diff options
Diffstat (limited to 'lib/mlibc/options/linux/generic/cpuset.cpp')
-rw-r--r-- | lib/mlibc/options/linux/generic/cpuset.cpp | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/lib/mlibc/options/linux/generic/cpuset.cpp b/lib/mlibc/options/linux/generic/cpuset.cpp new file mode 100644 index 0000000..d0292b7 --- /dev/null +++ b/lib/mlibc/options/linux/generic/cpuset.cpp @@ -0,0 +1,71 @@ +#include <limits.h> +#include <sched.h> +#include <stdlib.h> +#include <string.h> + +cpu_set_t *__mlibc_cpu_alloc(int num_cpus) { + return reinterpret_cast<cpu_set_t *>(calloc(1, CPU_ALLOC_SIZE(num_cpus))); +} + +#define CPU_MASK_BITS (CHAR_BIT * sizeof(__cpu_mask)) + +size_t __mlibc_cpu_alloc_size(int num_cpus) { + /* calculate the (unaligned) remainder that doesn't neatly fit in one __cpu_mask; 0 or 1 */ + size_t remainder = ((num_cpus % CPU_MASK_BITS) + CPU_MASK_BITS - 1) / CPU_MASK_BITS; + return sizeof(__cpu_mask) * (num_cpus / CPU_MASK_BITS + remainder); +} + +void __mlibc_cpu_zero(const size_t setsize, cpu_set_t *set) { + memset(set, 0, CPU_ALLOC_SIZE(setsize)); +} + +void __mlibc_cpu_set(const int cpu, const size_t setsize, cpu_set_t *set) { + if(cpu >= static_cast<int>(setsize * CHAR_BIT)) { + return; + } + + unsigned char *ptr = reinterpret_cast<unsigned char *>(set); + size_t off = cpu / CHAR_BIT; + size_t mask = 1 << (cpu % CHAR_BIT); + + ptr[off] |= mask; +} + +void __mlibc_cpu_clear(const int cpu, const size_t setsize, cpu_set_t *set) { + if(cpu >= static_cast<int>(setsize * CHAR_BIT)) { + return; + } + + unsigned char *ptr = reinterpret_cast<unsigned char *>(set); + size_t off = cpu / CHAR_BIT; + size_t mask = 1 << (cpu % CHAR_BIT); + + ptr[off] &= ~mask; +} + + +int __mlibc_cpu_isset(const int cpu, const size_t setsize, const cpu_set_t *set) { + if(cpu >= static_cast<int>(setsize * CHAR_BIT)) { + return false; + } + + const unsigned char *ptr = reinterpret_cast<const unsigned char *>(set); + size_t off = cpu / CHAR_BIT; + size_t mask = 1 << (cpu % CHAR_BIT); + + return (ptr[off] & mask); +} + +int __mlibc_cpu_count(const size_t setsize, const cpu_set_t *set) { + size_t count = 0; + const unsigned char *ptr = reinterpret_cast<const unsigned char *>(set); + + for(size_t i = 0; i < setsize; i++) { + for(size_t bit = 0; bit < CHAR_BIT; bit++) { + if((1 << bit) & ptr[i]) + count++; + } + } + + return count; +} |