Add Thread::join

This new API will be used by applications that previously used the
lower-level pthread APIs (including pthread_join).  Centralizing on the
Thread class instead of pthread will permit additional functionality to
be added later in only one location.

Change-Id: I8460169ac9c61ac9f85752405ed54c94651058d7

1 files changed, 19 insertions, 0 deletions

diff --git a/libs/utils/Threads.cpp b/libs/utils/Threads.cpp
index 15bb1d2262..48ce5d1254 100644
--- a/libs/utils/Threads.cpp
+++ b/libs/utils/Threads.cpp
@@ -842,6 +842,25 @@ status_t Thread::requestExitAndWait()
     return mStatus;
 }
 
+status_t Thread::join()
+{
+    Mutex::Autolock _l(mLock);
+    if (mThread == getThreadId()) {
+        LOGW(
+        "Thread (this=%p): don't call join() from this "
+        "Thread object's thread. It's a guaranteed deadlock!",
+        this);
+
+        return WOULD_BLOCK;
+    }
+
+    while (mRunning == true) {
+        mThreadExitedCondition.wait(mLock);
+    }
+
+    return mStatus;
+}
+
 bool Thread::exitPending() const
 {
     Mutex::Autolock _l(mLock);