fix issue #3119

[Cyan4973]

fix segfault error identified by @eli-schwartz when running zstreamtest with MALLOC_PERTURB_.

The quicker solution is to use calloc instead of malloc to ensure proper initialization.
I don't anticipate any speed impact, as these memory segments are relatively small.
On the other hand, calloc is bound to result in safer initialization.

Tested using MALLOC_PERTURB_=124, as in #3119. No failure after this patch.

[eli-schwartz]

FWIW, Meson actually generates a totally random number for you with the python code: env['MALLOC_PERTURB_'] = str(random.randint(1, 255))

This is also relatively easy to do in a bash shell (due to the presence of $RANDOM) but I'm not sure how to do it with a generic /bin/sh...

[Cyan4973]

Extended tests seem to show that failures are still possible.
It seems more rare, but still not zero.
I would appreciate @eli-schwartz if you could have a try at this branch on your test setup.

[eli-schwartz]

I tried this branch, and got the following results: https://github.com/mesonbuild/wrapdb/runs/6216706988?check_suite_focus=true

[86/92] Linking target subprojects/zstd-fix3119/build/meson/programs/zstd.exe
FAILED: subprojects/zstd-fix3119/build/meson/programs/zstd.exe subprojects/zstd-fix3119/build/meson/programs/zstd.pdb 
"link"  /MACHINE:x64 /OUT:subprojects/zstd-fix3119/build/meson/programs/zstd.exe subprojects/zstd-fix3119/build/meson/programs/subprojects_zstd-fix3119_build_meson_programs_.._.._.._build_VS2010_zstd_zstd.rc_zstd.res subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_zstdcli.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_util.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_timefn.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_fileio.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_fileio_asyncio.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_benchfn.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_benchzstd.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_datagen.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_dibio.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._programs_zstdcli_trace.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._lib_common_xxhash.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._lib_common_pool.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._lib_common_zstd_common.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd.exe.p/.._.._.._lib_common_error_private.c.obj "/nologo" "/release" "/nologo" "/DEBUG" "/PDB:subprojects\zstd-fix3119\build/meson/programs\zstd.pdb" "subprojects\zstd-fix3119\build/meson/lib\zstd.lib" "/SUBSYSTEM:CONSOLE" "kernel32.lib" "user32.lib" "gdi32.lib" "winspool.lib" "shell32.lib" "ole32.lib" "oleaut32.lib" "uuid.lib" "comdlg32.lib" "advapi32.lib"
.._.._.._lib_common_pool.c.obj : error LNK2019: unresolved external symbol ZSTD_pthread_create referenced in function POOL_create_advanced
.._.._.._lib_common_pool.c.obj : error LNK2019: unresolved external symbol ZSTD_pthread_join referenced in function POOL_join
subprojects\zstd-fix3119\build\meson\programs\zstd.exe : fatal error LNK1120: 2 unresolved externals
[87/92] Linking target subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe
FAILED: subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.pdb 
"link"  /MACHINE:x64 /OUT:subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe.p/.._.._.._programs_zstdcli.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe.p/.._.._.._programs_timefn.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe.p/.._.._.._programs_util.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe.p/.._.._.._programs_fileio.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe.p/.._.._.._programs_fileio_asyncio.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe.p/.._.._.._lib_common_pool.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe.p/.._.._.._lib_common_zstd_common.c.obj subprojects/zstd-fix3119/build/meson/programs/zstd-frugal.exe.p/.._.._.._lib_common_error_private.c.obj "/nologo" "/release" "/nologo" "/DEBUG" "/PDB:subprojects\zstd-fix3119\build/meson/programs\zstd-frugal.pdb" "subprojects\zstd-fix3119\build/meson/lib\zstd.lib" "/SUBSYSTEM:CONSOLE" "kernel32.lib" "user32.lib" "gdi32.lib" "winspool.lib" "shell32.lib" "ole32.lib" "oleaut32.lib" "uuid.lib" "comdlg32.lib" "advapi32.lib"
.._.._.._lib_common_pool.c.obj : error LNK2019: unresolved external symbol ZSTD_pthread_create referenced in function POOL_create_advanced
.._.._.._lib_common_pool.c.obj : error LNK2019: unresolved external symbol ZSTD_pthread_join referenced in function POOL_join
subprojects\zstd-fix3119\build\meson\programs\zstd-frugal.exe : fatal error LNK1120: 2 unresolved externals
[88/92] Linking target subprojects/zstd-fix3119/build/meson/tests/checkTag.exe
ninja: build stopped: subcommand failed.

It didn't get as far as the tests.

[Cyan4973]

Strange, this PR should have no impact on such kind of linking error...

[eli-schwartz]

I haven't tried the dev branch, only the latest release and then this PR branch. So it could be a preexisting issue. All I know is I can't currently compile this PR to test it.

I agree that it doesn't seem like calloc/malloc should affect whether pthread is linkable...

[eli-schwartz]

Alright, I tried the dev branch at https://github.com/mesonbuild/wrapdb/runs/6216706988?check_suite_focus=true

It is still broken there too. Looking around a bit, I think this goes back to the issue in #2976

[Cyan4973]

Ideally, we should have a meson build test able to catch such issue.
It seems this PR #2976 managed to pass CI tests.

[eli-schwartz]

This PR when applied to the latest dev branch compiles correctly, but zstreamtest still dies of SIGinvalid. Github Actions log: https://github.com/mesonbuild/wrapdb/runs/6632846325?check_suite_focus=true

[Cyan4973]

The first part of the PR, replacing malloc() by calloc(), looks correct, but doesn't fix the intended issue.
This is more likely a race condition, which requires having a deeper look at the pthread translation layer for Windows.