gcc/libgfortran/caf/shmem/shared_memory.h

97 lines
2.8 KiB
C

/* Copyright (C) 2025 Free Software Foundation, Inc.
Contributed by Thomas Koenig, Nicolas Koenig, Andre Vehreschild
This file is part of the GNU Fortran Shmem Coarray Library (caf_shmem).
Caf_shmem is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
Caf_shmem is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#ifndef SHARED_MEMORY_H
#define SHARED_MEMORY_H
#include "thread_support.h"
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
/* Global metadata for shared memory, always kept at offset 0. */
typedef struct
{
size_t used;
ptrdiff_t master;
} global_shared_memory_meta;
/* Type realization for shared_memory. */
typedef struct shared_memory_act
{
union
{
void *base;
global_shared_memory_meta *meta;
} glbl;
size_t size; // const
caf_shmem_fd shm_fd;
} shared_memory_act;
/* A struct to serve as shared memory object. */
typedef struct shared_memory_act * shared_memory;
#define SHMPTR_NULL ((shared_mem_ptr) {.offset = 0})
#define SHMPTR_IS_NULL(x) (x.offset == 0)
#define SHMPTR_DEREF(x, s, sm) ((x) = *(__typeof (x) *) s.p)
#define SHMPTR_AS(type, s, sm) ((type) (*((void **) sm) + s.offset))
#define AS_SHMPTR(p, sm) ((shared_mem_ptr) {.offset = (p) - sm.glbl.base})
#define SHARED_MEMORY_RAW_ALLOC(mem, t, n) \
shared_memory_get_mem_with_alignment (mem, sizeof (t) * n, __alignof__ (t))
#define SHARED_MEMORY_RAW_ALLOC_PTR(mem, t) \
SHMPTR_AS (t *, SHARED_MEMORY_RAW_ALLOC (mem, t, 1), mem)
/* A shared-memory pointer is implemented as an offset into the shared
memory region. */
typedef struct shared_mem_ptr
{
ptrdiff_t offset;
} shared_mem_ptr;
void shared_memory_init (shared_memory, size_t);
void shared_memory_cleanup (shared_memory);
void shared_memory_prepare (shared_memory);
shared_mem_ptr shared_memory_get_mem_with_alignment (shared_memory mem,
size_t size, size_t align);
shared_mem_ptr shared_memory_get_master (shared_memory pmem, size_t size,
size_t align);
void shared_memory_set_env (pid_t pid);
char *shared_memory_get_env (void);
#endif