task switch not allowed from inside gc finalizer

[jariji]

I don't have a reproducer yet but when I run my function in parallel under OhMyThreads.tmap instead of Base.map one of the threads failed.

@maleadt suggested it's because of behavior in AMDGPU.jl:

it shouldn't take locks from functionality that is used in finalizers (memory_stats)

ERROR: TaskFailedException
Stacktrace:
  [1] wait
    @ ./task.jl:352 [inlined]
  [2] fetch
    @ ./task.jl:372 [inlined]
  [3] fetch
    @ ~/.julia/packages/StableTasks/3CrzR/src/internals.jl:9 [inlined]
  [4] _mapreduce(f::typeof(fetch), op::typeof(append!!), ::IndexLinear, A::Vector{StableTasks.StableTask{Any}})
    @ Base ./reduce.jl:440
  [5] _mapreduce_dim(f::Function, op::Function, ::Base._InitialValue, A::Vector{StableTasks.StableTask{Any}}, ::Colon)
    @ Base ./reducedim.jl:365
  [6] mapreduce(f::Function, op::Function, A::Vector{StableTasks.StableTask{Any}})
    @ Base ./reducedim.jl:357
  [7] _tmapreduce(f::Function, op::Function, Arrs::Tuple{…}, ::Type{…}, scheduler::OhMyThreads.Schedulers.DynamicScheduler{…}, mapreduce_kwargs::@NamedTuple{})
    @ OhMyThreads.Implementation ~/.julia/packages/OhMyThreads/OK01i/src/implementation.jl:95
  [8] #tmapreduce#21
    @ ~/.julia/packages/OhMyThreads/OK01i/src/implementation.jl:67 [inlined]
  [9] _tmap(::OhMyThreads.Schedulers.DynamicScheduler{OhMyThreads.Schedulers.FixedCount}, ::Function, ::UnitRange{Int64})
    @ OhMyThreads.Implementation ~/.julia/packages/OhMyThreads/OK01i/src/implementation.jl:435
 [10] tmap(::Function, ::UnitRange{Int64}; scheduler::OhMyThreads.Schedulers.NotGiven, kwargs::@Kwargs{})
    @ OhMyThreads.Implementation ~/.julia/packages/OhMyThreads/OK01i/src/implementation.jl:357
 [11] tmap(::Function, ::UnitRange{Int64})
    @ OhMyThreads.Implementation ~/.julia/packages/OhMyThreads/OK01i/src/implementation.jl:322
 [12] top-level scope
    @ ./timing.jl:279 [inlined]
 [13] top-level scope


nested task error: schedule: Task not runnable
    Stacktrace:
      [1] error(s::String)
        @ Base ./error.jl:35
      [2] schedule(t::Task, arg::Any; error::Bool)
        @ Base ./task.jl:851
      [3] schedule
        @ ./task.jl:849 [inlined]
      [4] notify(c::Base.GenericCondition{Base.Threads.SpinLock}, arg::Any, all::Bool, error::Bool)
        @ Base ./condition.jl:154
      [5] notify (repeats 2 times)
        @ ./condition.jl:148 [inlined]
      [6] (::Base.var"#notifywaiters#649")(rl::ReentrantLock)
        @ Base ./lock.jl:187
      [7] (::Base.var"#_unlock#648")(rl::ReentrantLock)
        @ Base ./lock.jl:183
      [8] unlock
        @ ./lock.jl:177 [inlined]
      [9] macro expansion
        @ ./lock.jl:269 [inlined]
     [10] lock(f::AMDGPU.var"#27#29"{HIPDevice}, x::AMDGPU.LockedObject{Dict{Int64, AMDGPU.MemoryStats}})
        @ AMDGPU ~/.julia/packages/AMDGPU/LXtMw/src/AMDGPU.jl:42
     [11] memory_stats (repeats 2 times)
        @ ~/.julia/packages/AMDGPU/LXtMw/src/memory.jl:122 [inlined]
     [12] maybe_collect(; blocking::Bool)
        @ AMDGPU ~/.julia/packages/AMDGPU/LXtMw/src/memory.jl:141
     [13] maybe_collect
        @ ~/.julia/packages/AMDGPU/LXtMw/src/memory.jl:138 [inlined]
     [14] AMDGPU.Runtime.Mem.HIPBuffer(bytesize::Int64; stream::HIPStream)
        @ AMDGPU.Runtime.Mem ~/.julia/packages/AMDGPU/LXtMw/src/runtime/memory/hip.jl:37
     [15] HIPBuffer
        @ ~/.julia/packages/AMDGPU/LXtMw/src/runtime/memory/hip.jl:33 [inlined]
     [16] pool_alloc
        @ ~/.julia/packages/AMDGPU/LXtMw/src/memory.jl:261 [inlined]
     [17] ROCArray
        @ ~/.julia/packages/AMDGPU/LXtMw/src/array.jl:10 [inlined]
     [18] similar
        @ ./abstractarray.jl:877 [inlined]
     [19] similar
        @ ~/.julia/packages/AMDGPU/LXtMw/src/broadcast.jl:18 [inlined]
     [20] _mapreduce(::var"#44#45"{…}, ::typeof(+), ::ROCArray{…}, ::ROCArray{…}; dims::Colon, init::Nothing)
        @ GPUArrays ~/.julia/packages/GPUArrays/qt4ax/src/host/mapreduce.jl:62
     [21] _mapreduce
        @ ~/.julia/packages/GPUArrays/qt4ax/src/host/mapreduce.jl:33 [inlined]
     [22] mapreduce
        @ ~/.julia/packages/GPUArrays/qt4ax/src/host/mapreduce.jl:28 [inlined]

running finalizer: ErrorException("task switch not allowed from inside gc finalizer")
ijl_error at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/rtutils.c:41
ijl_switch at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/task.c:636
try_yieldto at ./task.jl:921
wait at ./task.jl:995
#wait#645 at ./condition.jl:130
wait at ./condition.jl:125 [inlined]
slowlock at ./lock.jl:156
lock at ./lock.jl:147 [inlined]
macro expansion at ./lock.jl:265 [inlined]
lock at /home/user/.julia/packages/AMDGPU/LXtMw/src/AMDGPU.jl:42
memory_stats at /home/user/.julia/packages/AMDGPU/LXtMw/src/memory.jl:122 [inlined]
#free#9 at /home/user/.julia/packages/AMDGPU/LXtMw/src/runtime/memory/hip.jl:79 [inlined]
free at /home/user/.julia/packages/AMDGPU/LXtMw/src/runtime/memory/hip.jl:74
unknown function (ip: 0x7fe637f1d4a9)
_jl_invoke at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:2895 [inlined]
ijl_apply_generic at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:3077
#34 at /home/user/.julia/packages/AMDGPU/LXtMw/src/memory.jl:272
context! at /home/user/.julia/packages/AMDGPU/LXtMw/src/tls.jl:131
_pool_free at /home/user/.julia/packages/AMDGPU/LXtMw/src/memory.jl:272
pool_free at /home/user/.julia/packages/AMDGPU/LXtMw/src/memory.jl:265
unknown function (ip: 0x7fe637f1d175)
_jl_invoke at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:2895 [inlined]
ijl_apply_generic at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:3077
release at /home/user/.julia/packages/GPUArrays/qt4ax/src/host/abstractarray.jl:42
unsafe_free! at /home/user/.julia/packages/GPUArrays/qt4ax/src/host/abstractarray.jl:91 [inlined]
unsafe_free! at /home/user/.julia/packages/AMDGPU/LXtMw/src/array.jl:24
unknown function (ip: 0x7fe636d42a55)
_jl_invoke at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:2895 [inlined]
ijl_apply_generic at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:3077
run_finalizer at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gc.c:318
jl_gc_run_finalizers_in_list at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gc.c:408
run_finalizers at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gc.c:454
enable_finalizers at ./gcutils.jl:157 [inlined]
unlock at ./locks-mt.jl:68 [inlined]
multiq_deletemin at ./partr.jl:168
trypoptask at ./task.jl:977
jfptr_trypoptask_75364.1 at /nix/store/x044gz5qmcy25gm3cjil3kg0mv5jnf5p-julia-bin-1.10.3/lib/julia/sys.so (unknown line)
_jl_invoke at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:2895 [inlined]
ijl_apply_generic at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:3077
get_next_task at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/partr.c:329 [inlined]
ijl_task_get_next at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/partr.c:382
poptask at ./task.jl:985
wait at ./task.jl:994
task_done_hook at ./task.jl:675
jfptr_task_done_hook_75287.1 at /nix/store/x044gz5qmcy25gm3cjil3kg0mv5jnf5p-julia-bin-1.10.3/lib/julia/sys.so (unknown line)
_jl_invoke at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:2895 [inlined]
ijl_apply_generic at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/gf.c:3077
jl_apply at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/julia.h:1982 [inlined]
jl_finish_task at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/task.c:320
start_task at /cache/build/builder-amdci4-2/julialang/julia-release-1-dot-10/src/task.c:1249