| Index: runtime/vm/os_thread.h
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| diff --git a/runtime/vm/os_thread.h b/runtime/vm/os_thread.h
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| index d03781af5fc075c896ee274db38f8c18022b2366..5d6a21e3448e747d179054051e444479ebdae4ee 100644
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| --- a/runtime/vm/os_thread.h
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| +++ b/runtime/vm/os_thread.h
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| @@ -29,6 +29,7 @@ class OSThread {
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|   public:
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|    static ThreadLocalKey kUnsetThreadLocalKey;
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|    static ThreadId kInvalidThreadId;
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| +  static ThreadJoinId kInvalidThreadJoinId;
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|  
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|    typedef void (*ThreadStartFunction) (uword parameter);
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|    typedef void (*ThreadDestructor) (void* parameter);
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| @@ -50,7 +51,8 @@ class OSThread {
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|    static intptr_t CurrentCurrentThreadIdAsIntPtr() {
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|      return ThreadIdToIntPtr(GetCurrentThreadId());
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|    }
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| -  static bool Join(ThreadId id);
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| +  static ThreadJoinId GetCurrentThreadJoinId();
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| +  static void Join(ThreadJoinId id);
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|    static intptr_t ThreadIdToIntPtr(ThreadId id);
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|    static ThreadId ThreadIdFromIntPtr(intptr_t id);
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|    static bool Compare(ThreadId a, ThreadId b);
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| 
 |