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| author | dhollowa@chromium.org <dhollowa@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2012-02-14 19:33:52 +0000 |
|---|---|---|
| committer | dhollowa@chromium.org <dhollowa@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2012-02-14 19:33:52 +0000 |
| commit | b5717a4f9f66283a9fe04ae1f9a3a89920d5b6b0 (patch) | |
| tree | 9d14cf64e2cbeed63b232ba09a8c1274280d81b0 /base/message_loop.h | |
| parent | bbdfcab9e264df0f264f56d8cb5f7ef61e5f96b6 (diff) | |
| download | chromium_src-b5717a4f9f66283a9fe04ae1f9a3a89920d5b6b0.zip chromium_src-b5717a4f9f66283a9fe04ae1f9a3a89920d5b6b0.tar.gz chromium_src-b5717a4f9f66283a9fe04ae1f9a3a89920d5b6b0.tar.bz2 | |
Prefer ScopedNestableTaskAllower over manual save/restore
Cleanup. Changes various calls sites to use the
ScopedNestableTaskAllower class to save/restore nestable task
state.
BUG=None
TEST=Existing unit tests
R=jar@chromium.org, scottbyer@chromium.org, sky@chromium.org, akalin@chromium.org, rsleevi@chromium.org, brettw@chromium.org, tony@chromium.org
Review URL: https://chromiumcodereview.appspot.com/9384024
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@121914 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'base/message_loop.h')
| -rw-r--r-- | base/message_loop.h | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/base/message_loop.h b/base/message_loop.h index e14baa7..f940502 100644 --- a/base/message_loop.h +++ b/base/message_loop.h @@ -67,11 +67,12 @@ class Histogram; // (DoDragDrop), printer functions (StartDoc) and *many* others. // // Sample workaround when inner task processing is needed: -// bool old_state = MessageLoop::current()->NestableTasksAllowed(); -// MessageLoop::current()->SetNestableTasksAllowed(true); -// HRESULT hr = DoDragDrop(...); // Implicitly runs a modal message loop here. -// MessageLoop::current()->SetNestableTasksAllowed(old_state); -// // Process hr (the result returned by DoDragDrop(). +// HRESULT hr; +// { +// MessageLoop::ScopedNestableTaskAllower allow(MessageLoop::current()); +// hr = DoDragDrop(...); // Implicitly runs a modal message loop. +// } +// // Process |hr| (the result returned by DoDragDrop()). // // Please be SURE your task is reentrant (nestable) and all global variables // are stable and accessible before calling SetNestableTasksAllowed(true). @@ -264,6 +265,10 @@ class BASE_EXPORT MessageLoop : public base::MessagePump::Delegate { // using common controls or printer functions. By default, recursive task // processing is disabled. // + // Please utilize |ScopedNestableTaskAllower| instead of calling these methods + // directly. In general nestable message loops are to be avoided. They are + // dangerous and difficult to get right, so please use with extreme caution. + // // The specific case where tasks get queued is: // - The thread is running a message loop. // - It receives a task #1 and execute it. |