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mdbx-windows: backport - always susppend local threads while resize DB (workaround for Windows kernel bug).

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We should not concern about performance on Windows platform,
it just unreasonable. Therefore just always suspend the local
threads to avoid this issue.

This resolves https://github.com/leo-yuriev/libmdbx/issues/48

Change-Id: I6e652692794b8c4c0d41625be62f2051b63c033a
This commit is contained in:
Leo Yuriev 2018-11-22 14:19:49 +03:00 committed by Leonid Yuriev
parent 850fe8408e
commit f183cef7d7
1 changed files with 15 additions and 13 deletions
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28
src/mdbx.c
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@ -1983,19 +1983,21 @@ static int mdbx_mapresize(MDBX_env *env, const pgno_t size_pgno,
env->me_dxb_mmap.current == env->me_dxb_mmap.filesize)
goto bailout;
if ((env->me_flags & MDBX_RDONLY) || limit_bytes != env->me_dxb_mmap.length ||
size_bytes < env->me_dxb_mmap.current) {
/* Windows allows only extending a read-write section, but not a
* corresponing mapped view. Therefore in other cases we must suspend
* the local threads for safe remap. */
array_onstack.limit = ARRAY_LENGTH(array_onstack.handles);
array_onstack.count = 0;
suspended = &array_onstack;
rc = mdbx_suspend_threads_before_remap(env, &suspended);
if (rc != MDBX_SUCCESS) {
mdbx_error("failed suspend-for-remap: errcode %d", rc);
goto bailout;
}
/* 1) Windows allows only extending a read-write section, but not a
* corresponing mapped view. Therefore in other cases we must suspend
* the local threads for safe remap.
* 2) At least on Windows 10 1803 the entire mapped section is unavailable
* for short time during NtExtendSection() or VirtualAlloc() execution.
*
* THEREFORE LOCAL THREADS SUSPENDING IS ALWAYS REQUIRED!
*/
array_onstack.limit = ARRAY_LENGTH(array_onstack.handles);
array_onstack.count = 0;
suspended = &array_onstack;
rc = mdbx_suspend_threads_before_remap(env, &suspended);
if (rc != MDBX_SUCCESS) {
mdbx_error("failed suspend-for-remap: errcode %d", rc);
goto bailout;
}
#else
/* Acquire guard to avoid collision between read and write txns