From 23750961d5b9052ddfe6d4746435e84ca0c87a10 Mon Sep 17 00:00:00 2001
From: Martin Willi <martin@revosec.ch>
Date: Wed, 11 Jun 2014 14:24:22 +0200
Subject: [PATCH] thread-value: Defer cleanup handling to thread termination on
 Windows

Instead of cleaning up all thread-values during destruction, cleanup handler
is invoked when a thread detaches. Thread detaching is cough using the Windows
DllMain() entry point, and allows us to basically revert 204098a7.

Using this mechanism, we make sure that the cleanup handler is invoked by the
the correct thread. Further, this mechanism works for externally-spawned
threads which run outside of our thread_cb() routine, and works more efficiently
with short-running threads.
---
 src/libstrongswan/threading/windows/thread.c  | 74 +++++++++++--------
 src/libstrongswan/threading/windows/thread.h  |  9 ---
 .../threading/windows/thread_value.c          |  8 +-
 3 files changed, 51 insertions(+), 40 deletions(-)

diff --git a/src/libstrongswan/threading/windows/thread.c b/src/libstrongswan/threading/windows/thread.c
index 2b273413c2..8792237e62 100644
--- a/src/libstrongswan/threading/windows/thread.c
+++ b/src/libstrongswan/threading/windows/thread.c
@@ -245,36 +245,6 @@ void* thread_tls_remove(void *key)
 	return value;
 }
 
-/**
- * See header.
- */
-void thread_tls_remove_all(void *key)
-{
-	private_thread_t *thread;
-	enumerator_t *enumerator;
-	void *value;
-	bool old;
-
-	old = set_leak_detective(FALSE);
-	threads_lock->lock(threads_lock);
-
-	enumerator = threads->create_enumerator(threads);
-	while (enumerator->enumerate(enumerator, NULL, &thread))
-	{
-		value = thread->tls->remove(thread->tls, key);
-		if (value)
-		{
-			set_leak_detective(old);
-			thread_tls_cleanup(value);
-			set_leak_detective(FALSE);
-		}
-	}
-	enumerator->destroy(enumerator);
-
-	threads_lock->unlock(threads_lock);
-	set_leak_detective(old);
-}
-
 /**
  * Thread cleanup data
  */
@@ -634,6 +604,50 @@ void thread_exit(void *val)
 	ExitThread(0);
 }
 
+/**
+ * Clean up thread data while it detaches
+ */
+static void cleanup_tls()
+{
+	private_thread_t *this;
+	bool old;
+
+	old = set_leak_detective(FALSE);
+	threads_lock->lock(threads_lock);
+
+	this = threads->remove(threads, (void*)(uintptr_t)GetCurrentThreadId());
+
+	threads_lock->unlock(threads_lock);
+	set_leak_detective(old);
+
+	if (this)
+	{
+		/* If the thread exited, but has not been joined, it is in terminated
+		 * state. We must not mangle it, as we target externally spawned
+		 * threads only. */
+		if (!this->terminated && !this->detached)
+		{
+			destroy(this);
+		}
+	}
+}
+
+/**
+ * DllMain called for dll events
+ */
+BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
+{
+	switch (fdwReason)
+	{
+		case DLL_THREAD_DETACH:
+			cleanup_tls();
+			break;
+		default:
+			break;
+	}
+	return TRUE;
+}
+
 /*
  * Described in header.
  */
diff --git a/src/libstrongswan/threading/windows/thread.h b/src/libstrongswan/threading/windows/thread.h
index 3c470522bb..965d9690e4 100644
--- a/src/libstrongswan/threading/windows/thread.h
+++ b/src/libstrongswan/threading/windows/thread.h
@@ -60,15 +60,6 @@ void* thread_tls_get(void *key);
  */
 void* thread_tls_remove(void *key);
 
-/**
- * Remove a thread specific value from all threads.
- *
- * For each found TLS value thread_tls_cleanup() is invoked.
- *
- * @param key		unique key specifying the TLS variable
- */
-void thread_tls_remove_all(void *key);
-
 /**
  * Cleanup function for thread specific value.
  *
diff --git a/src/libstrongswan/threading/windows/thread_value.c b/src/libstrongswan/threading/windows/thread_value.c
index 1dd8a78165..d7bd7e64c0 100644
--- a/src/libstrongswan/threading/windows/thread_value.c
+++ b/src/libstrongswan/threading/windows/thread_value.c
@@ -104,7 +104,13 @@ METHOD(thread_value_t, tls_get, void*,
 METHOD(thread_value_t, tls_destroy, void,
 	private_thread_value_t *this)
 {
-	thread_tls_remove_all(this);
+	entry_t *entry;
+
+	entry = thread_tls_remove(this);
+	if (entry)
+	{
+		thread_tls_cleanup(entry);
+	}
 	free(this);
 }
 
-- 
2.47.2