Always initialize session cache locks lazily.

net/third_party/nss/ssl/ssl3con.c

 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /*
  * SSL3 Protocol
  *
  * ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
@@ skipping 4506 matching lines @@
     PORT_SetError(SEC_ERROR_NOT_INITIALIZED);
     return SECFailure;
 }
 
 SECStatus
 SSL3_ShutdownServerCache(void)
 {
     int             i, j;
 
     if (!symWrapKeysLock)
         return SECSuccess;      /* lock was never initialized */

[wtc, 2012/06/13 23:08:21]

Note that SSL3_ShutdownServerCache does a null check on
symWrapKeysLock rather than initializing the locks.  I
copied this solution to SSL_ClearSessionCache.

     PZ_Lock(symWrapKeysLock);
     /* get rid of all symWrapKeys */
     for (i = 0; i < SSL_NUM_WRAP_MECHS; ++i) {
         for (j = 0; j < kt_kea_size; ++j) {
             PK11SymKey **   pSymWrapKey;
             pSymWrapKey = &symWrapKeys[i].symWrapKey[j];
             if (*pSymWrapKey) {
                 PK11_FreeSymKey(*pSymWrapKey);
                 *pSymWrapKey = NULL;
             }
         }
     }
 
     PZ_Unlock(symWrapKeysLock);
-    ssl_FreeSessionCacheLocks();

[wtc, 2012/06/13 23:08:21]

The ssl_FreeSessionCacheLocks function is used when we
initialize the locks early.  So ssl_FreeSessionCacheLocks
is also deleted.

     return SECSuccess;
 }
 
 SECStatus ssl_InitSymWrapKeysLock(void)
 {
     symWrapKeysLock = PZ_NewLock(nssILockOther);
     return symWrapKeysLock ? SECSuccess : SECFailure;
 }
 
 /* Try to get wrapping key for mechanism from in-memory array.
@@ skipping 31 matching lines @@
         return NULL;    /* why are we here?!? */
     }
 
     symWrapMechIndex = ssl_FindIndexByWrapMechanism(masterWrapMech);
     PORT_Assert(symWrapMechIndex >= 0);
     if (symWrapMechIndex < 0)
         return NULL;    /* invalid masterWrapMech. */
 
     pSymWrapKey = &symWrapKeys[symWrapMechIndex].symWrapKey[exchKeyType];
 
-    ssl_InitSessionCacheLocks(PR_TRUE);
-
     PZ_Lock(symWrapKeysLock);
 
     unwrappedWrappingKey = *pSymWrapKey;
     if (unwrappedWrappingKey != NULL) {
         if (PK11_VerifyKeyOK(unwrappedWrappingKey)) {
             unwrappedWrappingKey = PK11_ReferenceSymKey(unwrappedWrappingKey);
             goto done;
         }
         /* slot series has changed, so this key is no good any more. */
         PK11_FreeSymKey(unwrappedWrappingKey);
@@ skipping 6087 matching lines @@
             PORT_Free(ss->ssl3.hs.recvdFragments.buf);
         }
     }
 
     ss->ssl3.initialized = PR_FALSE;
 
     SECITEM_FreeItem(&ss->ssl3.nextProto, PR_FALSE);
 }
 
 /* End of ssl3con.c */