Commit 741f6f76 authored by Mat's avatar Mat
Browse files

Build the list method on Linux only. 

There is no portable way to list SHM segments, that's more or less a
flaw in the SHM API. On Linux SHM segments are implemented as regular
files on a tmpfs filesystem, usually mounted as /dev/shm. The list
method scans this mount point and looks for SharedArray headers. This
won't work on other operating systems (*BSD, Darwin, Solaris, etc.),
so disable the method on non-Linux targets.
parent f3e24b77

README.md

+1 −1
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ del a 
print(b[0])



# See how "test" is still present in shared memory even though we

# destroyed the array a.

# destroyed the array a. This method only works on Linux.

sa.list()



# Now destroy the array "test" from memory.

src/shared_array.c

+2 −0
Original line number Diff line number Diff line
@@ -50,9 +50,11 @@ static PyMethodDef module_functions[] = { 
	  METH_VARARGS,

	  "Delete an existing numpy array from shared memory" },



#ifdef __linux__

	{ "list", (PyCFunction) shared_array_list,

	  METH_VARARGS,

	  "List all existing numpy arrays from shared memory" },

#endif



	{ "msync", (PyCFunction) shared_array_msync,

	  METH_VARARGS | METH_KEYWORDS,

src/shared_array.h

+7 −1
Original line number Diff line number Diff line
@@ -43,11 +43,17 @@ struct array_meta { 
extern PyStructSequence_Desc PyArrayDescObject_Desc;

extern PyTypeObject PyArrayDescObject_Type;



/* Module functions */

/* Main functions */

extern PyObject *shared_array_create(PyObject *self, PyObject *args, PyObject *kwds);

extern PyObject *shared_array_attach(PyObject *self, PyObject *args);

extern PyObject *shared_array_delete(PyObject *self, PyObject *args);



/* SHM list function */

#ifdef __linux__

extern PyObject *shared_array_list(PyObject *self, PyObject *args);

#endif



/* Memory locking functions */

extern PyObject *shared_array_msync(PyObject *self, PyObject *args, PyObject *kwds);

extern PyObject *shared_array_mlock(PyObject *self, PyObject *args, PyObject *kwds);

extern PyObject *shared_array_munlock(PyObject *self, PyObject *args, PyObject *kwds);

src/shared_array_list.c

+7 −0
Original line number Diff line number Diff line
@@ -16,6 +16,11 @@ 
 * along with SharedArray.  If not, see <http://www.gnu.org/licenses/>.

 */



/* This only works on Linux where SHM segments are implemented as

 * regular files in a tmpfs filesystem. There doesn't seem to be a

 * portable way of listing SHM segments. */

#ifdef __linux__



#define NPY_NO_DEPRECATED_API	NPY_1_8_API_VERSION

#define PY_ARRAY_UNIQUE_SYMBOL	SHARED_ARRAY_ARRAY_API

#define NO_IMPORT_ARRAY
@@ -212,3 +217,5 @@ PyObject *shared_array_list(PyObject *self, PyObject *args) 
	/* Return the tuple */

	return tuple;

}



#endif /* __linux__ */