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-rw-r--r--mesalib/src/util/u_atomic.h261
1 files changed, 261 insertions, 0 deletions
diff --git a/mesalib/src/util/u_atomic.h b/mesalib/src/util/u_atomic.h
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+/**
+ * Many similar implementations exist. See for example libwsbm
+ * or the linux kernel include/atomic.h
+ *
+ * No copyright claimed on this file.
+ *
+ */
+
+#ifndef U_ATOMIC_H
+#define U_ATOMIC_H
+
+#include <stdbool.h>
+
+/* Favor OS-provided implementations.
+ *
+ * Where no OS-provided implementation is available, fall back to
+ * locally coded assembly, compiler intrinsic or ultimately a
+ * mutex-based implementation.
+ */
+#if defined(__sun)
+#define PIPE_ATOMIC_OS_SOLARIS
+#elif defined(_MSC_VER)
+#define PIPE_ATOMIC_MSVC_INTRINSIC
+#elif defined(__GNUC__)
+#define PIPE_ATOMIC_GCC_INTRINSIC
+#else
+#error "Unsupported platform"
+#endif
+
+
+/* Implementation using GCC-provided synchronization intrinsics
+ */
+#if defined(PIPE_ATOMIC_GCC_INTRINSIC)
+
+#define PIPE_ATOMIC "GCC Sync Intrinsics"
+
+#define p_atomic_set(_v, _i) (*(_v) = (_i))
+#define p_atomic_read(_v) (*(_v))
+#define p_atomic_dec_zero(v) (__sync_sub_and_fetch((v), 1) == 0)
+#define p_atomic_inc(v) (void) __sync_add_and_fetch((v), 1)
+#define p_atomic_dec(v) (void) __sync_sub_and_fetch((v), 1)
+#define p_atomic_add(v, i) (void) __sync_add_and_fetch((v), (i))
+#define p_atomic_inc_return(v) __sync_add_and_fetch((v), 1)
+#define p_atomic_dec_return(v) __sync_sub_and_fetch((v), 1)
+#define p_atomic_cmpxchg(v, old, _new) \
+ __sync_val_compare_and_swap((v), (old), (_new))
+
+#endif
+
+
+
+/* Unlocked version for single threaded environments, such as some
+ * windows kernel modules.
+ */
+#if defined(PIPE_ATOMIC_OS_UNLOCKED)
+
+#define PIPE_ATOMIC "Unlocked"
+
+#define p_atomic_set(_v, _i) (*(_v) = (_i))
+#define p_atomic_read(_v) (*(_v))
+#define p_atomic_dec_zero(_v) (p_atomic_dec_return(_v) == 0)
+#define p_atomic_inc(_v) ((void) p_atomic_inc_return(_v))
+#define p_atomic_dec(_v) ((void) p_atomic_dec_return(_v))
+#define p_atomic_add(_v, _i) (*(_v) = *(_v) + (_i))
+#define p_atomic_inc_return(_v) (++(*(_v)))
+#define p_atomic_dec_return(_v) (--(*(_v)))
+#define p_atomic_cmpxchg(_v, _old, _new) (*(_v) == (_old) ? (*(_v) = (_new), (_old)) : *(_v))
+
+#endif
+
+
+#if defined(PIPE_ATOMIC_MSVC_INTRINSIC)
+
+#define PIPE_ATOMIC "MSVC Intrinsics"
+
+/* We use the Windows header's Interlocked*64 functions instead of the
+ * _Interlocked*64 intrinsics wherever we can, as support for the latter varies
+ * with target CPU, whereas Windows headers take care of all portability
+ * issues: using intrinsics where available, falling back to library
+ * implementations where not.
+ */
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN 1
+#endif
+#include <windows.h>
+#include <intrin.h>
+#include <assert.h>
+
+#if _MSC_VER < 1600
+
+/* Implement _InterlockedCompareExchange8 in terms of _InterlockedCompareExchange16 */
+static __inline char
+_InterlockedCompareExchange8(char volatile *destination8, char exchange8, char comparand8)
+{
+ INT_PTR destinationAddr = (INT_PTR)destination8;
+ short volatile *destination16 = (short volatile *)(destinationAddr & ~1);
+ const short shift8 = (destinationAddr & 1) * 8;
+ const short mask8 = 0xff << shift8;
+ short initial16 = *destination16;
+ char initial8 = initial16 >> shift8;
+ while (initial8 == comparand8) {
+ /* initial *destination8 matches, so try exchange it while keeping the
+ * neighboring byte untouched */
+ short exchange16 = (initial16 & ~mask8) | ((short)exchange8 << shift8);
+ short comparand16 = initial16;
+ short initial16 = _InterlockedCompareExchange16(destination16, exchange16, comparand16);
+ if (initial16 == comparand16) {
+ /* succeeded */
+ return comparand8;
+ }
+ /* something changed, retry with the new initial value */
+ initial8 = initial16 >> shift8;
+ }
+ return initial8;
+}
+
+/* Implement _InterlockedExchangeAdd16 in terms of _InterlockedCompareExchange16 */
+static __inline short
+_InterlockedExchangeAdd16(short volatile *addend, short value)
+{
+ short initial = *addend;
+ short comparand;
+ do {
+ short exchange = initial + value;
+ comparand = initial;
+ /* if *addend==comparand then *addend=exchange, return original *addend */
+ initial = _InterlockedCompareExchange16(addend, exchange, comparand);
+ } while(initial != comparand);
+ return comparand;
+}
+
+/* Implement _InterlockedExchangeAdd8 in terms of _InterlockedCompareExchange8 */
+static __inline char
+_InterlockedExchangeAdd8(char volatile *addend, char value)
+{
+ char initial = *addend;
+ char comparand;
+ do {
+ char exchange = initial + value;
+ comparand = initial;
+ initial = _InterlockedCompareExchange8(addend, exchange, comparand);
+ } while(initial != comparand);
+ return comparand;
+}
+
+#endif /* _MSC_VER < 1600 */
+
+/* MSVC supports decltype keyword, but it's only supported on C++ and doesn't
+ * quite work here; and if a C++-only solution is worthwhile, then it would be
+ * better to use templates / function overloading, instead of decltype magic.
+ * Therefore, we rely on implicit casting to LONGLONG for the functions that return
+ */
+
+#define p_atomic_set(_v, _i) (*(_v) = (_i))
+#define p_atomic_read(_v) (*(_v))
+
+#define p_atomic_dec_zero(_v) \
+ (p_atomic_dec_return(_v) == 0)
+
+#define p_atomic_inc(_v) \
+ ((void) p_atomic_inc_return(_v))
+
+#define p_atomic_inc_return(_v) (\
+ sizeof *(_v) == sizeof(short) ? _InterlockedIncrement16((short *) (_v)) : \
+ sizeof *(_v) == sizeof(long) ? _InterlockedIncrement ((long *) (_v)) : \
+ sizeof *(_v) == sizeof(__int64) ? InterlockedIncrement64 ((__int64 *)(_v)) : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_dec(_v) \
+ ((void) p_atomic_dec_return(_v))
+
+#define p_atomic_dec_return(_v) (\
+ sizeof *(_v) == sizeof(short) ? _InterlockedDecrement16((short *) (_v)) : \
+ sizeof *(_v) == sizeof(long) ? _InterlockedDecrement ((long *) (_v)) : \
+ sizeof *(_v) == sizeof(__int64) ? InterlockedDecrement64 ((__int64 *)(_v)) : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_add(_v, _i) (\
+ sizeof *(_v) == sizeof(char) ? _InterlockedExchangeAdd8 ((char *) (_v), (_i)) : \
+ sizeof *(_v) == sizeof(short) ? _InterlockedExchangeAdd16((short *) (_v), (_i)) : \
+ sizeof *(_v) == sizeof(long) ? _InterlockedExchangeAdd ((long *) (_v), (_i)) : \
+ sizeof *(_v) == sizeof(__int64) ? InterlockedExchangeAdd64((__int64 *)(_v), (_i)) : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_cmpxchg(_v, _old, _new) (\
+ sizeof *(_v) == sizeof(char) ? _InterlockedCompareExchange8 ((char *) (_v), (char) (_new), (char) (_old)) : \
+ sizeof *(_v) == sizeof(short) ? _InterlockedCompareExchange16((short *) (_v), (short) (_new), (short) (_old)) : \
+ sizeof *(_v) == sizeof(long) ? _InterlockedCompareExchange ((long *) (_v), (long) (_new), (long) (_old)) : \
+ sizeof *(_v) == sizeof(__int64) ? InterlockedCompareExchange64 ((__int64 *)(_v), (__int64)(_new), (__int64)(_old)) : \
+ (assert(!"should not get here"), 0))
+
+#endif
+
+#if defined(PIPE_ATOMIC_OS_SOLARIS)
+
+#define PIPE_ATOMIC "Solaris OS atomic functions"
+
+#include <atomic.h>
+#include <assert.h>
+
+#define p_atomic_set(_v, _i) (*(_v) = (_i))
+#define p_atomic_read(_v) (*(_v))
+
+#define p_atomic_dec_zero(v) (\
+ sizeof(*v) == sizeof(uint8_t) ? atomic_dec_8_nv ((uint8_t *)(v)) == 0 : \
+ sizeof(*v) == sizeof(uint16_t) ? atomic_dec_16_nv((uint16_t *)(v)) == 0 : \
+ sizeof(*v) == sizeof(uint32_t) ? atomic_dec_32_nv((uint32_t *)(v)) == 0 : \
+ sizeof(*v) == sizeof(uint64_t) ? atomic_dec_64_nv((uint64_t *)(v)) == 0 : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_inc(v) (void) (\
+ sizeof(*v) == sizeof(uint8_t) ? atomic_inc_8 ((uint8_t *)(v)) : \
+ sizeof(*v) == sizeof(uint16_t) ? atomic_inc_16((uint16_t *)(v)) : \
+ sizeof(*v) == sizeof(uint32_t) ? atomic_inc_32((uint32_t *)(v)) : \
+ sizeof(*v) == sizeof(uint64_t) ? atomic_inc_64((uint64_t *)(v)) : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_inc_return(v) ((__typeof(*v)) \
+ sizeof(*v) == sizeof(uint8_t) ? atomic_inc_8_nv ((uint8_t *)(v)) : \
+ sizeof(*v) == sizeof(uint16_t) ? atomic_inc_16_nv((uint16_t *)(v)) : \
+ sizeof(*v) == sizeof(uint32_t) ? atomic_inc_32_nv((uint32_t *)(v)) : \
+ sizeof(*v) == sizeof(uint64_t) ? atomic_inc_64_nv((uint64_t *)(v)) : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_dec(v) ((void) \
+ sizeof(*v) == sizeof(uint8_t) ? atomic_dec_8 ((uint8_t *)(v)) : \
+ sizeof(*v) == sizeof(uint16_t) ? atomic_dec_16((uint16_t *)(v)) : \
+ sizeof(*v) == sizeof(uint32_t) ? atomic_dec_32((uint32_t *)(v)) : \
+ sizeof(*v) == sizeof(uint64_t) ? atomic_dec_64((uint64_t *)(v)) : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_dec_return(v) ((__typeof(*v)) \
+ sizeof(*v) == sizeof(uint8_t) ? atomic_dec_8_nv ((uint8_t *)(v)) : \
+ sizeof(*v) == sizeof(uint16_t) ? atomic_dec_16_nv((uint16_t *)(v)) : \
+ sizeof(*v) == sizeof(uint32_t) ? atomic_dec_32_nv((uint32_t *)(v)) : \
+ sizeof(*v) == sizeof(uint64_t) ? atomic_dec_64_nv((uint64_t *)(v)) : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_add(v, i) ((void) \
+ sizeof(*v) == sizeof(uint8_t) ? atomic_add_8 ((uint8_t *)(v), (i)) : \
+ sizeof(*v) == sizeof(uint16_t) ? atomic_add_16((uint16_t *)(v), (i)) : \
+ sizeof(*v) == sizeof(uint32_t) ? atomic_add_32((uint32_t *)(v), (i)) : \
+ sizeof(*v) == sizeof(uint64_t) ? atomic_add_64((uint64_t *)(v), (i)) : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_cmpxchg(v, old, _new) ((__typeof(*v)) \
+ sizeof(*v) == sizeof(uint8_t) ? atomic_cas_8 ((uint8_t *)(v), (uint8_t )(old), (uint8_t )(_new)) : \
+ sizeof(*v) == sizeof(uint16_t) ? atomic_cas_16((uint16_t *)(v), (uint16_t)(old), (uint16_t)(_new)) : \
+ sizeof(*v) == sizeof(uint32_t) ? atomic_cas_32((uint32_t *)(v), (uint32_t)(old), (uint32_t)(_new)) : \
+ sizeof(*v) == sizeof(uint64_t) ? atomic_cas_64((uint64_t *)(v), (uint64_t)(old), (uint64_t)(_new)) : \
+ (assert(!"should not get here"), 0))
+
+#endif
+
+#ifndef PIPE_ATOMIC
+#error "No pipe_atomic implementation selected"
+#endif
+
+
+
+#endif /* U_ATOMIC_H */
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