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author | tommycli@chromium.org <tommycli@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2013-07-26 14:23:56 +0000 |
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committer | tommycli@chromium.org <tommycli@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2013-07-26 14:23:56 +0000 |
commit | 5c0b44355d76bc88064b1363fe1591668b536da5 (patch) | |
tree | 40ad7a3881c473a356dc8b7653b2420fb49f22e2 /base/sequence_checker_impl.h | |
parent | 7a4fa4725a1b557b178c8053c5c7dd7ea8db9141 (diff) | |
download | chromium_src-5c0b44355d76bc88064b1363fe1591668b536da5.zip chromium_src-5c0b44355d76bc88064b1363fe1591668b536da5.tar.gz chromium_src-5c0b44355d76bc88064b1363fe1591668b536da5.tar.bz2 |
base: Re-apply WeakPtr support for SequencedWorkerPools, fixing deadlock
This reverts the revert found here: https://codereview.chromium.org/19882002
It also fixes the deadlock that caused the revert, reported here:
http://crbug.com/261448
Patchset 1 is simply what was originally committed (and reverted). Subsequent patchsets show the fix of the deadlock problem.
BUG=165590
TBR=darin
Review URL: https://chromiumcodereview.appspot.com/20163004
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@213906 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'base/sequence_checker_impl.h')
-rw-r--r-- | base/sequence_checker_impl.h | 42 |
1 files changed, 18 insertions, 24 deletions
diff --git a/base/sequence_checker_impl.h b/base/sequence_checker_impl.h index ccd1198..741aafe 100644 --- a/base/sequence_checker_impl.h +++ b/base/sequence_checker_impl.h @@ -7,48 +7,42 @@ #include "base/base_export.h" #include "base/basictypes.h" -#include "base/memory/ref_counted.h" #include "base/synchronization/lock.h" +#include "base/threading/sequenced_worker_pool.h" #include "base/threading/thread_checker_impl.h" namespace base { -class SequencedTaskRunner; - // SequenceCheckerImpl is used to help verify that some methods of a // class are called in sequence -- that is, called from the same // SequencedTaskRunner. It is a generalization of ThreadChecker; in -// particular, it behaves exactly like ThreadChecker if its passed a -// NULL SequencedTaskRunner. +// particular, it behaves exactly like ThreadChecker if constructed +// on a thread that is not part of a SequencedWorkerPool. class BASE_EXPORT SequenceCheckerImpl { public: - // |sequenced_task_runner| can be NULL. In that case, this object - // behaves exactly like a ThreadChecker bound to the current thread, - // i.e. CalledOnValidSequence() behaves like CalledOnValidThread(). - explicit SequenceCheckerImpl( - const scoped_refptr<SequencedTaskRunner>& sequenced_task_runner); + SequenceCheckerImpl(); ~SequenceCheckerImpl(); - // Returns whether the we are being called on the underyling - // SequencedTaskRunner. If we're not bound to a - // |sequenced_task_runner|, returns whether we are being called on - // the underlying ThreadChecker's thread. - bool CalledOnValidSequence() const; + // Returns whether the we are being called on the same sequence token + // as previous calls. If there is no associated sequence, then returns + // whether we are being called on the underlying ThreadChecker's thread. + bool CalledOnValidSequencedThread() const; - // Changes the underyling SequencedTaskRunner. - // |sequenced_task_runner| can be NULL. In that case, this object - // behaves exactly like a ThreadChecker that has been detached from - // its thread, i.e. we will be bound to the thread on which we next - // call CalledOnValidSequence(). - void ChangeSequence( - const scoped_refptr<SequencedTaskRunner>& sequenced_task_runner); + // Unbinds the checker from the currently associated sequence. The + // checker will be re-bound on the next call to CalledOnValidSequence(). + void DetachFromSequence(); private: + void EnsureSequenceTokenAssigned() const; + // Guards all variables below. mutable Lock lock_; - scoped_refptr<SequencedTaskRunner> sequenced_task_runner_; - // Used if |sequenced_task_runner_| is NULL. + + // Used if |sequence_token_| is not valid. ThreadCheckerImpl thread_checker_; + mutable bool sequence_token_assigned_; + + mutable SequencedWorkerPool::SequenceToken sequence_token_; DISALLOW_COPY_AND_ASSIGN(SequenceCheckerImpl); }; |