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/*
* Copyright (C) Max Romanov
* Copyright (C) NGINX, Inc.
*/
#ifndef _NXT_PORT_MEMORY_INT_H_INCLUDED_
#define _NXT_PORT_MEMORY_INT_H_INCLUDED_
#include <stdint.h>
#include <nxt_atomic.h>
#ifdef NXT_MMAP_TINY_CHUNK
#define PORT_MMAP_CHUNK_SIZE 16
#define PORT_MMAP_HEADER_SIZE 1024
#define PORT_MMAP_DATA_SIZE 1024
#else
#define PORT_MMAP_CHUNK_SIZE (1024 * 16)
#define PORT_MMAP_HEADER_SIZE (1024 * 4)
#define PORT_MMAP_DATA_SIZE (1024 * 1024 * 10)
#endif
#define PORT_MMAP_SIZE (PORT_MMAP_HEADER_SIZE + PORT_MMAP_DATA_SIZE)
#define PORT_MMAP_CHUNK_COUNT (PORT_MMAP_DATA_SIZE / PORT_MMAP_CHUNK_SIZE)
typedef uint32_t nxt_chunk_id_t;
typedef nxt_atomic_uint_t nxt_free_map_t;
#define FREE_BITS (sizeof(nxt_free_map_t) * 8)
#define FREE_IDX(nchunk) ((nchunk) / FREE_BITS)
#define FREE_MASK(nchunk) \
( 1ULL << ( (nchunk) % FREE_BITS ) )
#define MAX_FREE_IDX FREE_IDX(PORT_MMAP_CHUNK_COUNT)
/* Mapped at the start of shared memory segment. */
struct nxt_port_mmap_header_s {
uint32_t id;
nxt_pid_t pid; /* For sanity check. */
nxt_free_map_t free_map[MAX_FREE_IDX];
};
/*
* Element of nxt_process_t.incoming/outgoing, shared memory segment
* descriptor.
*/
struct nxt_port_mmap_s {
nxt_port_mmap_header_t *hdr;
};
typedef struct nxt_port_mmap_msg_s nxt_port_mmap_msg_t;
/* Passed as a second iov chunk when 'mmap' bit in nxt_port_msg_t is 1. */
struct nxt_port_mmap_msg_s {
uint32_t mmap_id; /* Mmap index in nxt_process_t.outgoing. */
nxt_chunk_id_t chunk_id; /* Mmap chunk index. */
uint32_t size; /* Payload data size. */
};
static nxt_bool_t
nxt_port_mmap_get_free_chunk(nxt_port_mmap_header_t *hdr, nxt_chunk_id_t *c);
#define nxt_port_mmap_get_chunk_busy(hdr, c) \
((hdr->free_map[FREE_IDX(c)] & FREE_MASK(c)) == 0)
nxt_inline void
nxt_port_mmap_set_chunk_busy(nxt_port_mmap_header_t *hdr, nxt_chunk_id_t c);
nxt_inline nxt_bool_t
nxt_port_mmap_chk_set_chunk_busy(nxt_port_mmap_header_t *hdr, nxt_chunk_id_t c);
nxt_inline void
nxt_port_mmap_set_chunk_free(nxt_port_mmap_header_t *hdr, nxt_chunk_id_t c);
nxt_inline nxt_chunk_id_t
nxt_port_mmap_chunk_id(nxt_port_mmap_header_t *hdr, u_char *p)
{
u_char *mm_start;
mm_start = (u_char *) hdr;
return ((p - mm_start) - PORT_MMAP_HEADER_SIZE) / PORT_MMAP_CHUNK_SIZE;
}
nxt_inline u_char *
nxt_port_mmap_chunk_start(nxt_port_mmap_header_t *hdr, nxt_chunk_id_t c)
{
u_char *mm_start;
mm_start = (u_char *) hdr;
return mm_start + PORT_MMAP_HEADER_SIZE + c * PORT_MMAP_CHUNK_SIZE;
}
static nxt_bool_t
nxt_port_mmap_get_free_chunk(nxt_port_mmap_header_t *hdr, nxt_chunk_id_t *c)
{
int ffs;
size_t i;
nxt_chunk_id_t chunk;
nxt_free_map_t bits;
nxt_free_map_t *free_map;
free_map = hdr->free_map;
for (i = 0; i < MAX_FREE_IDX; i++) {
bits = free_map[i];
if (bits == 0) {
continue;
}
ffs = __builtin_ffsll(bits);
if (ffs != 0) {
chunk = i * FREE_BITS + ffs - 1;
if (nxt_port_mmap_chk_set_chunk_busy(hdr, chunk)) {
*c = chunk;
return 1;
}
}
}
return 0;
}
nxt_inline void
nxt_port_mmap_set_chunk_busy(nxt_port_mmap_header_t *hdr, nxt_chunk_id_t c)
{
nxt_atomic_and_fetch(hdr->free_map + FREE_IDX(c), ~FREE_MASK(c));
}
nxt_inline nxt_bool_t
nxt_port_mmap_chk_set_chunk_busy(nxt_port_mmap_header_t *hdr, nxt_chunk_id_t c)
{
nxt_free_map_t *f;
nxt_free_map_t free_val, busy_val;
f = hdr->free_map + FREE_IDX(c);
while ( (*f & FREE_MASK(c)) != 0 ) {
free_val = *f | FREE_MASK(c);
busy_val = free_val & ~FREE_MASK(c);
if (nxt_atomic_cmp_set(f, free_val, busy_val) != 0) {
return 1;
}
}
return 0;
}
nxt_inline void
nxt_port_mmap_set_chunk_free(nxt_port_mmap_header_t *hdr, nxt_chunk_id_t c)
{
nxt_atomic_or_fetch(hdr->free_map + FREE_IDX(c), FREE_MASK(c));
}
#endif /* _NXT_PORT_MEMORY_INT_H_INCLUDED_ */
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