Bug #1245
Singleton factories do not work as expected on windows
| Status: | Resolved | Start date: | 11/19/2012 | |
|---|---|---|---|---|
| Priority: | Normal | Due date: | ||
| Assignee: | J. Wienke | % Done: | 100% | |
| Category: | C++ | |||
| Target version: | rsb-0.9 |
Description
As described in #1231, multiple instances of the singletons occur across build units on windows leading to unexpected effects.
I would propose the following strategy to solve the problem:- in 0.8:
- retain the singletons but mark there use as deprecated
- provide getters for singleton instances which are definitely created in the RSB dll
- in 0.9 or later:
- Remove the singleton base class of the respective factories so that they can only be used using the getters with predictable behavior on all platforms.
Any objections to this procedure?
Related issues
Associated revisions
Prevent the presence of multiple singleton factories on windows.
Due to the separate memory management of windows for different DLLs the
existing singleton implementation does not work there. All uses of the
singleton were replace by appropriate getters to a specific instance.
- Singleton base classes were made private to reuse the instantiation
support in static initializer code of the existing singleton
implementation - Appropriate getter methods were added falling back to the now private
singleton implementation - getInstance methods were redeclared using custom code going back to
the getters. These methods are now marked deprecated and singleton use
is discouraged.
For EventSendingStrategyFactory and the receiving counterpart these
changes could not be performed because they use a specific factory
implementation from RSC. However, they are probably never used from the
outside.
refs #1245
Prevent the presence of multiple singleton factories on windows.
Due to the separate memory management of windows for different DLLs the
existing singleton implementation does not work there. All uses of the
singleton were replace by appropriate getters to a specific instance.
- Singleton base classes were made private to reuse the instantiation
support in static initializer code of the existing singleton
implementation - Appropriate getter methods were added falling back to the now private
singleton implementation - getInstance methods were redeclared using custom code going back to
the getters. These methods are now marked deprecated and singleton use
is discouraged.
For EventSendingStrategyFactory and the receiving counterpart these
changes could not be performed because they use a specific factory
implementation from RSC. However, they are probably never used from the
outside.
refs #1245
Provide getters for factories instead of using singletons to overcome windows memory management issues.
Backwards compatibility is preserved (from an API point of view) but should be removed in one of the next versions. These functions are marked deprecated.
fixes #1245
Merge branch 'bug-1245'
History
#1 Updated by J. Moringen over 11 years ago
It may be possible to use the rsc::patterns::Singleton as a private base class instead of removing it entirely. This way, clients would not be able to call rsc::patterns::Singleton::getInstance directly and code duplication could still be avoided.
#2 Updated by J. Wienke over 11 years ago
- Status changed from New to In Progress
- Assignee set to J. Wienke
- % Done changed from 0 to 70
Jan, I have committed a fix for this issue to the respective bug branch, commit 27624814. Can you have a quick look at this as it is a rather larger change?
#3 Updated by J. Moringen over 11 years ago
Looks OK, but rsb::transport::ConnectorFactory<>::getInstance() could use a small explanatory comment.
#4 Updated by J. Wienke over 11 years ago
- Status changed from In Progress to Resolved
- % Done changed from 70 to 100
Applied in changeset rsb-cpp|commit:3e304f85f06b317efb7cc9998b5d8c9c3a74cee8.