1 files changed, 57 insertions, 0 deletions
diff --git a/nsprpub/pr/src/md/windows/ntdllmn.c b/nsprpub/pr/src/md/windows/ntdllmn.c
new file mode 100644
index 0000000000..e64b312d09
--- /dev/null
+++ b/nsprpub/pr/src/md/windows/ntdllmn.c
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * The DLL entry point (DllMain) for NSPR.
+ *
+ * The only reason we use DLLMain() now is to find out whether
+ * the NSPR DLL is statically or dynamically loaded.  When
+ * dynamically loaded, we cannot use static thread-local storage.
+ * However, static TLS is faster than the TlsXXX() functions.
+ * So we want to use static TLS whenever we can.  A global
+ * variable _pr_use_static_tls is set in DllMain() during process
+ * attachment to indicate whether it is safe to use static TLS
+ * or not.
+ */
+
+#include <windows.h>
+#include <primpl.h>
+
+extern BOOL _pr_use_static_tls;  /* defined in ntthread.c */
+
+BOOL WINAPI DllMain(
+    HINSTANCE hinstDLL,
+    DWORD fdwReason,
+    LPVOID lpvReserved)
+{
+    PRThread *me;
+
+    switch (fdwReason) {
+        case DLL_PROCESS_ATTACH:
+            /*
+             * If lpvReserved is NULL, we are dynamically loaded
+             * and therefore can't use static thread-local storage.
+             */
+            if (lpvReserved == NULL) {
+                _pr_use_static_tls = FALSE;
+            } else {
+                _pr_use_static_tls = TRUE;
+            }
+            break;
+        case DLL_THREAD_ATTACH:
+            break;
+        case DLL_THREAD_DETACH:
+            if (_pr_initialized) {
+                me = _MD_GET_ATTACHED_THREAD();
+                if ((me != NULL) && (me->flags & _PR_ATTACHED)) {
+                    _PRI_DetachThread();
+                }
+            }
+            break;
+        case DLL_PROCESS_DETACH:
+            break;
+    }
+    return TRUE;
+}