Merge branch 'main' into libptr-by-env

Author: cjdoris

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 * Add option `lib` to JuliaCall. Setting this will skip the discovery subprocess.
 * Add support for using a system image in `juliacall` that has `PythonCall` baked in.
+* Add method `pynext(x, d)` to return a default value `d` if there are no more elements.
 * Bug fixes.
 
 ## 0.9.34 (2026-05-18)

pyproject.toml

@@ -13,7 +13,7 @@ classifiers = [
     "Operating System :: OS Independent",
 ]
 requires-python = ">=3.10, <4"
-dependencies = ["juliapkg >=0.1.21, <0.2"]
+dependencies = ["juliapkg >=0.1.24, <0.2"]
 
 [dependency-groups]
 dev = [

pysrc/juliacall/__init__.py

@@ -201,6 +201,8 @@ def args_from_config(config):
         # Find the Julia executable and project
         CONFIG['exepath'] = exepath = juliapkg.executable()
         CONFIG['project'] = project = juliapkg.project()
+        if libpath is None:
+            CONFIG['libpath'] = libpath = juliapkg.libjulia()
     else:
         raise Exception("Both PYTHON_JULIACALL_PROJECT and PYTHON_JULIACALL_EXE must be set together, not only one of them.")
     if (libpath is not None) and (exepath is None):

src/Core/builtins.jl

@@ -507,11 +507,27 @@ Equivalent to `iter(x)` in Python.
 pyiter(x) = pynew(errcheck(@autopy x C.PyObject_GetIter(x_)))
 
 """
-    pynext(x)
+    pynext(x, [d])
 
-Equivalent to `next(x)` in Python.
+Equivalent to `next(x, d)` in Python.
+
+Returns the next item from the iterator `x`. If there are no more items, returns `d` if
+given, else raises `StopIteration`.
 """
-pynext(x) = pybuiltins.next(x)
+function pynext(x)
+    ptr = errcheck_ambig(C.PyIter_Next(x))
+    if ptr == C.PyNULL
+        errset(pybuiltins.StopIteration)
+        pythrow()
+    else
+        pynew(ptr)
+    end
+end
+
+function pynext(x, d)
+    ptr = errcheck_ambig(C.PyIter_Next(x))
+    ptr == C.PyNULL ? d : pynew(ptr)
+end
 
 """
     unsafe_pynext(x)

src/JlWrap/C.jl

@@ -23,8 +23,14 @@ const PyJuliaBase_Type = Ref(C.PyNULL)
 # we store the actual julia values here
 # the `value` field of `PyJuliaValueObject` indexes into here
 const PYJLVALUES = []
-# unused indices in PYJLVALUES
+# unused indices in PYJLVALUES; kept the same length as PYJLVALUES (extra slots
+# are pushed alongside PYJLVALUES so the dealloc/finalizer path never has to
+# resize this vector). Only the first PYJLFREEVALUECOUNT[] entries are valid
+# free indices; the rest are placeholders.
 const PYJLFREEVALUES = Int[]
+const PYJLFREEVALUECOUNT = Ref(0)
+# lock protecting PYJLVALUES, PYJLFREEVALUES and PYJLFREEVALUECOUNT
+const PYJL_LOCK = Threads.SpinLock()
 
 function _pyjl_new(t::C.PyPtr, ::C.PyPtr, ::C.PyPtr)
     alloc = C.PyType_GetSlot(t, C.Py_tp_alloc)
@@ -39,8 +45,14 @@ end
 function _pyjl_dealloc(o::C.PyPtr)
     idx = C.@ft UnsafePtr{PyJuliaValueObject}(o).value[]
     if idx != 0
+        # No allocation in this critical section: PYJLFREEVALUES has been pre-sized
+        # to match PYJLVALUES by PyJuliaValue_SetValue, so recording a free index is
+        # just a write to an existing slot plus a counter bump. This avoids the GC-triggered
+        lock(PYJL_LOCK)
         PYJLVALUES[idx] = nothing
-        push!(PYJLFREEVALUES, idx)
+        PYJLFREEVALUECOUNT[] += 1
+        PYJLFREEVALUES[PYJLFREEVALUECOUNT[]] = idx
+        unlock(PYJL_LOCK)
     end
     (C.@ft UnsafePtr{PyJuliaValueObject}(o).weaklist[!]) == C.PyNULL || C.PyObject_ClearWeakRefs(o)
     freeptr = C.PyType_GetSlot(C.Py_Type(o), C.Py_tp_free)
@@ -375,13 +387,19 @@ PyJuliaValue_SetValue(_o, @nospecialize(v)) = Base.GC.@preserve _o begin
     o = C.asptr(_o)
     idx = C.@ft UnsafePtr{PyJuliaValueObject}(o).value[]
     if idx == 0
-        if isempty(PYJLFREEVALUES)
+        lock(PYJL_LOCK)
+        if PYJLFREEVALUECOUNT[] == 0
+            # Grow both vectors together so length(PYJLFREEVALUES) == length(PYJLVALUES)
+            # is preserved. The 0 in PYJLFREEVALUES is just a placeholder
             push!(PYJLVALUES, v)
+            push!(PYJLFREEVALUES, 0)
             idx = length(PYJLVALUES)
         else
-            idx = pop!(PYJLFREEVALUES)
+            idx = PYJLFREEVALUES[PYJLFREEVALUECOUNT[]]
+            PYJLFREEVALUECOUNT[] -= 1
             PYJLVALUES[idx] = v
         end
+        unlock(PYJL_LOCK)
         C.@ft UnsafePtr{PyJuliaValueObject}(o).value[] = idx
     else
         PYJLVALUES[idx] = v

test/Core.jl

@@ -223,25 +223,45 @@
 end
 
 @testitem "iter" begin
-    @test_throws PyException pyiter(pybuiltins.None)
-    @test_throws PyException pyiter(pybuiltins.True)
-    # unsafe_pynext
-    it = pyiter(pyrange(2))
-    x = PythonCall.unsafe_pynext(it)
-    @test !PythonCall.pyisnull(x)
-    @test pyeq(Bool, x, 0)
-    x = PythonCall.unsafe_pynext(it)
-    @test !PythonCall.pyisnull(x)
-    @test pyeq(Bool, x, 1)
-    x = PythonCall.unsafe_pynext(it)
-    @test PythonCall.pyisnull(x)
-    # pynext
-    it = pyiter(pyrange(2))
-    x = pynext(it)
-    @test pyeq(Bool, x, 0)
-    x = pynext(it)
-    @test pyeq(Bool, x, 1)
-    @test_throws PyException pynext(it)
+    @testset "non-iterables" begin
+        @test_throws PyException pyiter(pybuiltins.None)
+        @test_throws PyException pyiter(pybuiltins.True)
+    end
+    @testset "unsafe_pynext" begin
+        it = pyiter(pyrange(2))
+        x = PythonCall.unsafe_pynext(it)
+        @test x isa Py
+        @test !PythonCall.pyisnull(x)
+        @test pyeq(Bool, x, 0)
+        x = PythonCall.unsafe_pynext(it)
+        @test x isa Py
+        @test !PythonCall.pyisnull(x)
+        @test pyeq(Bool, x, 1)
+        x = PythonCall.unsafe_pynext(it)
+        @test x isa Py
+        @test PythonCall.pyisnull(x)
+    end
+    @testset "pynext" begin
+        it = pyiter(pyrange(2))
+        x = pynext(it)
+        @test x isa Py
+        @test pyeq(Bool, x, 0)
+        x = pynext(it)
+        @test x isa Py
+        @test pyeq(Bool, x, 1)
+        @test_throws PyException pynext(it)
+    end
+    @testset "pynext with default" begin
+        it = pyiter(pyrange(2))
+        x = pynext(it, nothing)
+        @test x isa Py
+        @test pyeq(Bool, x, 0)
+        x = pynext(it, nothing)
+        @test x isa Py
+        @test pyeq(Bool, x, 1)
+        x = pynext(it, nothing)
+        @test x === nothing
+    end
 end
 
 @testitem "number" begin