cosmopolitan/libc/intrin/lockcmpxchg.h
Justine Tunney 046c7ebd4a Improve locks and signals
- Introduce fast spinlock API
- Double rand64() perf w/ spinlock
- Improve raise() on New Technology
- Support gettid() across platforms
- Implement SA_NODEFER on New Technology
- Move the lock intrinsics into LIBC_INTRIN
- Make SIGTRAP recoverable on New Technology
- Block SIGCHLD in wait4() on New Technology
- Add threading prototypes for XNU and FreeBSD
- Rewrite abort() fixing its minor bugs on XNU/NT
- Shave down a lot of the content in libc/bits/bits.h
- Let signal handlers modify CPU registers on New Technology
2022-04-12 05:20:17 -07:00

29 lines
1.4 KiB
C

#ifndef COSMOPOLITAN_LIBC_INTRIN_LOCKCMPXCHG_H_
#define COSMOPOLITAN_LIBC_INTRIN_LOCKCMPXCHG_H_
#include "libc/bits/asmflag.h"
#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_
bool _lockcmpxchg(void *, intptr_t, intptr_t, size_t);
#if defined(__GNUC__) && !defined(__STRICT_ANSI__) && defined(__x86__)
#define _lockcmpxchg(IFTHING, ISEQUALTOME, REPLACEITWITHME) \
({ \
bool DidIt; \
autotype(IFTHING) IfThing = (IFTHING); \
typeof(*IfThing) IsEqualToMe = (ISEQUALTOME); \
typeof(*IfThing) ReplaceItWithMe = (REPLACEITWITHME); \
asm volatile(ZFLAG_ASM("lock cmpxchg\t%3,%1") \
: ZFLAG_CONSTRAINT(DidIt), "+m"(*IfThing), "+a"(IsEqualToMe) \
: "r"(ReplaceItWithMe) \
: "cc"); \
DidIt; \
})
#else
#define _lockcmpxchg(MEM, CMP, VAL) \
_lockcmpxchg(MEM, (intptr_t)(CMP), (intptr_t)(VAL), sizeof(*(MEM)))
#endif /* GNUC && !ANSI && x86 */
COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_LIBC_INTRIN_LOCKCMPXCHG_H_ */