diff options
Diffstat (limited to 'atomic/win32/apr_atomic64.c')
| -rw-r--r-- | atomic/win32/apr_atomic64.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/atomic/win32/apr_atomic64.c b/atomic/win32/apr_atomic64.c index ca1f5e0ec..372003aaa 100644 --- a/atomic/win32/apr_atomic64.c +++ b/atomic/win32/apr_atomic64.c @@ -51,9 +51,16 @@ APR_DECLARE(void) apr_atomic_set64(volatile apr_uint64_t *mem, apr_uint64_t val) APR_DECLARE(apr_uint64_t) apr_atomic_read64(volatile apr_uint64_t *mem) { +#if defined(_M_X64) + /* https://docs.microsoft.com/en-us/windows/win32/sync/interlocked-variable-access + * "Simple reads and writes to properly aligned 64-bit variables are atomic + * on 64-bit Windows."*/ + return *mem; +#else /* 64-bit read is not atomic on 32-bit platform: use InterlockedCompareExchange to perform atomic read. */ return InterlockedCompareExchange64((volatile LONG64 *)mem, 0, 0); +#endif } APR_DECLARE(apr_uint64_t) apr_atomic_cas64(volatile apr_uint64_t *mem, apr_uint64_t with, |