scatterMap.asMap().toList() returns wrong values [310365754]

Fixed

Bug

Status Update

No update yet.

Description

ad...@google.com

created issue #1

Nov 11, 2023 07:35PM

Component used: ScatterMap

Version used: HEAD 949f3a11bf0a5d174b3516f3555a0e20bccd0f0e

Devices/Android versions reproduced on: emulator sdk 31

Running this unit test produces the following result:

    @Test
    fun testScatterMap() {
        val scatterMap = mutableScatterMapOf<Int, Int>()
        scatterMap[0] = 0
        scatterMap[1] = -1
        assertThat(scatterMap.asMap().toList()).containsExactly(0 to 0, 1 to -1)
    }

expected      : [(0, 0), (1, -1)]
but was       : [(1, -1), (1, -1)]

Comments

mo...@google.com <mo...@google.com> #2Nov 13, 2023 05:00PM

Reassigned to ro...@google.com.

Yigit, do you have time to fix it?

reemission of the same liveData is racy

ro...@google.com <ro...@google.com> #3Nov 15, 2023 10:59PM

Accepted by ro...@google.com.

yea i'll take it.

ap...@google.com <ap...@google.com> #4Nov 16, 2023 12:38AM

Marked as fixed.

Thanks for the detailed analysis. This may not be an issue anymore since we've started using Main.immediate there but I' not sure; I'll try to create a test case.

ad...@google.com <ad...@google.com> Nov 16, 2023 12:46AM

Reassigned to ro...@google.com.

ap...@google.com <ap...@google.com> #5Nov 16, 2023 04:48PM

just emitting same live data reproduces the issue.

@Test
fun raceTest() {
val subLiveData = MutableLiveData(1)
val subject = liveData(testScope.coroutineContext) {
emitSource(subLiveData)
emitSource(subLiveData) //crashes
}
subject.addObserver().apply {
testScope.advanceUntilIdle()
}
}

pr...@google.com <pr...@google.com> #6Nov 29, 2023 09:39PM

With 2.2.0-alpha04 (that use Main.immediate), the issue seems to be still there (I tested it by calling emitSource() twice, like your test case)

Issue 310365754