Fix pthreads functions that should return ESRCH.

imgtec pointed out that pthread_kill(3) was broken, but most of the
other functions that ought to return ESRCH for invalid/exited threads
were equally broken.

Change-Id: I96347f6195549aee0c72dc39063e6c5d06d2e01f
diff --git a/libc/bionic/pthread_join.cpp b/libc/bionic/pthread_join.cpp
new file mode 100644
index 0000000..e6acc34
--- /dev/null
+++ b/libc/bionic/pthread_join.cpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <errno.h>
+
+#include "pthread_accessor.h"
+
+int pthread_join(pthread_t t, void ** ret_val) {
+  if (t == pthread_self()) {
+    return EDEADLK;
+  }
+
+  pthread_accessor thread(t);
+  if (thread.get() == NULL) {
+      return ESRCH;
+  }
+
+  if (thread->attr.flags & PTHREAD_ATTR_FLAG_DETACHED) {
+    return EINVAL;
+  }
+
+  // Wait for thread death when needed.
+
+  // If the 'join_count' is negative, this is a 'zombie' thread that
+  // is already dead and without stack/TLS. Otherwise, we need to increment 'join-count'
+  // and wait to be signaled
+  int count = thread->join_count;
+  if (count >= 0) {
+    thread->join_count += 1;
+    pthread_cond_wait(&thread->join_cond, &gThreadListLock);
+    count = --thread->join_count;
+  }
+  if (ret_val) {
+    *ret_val = thread->return_value;
+  }
+
+  // Remove thread from thread list when we're the last joiner or when the
+  // thread was already a zombie.
+  if (count <= 0) {
+    _pthread_internal_remove_locked(thread.get());
+  }
+  return 0;
+}