import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

security/nss/lib/pk11wrap/pk11list.c

@@ -0,0 +1,99 @@
+/* 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/. */
+/*
+ * Locking and queue management primatives
+ *
+ */
+
+#include "seccomon.h"
+#include "nssilock.h"
+#include "secmod.h"
+#include "secmodi.h"
+#include "secmodti.h"
+#include "nssrwlk.h"
+
+/*
+ * create a new lock for a Module List
+ */
+SECMODListLock *
+SECMOD_NewListLock()
+{
+    return NSSRWLock_New(10, "moduleListLock");
+}
+
+/*
+ * destroy the lock
+ */
+void
+SECMOD_DestroyListLock(SECMODListLock *lock)
+{
+    NSSRWLock_Destroy(lock);
+}
+
+/*
+ * Lock the List for Read: NOTE: this assumes the reading isn't so common
+ * the writing will be starved.
+ */
+void
+SECMOD_GetReadLock(SECMODListLock *modLock)
+{
+    NSSRWLock_LockRead(modLock);
+}
+
+/*
+ * Release the Read lock
+ */
+void
+SECMOD_ReleaseReadLock(SECMODListLock *modLock)
+{
+    NSSRWLock_UnlockRead(modLock);
+}
+
+/*
+ * lock the list for Write
+ */
+void
+SECMOD_GetWriteLock(SECMODListLock *modLock)
+{
+    NSSRWLock_LockWrite(modLock);
+}
+
+/*
+ * Release the Write Lock: NOTE, this code is pretty inefficient if you have
+ * lots of write collisions.
+ */
+void
+SECMOD_ReleaseWriteLock(SECMODListLock *modLock)
+{
+    NSSRWLock_UnlockWrite(modLock);
+}
+
+/*
+ * must Hold the Write lock
+ */
+void
+SECMOD_RemoveList(SECMODModuleList **parent, SECMODModuleList *child)
+{
+    *parent = child->next;
+    child->next = NULL;
+}
+
+/*
+ * if lock is not specified, it must already be held
+ */
+void
+SECMOD_AddList(SECMODModuleList *parent, SECMODModuleList *child,
+               SECMODListLock *lock)
+{
+    if (lock) {
+        SECMOD_GetWriteLock(lock);
+    }
+
+    child->next = parent->next;
+    parent->next = child;
+
+    if (lock) {
+        SECMOD_ReleaseWriteLock(lock);
+    }
+}