Fix a few places where the lltrace debug output printed ``(null)`` instead of an opcode name, because it was calling ``_PyUOpName()`` on a Tier-1 opcode.
It can be used to set the location of a .python_history file
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Co-authored-by: Levi Sabah <0xl3vi@gmail.com>
Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>
This splits part of Modules/gcmodule.c of into Python/gc.c, which
now contains the core garbage collection implementation. The Python
module remain in the Modules/gcmodule.c file.
* gh-112532: Tag mimalloc heaps and pages
Mimalloc pages are data structures that contain contiguous allocations
of the same block size. Note that they are distinct from operating
system pages. Mimalloc pages are contained in segments.
When a thread exits, it abandons any segments and contained pages that
have live allocations. These segments and pages may be later reclaimed
by another thread. To support GC and certain thread-safety guarantees in
free-threaded builds, we want pages to only be reclaimed by the
corresponding heap in the claimant thread. For example, we want pages
containing GC objects to only be claimed by GC heaps.
This allows heaps and pages to be tagged with an integer tag that is
used to ensure that abandoned pages are only claimed by heaps with the
same tag. Heaps can be initialized with a tag (0-15); any page allocated
by that heap copies the corresponding tag.
* Fix conversion warning
* gh-112532: Isolate abandoned segments by interpreter
Mimalloc segments are data structures that contain memory allocations along
with metadata. Each segment is "owned" by a thread. When a thread exits,
it abandons its segments to a global pool to be later reclaimed by other
threads. This changes the pool to be per-interpreter instead of process-wide.
This will be important for when we use mimalloc to find GC objects in the
`--disable-gil` builds. We want heaps to only store Python objects from a
single interpreter. Absent this change, the abandoning and reclaiming process
could break this isolation.
* Add missing '&_mi_abandoned_default' to 'tld_empty'
* gh-112532: Use separate mimalloc heaps for GC objects
In `--disable-gil` builds, we now use four separate heaps in
anticipation of using mimalloc to find GC objects when the GIL is
disabled. To support this, we also make a few changes to mimalloc:
* `mi_heap_t` and `mi_tld_t` initialization is split from allocation.
This allows us to have a `mi_tld_t` per-`PyThreadState`, which is
important to keep interpreter isolation, since the same OS thread may
run in multiple interpreters (using different PyThreadStates.)
* Heap abandoning (mi_heap_collect_ex) can now be called from a
different thread than the one that created the heap. This is necessary
because we may clear and delete the containing PyThreadStates from a
different thread during finalization and after fork().
* Use enum instead of defines and guard mimalloc includes.
* The enum typedef will be convenient for future PRs that use the type.
* Guarding the mimalloc includes allows us to unconditionally include
pycore_mimalloc.h from other header files that rely on things like
`struct _mimalloc_thread_state`.
* Only define _mimalloc_thread_state in Py_GIL_DISABLED builds
Fix error check on mmap(2)
It should check MAP_FAILED instead of NULL for error.
On mmap(2) man page:
RETURN VALUE
On success, mmap() returns a pointer to the mapped area.
On error, the value MAP_FAILED (that is, (void *) -1) is
returned, and errno is set to indicate the error.
It was raised in two cases:
* in the import statement when looking up __import__
* in pickling some builtin type when looking up built-ins iter, getattr, etc.
We need the TracebackException of uncaught exceptions for a single purpose: the error display. Thus we only need to pass the formatted error display between interpreters. Passing a pickled TracebackException is overkill.
The `PyThreadState_Clear()` function must only be called with the GIL
held and must be called from the same interpreter as the passed in
thread state. Otherwise, any Python objects on the thread state may be
destroyed using the wrong interpreter, leading to memory corruption.
This is also important for `Py_GIL_DISABLED` builds because free lists
will be associated with PyThreadStates and cleared in
`PyThreadState_Clear()`.
This fixes two places that called `PyThreadState_Clear()` from the wrong
interpreter and adds an assertion to `PyThreadState_Clear()`.
When an exception is uncaught in Interpreter.exec_sync(), it helps to show that exception's error display if uncaught in the calling interpreter. We do so here by generating a TracebackException in the subinterpreter and passing it between interpreters using pickle.
This fixes a recently introduced bug where the deferred count is being unnecessarily decremented to counteract an increment elsewhere that is no longer happening. This caused the values to flip around to "very large" 64-bit numbers.
glibc-2.34 implements closefrom(3) using the same semantics as on BSD.
Check for closefrom() in configure and use the check result in
fileutils.c, rather than hardcoding a FreeBSD check.
Some implementations of closefrom() return an int. Explicitly discard
the return value by casting it to void, to avoid future compiler
warnings.
Signed-off-by: Sam James <sam@gentoo.org>
