Consolidate thread-local data.

[moonshot.git] / moonshot / mech_eap / util_tld.c

diff --git a/moonshot/mech_eap/util_tld.c b/moonshot/mech_eap/util_tld.c
new file mode 100644 (file)
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+++ b/moonshot/mech_eap/util_tld.c
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+/*
+ * Copyright (c) 2011, JANET(UK)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of JANET(UK) nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/* Access all thread-local data through these methods which 
+ * use pthreads to manage thread-local memory on Unix and TlsFoo() on Windows.
+ * This would be more flexible, scalable, and extensible 
+ * if implemented through a callback interface, but given that 
+ * there are currently only two 'clients', hard-coding seems more 
+ * straightforward
+ */
+#include "gssapiP_eap.h"
+
+/* Clean up thread-local data; called on thread detach */
+static void
+destroyThreadLocalData(struct gss_eap_thread_local_data* tld)
+{
+    if (tld->status_info)
+        gssEapDestroyStatusInfo(tld->status_info);
+    if (tld->context)
+        gssEapDestroyKrbContext(tld->context);
+    GSSEAP_FREE(tld);
+}
+
+#ifdef WIN32
+
+/* This is the tls index returned by TlsAlloc() on process init.  
+ * Each thread, on thread attach in DllMain(), allocates its thread-local data and uses this index with TlsSetValue() to store it.
+ * It can then subsequently be retrieved with TlsGetValue()
+ */
+static DWORD tlsIndex;
+
+/* Access thread-local data */
+struct gss_eap_thread_local_data *
+gssEapGetThreadLocalData()
+{
+    return TlsGetValue(tlsIndex);
+}
+ 
+/* DllMain() is the entry-point function for this DLL. */
+BOOL WINAPI DllMain(HINSTANCE hDLL, /* DLL module handle */
+    DWORD reason,                    /* reason called */
+    LPVOID reserved)                 /* reserved */
+{ 
+    struct gss_eap_thread_local_data *tlsData;
+
+    switch (reason) 
+    { 
+        // The DLL is loading due to process 
+        // initialization or a call to LoadLibrary. 
+        case DLL_PROCESS_ATTACH: 
+            /* Allocate a TLS index. */
+            if ((tlsIndex = TlsAlloc()) == TLS_OUT_OF_INDEXES) 
+                return FALSE; 
+            /* No break: Initialize the index for first thread.*/
+ 
+        /* The attached process creates a new thread. */
+        case DLL_THREAD_ATTACH: 
+            /* Initialize the TLS index for this thread. */
+            tlsData = GSSEAP_CALLOC(1, sizeof(*tlsData));
+            if (tlsData != NULL) 
+                TlsSetValue(tlsIndex, tlsData); 
+ 
+            break; 
+ 
+        /* The thread of the attached process terminates. */
+        case DLL_THREAD_DETACH: 
+            /* Release the allocated memory for this thread. */
+            tlsData = TlsGetValue(tlsIndex); 
+            if (tlsData != NULL) 
+            {
+                destroyThreadLocalData(tlsData); 
+                TlsSetValue(tlsIndex, NULL);
+            }
+ 
+            break; 
+ 
+        /* DLL unload due to process termination or FreeLibrary. */
+        case DLL_PROCESS_DETACH: 
+            /* Release the allocated memory for this thread. */
+            tlsData = TlsGetValue(tlsIndex); 
+            if (tlsData != NULL) 
+                destroyThreadLocalData(tlsData); 
+            /* Release the TLS index. */
+            TlsFree(tlsIndex); 
+            break; 
+ 
+        default: 
+            break; 
+    } 
+ 
+    return TRUE; 
+    UNREFERENCED_PARAMETER(hDLL); 
+    UNREFERENCED_PARAMETER(reserved); 
+}
+
+#else /* WIN32 */
+
+/* PTHREAD implementation */
+static GSSEAP_THREAD_ONCE tldKeyOnce = GSSEAP_ONCE_INITIALIZER;
+static GSSEAP_THREAD_KEY tldKey;
+static void 
+pthreadDestroyThreadLocalData(void* arg)
+{
+    struct gss_eap_thread_local_data* tld = arg;
+    if (tld)
+    {
+        destroyThreadLocalData(tld);
+    }
+}
+
+static void 
+createThreadLocalDataKey(void)
+{
+    GSSEAP_KEY_CREATE(&tldKey, pthreadDestroyThreadLocalData);
+}
+
+struct gss_eap_thread_local_data * 
+gssEapGetThreadLocalData()
+{
+    struct gss_eap_thread_local_data *tld;
+    GSSEAP_ONCE(&tldKeyOnce, createThreadLocalDataKey);
+    tld = GSSEAP_GETSPECIFIC(tldKey);
+    if (!tld)
+    {
+        tld = GSSEAP_CALLOC(1, sizeof(*tld));
+        GSSEAP_SETSPECIFIC(tldKey, tld);
+    }
+    return tld;
+}
+
+#endif /* WIN32 */