Refactor EnsureOpenSSLInit and openssl_util into base

base/openssl_util.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/openssl_util.h"
 
 #include <openssl/err.h>
+#include <openssl/ssl.h>
 
+#include "base/lock.h"
 #include "base/logging.h"
+#include "base/scoped_vector.h"
+#include "base/singleton.h"
 
 namespace base {
 
+namespace {
+
+unsigned long CurrentThreadId() {
+  return static_cast<unsigned long>(PlatformThread::CurrentId());
+}
+
+// Singleton for initializing and cleaning up the OpenSSL library.
+class OpenSSLInitSingleton {
+ private:
+  friend struct DefaultSingletonTraits<OpenSSLInitSingleton>;
+  OpenSSLInitSingleton() {
+    SSL_load_error_strings();
+    SSL_library_init();
+    OpenSSL_add_all_algorithms();
+    int num_locks = CRYPTO_num_locks();
+    locks_.reserve(num_locks);
+    for (int i = 0; i < num_locks; ++i)
+      locks_.push_back(new Lock());
+    CRYPTO_set_locking_callback(LockingCallback);
+    CRYPTO_set_id_callback(CurrentThreadId);
+  }
+
+  ~OpenSSLInitSingleton() {
+    CRYPTO_set_locking_callback(NULL);
+    EVP_cleanup();
+    ERR_free_strings();
+  }
+
+  static void LockingCallback(int mode, int n, const char* file, int line) {
+    Singleton<OpenSSLInitSingleton>::get()->OnLockingCallback(mode, n, file,
+                                                              line);
+  }
+
+  void OnLockingCallback(int mode, int n, const char* file, int line) {
+    CHECK_LT(static_cast<size_t>(n), locks_.size());
+    if (mode & CRYPTO_LOCK)
+      locks_[n]->Acquire();
+    else
+      locks_[n]->Release();
+  }
+
+  // These locks are used and managed by OpenSSL via LockingCallback().
+  ScopedVector<Lock> locks_;
+
+  DISALLOW_COPY_AND_ASSIGN(OpenSSLInitSingleton);
+};
+
+}  // namespace
+
+void EnsureOpenSSLInit() {
+  (void)Singleton<OpenSSLInitSingleton>::get();
+}
+
 void ClearOpenSSLERRStack() {
   if (logging::DEBUG_MODE && VLOG_IS_ON(1)) {
     int error_num = ERR_get_error();
     if (error_num == 0)
       return;
 
     DVLOG(1) << "OpenSSL ERR_get_error stack:";
     char buf[140];
     do {
       ERR_error_string_n(error_num, buf, arraysize(buf));
       DVLOG(1) << "\t" << error_num << ": " << buf;
       error_num = ERR_get_error();
     } while (error_num != 0);
   } else {
     ERR_clear_error();
   }
 }
 
 }  // namespace base