Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Sign up
Appearance settings

Commit cae6696

Browse files
committed
Fix a race condition in TexManager.make_dvi & make_png.
Previously, a race condition could occur if, while a process had called make_tex (generating the tex file in the global cache) and was going to call the latex subprocess (to generate the dvi file), another process also called make_tex for the same tex string and started rewriting the tex source. In that case, the latex subprocess could see a partially written (invalid) tex source. Fix that by generating the tex source in a process-private temporary directory, where the latex process is already going to run anyways. (This is cheap compared to the latex subprocess invocation.) Apply a similar strategy for make_png as well.
1 parent 780e66c commit cae6696

File tree

1 file changed

+27
-26
lines changed

1 file changed

+27
-26
lines changed

‎lib/matplotlib/texmanager.py

Lines changed: 27 additions & 26 deletions
Original file line numberDiff line numberDiff line change
@@ -281,11 +281,9 @@ def make_dvi(cls, tex, fontsize):
281281
282282
Return the file name.
283283
"""
284-
basefile = cls.get_basefile(tex, fontsize)
285-
dvifile = '%s.dvi' % basefile
286-
if not os.path.exists(dvifile):
287-
texfile = Path(cls.make_tex(tex, fontsize))
288-
# Generate the dvi in a temporary directory to avoid race
284+
dvifile = Path(cls.get_basefile(tex, fontsize)).with_suffix(".dvi")
285+
if not dvifile.exists():
286+
# Generate the tex and dvi in a temporary directory to avoid race
289287
# conditions e.g. if multiple processes try to process the same tex
290288
# string at the same time. Having tmpdir be a subdirectory of the
291289
# final output dir ensures that they are on the same filesystem,
@@ -294,15 +292,17 @@ def make_dvi(cls, tex, fontsize):
294292
# the absolute path may contain characters (e.g. ~) that TeX does
295293
# not support; n.b. relative paths cannot traverse parents, or it
296294
# will be blocked when `openin_any = p` in texmf.cnf).
297-
cwd=Path(dvifile).parent
298-
withTemporaryDirectory(dir=cwd) astmpdir:
299-
tmppath=Path(tmpdir)
295+
withTemporaryDirectory(dir=dvifile.parent) astmpdir:
296+
Path(tmpdir, "file.tex").write_text(
297+
cls._get_tex_source(tex, fontsize), encoding='utf-8')
300298
cls._run_checked_subprocess(
301299
["latex", "-interaction=nonstopmode", "--halt-on-error",
302-
f"--output-directory={tmppath.name}",
303-
f"{texfile.name}"], tex, cwd=cwd)
304-
(tmppath / Path(dvifile).name).replace(dvifile)
305-
return dvifile
300+
"file.tex"], tex, cwd=tmpdir)
301+
Path(tmpdir, "file.dvi").replace(dvifile)
302+
# Also move the tex source to the main cache directory, but
303+
# only for backcompat.
304+
Path(tmpdir, "file.tex").replace(dvifile.with_suffix(".tex"))
305+
return str(dvifile)
306306

307307
@classmethod
308308
def make_png(cls, tex, fontsize, dpi):
@@ -311,22 +311,23 @@ def make_png(cls, tex, fontsize, dpi):
311311
312312
Return the file name.
313313
"""
314-
basefile = cls.get_basefile(tex, fontsize, dpi)
315-
pngfile = '%s.png' % basefile
314+
pngfile = Path(cls.get_basefile(tex, fontsize)).with_suffix(".png")
316315
# see get_rgba for a discussion of the background
317-
if not os.path.exists(pngfile):
316+
if not pngfile.exists():
318317
dvifile = cls.make_dvi(tex, fontsize)
319-
cmd = ["dvipng", "-bg", "Transparent", "-D", str(dpi),
320-
"-T", "tight", "-o", pngfile, dvifile]
321-
# When testing, disable FreeType rendering for reproducibility; but
322-
# dvipng 1.16 has a bug (fixed in f3ff241) that breaks --freetype0
323-
# mode, so for it we keep FreeType enabled; the image will be
324-
# slightly off.
325-
if (getattr(mpl, "_called_from_pytest", False) and
326-
mpl._get_executable_info("dvipng").raw_version != "1.16"):
327-
cmd.insert(1, "--freetype0")
328-
cls._run_checked_subprocess(cmd, tex)
329-
return pngfile
318+
with TemporaryDirectory(dir=pngfile.parent) as tmpdir:
319+
cmd = ["dvipng", "-bg", "Transparent", "-D", str(dpi),
320+
"-T", "tight", "-o", "file.png", dvifile]
321+
# When testing, disable FreeType rendering for reproducibility;
322+
# but dvipng 1.16 has a bug (fixed in f3ff241) that breaks
323+
# --freetype0 mode, so for it we keep FreeType enabled; the
324+
# image will be slightly off.
325+
if (getattr(mpl, "_called_from_pytest", False) and
326+
mpl._get_executable_info("dvipng").raw_version != "1.16"):
327+
cmd.insert(1, "--freetype0")
328+
cls._run_checked_subprocess(cmd, tex, cwd=tmpdir)
329+
Path(tmpdir, "file.png").replace(pngfile)
330+
return str(pngfile)
330331

331332
@classmethod
332333
def get_grey(cls, tex, fontsize=None, dpi=None):

0 commit comments

Comments
(0)

AltStyle によって変換されたページ (->オリジナル) /