# Thread safety annotations for C API functions. # # Each line has the form: # function_name : level # # Where level is one of: # incompatible -- not safe even with external locking # compatible -- safe if the caller serializes all access with external locks # distinct -- safe on distinct objects without external synchronization # shared -- safe for concurrent use on the same object # atomic -- atomic # # Lines beginning with '#' are ignored. # The function name must match the C domain identifier used in the documentation. # Synchronization primitives (Doc/c-api/synchronization.rst) PyMutex_Lock:shared: PyMutex_Unlock:shared: PyMutex_IsLocked:atomic: # List objects (Doc/c-api/list.rst) # Type checks - read ob_type pointer, always safe PyList_Check:atomic: PyList_CheckExact:atomic: # Creation - pure allocation, no shared state PyList_New:atomic: # Size - uses atomic load on free-threaded builds PyList_Size:atomic: PyList_GET_SIZE:atomic: # Strong-reference lookup - lock-free with atomic ops PyList_GetItemRef:atomic: # Borrowed-reference lookups - no locking; returned borrowed # reference is unsafe in free-threaded builds without # external synchronization PyList_GetItem:compatible: PyList_GET_ITEM:compatible: # Single-item mutations - hold per-object lock for duration; # appear atomic to lock-free readers PyList_SetItem:atomic: PyList_Append:atomic: # Insert - protected by per-object critical section; shifts # elements so lock-free readers may observe intermediate states PyList_Insert:shared: # Initialization macro - no synchronization; normally only used # to fill in new lists where there is no previous content PyList_SET_ITEM:compatible: # Bulk operations - hold per-object lock for duration PyList_GetSlice:atomic: PyList_AsTuple:atomic: PyList_Clear:atomic: # Reverse - protected by per-object critical section; swaps # elements so lock-free readers may observe intermediate states PyList_Reverse:shared: # Slice assignment - lock target list; also lock source when it # is a list PyList_SetSlice:shared: # Sort - per-object lock held; the list is emptied before sorting # so other threads may observe an empty list, but they won't see the # intermediate states of the sort PyList_Sort:shared: # Extend - lock target list; also lock source when it is a # list, set, or dict PyList_Extend:shared: # Creation - pure allocation, no shared state PyBytes_FromString:atomic: PyBytes_FromStringAndSize:atomic: PyBytes_DecodeEscape:atomic: # Creation from formatting C primitives - pure allocation, no shared state PyBytes_FromFormat:atomic: PyBytes_FromFormatV:atomic: # Creation from object - uses buffer protocol so may call arbitrary code; # safe as long as the buffer is not mutated by another thread during the operation PyBytes_FromObject:shared: # Size - uses atomic load on free-threaded builds PyBytes_Size:atomic: PyBytes_GET_SIZE:atomic: # Raw data - no locking; mutating it is unsafe if the bytes object is shared between threads PyBytes_AsString:compatible: PyBytes_AS_STRING:compatible: PyBytes_AsStringAndSize:compatible: # Concatenation - uses buffer protocol; safe as long as buffer is not mutated by another thread during the operation PyBytes_Concat:shared: PyBytes_ConcatAndDel:shared: PyBytes_Join:shared: # Resizing - safe if the object is unique _PyBytes_Resize:distinct: # Repr - atomic as bytes are immutable PyBytes_Repr:atomic: # Creation from object - may call arbitrary code PyByteArray_FromObject:shared: # Creation - pure allocation, no shared state PyByteArray_FromStringAndSize:atomic: # Concatenation - uses buffer protocol; safe as long as buffer is not mutated by another thread during the operation PyByteArray_Concat:shared: # Size - uses atomic load on free-threaded builds PyByteArray_Size:atomic: PyByteArray_GET_SIZE:atomic: # Raw data - no locking; mutating it is unsafe if the bytearray object is shared between threads PyByteArray_AsString:compatible: PyByteArray_AS_STRING:compatible: # Capsule objects (Doc/c-api/capsule.rst) # Type check - read ob_type pointer, always safe PyCapsule_CheckExact:atomic: # Creation - pure allocation, no shared state PyCapsule_New:atomic: # Validation - reads pointer and name fields; safe on distinct objects PyCapsule_IsValid:distinct: # Getters - read struct fields; safe on distinct objects but # concurrent access to the same capsule requires external synchronization PyCapsule_GetPointer:distinct: PyCapsule_GetName:distinct: PyCapsule_GetDestructor:distinct: PyCapsule_GetContext:distinct: # Setters - write struct fields; safe on distinct objects but # concurrent access to the same capsule requires external synchronization PyCapsule_SetPointer:distinct: PyCapsule_SetName:distinct: PyCapsule_SetDestructor:distinct: PyCapsule_SetContext:distinct: # Import - looks up a capsule from a module attribute and # calls PyCapsule_GetPointer; may call arbitrary code PyCapsule_Import:compatible: