update docs

Author: Christopher Doris

docs/src/faq.md

@@ -4,19 +4,23 @@
 
 No.
 
-Some rules if you are writing multithreaded code:
-- Only call Python functions from the first thread.
-- You probably also need to call `PythonCall.GC.disable()` on the main thread before any
-  threaded block of code. Remember to call `PythonCall.GC.enable()` again afterwards.
-  (This is because Julia finalizers can be called from any thread.)
-- Julia intentionally causes segmentation faults as part of the GC safepoint mechanism.
-  If unhandled, these segfaults will result in termination of the process. To enable signal handling,
-  set `PYTHON_JULIACALL_HANDLE_SIGNALS=yes` before any calls to import juliacall. This is equivalent
-  to starting julia with `julia --handle-signals=yes`, the default behavior in Julia. 
-  See discussion [here](https://github.com/JuliaPy/PythonCall.jl/issues/219#issuecomment-1605087024) for more information.
-- You may still encounter problems.
-
-Related issues: [#201](https://github.com/JuliaPy/PythonCall.jl/issues/201), [#202](https://github.com/JuliaPy/PythonCall.jl/issues/202)
+However it is safe to use PythonCall with Julia with multiple threads, provided you only
+call Python code from the first thread. (Before v0.9.22, tricks such as disabling the
+garbage collector were required.)
+
+From Python, to use JuliaCall with multiple threads you probably need to set
+[`PYTHON_JULIACALL_HANDLE_SIGNALS=yes`](@ref julia-config) before importing JuliaCall.
+This is because Julia intentionally causes segmentation faults as part of the GC
+safepoint mechanism. If unhandled, these segfaults will result in termination of the
+process. This is equivalent to starting julia with `julia --handle-signals=yes`, the
+default behavior in Julia. See discussion
+[here](https://github.com/JuliaPy/PythonCall.jl/issues/219#issuecomment-1605087024)
+for more information.
+
+Related issues:
+[#201](https://github.com/JuliaPy/PythonCall.jl/issues/201),
+[#202](https://github.com/JuliaPy/PythonCall.jl/issues/202),
+[#529](https://github.com/JuliaPy/PythonCall.jl/pull/529)
 
 ## Issues when Numpy arrays are expected
 

docs/src/releasenotes.md

@@ -1,5 +1,13 @@
 # Release Notes
 
+## Unreleased
+* Finalizers are now thread-safe, meaning PythonCall now works in the presence of
+  multi-threaded Julia code. Previously, tricks such as disabling the garbage collector
+  were required. Python code must still be called on the main thread.
+* `GC.disable()` and `GC.enable()` are now a no-op and deprecated since they are no
+  longer required for thread-safety. These will be removed in v1.
+* Adds `GC.gc()`.
+
 ## 0.9.21 (2024-07-20)
 * `Serialization.serialize` can use `dill` instead of `pickle` by setting the env var `JULIA_PYTHONCALL_PICKLE=dill`.
 * `numpy.bool_` can now be converted to `Bool` and other number types.

src/GC/GC.jl

@@ -3,7 +3,7 @@
 
 Garbage collection of Python objects.
 
-See [`enable`](@ref), [`disable`](@ref) and [`gc`](@ref).
+See [`gc`](@ref).
 """
 module GC