diff options
Diffstat (limited to 'src/svm/svm.c')
| -rw-r--r-- | src/svm/svm.c | 1237 |
1 files changed, 1237 insertions, 0 deletions
diff --git a/src/svm/svm.c b/src/svm/svm.c new file mode 100644 index 00000000000..e4ca98e1ed2 --- /dev/null +++ b/src/svm/svm.c @@ -0,0 +1,1237 @@ +/* + *------------------------------------------------------------------ + * svm.c - shared VM allocation, mmap(...MAP_FIXED...) + * library + * + * Copyright (c) 2009 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + *------------------------------------------------------------------ + */ + +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <netinet/in.h> +#include <signal.h> +#include <pthread.h> +#include <unistd.h> +#include <time.h> +#include <fcntl.h> +#include <string.h> +#include <vppinfra/clib.h> +#include <vppinfra/vec.h> +#include <vppinfra/hash.h> +#include <vppinfra/bitmap.h> +#include <vppinfra/fifo.h> +#include <vppinfra/time.h> +#include <vppinfra/mheap.h> +#include <vppinfra/heap.h> +#include <vppinfra/pool.h> +#include <vppinfra/format.h> + +#include "svm.h" + +static svm_region_t *root_rp; +static int root_rp_refcount; + +#define MAXLOCK 2 +static pthread_mutex_t *mutexes_held[MAXLOCK]; +static int nheld; + +svm_region_t * +svm_get_root_rp (void) +{ + return root_rp; +} + +#define MUTEX_DEBUG + +static void +region_lock (svm_region_t * rp, int tag) +{ + pthread_mutex_lock (&rp->mutex); +#ifdef MUTEX_DEBUG + rp->mutex_owner_pid = getpid (); + rp->mutex_owner_tag = tag; +#endif + ASSERT (nheld < MAXLOCK); + /* + * Keep score of held mutexes so we can try to exit + * cleanly if the world comes to an end at the worst possible + * moment + */ + mutexes_held[nheld++] = &rp->mutex; +} + +static void +region_unlock (svm_region_t * rp) +{ + int i, j; +#ifdef MUTEX_DEBUG + rp->mutex_owner_pid = 0; + rp->mutex_owner_tag = 0; +#endif + + for (i = nheld - 1; i >= 0; i--) + { + if (mutexes_held[i] == &rp->mutex) + { + for (j = i; j < MAXLOCK - 1; j++) + mutexes_held[j] = mutexes_held[j + 1]; + nheld--; + goto found; + } + } + ASSERT (0); + +found: + CLIB_MEMORY_BARRIER (); + pthread_mutex_unlock (&rp->mutex); +} + + +static u8 * +format_svm_flags (u8 * s, va_list * args) +{ + uword f = va_arg (*args, uword); + + if (f & SVM_FLAGS_MHEAP) + s = format (s, "MHEAP "); + if (f & SVM_FLAGS_FILE) + s = format (s, "FILE "); + if (f & SVM_FLAGS_NODATA) + s = format (s, "NODATA "); + if (f & SVM_FLAGS_NEED_DATA_INIT) + s = format (s, "INIT "); + + return (s); +} + +static u8 * +format_svm_size (u8 * s, va_list * args) +{ + uword size = va_arg (*args, uword); + + if (size >= (1 << 20)) + { + s = format (s, "(%d mb)", size >> 20); + } + else if (size >= (1 << 10)) + { + s = format (s, "(%d kb)", size >> 10); + } + else + { + s = format (s, "(%d bytes)", size); + } + return (s); +} + +u8 * +format_svm_region (u8 * s, va_list * args) +{ + svm_region_t *rp = va_arg (*args, svm_region_t *); + int verbose = va_arg (*args, int); + int i; + uword lo, hi; + + s = format (s, "%s: base va 0x%x size 0x%x %U\n", + rp->region_name, rp->virtual_base, + rp->virtual_size, format_svm_size, rp->virtual_size); + s = format (s, " user_ctx 0x%x, bitmap_size %d\n", + rp->user_ctx, rp->bitmap_size); + + if (verbose) + { + s = format (s, " flags: 0x%x %U\n", rp->flags, + format_svm_flags, rp->flags); + s = format (s, + " region_heap 0x%x data_base 0x%x data_heap 0x%x\n", + rp->region_heap, rp->data_base, rp->data_heap); + } + + s = format (s, " %d clients, pids: ", vec_len (rp->client_pids)); + + for (i = 0; i < vec_len (rp->client_pids); i++) + s = format (s, "%d ", rp->client_pids[i]); + + s = format (s, "\n"); + + if (verbose) + { + lo = hi = ~0; + + s = format (s, " VM in use: "); + + for (i = 0; i < rp->bitmap_size; i++) + { + if (clib_bitmap_get_no_check (rp->bitmap, i) != 0) + { + if (lo == ~0) + { + hi = lo = rp->virtual_base + i * MMAP_PAGESIZE; + } + else + { + hi = rp->virtual_base + i * MMAP_PAGESIZE; + } + } + else + { + if (lo != ~0) + { + hi = rp->virtual_base + i * MMAP_PAGESIZE - 1; + s = format (s, " 0x%x - 0x%x (%dk)\n", lo, hi, + (hi - lo) >> 10); + lo = hi = ~0; + } + } + } + s = format (s, " rgn heap stats: %U", format_mheap, + rp->region_heap, 0); + if ((rp->flags & SVM_FLAGS_MHEAP) && rp->data_heap) + { + s = format (s, "\n data heap stats: %U", format_mheap, + rp->data_heap, 1); + } + s = format (s, "\n"); + } + + return (s); +} + +/* + * rnd_pagesize + * Round to a pagesize multiple, presumably 4k works + */ +static u64 +rnd_pagesize (u64 size) +{ + u64 rv; + + rv = (size + (MMAP_PAGESIZE - 1)) & ~(MMAP_PAGESIZE - 1); + return (rv); +} + +/* + * svm_data_region_setup + */ +static int +svm_data_region_create (svm_map_region_args_t * a, svm_region_t * rp) +{ + int fd; + u8 junk = 0; + uword map_size; + + map_size = rp->virtual_size - (MMAP_PAGESIZE + + (a->pvt_heap_size ? a->pvt_heap_size : + SVM_PVT_MHEAP_SIZE)); + + if (a->flags & SVM_FLAGS_FILE) + { + struct stat statb; + + fd = open (a->backing_file, O_RDWR | O_CREAT, 0777); + + if (fd < 0) + { + clib_unix_warning ("open"); + return -1; + } + + if (fstat (fd, &statb) < 0) + { + clib_unix_warning ("fstat"); + close (fd); + return -2; + } + + if (statb.st_mode & S_IFREG) + { + if (statb.st_size == 0) + { + if (lseek (fd, map_size, SEEK_SET) == (off_t) - 1) + { + clib_unix_warning ("seek region size"); + close (fd); + return -3; + } + if (write (fd, &junk, 1) != 1) + { + clib_unix_warning ("set region size"); + close (fd); + return -3; + } + } + else + { + map_size = rnd_pagesize (statb.st_size); + } + } + else + { + map_size = a->backing_mmap_size; + } + + ASSERT (map_size <= rp->virtual_size - + (MMAP_PAGESIZE + SVM_PVT_MHEAP_SIZE)); + + if (mmap (rp->data_base, map_size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_FIXED, fd, 0) == MAP_FAILED) + { + clib_unix_warning ("mmap"); + close (fd); + return -3; + } + close (fd); + rp->backing_file = (char *) format (0, "%s\0", a->backing_file); + rp->flags |= SVM_FLAGS_FILE; + } + + if (a->flags & SVM_FLAGS_MHEAP) + { + rp->data_heap = + mheap_alloc_with_flags ((void *) (rp->data_base), map_size, + MHEAP_FLAG_DISABLE_VM); + rp->flags |= SVM_FLAGS_MHEAP; + } + return 0; +} + +static int +svm_data_region_map (svm_map_region_args_t * a, svm_region_t * rp) +{ + int fd; + u8 junk = 0; + uword map_size; + struct stat statb; + + map_size = rp->virtual_size - + (MMAP_PAGESIZE + + (a->pvt_heap_size ? a->pvt_heap_size : SVM_PVT_MHEAP_SIZE)); + + if (a->flags & SVM_FLAGS_FILE) + { + + fd = open (a->backing_file, O_RDWR, 0777); + + if (fd < 0) + { + clib_unix_warning ("open"); + return -1; + } + + if (fstat (fd, &statb) < 0) + { + clib_unix_warning ("fstat"); + close (fd); + return -2; + } + + if (statb.st_mode & S_IFREG) + { + if (statb.st_size == 0) + { + if (lseek (fd, map_size, SEEK_SET) == (off_t) - 1) + { + clib_unix_warning ("seek region size"); + close (fd); + return -3; + } + if (write (fd, &junk, 1) != 1) + { + clib_unix_warning ("set region size"); + close (fd); + return -3; + } + } + else + { + map_size = rnd_pagesize (statb.st_size); + } + } + else + { + map_size = a->backing_mmap_size; + } + + ASSERT (map_size <= rp->virtual_size + - (MMAP_PAGESIZE + + + (a->pvt_heap_size ? a->pvt_heap_size : SVM_PVT_MHEAP_SIZE))); + + if (mmap (rp->data_base, map_size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_FIXED, fd, 0) == MAP_FAILED) + { + clib_unix_warning ("mmap"); + close (fd); + return -3; + } + close (fd); + } + return 0; +} + +u8 * +shm_name_from_svm_map_region_args (svm_map_region_args_t * a) +{ + u8 *path; + u8 *shm_name; + u8 *split_point; + u8 *mkdir_arg = 0; + int root_path_offset = 0; + int name_offset = 0; + + if (a->root_path) + { + /* Tolerate present or absent slashes */ + if (a->root_path[0] == '/') + root_path_offset++; + + /* create the root_path under /dev/shm + iterate through path creating directories */ + + path = format (0, "/dev/shm/%s%c", &a->root_path[root_path_offset], 0); + split_point = path + 1; + vec_add1 (mkdir_arg, '-'); + + while (*split_point) + { + while (*split_point && *split_point != '/') + { + vec_add1 (mkdir_arg, *split_point); + split_point++; + } + vec_add1 (mkdir_arg, 0); + + /* ready to descend another level */ + mkdir_arg[vec_len (mkdir_arg) - 1] = '-'; + split_point++; + } + vec_free (mkdir_arg); + vec_free (path); + + if (a->name[0] == '/') + name_offset = 1; + + shm_name = format (0, "/%s-%s%c", a->root_path, + &a->name[name_offset], 0); + } + else + shm_name = format (0, "%s%c", a->name, 0); + return (shm_name); +} + +/* + * svm_map_region + */ +void * +svm_map_region (svm_map_region_args_t * a) +{ + int svm_fd; + svm_region_t *rp; + pthread_mutexattr_t attr; + pthread_condattr_t cattr; + int deadman = 0; + u8 junk = 0; + void *oldheap; + int overhead_space; + int rv; + uword data_base; + int nbits, words, bit; + int pid_holding_region_lock; + u8 *shm_name; + int dead_region_recovery = 0; + int time_left; + struct stat stat; + struct timespec ts, tsrem; + + if (CLIB_DEBUG > 1) + clib_warning ("[%d] map region %s", getpid (), a->name); + + ASSERT ((a->size & ~(MMAP_PAGESIZE - 1)) == a->size); + ASSERT (a->name); + + shm_name = shm_name_from_svm_map_region_args (a); + + svm_fd = shm_open ((char *) shm_name, O_RDWR | O_CREAT | O_EXCL, 0777); + + if (svm_fd >= 0) + { + if (fchmod (svm_fd, 0770) < 0) + clib_unix_warning ("segment chmod"); + /* This turns out to fail harmlessly if the client starts first */ + if (fchown (svm_fd, a->uid, a->gid) < 0) + clib_unix_warning ("segment chown [ok if client starts first]"); + + vec_free (shm_name); + + if (lseek (svm_fd, a->size, SEEK_SET) == (off_t) - 1) + { + clib_warning ("seek region size"); + close (svm_fd); + return (0); + } + if (write (svm_fd, &junk, 1) != 1) + { + clib_warning ("set region size"); + close (svm_fd); + return (0); + } + + rp = mmap ((void *) a->baseva, a->size, + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FIXED, svm_fd, 0); + + if (rp == (svm_region_t *) MAP_FAILED) + { + clib_unix_warning ("mmap create"); + close (svm_fd); + return (0); + } + close (svm_fd); + memset (rp, 0, sizeof (*rp)); + + if (pthread_mutexattr_init (&attr)) + clib_unix_warning ("mutexattr_init"); + + if (pthread_mutexattr_setpshared (&attr, PTHREAD_PROCESS_SHARED)) + clib_unix_warning ("mutexattr_setpshared"); + + if (pthread_mutex_init (&rp->mutex, &attr)) + clib_unix_warning ("mutex_init"); + + if (pthread_mutexattr_destroy (&attr)) + clib_unix_warning ("mutexattr_destroy"); + + if (pthread_condattr_init (&cattr)) + clib_unix_warning ("condattr_init"); + + if (pthread_condattr_setpshared (&cattr, PTHREAD_PROCESS_SHARED)) + clib_unix_warning ("condattr_setpshared"); + + if (pthread_cond_init (&rp->condvar, &cattr)) + clib_unix_warning ("cond_init"); + + if (pthread_condattr_destroy (&cattr)) + clib_unix_warning ("condattr_destroy"); + + region_lock (rp, 1); + + rp->virtual_base = a->baseva; + rp->virtual_size = a->size; + + rp->region_heap = + mheap_alloc_with_flags ((void *) (a->baseva + MMAP_PAGESIZE), + (a->pvt_heap_size != 0) ? + a->pvt_heap_size : SVM_PVT_MHEAP_SIZE, + MHEAP_FLAG_DISABLE_VM); + oldheap = svm_push_pvt_heap (rp); + + rp->region_name = (char *) format (0, "%s%c", a->name, 0); + vec_add1 (rp->client_pids, getpid ()); + + nbits = rp->virtual_size / MMAP_PAGESIZE; + + ASSERT (nbits > 0); + rp->bitmap_size = nbits; + words = (nbits + BITS (uword) - 1) / BITS (uword); + vec_validate (rp->bitmap, words - 1); + + overhead_space = MMAP_PAGESIZE /* header */ + + ((a->pvt_heap_size != 0) ? a->pvt_heap_size : SVM_PVT_MHEAP_SIZE); + + bit = 0; + data_base = (uword) rp->virtual_base; + + if (a->flags & SVM_FLAGS_NODATA) + rp->flags |= SVM_FLAGS_NEED_DATA_INIT; + + do + { + clib_bitmap_set_no_check (rp->bitmap, bit, 1); + bit++; + overhead_space -= MMAP_PAGESIZE; + data_base += MMAP_PAGESIZE; + } + while (overhead_space > 0); + + rp->data_base = (void *) data_base; + + /* + * Note: although the POSIX spec guarantees that only one + * process enters this block, we have to play games + * to hold off clients until e.g. the mutex is ready + */ + rp->version = SVM_VERSION; + + /* setup the data portion of the region */ + + rv = svm_data_region_create (a, rp); + if (rv) + { + clib_warning ("data_region_create: %d", rv); + } + + region_unlock (rp); + + svm_pop_heap (oldheap); + + return ((void *) rp); + } + else + { + svm_fd = shm_open ((char *) shm_name, O_RDWR, 0777); + + vec_free (shm_name); + + if (svm_fd < 0) + { + perror ("svm_region_map(mmap open)"); + return (0); + } + + time_left = 20; + while (1) + { + if (0 != fstat (svm_fd, &stat)) + { + clib_warning ("fstat failed: %d", errno); + close (svm_fd); + return (0); + } + if (stat.st_size > 0) + { + break; + } + if (0 == time_left) + { + clib_warning ("waiting for resize of shm file timed out"); + close (svm_fd); + return (0); + } + ts.tv_sec = 0; + ts.tv_nsec = 100000000; + while (nanosleep (&ts, &tsrem) < 0) + ts = tsrem; + time_left--; + } + + rp = mmap (0, MMAP_PAGESIZE, + PROT_READ | PROT_WRITE, MAP_SHARED, svm_fd, 0); + + if (rp == (svm_region_t *) MAP_FAILED) + { + close (svm_fd); + clib_warning ("mmap"); + return (0); + } + /* + * We lost the footrace to create this region; make sure + * the winner has crossed the finish line. + */ + while (rp->version == 0 && deadman++ < 5) + { + sleep (1); + } + + /* + * <bleep>-ed? + */ + if (rp->version == 0) + { + clib_warning ("rp->version %d not %d", rp->version, SVM_VERSION); + close (svm_fd); + munmap (rp, a->size); + return (0); + } + /* Remap now that the region has been placed */ + a->baseva = rp->virtual_base; + a->size = rp->virtual_size; + munmap (rp, MMAP_PAGESIZE); + + rp = (void *) mmap ((void *) a->baseva, a->size, + PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_FIXED, svm_fd, 0); + if ((uword) rp == (uword) MAP_FAILED) + { + clib_unix_warning ("mmap"); + close (svm_fd); + return (0); + } + + if ((uword) rp != rp->virtual_base) + { + clib_warning ("mmap botch"); + } + + /* + * Try to fix the region mutex if it is held by + * a dead process + */ + pid_holding_region_lock = rp->mutex_owner_pid; + if (pid_holding_region_lock && kill (pid_holding_region_lock, 0) < 0) + { + clib_warning + ("region %s mutex held by dead pid %d, tag %d, force unlock", + rp->region_name, pid_holding_region_lock, rp->mutex_owner_tag); + /* owner pid is nonexistent */ + rp->mutex.__data.__owner = 0; + rp->mutex.__data.__lock = 0; + dead_region_recovery = 1; + } + + if (dead_region_recovery) + clib_warning ("recovery: attempt to re-lock region"); + + region_lock (rp, 2); + oldheap = svm_push_pvt_heap (rp); + vec_add1 (rp->client_pids, getpid ()); + + if (dead_region_recovery) + clib_warning ("recovery: attempt svm_data_region_map"); + + rv = svm_data_region_map (a, rp); + if (rv) + { + clib_warning ("data_region_map: %d", rv); + } + + if (dead_region_recovery) + clib_warning ("unlock and continue"); + + region_unlock (rp); + + svm_pop_heap (oldheap); + + return ((void *) rp); + + } + return 0; /* NOTREACHED */ +} + +static void +svm_mutex_cleanup (void) +{ + int i; + for (i = 0; i < nheld; i++) + { + pthread_mutex_unlock (mutexes_held[i]); + } +} + +static void +svm_region_init_internal (svm_map_region_args_t * a) +{ + svm_region_t *rp; + u64 ticks = clib_cpu_time_now (); + uword randomize_baseva; + + /* guard against klutz calls */ + if (root_rp) + return; + + root_rp_refcount++; + + atexit (svm_mutex_cleanup); + + /* Randomize the shared-VM base at init time */ + if (MMAP_PAGESIZE <= (4 << 10)) + randomize_baseva = (ticks & 15) * MMAP_PAGESIZE; + else + randomize_baseva = (ticks & 3) * MMAP_PAGESIZE; + + a->baseva += randomize_baseva; + + rp = svm_map_region (a); + ASSERT (rp); + + region_lock (rp, 3); + + /* Set up the main region data structures */ + if (rp->flags & SVM_FLAGS_NEED_DATA_INIT) + { + svm_main_region_t *mp = 0; + void *oldheap; + + rp->flags &= ~(SVM_FLAGS_NEED_DATA_INIT); + + oldheap = svm_push_pvt_heap (rp); + vec_validate (mp, 0); + mp->name_hash = hash_create_string (0, sizeof (uword)); + mp->root_path = a->root_path ? format (0, "%s%c", a->root_path, 0) : 0; + rp->data_base = mp; + svm_pop_heap (oldheap); + } + region_unlock (rp); + root_rp = rp; +} + +void +svm_region_init (void) +{ + svm_map_region_args_t _a, *a = &_a; + + memset (a, 0, sizeof (*a)); + a->root_path = 0; + a->name = SVM_GLOBAL_REGION_NAME; + a->baseva = SVM_GLOBAL_REGION_BASEVA; + a->size = SVM_GLOBAL_REGION_SIZE; + a->flags = SVM_FLAGS_NODATA; + a->uid = 0; + a->gid = 0; + + svm_region_init_internal (a); +} + +void +svm_region_init_chroot (char *root_path) +{ + svm_map_region_args_t _a, *a = &_a; + + memset (a, 0, sizeof (*a)); + a->root_path = root_path; + a->name = SVM_GLOBAL_REGION_NAME; + a->baseva = SVM_GLOBAL_REGION_BASEVA; + a->size = SVM_GLOBAL_REGION_SIZE; + a->flags = SVM_FLAGS_NODATA; + a->uid = 0; + a->gid = 0; + + svm_region_init_internal (a); +} + +void +svm_region_init_chroot_uid_gid (char *root_path, int uid, int gid) +{ + svm_map_region_args_t _a, *a = &_a; + + memset (a, 0, sizeof (*a)); + a->root_path = root_path; + a->name = SVM_GLOBAL_REGION_NAME; + a->baseva = SVM_GLOBAL_REGION_BASEVA; + a->size = SVM_GLOBAL_REGION_SIZE; + a->flags = SVM_FLAGS_NODATA; + a->uid = uid; + a->gid = gid; + + svm_region_init_internal (a); +} + +void +svm_region_init_args (svm_map_region_args_t * a) +{ + svm_region_init_internal (a); +} + +void * +svm_region_find_or_create (svm_map_region_args_t * a) +{ + svm_main_region_t *mp; + svm_region_t *rp; + uword need_nbits; + int index, i; + void *oldheap; + uword *p; + u8 *name; + svm_subregion_t *subp; + + ASSERT (root_rp); + + a->size += MMAP_PAGESIZE + + ((a->pvt_heap_size != 0) ? a->pvt_heap_size : SVM_PVT_MHEAP_SIZE); + a->size = rnd_pagesize (a->size); + + region_lock (root_rp, 4); + oldheap = svm_push_pvt_heap (root_rp); + mp = root_rp->data_base; + + ASSERT (mp); + + /* Map the named region from the correct chroot environment */ + a->root_path = (char *) mp->root_path; + + /* + * See if this region is already known. If it is, we're + * almost done... + */ + p = hash_get_mem (mp->name_hash, a->name); + + if (p) + { + rp = svm_map_region (a); + region_unlock (root_rp); + svm_pop_heap (oldheap); + return rp; + } + + /* Create the region. */ + ASSERT ((a->size & ~(MMAP_PAGESIZE - 1)) == a->size); + + need_nbits = a->size / MMAP_PAGESIZE; + + index = 1; /* $$$ fixme, figure out how many bit to really skip */ + + /* + * Scan the virtual space allocation bitmap, looking for a large + * enough chunk + */ + do + { + if (clib_bitmap_get_no_check (root_rp->bitmap, index) == 0) + { + for (i = 0; i < (need_nbits - 1); i++) + { + if (clib_bitmap_get_no_check (root_rp->bitmap, index + i) == 1) + { + index = index + i; + goto next; + } + } + break; + } + index++; + next:; + } + while (index < root_rp->bitmap_size); + + /* Completely out of VM? */ + if (index >= root_rp->bitmap_size) + { + clib_warning ("region %s: not enough VM to allocate 0x%llx (%lld)", + root_rp->region_name, a->size, a->size); + svm_pop_heap (oldheap); + region_unlock (root_rp); + return 0; + } + + /* + * Mark virtual space allocated + */ +#if CLIB_DEBUG > 1 + clib_warning ("set %d bits at index %d", need_nbits, index); +#endif + + for (i = 0; i < need_nbits; i++) + { + clib_bitmap_set_no_check (root_rp->bitmap, index + i, 1); + } + + /* Place this region where it goes... */ + a->baseva = root_rp->virtual_base + index * MMAP_PAGESIZE; + + rp = svm_map_region (a); + + pool_get (mp->subregions, subp); + name = format (0, "%s%c", a->name, 0); + subp->subregion_name = name; + + hash_set_mem (mp->name_hash, name, subp - mp->subregions); + + svm_pop_heap (oldheap); + + region_unlock (root_rp); + + return (rp); +} + +/* + * svm_region_unmap + * + * Let go of the indicated region. If the calling process + * is the last customer, throw it away completely. + * The root region mutex guarantees atomicity with respect to + * a new region client showing up at the wrong moment. + */ +void +svm_region_unmap (void *rp_arg) +{ + int i, mypid = getpid (); + int nclients_left; + void *oldheap; + uword virtual_base, virtual_size; + svm_region_t *rp = rp_arg; + char *name; + + /* + * If we take a signal while holding one or more shared-memory + * mutexes, we may end up back here from an otherwise + * benign exit handler. Bail out to avoid a recursive + * mutex screw-up. + */ + if (nheld) + return; + + ASSERT (rp); + ASSERT (root_rp); + + if (CLIB_DEBUG > 1) + clib_warning ("[%d] unmap region %s", getpid (), rp->region_name); + + region_lock (root_rp, 5); + region_lock (rp, 6); + + oldheap = svm_push_pvt_heap (rp); /* nb vec_delete() in the loop */ + + /* Remove the caller from the list of mappers */ + for (i = 0; i < vec_len (rp->client_pids); i++) + { + if (rp->client_pids[i] == mypid) + { + vec_delete (rp->client_pids, 1, i); + goto found; + } + } + clib_warning ("pid %d AWOL", mypid); + +found: + + svm_pop_heap (oldheap); + + nclients_left = vec_len (rp->client_pids); + virtual_base = rp->virtual_base; + virtual_size = rp->virtual_size; + + if (nclients_left == 0) + { + int index, nbits, i; + svm_main_region_t *mp; + uword *p; + svm_subregion_t *subp; + + /* Kill the region, last guy on his way out */ + + oldheap = svm_push_pvt_heap (root_rp); + name = vec_dup (rp->region_name); + + virtual_base = rp->virtual_base; + virtual_size = rp->virtual_size; + + /* Figure out which bits to clear in the root region bitmap */ + index = (virtual_base - root_rp->virtual_base) / MMAP_PAGESIZE; + + nbits = (virtual_size + MMAP_PAGESIZE - 1) / MMAP_PAGESIZE; + +#if CLIB_DEBUG > 1 + clib_warning ("clear %d bits at index %d", nbits, index); +#endif + /* Give back the allocated VM */ + for (i = 0; i < nbits; i++) + { + clib_bitmap_set_no_check (root_rp->bitmap, index + i, 0); + } + + mp = root_rp->data_base; + + p = hash_get_mem (mp->name_hash, name); + + /* Better never happen ... */ + if (p == NULL) + { + region_unlock (rp); + region_unlock (root_rp); + svm_pop_heap (oldheap); + clib_warning ("Region name '%s' not found?", name); + return; + } + + /* Remove from the root region subregion pool */ + subp = mp->subregions + p[0]; + pool_put (mp->subregions, subp); + + hash_unset_mem (mp->name_hash, name); + + vec_free (name); + + region_unlock (rp); + shm_unlink (rp->region_name); + munmap ((void *) virtual_base, virtual_size); + region_unlock (root_rp); + svm_pop_heap (oldheap); + return; + } + + region_unlock (rp); + region_unlock (root_rp); + + munmap ((void *) virtual_base, virtual_size); +} + +/* + * svm_region_exit + * There is no clean way to unlink the + * root region when all clients go away, + * so remove the pid entry and call it a day. + */ +void +svm_region_exit () +{ + void *oldheap; + int i, mypid = getpid (); + uword virtual_base, virtual_size; + + /* It felt so nice we did it twice... */ + if (root_rp == 0) + return; + + if (--root_rp_refcount > 0) + return; + + /* + * If we take a signal while holding one or more shared-memory + * mutexes, we may end up back here from an otherwise + * benign exit handler. Bail out to avoid a recursive + * mutex screw-up. + */ + if (nheld) + return; + + region_lock (root_rp, 7); + oldheap = svm_push_pvt_heap (root_rp); + + virtual_base = root_rp->virtual_base; + virtual_size = root_rp->virtual_size; + + for (i = 0; i < vec_len (root_rp->client_pids); i++) + { + if (root_rp->client_pids[i] == mypid) + { + vec_delete (root_rp->client_pids, 1, i); + goto found; + } + } + clib_warning ("pid %d AWOL", mypid); + +found: + + region_unlock (root_rp); + svm_pop_heap (oldheap); + + root_rp = 0; + munmap ((void *) virtual_base, virtual_size); +} + +void +svm_client_scan_this_region_nolock (svm_region_t * rp) +{ + int j; + int mypid = getpid (); + void *oldheap; + + for (j = 0; j < vec_len (rp->client_pids); j++) + { + if (mypid == rp->client_pids[j]) + continue; + if (rp->client_pids[j] && (kill (rp->client_pids[j], 0) < 0)) + { + clib_warning ("%s: cleanup ghost pid %d", + rp->region_name, rp->client_pids[j]); + /* nb: client vec in rp->region_heap */ + oldheap = svm_push_pvt_heap (rp); + vec_delete (rp->client_pids, 1, j); + j--; + svm_pop_heap (oldheap); + } + } +} + + +/* + * Scan svm regions for dead clients + */ +void +svm_client_scan (char *root_path) +{ + int i, j; + svm_main_region_t *mp; + svm_map_region_args_t *a = 0; + svm_region_t *root_rp; + svm_region_t *rp; + svm_subregion_t *subp; + u8 *name = 0; + u8 **svm_names = 0; + void *oldheap; + int mypid = getpid (); + + vec_validate (a, 0); + + svm_region_init_chroot (root_path); + + root_rp = svm_get_root_rp (); + + pthread_mutex_lock (&root_rp->mutex); + + mp = root_rp->data_base; + + for (j = 0; j < vec_len (root_rp->client_pids); j++) + { + if (mypid == root_rp->client_pids[j]) + continue; + if (root_rp->client_pids[j] && (kill (root_rp->client_pids[j], 0) < 0)) + { + clib_warning ("%s: cleanup ghost pid %d", + root_rp->region_name, root_rp->client_pids[j]); + /* nb: client vec in root_rp->region_heap */ + oldheap = svm_push_pvt_heap (root_rp); + vec_delete (root_rp->client_pids, 1, j); + j--; + svm_pop_heap (oldheap); + } + } + + /* + * Snapshoot names, can't hold root rp mutex across + * find_or_create. + */ + /* *INDENT-OFF* */ + pool_foreach (subp, mp->subregions, ({ + name = vec_dup (subp->subregion_name); + vec_add1(svm_names, name); + })); + /* *INDENT-ON* */ + + pthread_mutex_unlock (&root_rp->mutex); + + for (i = 0; i < vec_len (svm_names); i++) + { + vec_validate (a, 0); + a->root_path = root_path; + a->name = (char *) svm_names[i]; + rp = svm_region_find_or_create (a); + if (rp) + { + pthread_mutex_lock (&rp->mutex); + + svm_client_scan_this_region_nolock (rp); + + pthread_mutex_unlock (&rp->mutex); + svm_region_unmap (rp); + vec_free (svm_names[i]); + } + vec_free (a); + } + vec_free (svm_names); + + svm_region_exit (); + + vec_free (a); +} + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |