1 files changed, 57 insertions, 0 deletions
diff --git a/libc/bionic/__thread_entry.cpp b/libc/bionic/__thread_entry.cpp
new file mode 100644
index 0000000..8300a64
--- /dev/null
+++ b/libc/bionic/__thread_entry.cpp
@@ -0,0 +1,57 @@
+/*
+ * 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 <pthread.h>
+
+#include "pthread_internal.h"
+
+#include "private/bionic_tls.h"
+
+// This trampoline is called from the assembly _pthread_clone function.
+// Our 'tls' and __pthread_clone's 'child_stack' are one and the same, just growing in
+// opposite directions.
+extern "C" void __thread_entry(void* (*func)(void*), void* arg, void** tls) {
+  // Wait for our creating thread to release us. This lets it have time to
+  // notify gdb about this thread before we start doing anything.
+  // This also provides the memory barrier needed to ensure that all memory
+  // accesses previously made by the creating thread are visible to us.
+  pthread_mutex_t* start_mutex = (pthread_mutex_t*) &tls[TLS_SLOT_SELF];
+  pthread_mutex_lock(start_mutex);
+  pthread_mutex_destroy(start_mutex);
+
+  pthread_internal_t* thread = (pthread_internal_t*) tls[TLS_SLOT_THREAD_ID];
+  thread->tls = tls;
+  __init_tls(thread);
+
+  if ((thread->internal_flags & PTHREAD_INTERNAL_FLAG_THREAD_INIT_FAILED) != 0) {
+    pthread_exit(NULL);
+  }
+
+  void* result = func(arg);
+  pthread_exit(result);
+}