Move utilities to libs/net
These files used to be in the network stack directory, but the libs
directory is a much more suitable place for them.
Also fix a typo : ConcurrentIntepreter → ConcurrentInterpreter
Also move {FdEvents,Packet}Reader to internal annotations. That's
what they should have been using in the first place anyway.
Note that this does not fix preupload issues reported by
checkstyle to make review easier. The fixes are in a followup
patch to this one.
Test: checkbuild
Change-Id: I675077fd42cbb092c0e6bd56571f2fc022e582fd
diff --git a/staticlibs/devicetests/com/android/testutils/ConcurrentInterpreter.kt b/staticlibs/devicetests/com/android/testutils/ConcurrentInterpreter.kt
new file mode 100644
index 0000000..98464eb
--- /dev/null
+++ b/staticlibs/devicetests/com/android/testutils/ConcurrentInterpreter.kt
@@ -0,0 +1,188 @@
+package com.android.testutils
+
+import android.os.SystemClock
+import java.util.concurrent.CyclicBarrier
+import kotlin.system.measureTimeMillis
+import kotlin.test.assertEquals
+import kotlin.test.assertFails
+import kotlin.test.assertNull
+import kotlin.test.assertTrue
+
+// The table contains pairs associating a regexp with the code to run. The statement is matched
+// against each matcher in sequence and when a match is found the associated code is run, passing
+// it the TrackRecord under test and the result of the regexp match.
+typealias InterpretMatcher<T> = Pair<Regex, (ConcurrentInterpreter<T>, T, MatchResult) -> Any?>
+
+// The default unit of time for interpreted tests
+val INTERPRET_TIME_UNIT = 40L // ms
+
+/**
+ * A small interpreter for testing parallel code. The interpreter will read a list of lines
+ * consisting of "|"-separated statements. Each column runs in a different concurrent thread
+ * and all threads wait for each other in between lines. Each statement is split on ";" then
+ * matched with regular expressions in the instructionTable constant, which contains the
+ * code associated with each statement. The interpreter supports an object being passed to
+ * the interpretTestSpec() method to be passed in each lambda (think about the object under
+ * test), and an optional transform function to be executed on the object at the start of
+ * every thread.
+ *
+ * The time unit is defined in milliseconds by the interpretTimeUnit member, which has a default
+ * value but can be passed to the constructor. Whitespace is ignored.
+ *
+ * The interpretation table has to be passed as an argument. It's a table associating a regexp
+ * with the code that should execute, as a function taking three arguments : the interpreter,
+ * the regexp match, and the object. See the individual tests for the DSL of that test.
+ * Implementors for new interpreting languages are encouraged to look at the defaultInterpretTable
+ * constant below for an example of how to write an interpreting table.
+ * Some expressions already exist by default and can be used by all interpreters. They include :
+ * sleep(x) : sleeps for x time units and returns Unit ; sleep alone means sleep(1)
+ * EXPR = VALUE : asserts that EXPR equals VALUE. EXPR is interpreted. VALUE can either be the
+ * string "null" or an int. Returns Unit.
+ * EXPR time x..y : measures the time taken by EXPR and asserts it took at least x and at most
+ * y time units.
+ * EXPR // any text : comments are ignored.
+ */
+open class ConcurrentInterpreter<T>(
+ localInterpretTable: List<InterpretMatcher<T>>,
+ val interpretTimeUnit: Long = INTERPRET_TIME_UNIT
+) {
+ private val interpretTable: List<InterpretMatcher<T>> =
+ localInterpretTable + getDefaultInstructions()
+
+ // Split the line into multiple statements separated by ";" and execute them. Return whatever
+ // the last statement returned.
+ fun interpretMultiple(instr: String, r: T): Any? {
+ return instr.split(";").map { interpret(it.trim(), r) }.last()
+ }
+
+ // Match the statement to a regex and interpret it.
+ fun interpret(instr: String, r: T): Any? {
+ val (matcher, code) =
+ interpretTable.find { instr matches it.first } ?: throw SyntaxException(instr)
+ val match = matcher.matchEntire(instr) ?: throw SyntaxException(instr)
+ return code(this, r, match)
+ }
+
+ // Spins as many threads as needed by the test spec and interpret each program concurrently,
+ // having all threads waiting on a CyclicBarrier after each line.
+ // |lineShift| says how many lines after the call the spec starts. This is used for error
+ // reporting. Unfortunately AFAICT there is no way to get the line of an argument rather
+ // than the line at which the expression starts.
+ fun interpretTestSpec(
+ spec: String,
+ initial: T,
+ lineShift: Int = 0,
+ threadTransform: (T) -> T = { it }
+ ) {
+ // For nice stack traces
+ val callSite = getCallingMethod()
+ val lines = spec.trim().trim('\n').split("\n").map { it.split("|") }
+ // |threads| contains arrays of strings that make up the statements of a thread : in other
+ // words, it's an array that contains a list of statements for each column in the spec.
+ val threadCount = lines[0].size
+ assertTrue(lines.all { it.size == threadCount })
+ val threadInstructions = (0 until threadCount).map { i -> lines.map { it[i].trim() } }
+ val barrier = CyclicBarrier(threadCount)
+ var crash: InterpretException? = null
+ threadInstructions.mapIndexed { threadIndex, instructions ->
+ Thread {
+ val threadLocal = threadTransform(initial)
+ barrier.await()
+ var lineNum = 0
+ instructions.forEach {
+ if (null != crash) return@Thread
+ lineNum += 1
+ try {
+ interpretMultiple(it, threadLocal)
+ } catch (e: Throwable) {
+ // If fail() or some exception was called, the thread will come here ; if
+ // the exception isn't caught the process will crash, which is not nice for
+ // testing. Instead, catch the exception, cancel other threads, and report
+ // nicely. Catch throwable because fail() is AssertionError, which inherits
+ // from Error.
+ crash = InterpretException(threadIndex, it,
+ callSite.lineNumber + lineNum + lineShift,
+ callSite.className, callSite.methodName, callSite.fileName, e)
+ }
+ barrier.await()
+ }
+ }.also { it.start() }
+ }.forEach { it.join() }
+ // If the test failed, crash with line number
+ crash?.let { throw it }
+ }
+
+ // Helper to get the stack trace for a calling method
+ private fun getCallingStackTrace(): Array<StackTraceElement> {
+ try {
+ throw RuntimeException()
+ } catch (e: RuntimeException) {
+ return e.stackTrace
+ }
+ }
+
+ // Find the calling method. This is the first method in the stack trace that is annotated
+ // with @Test.
+ fun getCallingMethod(): StackTraceElement {
+ val stackTrace = getCallingStackTrace()
+ return stackTrace.find { element ->
+ val clazz = Class.forName(element.className)
+ // Because the stack trace doesn't list the formal arguments, find all methods with
+ // this name and return this name if any of them is annotated with @Test.
+ clazz.declaredMethods
+ .filter { method -> method.name == element.methodName }
+ .any { method -> method.getAnnotation(org.junit.Test::class.java) != null }
+ } ?: stackTrace[3]
+ // If no method is annotated return the 4th one, because that's what it usually is :
+ // 0 is getCallingStackTrace, 1 is this method, 2 is ConcurrentInterpreter#interpretTestSpec
+ }
+}
+
+private fun <T> getDefaultInstructions() = listOf<InterpretMatcher<T>>(
+ // Interpret an empty line as doing nothing.
+ Regex("") to { _, _, _ -> null },
+ // Ignore comments.
+ Regex("(.*)//.*") to { i, t, r -> i.interpret(r.strArg(1), t) },
+ // Interpret "XXX time x..y" : run XXX and check it took at least x and not more than y
+ Regex("""(.*)\s*time\s*(\d+)\.\.(\d+)""") to { i, t, r ->
+ val time = measureTimeMillis { i.interpret(r.strArg(1), t) }
+ assertTrue(time in r.timeArg(2)..r.timeArg(3), "$time not in ${r.timeArg(2)..r.timeArg(3)}")
+ },
+ // Interpret "XXX = YYY" : run XXX and assert its return value is equal to YYY. "null" supported
+ Regex("""(.*)\s*=\s*(null|\d+)""") to { i, t, r ->
+ i.interpret(r.strArg(1), t).also {
+ if ("null" == r.strArg(2)) assertNull(it) else assertEquals(r.intArg(2), it)
+ }
+ },
+ // Interpret sleep. Optional argument for the count, in INTERPRET_TIME_UNIT units.
+ Regex("""sleep(\((\d+)\))?""") to { i, t, r ->
+ SystemClock.sleep(if (r.strArg(2).isEmpty()) i.interpretTimeUnit else r.timeArg(2))
+ },
+ Regex("""(.*)\s*fails""") to { i, t, r ->
+ assertFails { i.interpret(r.strArg(1), t) }
+ }
+)
+
+class SyntaxException(msg: String, cause: Throwable? = null) : RuntimeException(msg, cause)
+class InterpretException(
+ threadIndex: Int,
+ instr: String,
+ lineNum: Int,
+ className: String,
+ methodName: String,
+ fileName: String,
+ cause: Throwable
+) : RuntimeException("Failure: $instr", cause) {
+ init {
+ stackTrace = arrayOf(StackTraceElement(
+ className,
+ "$methodName:thread$threadIndex",
+ fileName,
+ lineNum)) + super.getStackTrace()
+ }
+}
+
+// Some small helpers to avoid to say the large ".groupValues[index].trim()" every time
+fun MatchResult.strArg(index: Int) = this.groupValues[index].trim()
+fun MatchResult.intArg(index: Int) = strArg(index).toInt()
+fun MatchResult.timeArg(index: Int) = INTERPRET_TIME_UNIT * intArg(index)