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author | Thomas Schwinge <tschwinge@gnu.org> | 2007-08-12 22:14:29 +0200 |
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committer | Thomas Schwinge <tschwinge@gnu.org> | 2007-08-12 22:14:29 +0200 |
commit | 80af51ad8c2b60abd1295f7209c2a8099211c899 (patch) | |
tree | 7f27aa87cc29f330d01927e62d401db42ef231bd /Hurd/DesignPrinciples.mdwn | |
parent | ae128d097693da524c4a35d42fdc39b8d8b557dd (diff) | |
download | web-80af51ad8c2b60abd1295f7209c2a8099211c899.tar.gz web-80af51ad8c2b60abd1295f7209c2a8099211c899.tar.bz2 web-80af51ad8c2b60abd1295f7209c2a8099211c899.zip |
Move the NextHurd files to where they belong.
Diffstat (limited to 'Hurd/DesignPrinciples.mdwn')
-rw-r--r-- | Hurd/DesignPrinciples.mdwn | 39 |
1 files changed, 0 insertions, 39 deletions
diff --git a/Hurd/DesignPrinciples.mdwn b/Hurd/DesignPrinciples.mdwn deleted file mode 100644 index 42faa52f..00000000 --- a/Hurd/DesignPrinciples.mdwn +++ /dev/null @@ -1,39 +0,0 @@ -# <a name="Design_Principles"> Design Principles </a> - -A design principle is a test that lets us **reject** things. Hopefully, when combined with other design principles, it forms a basis for making coherent and consistent decisions about design goals and system features. [1] - -## <a name="Stated_design_principles"> Stated design principles </a> - -None defined yet, but there seems to be consensus that ngHurd should be a principle-driven design. - -## <a name="Potential_design_principles"> Potential design principles </a> - -Here is an incomplete list of potential design principles for the ngHurd. It is taken from [2]. I left out some principles I think do not apply or are not in question. Feel free to add more. - -### <a name="Principles_from_the_Multics_Proj"> Principles from the Multics Project </a> - -* _Economy of mechanism_: Keep the design as simple as possible. -* _Fail-safe defaults_: Base access decisions on permission rather than exclusion. -* _Least priviledge_: Components should have no more authority than they require. -* _Least common mechanism_: Minimize the amount of shared instances in the system. - -### <a name="Commonly_accepted_principles"> Commonly accepted principles </a> - -* _Separation of policy and mechanism_ -* _Least astonishment (also known as principle of least surprise):_ The system�s behavior should match what is naively expected. -* _Complete accountability_: All real resources held by an application must come from some accounted pool. -* _Safe restart_: On restart, the system must either already have, or be able to rapidly establish, a consistent and secure execution state. -* _Reproducibility_: Correct operations should produce identical results regardless of workload. - -### <a name="Principles_specific_to_EROS"> </a> Principles specific to EROS - -* _Credible policy_: If a security policy cannot be implemented by correct application of the system�s protection mechanisms, do not claim to enforce it. -* _Explicit authority designation_: Every operation that uses authority should explicitely designate the source of the authority it is using. -* _Relinquishable authority_: If an application holds some authority, it should be able to voluntarily reduce this authority. - ----- - -See also: - -* [1] <http://lists.gnu.org/archive/html/l4-hurd/2005-11/msg00120.html> -* [2] EROS: A Principle-Driven Operating System from the Ground Up |