mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 11:37:35 +00:00
046c7ebd4a
- 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
29 lines
999 B
C
29 lines
999 B
C
#ifndef COSMOPOLITAN_LIBC_INTRIN_LOCKXCHG_H_
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#define COSMOPOLITAN_LIBC_INTRIN_LOCKXCHG_H_
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#if !(__ASSEMBLER__ + __LINKER__ + 0)
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COSMOPOLITAN_C_START_
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intptr_t lockxchg(void *, void *, size_t);
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#if defined(__GNUC__) && !defined(__STRICT_ANSI__)
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/**
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* Exchanges *MEMORY into *LOCALVAR w/ one operation.
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*
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* @param MEMORY is uint𝑘_t[hasatleast 1] where 𝑘 ∈ {8,16,32,64}
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* @param LOCALVAR is uint𝑘_t[hasatleast 1]
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* @return LOCALVAR[0]
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* @see xchg()
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*/
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#define lockxchg(MEMORY, LOCALVAR) \
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({ \
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asm("xchg\t%0,%1" : "+%m"(*(MEMORY)), "+r"(*(LOCALVAR))); \
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*(LOCALVAR); \
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})
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#else
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#define lockxchg(MEM, VAR) \
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lockxchg(MEM, VAR, sizeof(*(MEM)) / (sizeof(*(MEM)) == sizeof(*(VAR))))
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#endif /* __GNUC__ && !__STRICT_ANSI__ */
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COSMOPOLITAN_C_END_
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#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
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#endif /* COSMOPOLITAN_LIBC_INTRIN_LOCKXCHG_H_ */
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