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b774b99db5
Use a more simple tranport protocol for the realtime data. Use a piece of shared memory and a socket where we use a 1byte read/write to trigger remote actions. Also use a ringbuffer for events.
150 lines
4.1 KiB
C
150 lines
4.1 KiB
C
/* Pinos
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* Copyright (C) 2016 Wim Taymans <wim.taymans@gmail.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
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* Boston, MA 02110-1301, USA.
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*/
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#include <string.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <errno.h>
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#include <sys/mman.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <sys/syscall.h>
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#include <pinos/client/log.h>
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#include <pinos/client/mem.h>
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/*
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* No glibc wrappers exist for memfd_create(2), so provide our own.
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*
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* Also define memfd fcntl sealing macros. While they are already
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* defined in the kernel header file <linux/fcntl.h>, that file as
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* a whole conflicts with the original glibc header <fnctl.h>.
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*/
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static inline int memfd_create(const char *name, unsigned int flags) {
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return syscall(SYS_memfd_create, name, flags);
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}
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/* memfd_create(2) flags */
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#ifndef MFD_CLOEXEC
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#define MFD_CLOEXEC 0x0001U
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#endif
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#ifndef MFD_ALLOW_SEALING
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#define MFD_ALLOW_SEALING 0x0002U
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#endif
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/* fcntl() seals-related flags */
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#ifndef F_LINUX_SPECIFIC_BASE
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#define F_LINUX_SPECIFIC_BASE 1024
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#endif
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#ifndef F_ADD_SEALS
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#define F_ADD_SEALS (F_LINUX_SPECIFIC_BASE + 9)
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#define F_GET_SEALS (F_LINUX_SPECIFIC_BASE + 10)
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#define F_SEAL_SEAL 0x0001 /* prevent further seals from being set */
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#define F_SEAL_SHRINK 0x0002 /* prevent file from shrinking */
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#define F_SEAL_GROW 0x0004 /* prevent file from growing */
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#define F_SEAL_WRITE 0x0008 /* prevent writes */
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#endif
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#undef USE_MEMFD
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SpaResult
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pinos_memblock_alloc (PinosMemblockFlags flags,
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size_t size,
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PinosMemblock *mem)
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{
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if (mem == NULL || size == 0)
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return SPA_RESULT_INVALID_ARGUMENTS;
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mem->flags = flags;
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mem->size = size;
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if (flags & PINOS_MEMBLOCK_FLAG_WITH_FD) {
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#ifdef USE_MEMFD
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mem->fd = memfd_create ("pinos-memfd", MFD_CLOEXEC | MFD_ALLOW_SEALING);
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if (mem->fd == -1) {
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pinos_log_error ("Failed to create memfd: %s\n", strerror (errno));
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return SPA_RESULT_ERROR;
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}
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#else
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char filename[] = "/dev/shm/spa-tmpfile.XXXXXX";
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mem->fd = mkostemp (filename, O_CLOEXEC);
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if (mem->fd == -1) {
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pinos_log_error ("Failed to create temporary file: %s\n", strerror (errno));
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return SPA_RESULT_ERROR;
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}
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unlink (filename);
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#endif
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if (ftruncate (mem->fd, size) < 0) {
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pinos_log_warn ("Failed to truncate temporary file: %s", strerror (errno));
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close (mem->fd);
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return SPA_RESULT_ERROR;
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}
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#ifdef USE_MEMFD
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if (flags & PINOS_MEMBLOCK_FLAG_SEAL) {
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unsigned int seals = F_SEAL_GROW | F_SEAL_SHRINK | F_SEAL_SEAL;
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if (fcntl (mem->fd, F_ADD_SEALS, seals) == -1) {
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pinos_log_warn ("Failed to add seals: %s", strerror (errno));
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}
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}
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#endif
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if (flags & PINOS_MEMBLOCK_FLAG_MAP_READWRITE) {
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int prot = 0;
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if (flags & PINOS_MEMBLOCK_FLAG_MAP_READ)
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prot |= PROT_READ;
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if (flags & PINOS_MEMBLOCK_FLAG_MAP_WRITE)
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prot |= PROT_WRITE;
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mem->ptr = mmap (NULL, size, prot, MAP_SHARED, mem->fd, 0);
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} else {
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mem->ptr = NULL;
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}
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} else {
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mem->ptr = malloc (size);
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mem->fd = -1;
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}
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return SPA_RESULT_OK;
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}
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void
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pinos_memblock_free (PinosMemblock *mem)
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{
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if (mem == NULL)
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return;
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if (mem->flags & PINOS_MEMBLOCK_FLAG_WITH_FD) {
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if (mem->ptr)
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munmap (mem->ptr, mem->size);
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if (mem->fd != -1)
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close (mem->fd);
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} else {
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free (mem->ptr);
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}
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mem->ptr = NULL;
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mem->fd = -1;
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}
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