search for: py_api_version

...hon.c +++ b/plugins/python/python.c @@ -46,6 +46,8 @@ #define PY_SSIZE_T_CLEAN 1 #include <Python.h> +#define NBDKIT_API_VERSION 2 + #include <nbdkit-plugin.h> #include "cleanup.h" @@ -60,6 +62,7 @@ */ static const char *script; static PyObject *module; +static int py_api_version = 1; static int last_error; @@ -356,6 +359,26 @@ py_config (const char *key, const char *value) "nbdkit requires these callbacks.", script); return -1; } + + /* Get the API version. */ + if (callback_defined ("api_version", &fn)) {...

...hon.c +++ b/plugins/python/python.c @@ -46,6 +46,8 @@ #define PY_SSIZE_T_CLEAN 1 #include <Python.h> +#define NBDKIT_API_VERSION 2 + #include <nbdkit-plugin.h> #include "cleanup.h" @@ -60,6 +62,7 @@ */ static const char *script; static PyObject *module; +static int py_api_version = 1; static int last_error; @@ -285,9 +288,14 @@ py_dump_plugin (void) PyObject *fn; PyObject *r; + /* Python version and ABI. */ printf ("python_version=%s\n", PY_VERSION); printf ("python_pep_384_abi_version=%d\n", PYTHON_ABI_VERSION); + /* Maximum nbdki...

And fill out most of the missing bits of the API. Rich.

v1: https://www.redhat.com/archives/libguestfs/2019-November/msg00153.html v2: - Fix implementation of can_cache. - Add implementation of can_fua. - Add a very thorough test suite which tests every command + flag combination.

v3 was here: https://www.redhat.com/archives/libguestfs/2019-November/msg00209.html In v4: - Rebase on top of current master. Includes various fixes and updates required because of Nir's patches that went into master. - Fix api_version() -> API_VERSION in patch 2 noted previously on the mailing list. Rich.

v2 was here: https://www.redhat.com/archives/libguestfs/2019-November/msg00163.html I pushed patch 1 (with spelling fix), patch 4 and patch 5 since those were previously ACKed on the list. Differences in v3: - Add error checking to PyModule_AddIntConstant. - Use API_VERSION constant instead of function. - Add max API version supported to --dump-plugin output. - Print API_VERSION selected by

...quot;, &fn)) { >>> PyErr_Clear (); >>> - r = PyObject_CallFunction (fn, "ONL", obj, >>> - PyByteArray_FromStringAndSize (buf, count), >>> - offset, NULL); >>> + switch (py_api_version) { >>> + case 1: >>> + r = PyObject_CallFunction (fn, "ONL", obj, >>> + PyByteArray_FromStringAndSize (buf, count), >>> + offset, NULL); >> >> Here, we could assert (fla...

When I added .can_FOO caching in 1.16, I missed the case that the sh plugin itself was calling .can_flush twice in some situations (in order to default .can_fua). Then right after, I regressed it to call .can_zero twice (in order to default .can_fast_zero). I also missed that .thread_model could use better caching, because at the time, I did not add testsuite coverage. Fix that now. Eric Blake

...(callback_defined ("pwrite", &fn)) { > PyErr_Clear (); > > - r = PyObject_CallFunction (fn, "ONL", obj, > - PyByteArray_FromStringAndSize (buf, count), > - offset, NULL); > + switch (py_api_version) { > + case 1: > + r = PyObject_CallFunction (fn, "ONL", obj, > + PyByteArray_FromStringAndSize (buf, count), > + offset, NULL); Here, we could assert (flags == 0) (the FUA flag should not be set if the...

...unt, uint64_t offset, uint32_t flags) return -1; } +static int +py_cache (void *handle, uint32_t count, uint64_t offset, uint32_t flags) +{ + PyObject *obj = handle; + PyObject *fn; + PyObject *r; + + if (callback_defined ("cache", &fn)) { + PyErr_Clear (); + + switch (py_api_version) { + case 1: + nbdkit_error ("%s can only be called when using api_version >= 2", + "cache"); + return -1; + case 2: + r = PyObject_CallFunction (fn, "OiLI", obj, count, offset, flags, NULL); + break; + default: abort...

...unt, uint64_t offset, uint32_t flags) return -1; } +static int +py_cache (void *handle, uint32_t count, uint64_t offset, uint32_t flags) +{ + PyObject *obj = handle; + PyObject *fn; + PyObject *r; + + if (callback_defined ("cache", &fn)) { + PyErr_Clear (); + + switch (py_api_version) { + case 1: + nbdkit_error ("%s can only be called when using api_version >= 2", + "cache"); + return -1; + case 2: + r = PyObject_CallFunction (fn, "OiLI", obj, count, offset, flags, NULL); + break; + default: abort...

...fined ("pwrite", &fn)) { > > PyErr_Clear (); > >- r = PyObject_CallFunction (fn, "ONL", obj, > >- PyByteArray_FromStringAndSize (buf, count), > >- offset, NULL); > >+ switch (py_api_version) { > >+ case 1: > >+ r = PyObject_CallFunction (fn, "ONL", obj, > >+ PyByteArray_FromStringAndSize (buf, count), > >+ offset, NULL); > > Here, we could assert (flags == 0) (the FUA flag...

...ure ("pread") == -1) return ret; - if (PyObject_GetBuffer (r, &view, PyBUF_SIMPLE) == -1) { - nbdkit_error ("%s: value returned from pread does not support the " - "buffer protocol", - script); - goto out; - } + if (py_api_version == 1) { + /* In API v1 the Python pread function had to return a buffer + * protocol compatible function. In API v2+ it writes directly to + * the C buffer so this code is not used. + */ + if (PyObject_GetBuffer (r, &view, PyBUF_SIMPLE) == -1) { + nbdkit_error ("%s:...

As suggested by Nir, here: https://www.redhat.com/archives/libguestfs/2019-November/thread.html#00220

This is working for me now, although possibly only on Python 3.9. Dan suggested PyEval_InitThreads but that was deprecated in Python 3.7. Rich.

Patch 2 certainly allows you to set the thread model. However patch 3 shows that if you set it to nbdkit.THREAD_MODEL_PARALLEL it will crash. If you look closely at the stack trace (attached below) you can see that ignoring threads which are in parts of nbdkit unrelated to Python: Thread 4: In pread, waiting in time.sleep(). This thread has released the GIL. Thread 2: Started to