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mdbx: shrinking memory-mapping for Windows (initial).

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Change-Id: I3c3c2df0747c788ea36d7764c1e8139098ca62be
This commit is contained in:
Leo Yuriev
2018-01-07 14:37:38 +03:00
parent f10f5b376f
commit 30bd7d3078
5 changed files with 301 additions and 67 deletions
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109
src/mdbx.c
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@@ -1632,19 +1632,70 @@ static int mdbx_mapresize(MDBX_env *env, const pgno_t size_pgno,
mdbx_assert(env, limit_bytes >= size_bytes);
mdbx_assert(env, bytes2pgno(env, size_bytes) == size_pgno);
mdbx_assert(env, bytes2pgno(env, limit_bytes) == limit_pgno);
const int rc =
mdbx_mresize(env->me_flags, &env->me_dxb_mmap, size_bytes, limit_bytes);
#if defined(_WIN32) || defined(_WIN64)
/* Acquire guard in exclusive mode for:
* - to avoid collision between read and write txns around env->me_dbgeo;
* - to avoid attachment of new reading threads (see mdbx_rdt_lock); */
AcquireSRWLockExclusive(&env->me_remap_guard);
mdbx_handle_array_t *suspended = NULL;
mdbx_handle_array_t array_onstack;
int rc = MDBX_SUCCESS;
if (limit_bytes == env->me_dxb_mmap.length &&
size_bytes == env->me_dxb_mmap.current &&
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;
}
}
#else
/* Acquire guard to avoid collision between read and write txns
* around env->me_dbgeo */
int rc = mdbx_fastmutex_acquire(&env->me_remap_guard);
if (rc != MDBX_SUCCESS)
return rc;
if (limit_bytes == env->me_dxb_mmap.length &&
bytes2pgno(env, size_bytes) == env->me_dbgeo.now)
goto bailout;
#endif /* Windows */
rc = mdbx_mresize(env->me_flags, &env->me_dxb_mmap, size_bytes, limit_bytes);
bailout:
if (rc == MDBX_SUCCESS) {
env->me_dbgeo.now = size_bytes;
env->me_dbgeo.upper = limit_bytes;
if (env->me_txn) {
mdbx_tassert(env->me_txn, size_pgno >= env->me_txn->mt_next_pgno);
env->me_txn->mt_end_pgno = size_pgno;
}
#ifdef USE_VALGRIND
if (prev_mapsize != env->me_mapsize || prev_mapaddr != env->me_map) {
VALGRIND_DISCARD(env->me_valgrind_handle);
env->me_valgrind_handle = 0;
if (env->me_mapsize)
env->me_valgrind_handle =
VALGRIND_CREATE_BLOCK(env->me_map, env->me_mapsize, "mdbx");
}
#endif
} else if (rc != MDBX_RESULT_TRUE) {
mdbx_error("failed resize datafile/mapping: "
"present %" PRIuPTR " -> %" PRIuPTR ", "
"limit %" PRIuPTR " -> %" PRIuPTR ", errcode %d",
env->me_dbgeo.now, size_bytes, env->me_dbgeo.upper, limit_bytes,
rc);
return rc;
} else {
mdbx_notice("unable resize datafile/mapping: "
"present %" PRIuPTR " -> %" PRIuPTR ", "
@@ -1653,21 +1704,22 @@ static int mdbx_mapresize(MDBX_env *env, const pgno_t size_pgno,
rc);
}
#ifdef USE_VALGRIND
if (prev_mapsize != env->me_mapsize || prev_mapaddr != env->me_map) {
VALGRIND_DISCARD(env->me_valgrind_handle);
env->me_valgrind_handle = 0;
if (env->me_mapsize)
env->me_valgrind_handle =
VALGRIND_CREATE_BLOCK(env->me_map, env->me_mapsize, "mdbx");
#if defined(_WIN32) || defined(_WIN64)
int err = MDBX_SUCCESS;
ReleaseSRWLockExclusive(&env->me_remap_guard);
if (suspended) {
err = mdbx_resume_threads_after_remap(suspended);
if (suspended != &array_onstack)
free(suspended);
}
#endif
if (env->me_txn) {
mdbx_tassert(env->me_txn, size_pgno >= env->me_txn->mt_next_pgno);
env->me_txn->mt_end_pgno = size_pgno;
#else
int err = mdbx_fastmutex_release(&env->me_remap_guard);
#endif /* Windows */
if (err != MDBX_SUCCESS) {
mdbx_fatal("failed resume-after-remap: errcode %d", err);
return MDBX_PANIC;
}
return MDBX_SUCCESS;
return rc;
}
/* Allocate page numbers and memory for writing. Maintain me_last_reclaimed,
@@ -4109,9 +4161,6 @@ static int mdbx_sync_locked(MDBX_env *env, unsigned flags,
}
}
#if defined(_WIN32) || defined(_WIN64)
/* Windows is unable shrinking a mapped file */
#else
/* LY: check conditions to shrink datafile */
const pgno_t backlog_gap =
pending->mm_dbs[FREE_DBI].md_depth + mdbx_backlog_extragap(env);
@@ -4133,7 +4182,6 @@ static int mdbx_sync_locked(MDBX_env *env, unsigned flags,
mdbx_meta_set_txnid(env, pending, pending->mm_txnid_a + 1);
}
}
#endif /* not a Windows */
/* Steady or Weak */
if (env->me_sync_pending == 0) {
@@ -4281,9 +4329,6 @@ static int mdbx_sync_locked(MDBX_env *env, unsigned flags,
}
}
#if defined(_WIN32) || defined(_WIN64)
/* Windows is unable shrinking a mapped file */
#else
/* LY: shrink datafile if needed */
if (unlikely(shrink)) {
mdbx_info("shrink to %" PRIaPGNO " pages (-%" PRIaPGNO ")",
@@ -4292,7 +4337,6 @@ static int mdbx_sync_locked(MDBX_env *env, unsigned flags,
if (MDBX_IS_ERROR(rc))
goto fail;
}
#endif /* not a Windows */
return MDBX_SUCCESS;
@@ -4384,6 +4428,16 @@ int __cold mdbx_env_create(MDBX_env **penv) {
if (unlikely(rc != MDBX_SUCCESS))
goto bailout;
#if defined(_WIN32) || defined(_WIN64)
InitializeSRWLock(&env->me_remap_guard);
#else
rc = mdbx_fastmutex_init(&env->me_remap_guard);
if (unlikely(rc != MDBX_SUCCESS)) {
mdbx_fastmutex_destroy(&env->me_dbi_lock);
goto bailout;
}
#endif /* Windows */
VALGRIND_CREATE_MEMPOOL(env, 0, 0);
env->me_signature = MDBX_ME_SIGNATURE;
*penv = env;
@@ -4501,13 +4555,6 @@ LIBMDBX_API int mdbx_env_set_geometry(MDBX_env *env, intptr_t size_lower,
}
if ((size_t)size_now < usedbytes)
size_now = usedbytes;
#if defined(_WIN32) || defined(_WIN64)
if ((size_t)size_now < env->me_dbgeo.now ||
(size_t)size_upper < env->me_dbgeo.upper) {
/* Windows is unable shrinking a mapped file */
return ERROR_USER_MAPPED_FILE;
}
#endif /* Windows */
} else {
/* env NOT yet mapped */
if (unlikely(inside_txn))