luv_fs: fix gc of string during a fs.write #223
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In virgo we hit a bug that only revealed itself when we were writing out to a
file over NFS. This is likely because the NFS write out took a relatively long
time and revealed a race. Example corrupted text file:
#
ch0002
tests/tmp/0002.chk
OK
»A¿7—A
ch0003
tests/tmp/0003.chk
OK
1337118370
Notice that the fifth line is garbage. That is because the string was getting
GC'd before it was written to disk. So, we need to ref the string so this
doesn't happen just as we ref the callback function.
| @@ -258,7 +279,10 @@ int luv_fs_write(lua_State* L) { | |||
| off_t offset = luaL_checkint(L, 2); | |||
| size_t length; | |||
| void* chunk = (void*)luaL_checklstring(L, 3, &length); | |||
| uv_fs_t* req = luv_fs_store_callback(L, 4); | |||
| luv_fs_ref_t* ref = luv_fs_ref_alloc(L); | |||
| luv_fs_ref_string(ref, 3); | |||
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is the unref someplace else in the code?
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hrm, weird, I wrote the code but must have forgotten that second git add. I will fix.
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Oops, no the unref is here: https://github.com/luvit/luvit/pull/223/files#L0R181
|
@rphillips fwiw, the windows build failure on virgo-bb is because of this: https://virgo-bb.k1k.me/builders/virgo-windows2008_x64/builds/842/steps/integration%20tests/logs/stdio |
|
lgtm, +1 |
philips
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May 16, 2012
luv_fs: fix gc of string during a fs.write
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In virgo we hit a bug that only revealed itself when we were writing out to a
file over NFS. This is likely because the NFS write out took a relatively long
time and revealed a race. Example corrupted text file:
Notice that the fifth line is garbage. That is because the string was getting
GC'd before it was written to disk. So, we need to ref the string so this
doesn't happen just as we ref the callback function.