1From 28a638ff22f598f6aa9388db6a4cf13fe9f11644 Mon Sep 17 00:00:00 2001
2From: Hirokazu Honda <hiroh@google.com>
3Date: Wed, 1 Aug 2018 17:03:18 +0900
4Subject: [PATCH] ThreadLocalStorage: Add a function to destroy pthread key
5 used in libchrome
6
7MojoProcessSupport needs to destroy pthread key which is globally used in libchrome. The key is
8stored in a local variable in thread_local_storage.cc.
9This adds a function to destroy the key so that MojoProcessSupport can do it.
10
11Bug: 110722333
12Test: No crash in opening DRMInfo.app
13Test: PlayStore still works
14Test: cheets_ContainerSmokeTest and cheets_LoginScreen
15Change-Id: Ib10c83deb5f7ef141d4ab9883e0d2c31d422a1b1
16---
17 base/threading/thread_local_storage.cc | 11 +++++++++++
18 base/threading/thread_local_storage.h  |  7 +++++++
19 2 files changed, 18 insertions(+)
20
21diff --git a/base/threading/thread_local_storage.cc b/base/threading/thread_local_storage.cc
22index 48c1dd5..90ae69e 100644
23--- a/base/threading/thread_local_storage.cc
24+++ b/base/threading/thread_local_storage.cc
25@@ -247,6 +247,17 @@ void PlatformThreadLocalStorage::OnThreadExit() {
26 void PlatformThreadLocalStorage::OnThreadExit(void* value) {
27   OnThreadExitInternal(static_cast<TlsVectorEntry*>(value));
28 }
29+
30+// static
31+void PlatformThreadLocalStorage::ForceFreeTLS() {
32+  PlatformThreadLocalStorage::TLSKey key =
33+      base::subtle::NoBarrier_AtomicExchange(
34+          &g_native_tls_key,
35+          PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES);
36+  if (key == PlatformThreadLocalStorage::TLS_KEY_OUT_OF_INDEXES)
37+    return;
38+  PlatformThreadLocalStorage::FreeTLS(key);
39+}
40 #endif  // defined(OS_WIN)
41
42 }  // namespace internal
43diff --git a/base/threading/thread_local_storage.h b/base/threading/thread_local_storage.h
44index fd2a789..c5c7759 100644
45--- a/base/threading/thread_local_storage.h
46+++ b/base/threading/thread_local_storage.h
47@@ -75,6 +75,13 @@ class BASE_EXPORT PlatformThreadLocalStorage {
48   // GetTLSValue() to retrieve the value of slot as it has already been reset
49   // in Posix.
50   static void OnThreadExit(void* value);
51+  // Normally, Chrome runs as a process, so freeing the TLS is not needed since
52+  // the OS will perform that while it's reclaiming the process' memory upon
53+  // termination. If, however, this code is used inside a library that is
54+  // dynamically loaded and unloaded, the consumer is responsible for calling
55+  // this after all Chrome threads have stopped and prior to unloading the
56+  // library.
57+  static void ForceFreeTLS();
58 #endif
59 };
60
61--
622.18.0.345.g5c9ce644c3-goog
63
64