Mercurial > hg > Members > kono > jpf-core
annotate doc/user/api.md @ 0:61d41facf527
initial v8 import (history reset)
author | Peter Mehlitz <Peter.C.Mehlitz@nasa.gov> |
---|---|
date | Fri, 23 Jan 2015 10:14:01 -0800 |
parents | |
children |
rev | line source |
---|---|
0
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
1 # The Verify API # |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
2 Although the primary purpose of JPF is to verify applications that are not JPF dependent, it can also be used to check programs that are explicitly written to execute under JPF. There are two ways to do this |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
3 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
4 * use of jpf annotations such as `@gov.nasa.jpf.annotation.JPFConfig` and `@gov.nasa.jpf.annotation.FilterField` |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
5 * use of the various `gov.nasa.jpf.vm.Verify` APIs |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
6 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
7 The first method provides only directives to JPF (by means of Java annotations), and does not modify or add any specific code to your system under test. The second one is imperative and should only be used by JPF specific test drivers. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
8 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
9 ## JPF Annotations ## |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
10 The JPF core currently supports two annotation types: `@JPFConfig` and `@FilterField` |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
11 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
12 ~~~~~~~~ {.java} |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
13 import gov.nasa.jpf.annotation.JPFConfig |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
14 ... |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
15 @JPFConfig({"listener+=,gov.nasa.jpf.aprop.listener.SharedChecker", ..}) |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
16 public class MyClass { |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
17 .. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
18 } |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
19 ~~~~~~~~ |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
20 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
21 The `@JPFConfig` annotation allows to set JPF properties (<key>=<value> pairs) for classes and methods of your application, which is especially useful to add specific listeners. You have to be aware of the property effects though, since not all behavior can be changed at runtime, and you usually cannot reverse features with this method |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
22 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
23 The `@FilterField` annotation is used to mark certain fields in your application as not relevant for state matching. This is useful if you have to add debugging information like counters that would otherwise increase the state space (i.e. would prevent state matching). |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
24 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
25 ~~~~~~~~ {.java} |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
26 import gov.nasa.jpf.annotation.FilterField; |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
27 ... |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
28 public class MyClass { |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
29 .. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
30 @FilterField int counter; |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
31 .. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
32 } |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
33 ~~~~~~~~ |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
34 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
35 This does not change execution of your program in any way, and also does not affect backtracking within JPF (i.e. values are properly restored). It only tells JPF to ignore marked fields when hashing/matching program states. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
36 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
37 There is a [jpf-aprop](wiki:projects/jpf-aprop) JPF module that is dedicated to Java annotation based program properties such as `@Nonnull`, `@NonShared`, `@Immutable`, `@Requires` and many others. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
38 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
39 ## The Verify API ## |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
40 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
41 Sometimes it is useful to create JPF specific test drivers, like you create JUnit test cases. In this code, you can make explicit use of JPF APIs, since it is not supposed to run outside JPF. There are several categories of APIs which are encapsulated in the `gov.nasa.jpf.vm.Verify` class. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
42 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
43 ### Data ChoiceGenerators ### |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
44 Data ChoiceGenerators (CGs) are suitable for writing test drivers that are JPF aware. The idea is to obtain non-deterministic input values from JPF in a way that it can systematically analyze all relevant choices. In its most simple form, this can be used like |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
45 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
46 ~~~~~~~~ {.java} |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
47 // test driver code |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
48 import gov.nasa.jpf.vm.Verify; |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
49 .. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
50 boolean cond = Verify.getBoolean(); |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
51 // following code is executed for both cond=true AND cond=false |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
52 .. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
53 ~~~~~~~~ |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
54 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
55 The `Verify` class contains methods for creating a number of different choice generators for builtin Java types, like |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
56 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
57 ~~~~~~~~ {.java} |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
58 .. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
59 int i = Verify.getInt(min,max); // evaluates for all values between 'min' and 'max' (inclusive) |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
60 .. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
61 double d = Verify.getDoubleFromSet(-42.0, 0.0, 42.0 ..); // evaluates all given values |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
62 .. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
63 ~~~~~~~~ |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
64 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
65 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
66 CGs don't stop at value sets that can be completely enumerated based on their type (like boolean, and - at least theoretically - integers). JPF also supports configured heuristics based choice generators, where the values sets are application dependent and can be specified in property files. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
67 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
68 ![Figure: Data ChoiceGenerators](../graphics/choicegen-example.svg){align=center width=750} |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
69 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
70 Choice generator implementation is described in a [separate section](wiki:devel/choicegenerator) of this documentation. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
71 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
72 ### Search Pruning ### |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
73 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
74 Explicitly restricting the search is useful for highly application specific properties, where it is obvious that certain values are not of interest with respect to the property. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
75 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
76 ~~~~~~~~ {.java} |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
77 // ..compute some data.. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
78 Verify.ignoreIf(data > someValue); // prune search if true |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
79 // ..do some stuff with data.. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
80 ~~~~~~~~ |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
81 If the provided expression evaluates to true, JPF does not continue to execute the current path, and backtracks to the previous non-deterministic choice point. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
82 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
83 ### State Annotation ### |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
84 Based on certain value combinations, an application might give JPF hints about the relevance of a program state that can be subsequently used by Search and/or Heuristic implementations. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
85 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
86 ~~~~~~~~ {.java} |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
87 // ..compute some data |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
88 Verify.interesting( data < someValue ); |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
89 // ..do some stuff with data |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
90 ~~~~~~~~ |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
91 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
92 This does not stop execution by JPF, but stores an 'interesting' attribute for the current state. Its more general version is used to attach arbitrary strings to states: |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
93 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
94 ~~~~~~~~ {.java} |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
95 // ..compute some data |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
96 if (data < someValue) { |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
97 Verify.setAnnotation("critical data value"); |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
98 // ..do some stuff with dat |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
99 ~~~~~~~~ |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
100 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
101 Again, this category is about to become less important since Search- and VMListeners are superior mechanisms to store not just strings but arbitrary objects as state annotations. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
102 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
103 ### Verification Output ### |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
104 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
105 This is the most simple category, which is used to differentiate between normal program output (that is executed and analyzed by JPF), and output that is strictly verification relevant, i.e. should not appear when executing a program outside JPF. Not very surprising, it contains a number of print(..) methods. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
106 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
107 ### Atomicity Control ### |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
108 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
109 this category can be used to control the number of thread interleavings JPF has to analyze. While this is problematic in terms of missing potential defects, it is was often the only way to constrain the state space so that JPF could verify a given application. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
110 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
111 ~~~~~~~~ {.java} |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
112 Verify.beginAtomic(); |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
113 ... |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
114 // all code in here is executed by JPF in one transition |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
115 ... |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
116 Verify.endAtomic(); |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
117 ~~~~~~~~ |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
118 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
119 Direct atomicity control was mainly used before the automatic, on-the-fly partial order reduction (POR) was implemented, and only remains relevant for applications that are (still) problematic with respect to POR. JPF's on-the-fly POR implementation is described in a [separate section](../devel/partial_order_reduction) of this documentation. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
120 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
121 ### Other Usages ### |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
122 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
123 Some `Verify` methods support collecting information during JPF execution, which is persistent and can be later-on queried by JPF embedding code (programs that execute JPF). This uses an MJI trick where the [native peer](../devel/mji) class (`JPF_gov_nasa_jpf_vm_Verify`) is used to set some data during JPF execution, which can be later-on retrieved by model class code (through `gov.nasa.jpf.vm.Verify`) that is executed outside of JPF. This is currently used to implement counters, which in turn are used to verify JPF itself. |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
124 |
61d41facf527
initial v8 import (history reset)
Peter Mehlitz <Peter.C.Mehlitz@nasa.gov>
parents:
diff
changeset
|
125 It should be noted that while most of the Verify APIs have alternative implementations that enable execution outside of JPF, applications using them at least don't build outside the JPF environment. Their use therefore is only recommended for JPF specific test drivers. |