Replace Distributed with Malt

- Remove `workspace_use_distributed` flag. Pluto will now always use
  separate processes.
- Replace calls to `remotecall_eval` with the appropiate Malt calls.
- Replace Distributed with Malt in tests to remove it from dependencies.
  - Add `unmake_workspace` calls in `MacroAnalysis` to prevent creating
    too many processes at the same time.
- Replace Distributed exceptions with Malt exceptions.
- Replace `pid::Integer` with `worker::Worker` in WorkspaceManager.
- Rename `workspaces` to `active_workspaces`.
- Rename `distributed_exception_result` to `workspace_exception_result`.
- Rename `make_distributed_serializable` to `make_serializable`.

Project.toml

@@ -8,20 +8,21 @@ version = "0.19.12"
 Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
 Configurations = "5218b696-f38b-4ac9-8b61-a12ec717816d"
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
-Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
 FileWatching = "7b1f6079-737a-58dc-b8bc-7a2ca5c1b5ee"
 FuzzyCompletions = "fb4132e2-a121-4a70-b8a1-d5b831dcdcc2"
 HTTP = "cd3eb016-35fb-5094-929b-558a96fad6f3"
 HypertextLiteral = "ac1192a8-f4b3-4bfe-ba22-af5b92cd3ab2"
 InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
 Logging = "56ddb016-857b-54e1-b83d-db4d58db5568"
 MIMEs = "6c6e2e6c-3030-632d-7369-2d6c69616d65"
+Malt = "36869731-bdee-424d-aa32-cab38c994e3b"
 Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 MsgPack = "99f44e22-a591-53d1-9472-aa23ef4bd671"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 PrecompileSignatures = "91cefc8d-f054-46dc-8f8c-26e11d7c5411"
 REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
 RelocatableFolders = "05181044-ff0b-4ac5-8273-598c1e38db00"
+Serialization = "9e88b42a-f829-5b0c-bbe9-9e923198166b"
 Sockets = "6462fe0b-24de-5631-8697-dd941f90decc"
 TOML = "fa267f1f-6049-4f14-aa54-33bafae1ed76"
 Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
@@ -43,12 +44,12 @@ julia = "^1.6"
 
 [extras]
 DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"
+Memoize = "c03570c3-d221-55d1-a50c-7939bbd78826"
 OffsetArrays = "6fe1bfb0-de20-5000-8ca7-80f57d26f881"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Sockets = "6462fe0b-24de-5631-8697-dd941f90decc"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 TimerOutputs = "a759f4b9-e2f1-59dc-863e-4aeb61b1ea8f"
-Memoize = "c03570c3-d221-55d1-a50c-7939bbd78826"
 
 [targets]
 test = ["DataFrames", "OffsetArrays", "Random", "Sockets", "Test", "TimerOutputs", "Memoize"]

src/Configuration.jl

@@ -128,7 +128,6 @@ Note that Pluto is quickly evolving software, maintained by designers, educators
 end
 
 const RUN_NOTEBOOK_ON_LOAD_DEFAULT = true
-const WORKSPACE_USE_DISTRIBUTED_DEFAULT = true
 const LAZY_WORKSPACE_CREATION_DEFAULT = false
 const CAPTURE_STDOUT_DEFAULT = true
 
@@ -138,13 +137,11 @@ const CAPTURE_STDOUT_DEFAULT = true
 Options to change Pluto's evaluation behaviour during internal testing. These options are not intended to be changed during normal use.
 
 - `run_notebook_on_load::Bool = $RUN_NOTEBOOK_ON_LOAD_DEFAULT` Whether to evaluate a notebook on load.
-- `workspace_use_distributed::Bool = $WORKSPACE_USE_DISTRIBUTED_DEFAULT` Whether to start notebooks in a separate process.
 - `lazy_workspace_creation::Bool = $LAZY_WORKSPACE_CREATION_DEFAULT`
 - `capture_stdout::Bool = $CAPTURE_STDOUT_DEFAULT`
 """
 @option mutable struct EvaluationOptions
     run_notebook_on_load::Bool = RUN_NOTEBOOK_ON_LOAD_DEFAULT
-    workspace_use_distributed::Bool = WORKSPACE_USE_DISTRIBUTED_DEFAULT
     lazy_workspace_creation::Bool = LAZY_WORKSPACE_CREATION_DEFAULT
     capture_stdout::Bool = CAPTURE_STDOUT_DEFAULT
 end
@@ -250,7 +247,6 @@ function from_flat_kwargs(;
         require_secret_for_open_links::Bool = REQUIRE_SECRET_FOR_OPEN_LINKS_DEFAULT,
         require_secret_for_access::Bool = REQUIRE_SECRET_FOR_ACCESS_DEFAULT,
         run_notebook_on_load::Bool = RUN_NOTEBOOK_ON_LOAD_DEFAULT,
-        workspace_use_distributed::Bool = WORKSPACE_USE_DISTRIBUTED_DEFAULT,
         lazy_workspace_creation::Bool = LAZY_WORKSPACE_CREATION_DEFAULT,
         capture_stdout::Bool = CAPTURE_STDOUT_DEFAULT,
         compile::Union{Nothing,String} = COMPILE_DEFAULT,
@@ -289,7 +285,6 @@ function from_flat_kwargs(;
     )
     evaluation = EvaluationOptions(;
         run_notebook_on_load,
-        workspace_use_distributed,
         lazy_workspace_creation,
         capture_stdout,
     )