1 | #ifndef JEMALLOC_INTERNAL_SPIN_H |
2 | #define JEMALLOC_INTERNAL_SPIN_H |
3 | |
4 | #define SPIN_INITIALIZER {0U} |
5 | |
6 | typedef struct { |
7 | unsigned iteration; |
8 | } spin_t; |
9 | |
10 | static inline void |
11 | spin_cpu_spinwait() { |
12 | # if HAVE_CPU_SPINWAIT |
13 | CPU_SPINWAIT; |
14 | # else |
15 | volatile int x = 0; |
16 | x = x; |
17 | # endif |
18 | } |
19 | |
20 | static inline void |
21 | spin_adaptive(spin_t *spin) { |
22 | volatile uint32_t i; |
23 | |
24 | if (spin->iteration < 5) { |
25 | for (i = 0; i < (1U << spin->iteration); i++) { |
26 | spin_cpu_spinwait(); |
27 | } |
28 | spin->iteration++; |
29 | } else { |
30 | #ifdef _WIN32 |
31 | SwitchToThread(); |
32 | #else |
33 | sched_yield(); |
34 | #endif |
35 | } |
36 | } |
37 | |
38 | #undef SPIN_INLINE |
39 | |
40 | #endif /* JEMALLOC_INTERNAL_SPIN_H */ |
41 | |