diff options
Diffstat (limited to 'tools/memshr/shm.c')
| -rw-r--r-- | tools/memshr/shm.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/tools/memshr/shm.c b/tools/memshr/shm.c new file mode 100644 index 0000000000..6489f61466 --- /dev/null +++ b/tools/memshr/shm.c @@ -0,0 +1,182 @@ +/****************************************************************************** + * + * Copyright (c) 2009 Citrix (R&D) Inc. (Grzegorz Milos) + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <assert.h> +#include <stdlib.h> +#include <string.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/types.h> + +#include "memshr-priv.h" +#include "bidir-hash.h" +#include "shm.h" + +#define MEMSHR_INFO_SHM_FILE "/memshr-info" +#define MEMSHR_INFO_MAGIC 0x15263748 + +#define FGPRT_HASH_SHM_FILE "/blktap-fgprts" +#define FGPRT_HASH_PAGES 10000 + +#define BLOCK_HASH_SHM_FILE "/blktap-blks" +#define BLOCK_HASH_PAGES 10000 + +typedef struct shm_area { + void* base_addr; + size_t size; + int fd; +} shm_area_t; + +typedef struct { + struct shm_area shared_info_area; + struct shm_area fgprts_area; + struct shm_area blocks_area; +} private_shm_info_t; + +private_shm_info_t shm_info; + + + +static int shm_area_open(const char *file, size_t size, int unlink, shm_area_t *shma) +{ + /* TODO: If blktapctrl can be restarted while system is running, this needs + * to be cleverer */ + if(unlink) shm_unlink(file); + + shma->size = size; + shma->fd = shm_open(file, + (O_CREAT | O_RDWR), + (S_IREAD | S_IWRITE)); + + if(shma->fd < 0) return -1; + + if(ftruncate(shma->fd, size) < 0) return -2; + + shma->base_addr = mmap(NULL, + size, + PROT_READ | PROT_WRITE, + MAP_SHARED, + shma->fd, + 0); + + if(shma->base_addr == MAP_FAILED) return -2; + + return 0; +} + +static void shm_area_close(shm_area_t *shma) +{ + munmap(shma->base_addr, shma->size); + close(shma->fd); +} + + +shared_memshr_info_t * shm_shared_info_open(int unlink) +{ + shared_memshr_info_t *shared_info; + pthread_mutexattr_t lock_attr; + + assert(sizeof(shared_memshr_info_t) < XC_PAGE_SIZE); + if(shm_area_open(MEMSHR_INFO_SHM_FILE, + XC_PAGE_SIZE, + unlink, + &(shm_info.shared_info_area)) < 0) + { + DPRINTF("Failed to open shma for shared info.\n"); + return NULL; + } + shared_info = (shared_memshr_info_t *) + shm_info.shared_info_area.base_addr; + if(unlink) + { + memset(shared_info, 0, sizeof(shared_memshr_info_t)); + if(pthread_mutexattr_init(&lock_attr) || + pthread_mutexattr_setpshared(&lock_attr, PTHREAD_PROCESS_SHARED) || + pthread_mutex_init(&shared_info->lock, &lock_attr) || + pthread_mutexattr_destroy(&lock_attr)) + { + DPRINTF("Failed to init shared info lock.\n"); + return NULL; + } + shared_info->magic = MEMSHR_INFO_MAGIC; + } + else + if(shared_info->magic != MEMSHR_INFO_MAGIC) + { + DPRINTF("Incorrect magic in shared info.\n"); + return NULL; + } + + return shared_info; +} + + +struct fgprtshr_hash * shm_fgprtshr_hash_open(int unlink) +{ + struct fgprtshr_hash *h; + if(shm_area_open(FGPRT_HASH_SHM_FILE, + FGPRT_HASH_PAGES * XC_PAGE_SIZE, + unlink, + &(shm_info.fgprts_area)) < 0) + { + DPRINTF("Failed to init shma for fgprtshr_hash.\n"); + return NULL; + } + + if(unlink) + { + h = fgprtshr_shm_hash_init( + (unsigned long) shm_info.fgprts_area.base_addr, + FGPRT_HASH_PAGES * XC_PAGE_SIZE); + } else + { + h = fgprtshr_shm_hash_get( + (unsigned long) shm_info.fgprts_area.base_addr); + } + + return h; +} + +struct blockshr_hash * shm_blockshr_hash_open(int unlink) +{ + struct blockshr_hash *h; + if(shm_area_open(BLOCK_HASH_SHM_FILE, + BLOCK_HASH_PAGES * XC_PAGE_SIZE, + unlink, + &(shm_info.blocks_area)) < 0) + { + DPRINTF("Failed to init shma for blockshr_hash.\n"); + return NULL; + } + + if(unlink) + { + h = blockshr_shm_hash_init( + (unsigned long) shm_info.blocks_area.base_addr, + BLOCK_HASH_PAGES * XC_PAGE_SIZE); + } else + { + h = blockshr_shm_hash_get( + (unsigned long) shm_info.blocks_area.base_addr); + } + + return h; +} + |