/Users/deen/code/yugabyte-db/src/yb/gutil/atomicops-internals-macosx.h

Source (jump to first uncovered line)
// Copyright 2006 Google Inc.
// All Rights Reserved.
//
// The following only applies to changes made to this file as part of YugaByte development.
//
// Portions Copyright (c) YugaByte, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
// in compliance with the License.  You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software distributed under the License
// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
// or implied.  See the License for the specific language governing permissions and limitations
// under the License.
//
//
// Implementation of atomic operations for Mac OS X.  This file should not
// be included directly.  Clients should instead include
// "base/atomicops.h".

#ifndef YB_GUTIL_ATOMICOPS_INTERNALS_MACOSX_H
#define YB_GUTIL_ATOMICOPS_INTERNALS_MACOSX_H

typedef int32_t Atomic32;
typedef int64_t Atomic64;

// MacOS uses long for intptr_t, AtomicWord and Atomic32 are always different
// on the Mac, even when they are the same size.  Similarly, on __ppc64__,
// AtomicWord and Atomic64 are always different.  Thus, we need explicit
// casting.
#ifdef __LP64__
#define AtomicWordCastType base::subtle::Atomic64
#else
#define AtomicWordCastType Atomic32
#endif

#if defined(__LP64__) || defined(__i386__)
#define BASE_HAS_ATOMIC64 1  // Use only in tests and base/atomic*
#endif

#include <libkern/OSAtomic.h>

#if !defined(__LP64__) && defined(__ppc__)

// The Mac 64-bit OSAtomic implementations are not available for 32-bit PowerPC,
// while the underlying assembly instructions are available only some
// implementations of PowerPC.

// The following inline functions will fail with the error message at compile
// time ONLY IF they are called.  So it is safe to use this header if user
// code only calls AtomicWord and Atomic32 operations.
//
// NOTE(user): Implementation notes to implement the atomic ops below may
// be found in "PowerPC Virtual Environment Architecture, Book II,
// Version 2.02", January 28, 2005, Appendix B, page 46.  Unfortunately,
// extra care must be taken to ensure data are properly 8-byte aligned, and
// that data are returned correctly according to Mac OS X ABI specs.

inline int64_t OSAtomicCompareAndSwap64(
    int64_t oldValue, int64_t newValue, int64_t *theValue) {
  __asm__ __volatile__(
      "_OSAtomicCompareAndSwap64_not_supported_for_32_bit_ppc\n\t");
  return 0;
}

inline int64_t OSAtomicAdd64(int64_t theAmount, int64_t *theValue) {
  __asm__ __volatile__(
      "_OSAtomicAdd64_not_supported_for_32_bit_ppc\n\t");
  return 0;
}

inline int64_t OSAtomicCompareAndSwap64Barrier(
    int64_t oldValue, int64_t newValue, int64_t *theValue) {
  int64_t prev = OSAtomicCompareAndSwap64(oldValue, newValue, theValue);
  OSMemoryBarrier();
  return prev;
}

inline int64_t OSAtomicAdd64Barrier(
    int64_t theAmount, int64_t *theValue) {
  int64_t new_val = OSAtomicAdd64(theAmount, theValue);
  OSMemoryBarrier();
  return new_val;
}
#endif


namespace base {
namespace subtle {

typedef int32_t Atomic32;
typedef int64_t Atomic64;

inline void MemoryBarrier() {
  OSMemoryBarrier();
}

// 32-bit Versions.

inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32 *ptr,
                                         Atomic32 old_value,
                                         Atomic32 new_value) {
  Atomic32 prev_value;
  do {
    if (OSAtomicCompareAndSwap32(old_value, new_value,
                                 const_cast<Atomic32*>(ptr))) {
      return old_value;
    }
    prev_value = *ptr;
  } while (prev_value == old_value);
  return prev_value;
}

inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32 *ptr,
                                         Atomic32 new_value) {
  Atomic32 old_value;
  do {
    old_value = *ptr;
  } while (!OSAtomicCompareAndSwap32(old_value, new_value,
                                     const_cast<Atomic32*>(ptr)));
  return old_value;
}

inline Atomic32 Acquire_AtomicExchange(volatile Atomic32 *ptr,
                                       Atomic32 new_value) {
  Atomic32 old_value;
  do {
    old_value = *ptr;
  } while (!OSAtomicCompareAndSwap32Barrier(old_value, new_value,
                                            const_cast<Atomic32*>(ptr)));
  return old_value;
}

inline Atomic32 Release_AtomicExchange(volatile Atomic32 *ptr,
                                       Atomic32 new_value) {
  return Acquire_AtomicExchange(ptr, new_value);
}

inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32 *ptr,
                                          Atomic32 increment) {
  return OSAtomicAdd32(increment, const_cast<Atomic32*>(ptr));
}

inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32 *ptr,
                                          Atomic32 increment) {
  return OSAtomicAdd32Barrier(increment, const_cast<Atomic32*>(ptr));
}

inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32 *ptr,
                                       Atomic32 old_value,
                                       Atomic32 new_value) {
  Atomic32 prev_value;
  do {
    if (OSAtomicCompareAndSwap32Barrier(old_value, new_value,
                                        const_cast<Atomic32*>(ptr))) {
      return old_value;
    }
    prev_value = *ptr;
  } while (prev_value == old_value);
  return prev_value;
}

inline Atomic32 Release_CompareAndSwap(volatile Atomic32 *ptr,
                                       Atomic32 old_value,
                                       Atomic32 new_value) {
  return Acquire_CompareAndSwap(ptr, old_value, new_value);
}

inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
  *ptr = value;
}

inline void Acquire_Store(volatile Atomic32 *ptr, Atomic32 value) {
  *ptr = value;
  MemoryBarrier();
}

inline void Release_Store(volatile Atomic32 *ptr, Atomic32 value) {
  MemoryBarrier();
  *ptr = value;
}

inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
  return *ptr;
}

inline Atomic32 Acquire_Load(volatile const Atomic32 *ptr) {
  Atomic32 value = *ptr;
  MemoryBarrier();
  return value;
}

inline Atomic32 Release_Load(volatile const Atomic32 *ptr) {
  MemoryBarrier();
  return *ptr;
}

// 64-bit version

inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64 *ptr,
                                         Atomic64 old_value,
                                         Atomic64 new_value) {
  Atomic64 prev_value;
  do {
    if (OSAtomicCompareAndSwap64(old_value, new_value,
                                 const_cast<Atomic64*>(ptr))) {
      return old_value;
    }
    prev_value = *ptr;
  } while (prev_value == old_value);
  return prev_value;
}

inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64 *ptr,
                                         Atomic64 new_value) {
  Atomic64 old_value;
  do {
    old_value = *ptr;
  } while (!OSAtomicCompareAndSwap64(old_value, new_value,
                                     const_cast<Atomic64*>(ptr)));
  return old_value;
}

inline Atomic64 Acquire_AtomicExchange(volatile Atomic64 *ptr,
                                       Atomic64 new_value) {
  Atomic64 old_value;
  do {
    old_value = *ptr;
  } while (!OSAtomicCompareAndSwap64Barrier(old_value, new_value,
                                            const_cast<Atomic64*>(ptr)));
  return old_value;
}

inline Atomic64 Release_AtomicExchange(volatile Atomic64 *ptr,
                                       Atomic64 new_value) {
  return Acquire_AtomicExchange(ptr, new_value);
}

inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64 *ptr,
                                          Atomic64 increment) {
  return OSAtomicAdd64(increment, const_cast<Atomic64*>(ptr));
}

inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64 *ptr,
                                        Atomic64 increment) {
  return OSAtomicAdd64Barrier(increment, const_cast<Atomic64*>(ptr));
}

inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64 *ptr,
                                       Atomic64 old_value,
                                       Atomic64 new_value) {
  Atomic64 prev_value;
  do {
    if (OSAtomicCompareAndSwap64Barrier(old_value, new_value,
                                        const_cast<Atomic64*>(ptr))) {
      return old_value;
    }
    prev_value = *ptr;
  } while (prev_value == old_value);
  return prev_value;
}

inline Atomic64 Release_CompareAndSwap(volatile Atomic64 *ptr,
                                       Atomic64 old_value,
                                       Atomic64 new_value) {
  // The lib kern interface does not distinguish between
  // Acquire and Release memory barriers; they are equivalent.
  return Acquire_CompareAndSwap(ptr, old_value, new_value);
}

#ifdef __LP64__

// 64-bit implementation on 64-bit platform

inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
  *ptr = value;
}

// Issue the x86 "pause" instruction, which tells the CPU that we
// are in a spinlock wait loop and should allow other hyperthreads
// to run, not speculate memory access, etc.
inline void PauseCPU() {
#ifdef __x86_64__
  __asm__ __volatile__("pause" : : : "memory");
#elif defined(__arm64__)
  __asm__ __volatile__("yield" : : : "memory");
#else
  #error "PauseCPU is only supported for x86_64 and arm64 on macOS"
#endif
}

inline void Acquire_Store(volatile Atomic64 *ptr, Atomic64 value) {
  *ptr = value;
  MemoryBarrier();
}

inline void Release_Store(volatile Atomic64 *ptr, Atomic64 value) {
  MemoryBarrier();
  *ptr = value;
}

inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
  return *ptr;
}

inline Atomic64 Acquire_Load(volatile const Atomic64 *ptr) {
  Atomic64 value = *ptr;
  MemoryBarrier();
  return value;
}

inline Atomic64 Release_Load(volatile const Atomic64 *ptr) {
  MemoryBarrier();
  return *ptr;
}

#else

// 64-bit implementation on 32-bit platform

#if defined(__ppc__)

inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
  __asm__ __volatile__(
      "_NoBarrier_Store_not_supported_for_32_bit_ppc\n\t");
}

inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
  __asm__ __volatile__(
      "_NoBarrier_Load_not_supported_for_32_bit_ppc\n\t");
  return 0;
}

#elif defined(__i386__)

inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
  __asm__ __volatile__("movq %1, %%mm0\n\t"    // Use mmx reg for 64-bit atomic
                       "movq %%mm0, %0\n\t"  // moves (ptr could be read-only)
                       "emms\n\t"              // Reset FP registers
                       : "=m" (*ptr)
                       : "m" (value)
                       : // mark the FP stack and mmx registers as clobbered
                         "st", "st(1)", "st(2)", "st(3)", "st(4)",
                         "st(5)", "st(6)", "st(7)", "mm0", "mm1",
                         "mm2", "mm3", "mm4", "mm5", "mm6", "mm7");

}

inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
  Atomic64 value;
  __asm__ __volatile__("movq %1, %%mm0\n\t"  // Use mmx reg for 64-bit atomic
                       "movq %%mm0, %0\n\t"  // moves (ptr could be read-only)
                       "emms\n\t"            // Reset FP registers
                       : "=m" (value)
                       : "m" (*ptr)
                       : // mark the FP stack and mmx registers as clobbered
                         "st", "st(1)", "st(2)", "st(3)", "st(4)",
                         "st(5)", "st(6)", "st(7)", "mm0", "mm1",
                         "mm2", "mm3", "mm4", "mm5", "mm6", "mm7");

  return value;
}

#elif defined(__arm__)

inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
  int store_failed;
  Atomic64 dummy;
  __asm__ __volatile__(
      "1:\n"
      // Dummy load to lock cache line.
      "ldrexd  %1, [%3]\n"
      "strexd  %0, %2, [%3]\n"
      "teq     %0, #0\n"
      "bne     1b"
      : "=&r" (store_failed), "=&r"(dummy)
      : "r"(value), "r" (ptr)
      : "cc", "memory");
}

inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
  Atomic64 res;
  __asm__ __volatile__(
      "ldrexd   %0, [%1]\n"
      "clrex\n"
      : "=r" (res)
      : "r"(ptr), "Q"(*ptr));
  return res;
}

#endif


inline void Acquire_Store(volatile Atomic64 *ptr, Atomic64 value) {
  NoBarrier_Store(ptr, value);
  MemoryBarrier();
}

inline void Release_Store(volatile Atomic64 *ptr, Atomic64 value) {
  MemoryBarrier();
  NoBarrier_Store(ptr, value);
}

inline Atomic64 Acquire_Load(volatile const Atomic64 *ptr) {
  Atomic64 value = NoBarrier_Load(ptr);
  MemoryBarrier();
  return value;
}

inline Atomic64 Release_Load(volatile const Atomic64 *ptr) {
  MemoryBarrier();
  return NoBarrier_Load(ptr);
}
#endif  // __LP64__

}   // namespace subtle
}   // namespace base

// NOTE(user): The following is also deprecated.  New callers should use
// the base::subtle namespace.
inline void MemoryBarrier() {
  base::subtle::MemoryBarrier();
}

#endif  // YB_GUTIL_ATOMICOPS_INTERNALS_MACOSX_H

YugabyteDB (2.13.1.0-b60, 21121d69985fbf76aa6958d8f04a9bfa936293b5)

Coverage Report

Created: 2022-03-22 16:43

Line	Count	Source (jump to first uncovered line)
1		// Copyright 2006 Google Inc.
2		// All Rights Reserved.
3		//
4		// The following only applies to changes made to this file as part of YugaByte development.
5		//
6		// Portions Copyright (c) YugaByte, Inc.
7		//
8		// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
9		// in compliance with the License. You may obtain a copy of the License at
10		//
11		// http://www.apache.org/licenses/LICENSE-2.0
12		//
13		// Unless required by applicable law or agreed to in writing, software distributed under the License
14		// is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
15		// or implied. See the License for the specific language governing permissions and limitations
16		// under the License.
17		//
18		//
19		// Implementation of atomic operations for Mac OS X. This file should not
20		// be included directly. Clients should instead include
21		// "base/atomicops.h".
22
23		#ifndef YB_GUTIL_ATOMICOPS_INTERNALS_MACOSX_H
24		#define YB_GUTIL_ATOMICOPS_INTERNALS_MACOSX_H
25
26		typedef int32_t Atomic32;
27		typedef int64_t Atomic64;
28
29		// MacOS uses long for intptr_t, AtomicWord and Atomic32 are always different
30		// on the Mac, even when they are the same size. Similarly, on __ppc64__,
31		// AtomicWord and Atomic64 are always different. Thus, we need explicit
32		// casting.
33		#ifdef __LP64__
34		#define AtomicWordCastType base::subtle::Atomic64
35		#else
36		#define AtomicWordCastType Atomic32
37		#endif
38
39		#if defined(__LP64__) \|\| defined(__i386__)
40		#define BASE_HAS_ATOMIC64 1 // Use only in tests and base/atomic*
41		#endif
42
43		#include <libkern/OSAtomic.h>
44
45		#if !defined(__LP64__) && defined(__ppc__)
46
47		// The Mac 64-bit OSAtomic implementations are not available for 32-bit PowerPC,
48		// while the underlying assembly instructions are available only some
49		// implementations of PowerPC.
50
51		// The following inline functions will fail with the error message at compile
52		// time ONLY IF they are called. So it is safe to use this header if user
53		// code only calls AtomicWord and Atomic32 operations.
54		//
55		// NOTE(user): Implementation notes to implement the atomic ops below may
56		// be found in "PowerPC Virtual Environment Architecture, Book II,
57		// Version 2.02", January 28, 2005, Appendix B, page 46. Unfortunately,
58		// extra care must be taken to ensure data are properly 8-byte aligned, and
59		// that data are returned correctly according to Mac OS X ABI specs.
60
61		inline int64_t OSAtomicCompareAndSwap64(
62		int64_t oldValue, int64_t newValue, int64_t *theValue) {
63		__asm__ __volatile__(
64		"_OSAtomicCompareAndSwap64_not_supported_for_32_bit_ppc\n\t");
65		return 0;
66		}
67
68		inline int64_t OSAtomicAdd64(int64_t theAmount, int64_t *theValue) {
69		__asm__ __volatile__(
70		"_OSAtomicAdd64_not_supported_for_32_bit_ppc\n\t");
71		return 0;
72		}
73
74		inline int64_t OSAtomicCompareAndSwap64Barrier(
75		int64_t oldValue, int64_t newValue, int64_t *theValue) {
76		int64_t prev = OSAtomicCompareAndSwap64(oldValue, newValue, theValue);
77		OSMemoryBarrier();
78		return prev;
79		}
80
81		inline int64_t OSAtomicAdd64Barrier(
82		int64_t theAmount, int64_t *theValue) {
83		int64_t new_val = OSAtomicAdd64(theAmount, theValue);
84		OSMemoryBarrier();
85		return new_val;
86		}
87		#endif
88
89
90		namespace base {
91		namespace subtle {
92
93		typedef int32_t Atomic32;
94		typedef int64_t Atomic64;
95
96	2.29G	inline void MemoryBarrier() {
97	2.29G	OSMemoryBarrier();
98	2.29G	}
99
100		// 32-bit Versions.
101
102		inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32 *ptr,
103		Atomic32 old_value,
104	83.8M	Atomic32 new_value) {
105	83.8M	Atomic32 prev_value;
106	83.8M	do {
107	83.8M	if (OSAtomicCompareAndSwap32(old_value, new_value,
108	83.8M	const_cast<Atomic32*>(ptr))) {
109	75.8M	return old_value;
110	75.8M	}
111	7.93M	prev_value = *ptr;
112	7.93M	} while (prev_value == old_value);
113	7.92M	return prev_value;
114	83.8M	}
115
116		inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32 *ptr,
117	94.2k	Atomic32 new_value) {
118	94.2k	Atomic32 old_value;
119	94.2k	do {
120	94.2k	old_value = *ptr;
121	94.2k	} while (!OSAtomicCompareAndSwap32(old_value, new_value,
122	94.2k	const_cast<Atomic32*>(ptr)));
123	94.2k	return old_value;
124	94.2k	}
125
126		inline Atomic32 Acquire_AtomicExchange(volatile Atomic32 *ptr,
127	4.41G	Atomic32 new_value) {
128	4.41G	Atomic32 old_value;
129	4.41G	do {
130	4.41G	old_value = *ptr;
131	4.41G	} while (!OSAtomicCompareAndSwap32Barrier(old_value, new_value,
132	4.41G	const_cast<Atomic32*>(ptr)));
133	4.41G	return old_value;
134	4.41G	}
135
136		inline Atomic32 Release_AtomicExchange(volatile Atomic32 *ptr,
137	4.41G	Atomic32 new_value) {
138	4.41G	return Acquire_AtomicExchange(ptr, new_value);
139	4.41G	}
140
141		inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32 *ptr,
142	10.1M	Atomic32 increment) {
143	10.1M	return OSAtomicAdd32(increment, const_cast<Atomic32*>(ptr));
144	10.1M	}
145
146		inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32 *ptr,
147	11	Atomic32 increment) {
148	11	return OSAtomicAdd32Barrier(increment, const_cast<Atomic32*>(ptr));
149	11	}
150
151		inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32 *ptr,
152		Atomic32 old_value,
153	6.89G	Atomic32 new_value) {
154	6.89G	Atomic32 prev_value;
155	6.89G	do {
156	6.89G	if (OSAtomicCompareAndSwap32Barrier(old_value, new_value,
157	6.89G	const_cast<Atomic32*>(ptr))) {
158	6.61G	return old_value;
159	6.61G	}
160	287M	prev_value = *ptr;
161	287M	} while (prev_value == old_value);
162	286M	return prev_value;
163	6.89G	}
164
165		inline Atomic32 Release_CompareAndSwap(volatile Atomic32 *ptr,
166		Atomic32 old_value,
167	1.08G	Atomic32 new_value) {
168	1.08G	return Acquire_CompareAndSwap(ptr, old_value, new_value);
169	1.08G	}
170
171	12.2M	inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
172	12.2M	*ptr = value;
173	12.2M	}
174
175	7	inline void Acquire_Store(volatile Atomic32 *ptr, Atomic32 value) {
176	7	*ptr = value;
177	7	MemoryBarrier();
178	7	}
179
180	76.5M	inline void Release_Store(volatile Atomic32 *ptr, Atomic32 value) {
181	76.5M	MemoryBarrier();
182	76.5M	*ptr = value;
183	76.5M	}
184
185	29.1G	inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
186	29.1G	return *ptr;
187	29.1G	}
188
189	1.55G	inline Atomic32 Acquire_Load(volatile const Atomic32 *ptr) {
190	1.55G	Atomic32 value = *ptr;
191	1.55G	MemoryBarrier();
192	1.55G	return value;
193	1.55G	}
194
195	41	inline Atomic32 Release_Load(volatile const Atomic32 *ptr) {
196	41	MemoryBarrier();
197	41	return *ptr;
198	41	}
199
200		// 64-bit version
201
202		inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64 *ptr,
203		Atomic64 old_value,
204	1.21G	Atomic64 new_value) {
205	1.21G	Atomic64 prev_value;
206	1.21G	do {
207	1.21G	if (OSAtomicCompareAndSwap64(old_value, new_value,
208	1.21G	const_cast<Atomic64*>(ptr))) {
209	1.13G	return old_value;
210	1.13G	}
211	80.1M	prev_value = *ptr;
212	80.1M	} while (prev_value == old_value);
213	80.1M	return prev_value;
214	1.21G	}
215
216		inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64 *ptr,
217	4	Atomic64 new_value) {
218	4	Atomic64 old_value;
219	4	do {
220	4	old_value = *ptr;
221	4	} while (!OSAtomicCompareAndSwap64(old_value, new_value,
222	4	const_cast<Atomic64*>(ptr)));
223	4	return old_value;
224	4	}
225
226		inline Atomic64 Acquire_AtomicExchange(volatile Atomic64 *ptr,
227	30	Atomic64 new_value) {
228	30	Atomic64 old_value;
229	30	do {
230	30	old_value = *ptr;
231	30	} while (!OSAtomicCompareAndSwap64Barrier(old_value, new_value,
232	30	const_cast<Atomic64*>(ptr)));
233	30	return old_value;
234	30	}
235
236		inline Atomic64 Release_AtomicExchange(volatile Atomic64 *ptr,
237	2	Atomic64 new_value) {
238	2	return Acquire_AtomicExchange(ptr, new_value);
239	2	}
240
241		inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64 *ptr,
242	10.0G	Atomic64 increment) {
243	10.0G	return OSAtomicAdd64(increment, const_cast<Atomic64*>(ptr));
244	10.0G	}
245
246		inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64 *ptr,
247	370M	Atomic64 increment) {
248	370M	return OSAtomicAdd64Barrier(increment, const_cast<Atomic64*>(ptr));
249	370M	}
250
251		inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64 *ptr,
252		Atomic64 old_value,
253	44	Atomic64 new_value) {
254	44	Atomic64 prev_value;
255	44	do {
256	44	if (OSAtomicCompareAndSwap64Barrier(old_value, new_value,
257	44	const_cast<Atomic64*>(ptr))) {
258	36	return old_value;
259	36	}
260	8	prev_value = *ptr;
261	8	} while (prev_value == old_value);
262	8	return prev_value;
263	44	}
264
265		inline Atomic64 Release_CompareAndSwap(volatile Atomic64 *ptr,
266		Atomic64 old_value,
267	22	Atomic64 new_value) {
268		// The lib kern interface does not distinguish between
269		// Acquire and Release memory barriers; they are equivalent.
270	22	return Acquire_CompareAndSwap(ptr, old_value, new_value);
271	22	}
272
273		#ifdef __LP64__
274
275		// 64-bit implementation on 64-bit platform
276
277	8.94G	inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
278	8.94G	*ptr = value;
279	8.94G	}
280
281		// Issue the x86 "pause" instruction, which tells the CPU that we
282		// are in a spinlock wait loop and should allow other hyperthreads
283		// to run, not speculate memory access, etc.
284	26.3G	inline void PauseCPU() {
285		#ifdef __x86_64__
286		__asm__ __volatile__("pause" : : : "memory");
287		#elif defined(__arm64__)
288	26.3G	__asm__ __volatile__("yield" : : : "memory");
289		#else
290		#error "PauseCPU is only supported for x86_64 and arm64 on macOS"
291		#endif
292	26.3G	}
293
294	6	inline void Acquire_Store(volatile Atomic64 *ptr, Atomic64 value) {
295	6	*ptr = value;
296	6	MemoryBarrier();
297	6	}
298
299	3.98M	inline void Release_Store(volatile Atomic64 *ptr, Atomic64 value) {
300	3.98M	MemoryBarrier();
301	3.98M	*ptr = value;
302	3.98M	}
303
304	9.46G	inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
305	9.46G	return *ptr;
306	9.46G	}
307
308	535M	inline Atomic64 Acquire_Load(volatile const Atomic64 *ptr) {
309	535M	Atomic64 value = *ptr;
310	535M	MemoryBarrier();
311	535M	return value;
312	535M	}
313
314	121M	inline Atomic64 Release_Load(volatile const Atomic64 *ptr) {
315	121M	MemoryBarrier();
316	121M	return *ptr;
317	121M	}
318
319		#else
320
321		// 64-bit implementation on 32-bit platform
322
323		#if defined(__ppc__)
324
325		inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
326		__asm__ __volatile__(
327		"_NoBarrier_Store_not_supported_for_32_bit_ppc\n\t");
328		}
329
330		inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
331		__asm__ __volatile__(
332		"_NoBarrier_Load_not_supported_for_32_bit_ppc\n\t");
333		return 0;
334		}
335
336		#elif defined(__i386__)
337
338		inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
339		__asm__ __volatile__("movq %1, %%mm0\n\t" // Use mmx reg for 64-bit atomic
340		"movq %%mm0, %0\n\t" // moves (ptr could be read-only)
341		"emms\n\t" // Reset FP registers
342		: "=m" (*ptr)
343		: "m" (value)
344		: // mark the FP stack and mmx registers as clobbered
345		"st", "st(1)", "st(2)", "st(3)", "st(4)",
346		"st(5)", "st(6)", "st(7)", "mm0", "mm1",
347		"mm2", "mm3", "mm4", "mm5", "mm6", "mm7");
348
349		}
350
351		inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
352		Atomic64 value;
353		__asm__ __volatile__("movq %1, %%mm0\n\t" // Use mmx reg for 64-bit atomic
354		"movq %%mm0, %0\n\t" // moves (ptr could be read-only)
355		"emms\n\t" // Reset FP registers
356		: "=m" (value)
357		: "m" (*ptr)
358		: // mark the FP stack and mmx registers as clobbered
359		"st", "st(1)", "st(2)", "st(3)", "st(4)",
360		"st(5)", "st(6)", "st(7)", "mm0", "mm1",
361		"mm2", "mm3", "mm4", "mm5", "mm6", "mm7");
362
363		return value;
364		}
365
366		#elif defined(__arm__)
367
368		inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
369		int store_failed;
370		Atomic64 dummy;
371		__asm__ __volatile__(
372		"1:\n"
373		// Dummy load to lock cache line.
374		"ldrexd %1, [%3]\n"
375		"strexd %0, %2, [%3]\n"
376		"teq %0, #0\n"
377		"bne 1b"
378		: "=&r" (store_failed), "=&r"(dummy)
379		: "r"(value), "r" (ptr)
380		: "cc", "memory");
381		}
382
383		inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
384		Atomic64 res;
385		__asm__ __volatile__(
386		"ldrexd %0, [%1]\n"
387		"clrex\n"
388		: "=r" (res)
389		: "r"(ptr), "Q"(*ptr));
390		return res;
391		}
392
393		#endif
394
395
396		inline void Acquire_Store(volatile Atomic64 *ptr, Atomic64 value) {
397		NoBarrier_Store(ptr, value);
398		MemoryBarrier();
399		}
400
401		inline void Release_Store(volatile Atomic64 *ptr, Atomic64 value) {
402		MemoryBarrier();
403		NoBarrier_Store(ptr, value);
404		}
405
406		inline Atomic64 Acquire_Load(volatile const Atomic64 *ptr) {
407		Atomic64 value = NoBarrier_Load(ptr);
408		MemoryBarrier();
409		return value;
410		}
411
412		inline Atomic64 Release_Load(volatile const Atomic64 *ptr) {
413		MemoryBarrier();
414		return NoBarrier_Load(ptr);
415		}
416		#endif // __LP64__
417
418		} // namespace subtle
419		} // namespace base
420
421		// NOTE(user): The following is also deprecated. New callers should use
422		// the base::subtle namespace.
423	0	inline void MemoryBarrier() {
424	0	base::subtle::MemoryBarrier();
425	0	}
426
427		#endif // YB_GUTIL_ATOMICOPS_INTERNALS_MACOSX_H