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vpp/svm/svm.c
Dave Barach c379999665 VPP-327 Coding standards cleanup for vppinfra 
Fix additional a few additional deviations reported elsewhere by
checkstyle

Change-Id: I026a8ae1c5b1856bbe3c4a555e1b690e7501b045
Signed-off-by: Dave Barach <dave@barachs.net>
2016-08-15 11:12:40 -04:00

1238 lines
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/*
*------------------------------------------------------------------
* 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:
*/
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