strict cstyle pthread

src/utils/thread.h

@@ -123,16 +123,33 @@ class Semaphore {
   #endif  
 };
 
+// helper for c thread
+// used to strictly call c++ function from pthread
+struct ThreadContext {
+  void *(*entry)(void*);
+  void *param;
+};
+extern "C" {
+  inline void *RunThreadContext(void *ctx_) {
+    ThreadContext *ctx = reinterpret_cast<ThreadContext*>(ctx_);
+    void *ret = (*ctx->entry)(ctx->param);
+    delete ctx;
+    return ret;
+  }
+}
 /*!\brief simple thread class */
 class Thread {
  private:
   pthread_t thread;                
+
  public :
-  inline void Start(void * entry(void*), void *param) {
+  inline void Start(void *entry(void*), void *param) {
     pthread_attr_t attr;
     pthread_attr_init(&attr);
     pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
-    pthread_create(&thread, &attr, entry, param);
+    ThreadContext *ctx = new ThreadContext();
+    ctx->entry = entry; ctx->param = param;
+    pthread_create(&thread, &attr, RunThreadContext, ctx);
   }
   inline int Join(void) {
     void *status;
@@ -142,6 +159,7 @@ class Thread {
 inline void ThreadExit(void *status) {
   pthread_exit(status);
 }
+
 }  // namespace utils
 }  // namespace xgboost
 #define XGBOOST_THREAD_PREFIX void *

src/utils/thread_buffer.h

@@ -167,7 +167,6 @@ class ThreadBuffer {
   /*!\brief entry point of loader thread */
   inline static XGBOOST_THREAD_PREFIX LoaderEntry(void *pthread) {
     static_cast< ThreadBuffer<Elem,ElemFactory>* >(pthread)->RunLoader();
-    ThreadExit(NULL);
     return NULL;
   }
   /*!\brief start loader thread */
@@ -199,6 +198,7 @@ class ThreadBuffer {
     loading_need.Post();
   }
 };
+
 }  // namespace utils
 }  // namespace xgboost
 #endif