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-rw-r--r--svm/svm.c1045
1 files changed, 1045 insertions, 0 deletions
diff --git a/svm/svm.c b/svm/svm.c
new file mode 100644
index 00000000000..c629f932008
--- /dev/null
+++ b/svm/svm.c
@@ -0,0 +1,1045 @@
+/*
+ *------------------------------------------------------------------
+ * 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 unsigned int rnd_pagesize(unsigned int size)
+{
+ unsigned int 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 + 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");
+ return -2;
+ }
+
+ if (statb.st_mode & S_IFREG) {
+ if (statb.st_size == 0) {
+ lseek(fd, map_size, SEEK_SET);
+ if (write(fd, &junk, 1) != 1)
+ clib_unix_warning ("set region size");
+ } 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");
+ 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 + 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");
+ return -2;
+ }
+
+ if (statb.st_mode & S_IFREG) {
+ if (statb.st_size == 0) {
+ lseek(fd, map_size, SEEK_SET);
+ if (write(fd, &junk, 1) != 1)
+ clib_unix_warning ("set region size");
+ } 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");
+ 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);
+ if (mkdir ((char *) mkdir_arg, 0777) < 0 && errno != EEXIST)
+ clib_unix_warning ("mkdir %s", mkdir_arg);
+
+ /* 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) {
+
+ vec_free(shm_name);
+
+ lseek(svm_fd, a->size, SEEK_SET);
+ if (write(svm_fd, &junk, 1) != 1)
+ clib_warning ("set region size");
+
+ 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");
+ 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),
+ 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 */ +
+ 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);
+ return (0);
+ }
+ if (stat.st_size > 0) {
+ break;
+ }
+ if (0 == time_left) {
+ clib_warning("waiting for resize of shm file timed out");
+ 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) {
+ close(svm_fd);
+ munmap(rp, a->size);
+ clib_warning("rp->version %d not %d", rp->version,
+ SVM_VERSION);
+ 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");
+ 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 (char *root_path)
+{
+ svm_region_t *rp;
+ svm_map_region_args_t *a=0;
+ u64 ticks = clib_cpu_time_now();
+ uword randomize_baseva;
+
+ /* guard against klutz calls */
+ root_rp_refcount++;
+ if (root_rp)
+ return;
+
+ atexit(svm_mutex_cleanup);
+
+ /* Randomize the shared-VM base at init time */
+ randomize_baseva = (ticks & 15) * 4096;
+
+ vec_validate(a,0);
+ a->root_path = root_path;
+ a->name = SVM_GLOBAL_REGION_NAME;
+ a->baseva = SVM_GLOBAL_REGION_BASEVA + randomize_baseva;
+ a->size = SVM_GLOBAL_REGION_SIZE;
+ a->flags = SVM_FLAGS_NODATA;
+
+ 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 = root_path
+ ? format (0, "%s%c", root_path, 0) : 0 ;
+ rp->data_base = mp;
+ svm_pop_heap (oldheap);
+ }
+ region_unlock(rp);
+ vec_free (a);
+ root_rp = rp;
+}
+
+void svm_region_init (void)
+{
+ svm_region_init_internal (0);
+}
+
+void svm_region_init_chroot (char *root_path)
+{
+ svm_region_init_internal (root_path);
+}
+
+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 + 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%x",
+ root_rp->region_name, 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.
+ */
+ pool_foreach (subp, mp->subregions, ({
+ name = vec_dup (subp->subregion_name);
+ vec_add1(svm_names, name);
+ }));
+
+ 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);
+}