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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2014-12-02 11:23:15 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-06-05 17:10:00 +0200 |
| commit | 36546e5b803f6e363906607307f27c489441fd15 (patch) | |
| tree | ab898dc907aa2a93f39ec00117649bde2dd27e0a /include/qemu | |
| parent | 9f02cfc84b85929947b32fe1674fbc6a429f332a (diff) | |
| download | hqemu-36546e5b803f6e363906607307f27c489441fd15.zip hqemu-36546e5b803f6e363906607307f27c489441fd15.tar.gz | |
bitmap: add atomic test and clear
The new bitmap_test_and_clear_atomic() function clears a range and
returns whether or not the bits were set.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <1417519399-3166-3-git-send-email-stefanha@redhat.com>
[Test before xchg; then a full barrier is needed at the end just like
in the previous patch. The barrier can be avoided if we did at least
one xchg. - Paolo]
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/qemu')
| -rw-r--r-- | include/qemu/bitmap.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h index 3e0a4f3..86dd9cd 100644 --- a/include/qemu/bitmap.h +++ b/include/qemu/bitmap.h @@ -41,6 +41,7 @@ * bitmap_set(dst, pos, nbits) Set specified bit area * bitmap_set_atomic(dst, pos, nbits) Set specified bit area with atomic ops * bitmap_clear(dst, pos, nbits) Clear specified bit area + * bitmap_test_and_clear_atomic(dst, pos, nbits) Test and clear area * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area */ @@ -229,6 +230,7 @@ static inline int bitmap_intersects(const unsigned long *src1, void bitmap_set(unsigned long *map, long i, long len); void bitmap_set_atomic(unsigned long *map, long i, long len); void bitmap_clear(unsigned long *map, long start, long nr); +bool bitmap_test_and_clear_atomic(unsigned long *map, long start, long nr); unsigned long bitmap_find_next_zero_area(unsigned long *map, unsigned long size, unsigned long start, |
