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8256287: [windows] add loop fuse to map_or_reserve_memory_aligned

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Reviewed-by: luhenry, iklam, minqi
This commit is contained in:
Thomas Stuefe 2020-11-16 20:08:49 +00:00
parent 6e35bcbf03
commit 0357db3581
1 changed files with 15 additions and 12 deletions
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27
src/hotspot/os/windows/os_windows.cpp
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@ -3238,28 +3238,31 @@ static char* map_or_reserve_memory_aligned(size_t size, size_t alignment, int fi
assert(extra_size >= size, "overflow, size is too large to allow alignment"); assert(extra_size >= size, "overflow, size is too large to allow alignment");
char* aligned_base = NULL; char* aligned_base = NULL;
static const int max_attempts = 20;
do { for (int attempt = 0; attempt < max_attempts && aligned_base == NULL; attempt ++) {
char* extra_base = file_desc != -1 ? char* extra_base = file_desc != -1 ? os::map_memory_to_file(extra_size, file_desc) :
os::map_memory_to_file(extra_size, file_desc) : os::reserve_memory(extra_size);
os::reserve_memory(extra_size);
if (extra_base == NULL) { if (extra_base == NULL) {
return NULL; return NULL;
} }
// Do manual alignment // Do manual alignment
aligned_base = align_up(extra_base, alignment); aligned_base = align_up(extra_base, alignment);
if (file_desc != -1) { bool rc = (file_desc != -1) ? os::unmap_memory(extra_base, extra_size) :
os::unmap_memory(extra_base, extra_size); os::release_memory(extra_base, extra_size);
} else { assert(rc, "release failed");
os::release_memory(extra_base, extra_size); if (!rc) {
return NULL;
} }
aligned_base = file_desc != -1 ? // Attempt to map, into the just vacated space, the slightly smaller aligned area.
os::attempt_map_memory_to_file_at(aligned_base, size, file_desc) : // Which may fail, hence the loop.
os::attempt_reserve_memory_at(aligned_base, size); aligned_base = file_desc != -1 ? os::attempt_map_memory_to_file_at(aligned_base, size, file_desc) :
os::attempt_reserve_memory_at(aligned_base, size);
}
} while (aligned_base == NULL); assert(aligned_base != NULL, "Did not manage to re-map after %d attempts?", max_attempts);
return aligned_base; return aligned_base;
} }