generic-library/cxx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[libc++] Fix PR22606 - Leak pthread_key with static storage duration to ensure all of thread-local destructors are called.

Browse Source 
Summary:
See https://llvm.org/bugs/show_bug.cgi?id=22606 for more discussion.

Most of the changes in this patch are file reorganization to help ensure assumptions about how __thread_specific_pointer is used hold. The assumptions are:

* `__thread_specific_ptr<Tp>` is only created with a `__thread_struct` pointer.
* `__thread_specific_ptr<Tp>` can only be constructed inside the `__thread_local_data()` function.

I'll remove the comments before committing. They are there for clarity during review.

Reviewers: earthdok, mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D8802

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@245334 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eric Fiselier
2015-08-18 19:40:38 +00:00
parent 85d45f6c0d
commit 0376dfaca0
1 changed files with 31 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

53
include/thread
View File

@@ -113,11 +113,38 @@ void sleep_for(const chrono::duration<Rep, Period>& rel_time);
_LIBCPP_BEGIN_NAMESPACE_STD
template <class _Tp> class __thread_specific_ptr;
class _LIBCPP_TYPE_VIS __thread_struct;
class _LIBCPP_HIDDEN __thread_struct_imp;
class __assoc_sub_state;
_LIBCPP_FUNC_VIS __thread_specific_ptr<__thread_struct>& __thread_local_data();
class _LIBCPP_TYPE_VIS __thread_struct
{
__thread_struct_imp* __p_;
__thread_struct(const __thread_struct&);
__thread_struct& operator=(const __thread_struct&);
public:
__thread_struct();
~__thread_struct();
void notify_all_at_thread_exit(condition_variable*, mutex*);
void __make_ready_at_thread_exit(__assoc_sub_state*);
};
template <class _Tp>
class __thread_specific_ptr
{
pthread_key_t __key_;
// Only __thread_local_data() may construct a __thread_specific_ptr
// and only with _Tp == __thread_struct.
static_assert(is_same<_Tp, __thread_struct>::value, "");
__thread_specific_ptr();
friend _LIBCPP_FUNC_VIS __thread_specific_ptr<__thread_struct>& __thread_local_data();
__thread_specific_ptr(const __thread_specific_ptr&);
__thread_specific_ptr& operator=(const __thread_specific_ptr&);
@@ -125,7 +152,6 @@ class __thread_specific_ptr
public:
typedef _Tp* pointer;
__thread_specific_ptr();
~__thread_specific_ptr();
_LIBCPP_INLINE_VISIBILITY
@@ -159,7 +185,10 @@ __thread_specific_ptr<_Tp>::__thread_specific_ptr()
template <class _Tp>
__thread_specific_ptr<_Tp>::~__thread_specific_ptr()
{
pthread_key_delete(__key_);
// __thread_specific_ptr is only created with a static storage duration
// so this destructor is only invoked during program termination. Invoking
// pthread_key_delete(__key_) may prevent other threads from deleting their
// thread local data. For this reason we leak the key.
}
template <class _Tp>
@@ -307,26 +336,6 @@ public:
static unsigned hardware_concurrency() _NOEXCEPT;
};
class __assoc_sub_state;
class _LIBCPP_HIDDEN __thread_struct_imp;
class _LIBCPP_TYPE_VIS __thread_struct
{
__thread_struct_imp* __p_;
__thread_struct(const __thread_struct&);
__thread_struct& operator=(const __thread_struct&);
public:
__thread_struct();
~__thread_struct();
void notify_all_at_thread_exit(condition_variable*, mutex*);
void __make_ready_at_thread_exit(__assoc_sub_state*);
};
_LIBCPP_FUNC_VIS __thread_specific_ptr<__thread_struct>& __thread_local_data();
#ifndef _LIBCPP_HAS_NO_VARIADICS
template <class _Fp, class ..._Args, size_t ..._Indices>