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Merged
hugovk merged 8 commits into from
Aug 1, 2024
Merged

Lock around usages of imaging memory arenas #8238

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ea7b5c5
Lock around usages of imaging memory arenas
lysnikolaou Jul 16, 2024
9f110aa
[pre-commit.ci] auto fixes from pre-commit.com hooks
pre-commit-ci[bot] Jul 16, 2024
5999b9b
Initialize PyMutex only under the free-threaded build
lysnikolaou Jul 16, 2024
06767fc
Address feedback; do not lock in a loop
lysnikolaou Jul 16, 2024
98b1739
Address more feedback; don't unlock around sizeof
lysnikolaou Jul 16, 2024
e144707
[pre-commit.ci] auto fixes from pre-commit.com hooks
pre-commit-ci[bot] Jul 16, 2024
8a54f58
Merge branch 'main' into arena-thread-safe
lysnikolaou Jul 19, 2024
aa8d876
[pre-commit.ci] auto fixes from pre-commit.com hooks
pre-commit-ci[bot] Jul 19, 2024
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48 changes: 38 additions & 10 deletions src/_imaging.c
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Original file line number Diff line number Diff line change
Expand Up @@ -92,6 +92,7 @@

#define _USE_MATH_DEFINES
#include <math.h>
#include <stddef.h>

/* Configuration stuff. Feel free to undef things you don't need. */
#define WITH_IMAGECHOPS /* ImageChops support */
Expand Down Expand Up @@ -3934,7 +3935,6 @@ static PyObject *
_get_stats(PyObject *self, PyObject *args) {
PyObject *d;
PyObject *v;
ImagingMemoryArena arena = &ImagingDefaultArena;

if (!PyArg_ParseTuple(args, ":get_stats")) {
return NULL;
Expand All @@ -3944,6 +3944,10 @@ _get_stats(PyObject *self, PyObject *args) {
if (!d) {
return NULL;
}

MUTEX_LOCK(&ImagingDefaultArena.mutex);
ImagingMemoryArena arena = &ImagingDefaultArena;

v = PyLong_FromLong(arena->stats_new_count);
PyDict_SetItemString(d, "new_count", v ? v : Py_None);
Py_XDECREF(v);
Expand All @@ -3967,22 +3971,25 @@ _get_stats(PyObject *self, PyObject *args) {
v = PyLong_FromLong(arena->blocks_cached);
PyDict_SetItemString(d, "blocks_cached", v ? v : Py_None);
Py_XDECREF(v);

MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
return d;
}

static PyObject *
_reset_stats(PyObject *self, PyObject *args) {
ImagingMemoryArena arena = &ImagingDefaultArena;

if (!PyArg_ParseTuple(args, ":reset_stats")) {
return NULL;
}

MUTEX_LOCK(&ImagingDefaultArena.mutex);
ImagingMemoryArena arena = &ImagingDefaultArena;
arena->stats_new_count = 0;
arena->stats_allocated_blocks = 0;
arena->stats_reused_blocks = 0;
arena->stats_reallocated_blocks = 0;
arena->stats_freed_blocks = 0;
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);

Py_INCREF(Py_None);
return Py_None;
Expand All @@ -3994,7 +4001,10 @@ _get_alignment(PyObject *self, PyObject *args) {
return NULL;
}

return PyLong_FromLong(ImagingDefaultArena.alignment);
MUTEX_LOCK(&ImagingDefaultArena.mutex);
int alignment = ImagingDefaultArena.alignment;
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
return PyLong_FromLong(alignment);
}

static PyObject *
Expand All @@ -4003,7 +4013,10 @@ _get_block_size(PyObject *self, PyObject *args) {
return NULL;
}

return PyLong_FromLong(ImagingDefaultArena.block_size);
MUTEX_LOCK(&ImagingDefaultArena.mutex);
int block_size = ImagingDefaultArena.block_size;
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
return PyLong_FromLong(block_size);
}

static PyObject *
Expand All @@ -4012,7 +4025,10 @@ _get_blocks_max(PyObject *self, PyObject *args) {
return NULL;
}

return PyLong_FromLong(ImagingDefaultArena.blocks_max);
MUTEX_LOCK(&ImagingDefaultArena.mutex);
int blocks_max = ImagingDefaultArena.blocks_max;
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
return PyLong_FromLong(blocks_max);
}

static PyObject *
Expand All @@ -4032,7 +4048,9 @@ _set_alignment(PyObject *self, PyObject *args) {
return NULL;
}

MUTEX_LOCK(&ImagingDefaultArena.mutex);
ImagingDefaultArena.alignment = alignment;
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);

Py_INCREF(Py_None);
return Py_None;
Expand All @@ -4055,7 +4073,9 @@ _set_block_size(PyObject *self, PyObject *args) {
return NULL;
}

MUTEX_LOCK(&ImagingDefaultArena.mutex);
ImagingDefaultArena.block_size = block_size;
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);

Py_INCREF(Py_None);
return Py_None;
Expand All @@ -4071,14 +4091,20 @@ _set_blocks_max(PyObject *self, PyObject *args) {
if (blocks_max < 0) {
PyErr_SetString(PyExc_ValueError, "blocks_max should be greater than 0");
return NULL;
} else if (
(unsigned long)blocks_max >
SIZE_MAX / sizeof(ImagingDefaultArena.blocks_pool[0])) {
}

MUTEX_LOCK(&ImagingDefaultArena.mutex);
size_t blocksize = sizeof(ImagingDefaultArena.blocks_pool[0]);
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
if ((unsigned long)blocks_max > SIZE_MAX / blocksize) {
PyErr_SetString(PyExc_ValueError, "blocks_max is too large");
return NULL;
}

if (!ImagingMemorySetBlocksMax(&ImagingDefaultArena, blocks_max)) {
MUTEX_LOCK(&ImagingDefaultArena.mutex);
int status = ImagingMemorySetBlocksMax(&ImagingDefaultArena, blocks_max);
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
if (!status) {
return ImagingError_MemoryError();
}

Expand All @@ -4094,7 +4120,9 @@ _clear_cache(PyObject *self, PyObject *args) {
return NULL;
}

MUTEX_LOCK(&ImagingDefaultArena.mutex);
ImagingMemoryClearCache(&ImagingDefaultArena, i);
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);

Py_INCREF(Py_None);
return Py_None;
Expand Down
12 changes: 12 additions & 0 deletions src/libImaging/Imaging.h
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Original file line number Diff line number Diff line change
Expand Up @@ -161,6 +161,9 @@ typedef struct ImagingMemoryArena {
int stats_reallocated_blocks; /* Number of blocks which were actually reallocated
after retrieving */
int stats_freed_blocks; /* Number of freed blocks */
#ifdef Py_GIL_DISABLED
PyMutex mutex;
#endif
} *ImagingMemoryArena;

/* Objects */
Expand Down Expand Up @@ -690,6 +693,15 @@ _imaging_tell_pyFd(PyObject *fd);
#include "ImagingUtils.h"
extern UINT8 *clip8_lookups;

/* Mutex lock/unlock helpers */
#ifdef Py_GIL_DISABLED
#define MUTEX_LOCK(m) PyMutex_Lock(m)
#define MUTEX_UNLOCK(m) PyMutex_Unlock(m)
#else
#define MUTEX_LOCK(m)
#define MUTEX_UNLOCK(m)
#endif

#if defined(__cplusplus)
}
#endif
23 changes: 18 additions & 5 deletions src/libImaging/Storage.c
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Original file line number Diff line number Diff line change
Expand Up @@ -219,7 +219,9 @@ ImagingNewPrologueSubtype(const char *mode, int xsize, int ysize, int size) {
break;
}

MUTEX_LOCK(&ImagingDefaultArena.mutex);
ImagingDefaultArena.stats_new_count += 1;
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);

return im;
}
Expand Down Expand Up @@ -267,7 +269,10 @@ struct ImagingMemoryArena ImagingDefaultArena = {
0,
0,
0,
0 // Stats
0, // Stats
#ifdef Py_GIL_DISABLED
{0},
#endif
};

int
Expand Down Expand Up @@ -364,18 +369,19 @@ ImagingDestroyArray(Imaging im) {
int y = 0;

if (im->blocks) {
MUTEX_LOCK(&ImagingDefaultArena.mutex);
while (im->blocks[y].ptr) {
memory_return_block(&ImagingDefaultArena, im->blocks[y]);
y += 1;
}
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
free(im->blocks);
}
}

Imaging
ImagingAllocateArray(Imaging im, int dirty, int block_size) {
ImagingAllocateArray(Imaging im, ImagingMemoryArena arena, int dirty, int block_size) {
int y, line_in_block, current_block;
ImagingMemoryArena arena = &ImagingDefaultArena;
ImagingMemoryBlock block = {NULL, 0};
int aligned_linesize, lines_per_block, blocks_count;
char *aligned_ptr = NULL;
Expand Down Expand Up @@ -498,14 +504,21 @@ ImagingNewInternal(const char *mode, int xsize, int ysize, int dirty) {
return NULL;
}

if (ImagingAllocateArray(im, dirty, ImagingDefaultArena.block_size)) {
MUTEX_LOCK(&ImagingDefaultArena.mutex);
Imaging tmp = ImagingAllocateArray(
im, &ImagingDefaultArena, dirty, ImagingDefaultArena.block_size);
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
if (tmp) {
return im;
}

ImagingError_Clear();

// Try to allocate the image once more with smallest possible block size
if (ImagingAllocateArray(im, dirty, IMAGING_PAGE_SIZE)) {
MUTEX_LOCK(&ImagingDefaultArena.mutex);
tmp = ImagingAllocateArray(im, &ImagingDefaultArena, dirty, IMAGING_PAGE_SIZE);
MUTEX_UNLOCK(&ImagingDefaultArena.mutex);
if (tmp) {
return im;
}

Expand Down