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restructure the page flags to use explicit masks

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This commit is contained in:
daan 2019-08-10 17:48:00 -07:00
parent c0258b2d29
commit ed785253bf
6 changed files with 53 additions and 45 deletions
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21
include/mimalloc-types.h
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@ -123,25 +123,12 @@ typedef enum mi_delayed_e {
} mi_delayed_t;
// Use the lowest two bits of a thread id for the `in_full` and `has_aligned` flags
// Use the bottom 2 bits for the `in_full` and `has_aligned` flags
// and the rest for the threadid (we assume tid's never use those lower 2 bits).
// This allows a single test in `mi_free` to check for unlikely cases
// (namely, non-local free, aligned free, or freeing in a full page)
#define MI_PAGE_FLAGS_BITS (2)
#define MI_PAGE_FLAGS_TID_BITS (MI_INTPTR_SIZE*8 - MI_PAGE_FLAGS_BITS)
typedef union mi_page_flags_u {
uintptr_t value;
struct {
#ifdef MI_BIG_ENDIAN
uintptr_t xthread_id : MI_PAGE_FLAGS_TID_BITS;
#endif
uintptr_t in_full : 1;
uintptr_t has_aligned : 1;
#ifndef MI_BIG_ENDIAN
uintptr_t xthread_id : MI_PAGE_FLAGS_TID_BITS;
#endif
};
} mi_page_flags_t;
#define MI_PAGE_FLAGS_MASK ((uintptr_t)0x03)
typedef uintptr_t mi_page_flags_t;
// Thread free list.
// We use the bottom 2 bits of the pointer for mi_delayed_t flags