { return (void*)TlsGetValue(key); }
+private:
+    DWORD key;
+};
+#else // (defined _WIN32 && !(defined __MINGW32__))
+class Mutex
+{
+public:
+    Mutex() { pthread_mutex_init(&mutex, 0); }
+    ~Mutex() { pthread_mutex_destroy(&mutex); }
+    void lock() { pthread_mutex_lock(&mutex); }
+    void unlock() { pthread_mutex_unlock(&mutex); }
+private:
+    friend class ConditionVariable;
+    pthread_mutex_t mutex;
+};
+
+class ConditionVariable
+{
+public:
+    ConditionVariable() { pthread_cond_init(&cond, 0); }
+    ~ConditionVariable() { pthread_cond_destroy(&cond); }
+    void wait(Mutex& mutex) { pthread_cond_wait(&cond, &mutex.mutex); }
+    void broadcast() { pthread_cond_broadcast(&cond); }
+    void signal() { pthread_cond_signal(&cond); }
+private:
+    pthread_cond_t cond;
+};
+
 class Thread
 {
 public:
@@ -139,7 +136,18 @@ public:
 private:
     pthread_t t;
 };
-#endif // _WIN32
+
+class ThreadLocalStorage
+{
+public:
+    ThreadLocalStorage() { pthread_key_create(&key, 0); }
+    ~ThreadLocalStorage() { pthread_key_delete(key); }
+    void set(void* value) { pthread_setspecific(key, value); }
+    void* get() { return pthread_getspecific(key); }
+private:
+    pthread_key_t key;
+};
+#endif // (defined _WIN32 && !(defined __MINGW32__))
 #else // NCNN_THREADS
 class Mutex
 {
@@ -167,8 +175,26 @@ public:
     ~Thread() {}
     void join() {}
 };
+
+class ThreadLocalStorage
+{
+public:
+    ThreadLocalStorage() {}
+    ~ThreadLocalStorage() {}
+    void set(void* /*value*/) {}
+    void* get() { return 0; }
+};
 #endif // NCNN_THREADS
 
+class MutexLockGuard
+{
+public:
+    MutexLockGuard(Mutex& _mutex) : mutex(_mutex) { mutex.lock(); }
+    ~MutexLockGuard() { mutex.unlock(); }
+private:
+    Mutex& mutex;
+};
+
 } // namespace ncnn
 
 #if NCNN_SIMPLESTL