1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/security/manager/ssl/src/CryptoTask.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,93 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.8 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef mozilla__CryptoTask_h
1.11 +#define mozilla__CryptoTask_h
1.12 +
1.13 +#include "mozilla/Attributes.h"
1.14 +#include "nsThreadUtils.h"
1.15 +#include "nsNSSShutDown.h"
1.16 +
1.17 +namespace mozilla {
1.18 +
1.19 +/**
1.20 + * Frequently we need to run a task on a background thread without blocking
1.21 + * the main thread, and then call a callback on the main thread with the
1.22 + * result. This class provides the framework for that. Subclasses must:
1.23 + *
1.24 + * (1) Override CalculateResult for the off-the-main-thread computation.
1.25 + * NSS functionality may only be accessed within CalculateResult.
1.26 + * (2) Override ReleaseNSSResources to release references to all NSS
1.27 + * resources (that do implement nsNSSShutDownObject themselves).
1.28 + * (3) Override CallCallback() for the on-the-main-thread call of the
1.29 + * callback.
1.30 + *
1.31 + * CalculateResult, ReleaseNSSResources, and CallCallback are called in order,
1.32 + * except CalculateResult might be skipped if NSS is shut down before it can
1.33 + * be called; in that case ReleaseNSSResources will be called and then
1.34 + * CallCallback will be called with an error code.
1.35 + */
1.36 +class CryptoTask : public nsRunnable,
1.37 + public nsNSSShutDownObject
1.38 +{
1.39 +public:
1.40 + template <size_t LEN>
1.41 + nsresult Dispatch(const char (&taskThreadName)[LEN])
1.42 + {
1.43 + static_assert(LEN <= 15,
1.44 + "Thread name must be no more than 15 characters");
1.45 + // Can't add 'this' as the event to run, since mThread may not be set yet
1.46 + nsresult rv = NS_NewNamedThread(taskThreadName, getter_AddRefs(mThread));
1.47 + if (NS_SUCCEEDED(rv)) {
1.48 + // Note: event must not null out mThread!
1.49 + rv = mThread->Dispatch(this, NS_DISPATCH_NORMAL);
1.50 + }
1.51 + return rv;
1.52 + }
1.53 +
1.54 +protected:
1.55 + CryptoTask()
1.56 + : mRv(NS_ERROR_NOT_INITIALIZED),
1.57 + mReleasedNSSResources(false)
1.58 + {
1.59 + }
1.60 +
1.61 + virtual ~CryptoTask();
1.62 +
1.63 + /**
1.64 + * Called on a background thread (never the main thread). If CalculateResult
1.65 + * is called, then its result will be passed to CallCallback on the main
1.66 + * thread.
1.67 + */
1.68 + virtual nsresult CalculateResult() = 0;
1.69 +
1.70 + /**
1.71 + * Called on the main thread during NSS shutdown or just before CallCallback
1.72 + * has been called. All NSS resources must be released. Usually, this just
1.73 + * means assigning nullptr to the ScopedNSSType-based memory variables.
1.74 + */
1.75 + virtual void ReleaseNSSResources() = 0;
1.76 +
1.77 + /**
1.78 + * Called on the main thread with the result from CalculateResult() or
1.79 + * with an error code if NSS was shut down before CalculateResult could
1.80 + * be called.
1.81 + */
1.82 + virtual void CallCallback(nsresult rv) = 0;
1.83 +
1.84 +private:
1.85 + NS_IMETHOD Run() MOZ_OVERRIDE MOZ_FINAL;
1.86 + virtual void virtualDestroyNSSReference() MOZ_OVERRIDE MOZ_FINAL;
1.87 +
1.88 + nsresult mRv;
1.89 + bool mReleasedNSSResources;
1.90 +
1.91 + nsCOMPtr<nsIThread> mThread;
1.92 +};
1.93 +
1.94 +} // namespace mozilla
1.95 +
1.96 +#endif // mozilla__CryptoTask_h
