--- /dev/null
+/*
+ * libcounter/shm.c
+ *
+ * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#define _LGPL_SOURCE
+#include <config.h>
+#include "shm.h"
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h> /* For mode constants */
+#include <fcntl.h> /* For O_* constants */
+#include <assert.h>
+#include <stdio.h>
+#include <signal.h>
+#include <dirent.h>
+#include <lttng/align.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#ifdef HAVE_LIBNUMA
+#include <numa.h>
+#include <numaif.h>
+#endif
+#include <helper.h>
+#include <ust-fd.h>
+#include "../libringbuffer/mmap.h"
+
+/*
+ * Ensure we have the required amount of space available by writing 0
+ * into the entire buffer. Not doing so can trigger SIGBUS when going
+ * beyond the available shm space.
+ */
+static
+int zero_file(int fd, size_t len)
+{
+ ssize_t retlen;
+ size_t written = 0;
+ char *zeropage;
+ long pagelen;
+ int ret;
+
+ pagelen = sysconf(_SC_PAGESIZE);
+ if (pagelen < 0)
+ return (int) pagelen;
+ zeropage = calloc(pagelen, 1);
+ if (!zeropage)
+ return -ENOMEM;
+
+ while (len > written) {
+ do {
+ retlen = write(fd, zeropage,
+ min_t(size_t, pagelen, len - written));
+ } while (retlen == -1UL && errno == EINTR);
+ if (retlen < 0) {
+ ret = (int) retlen;
+ goto error;
+ }
+ written += retlen;
+ }
+ ret = 0;
+error:
+ free(zeropage);
+ return ret;
+}
+
+struct lttng_counter_shm_object_table *lttng_counter_shm_object_table_create(size_t max_nb_obj)
+{
+ struct lttng_counter_shm_object_table *table;
+
+ table = zmalloc(sizeof(struct lttng_counter_shm_object_table) +
+ max_nb_obj * sizeof(table->objects[0]));
+ if (!table)
+ return NULL;
+ table->size = max_nb_obj;
+ return table;
+}
+
+static
+struct lttng_counter_shm_object *_lttng_counter_shm_object_table_alloc_shm(struct lttng_counter_shm_object_table *table,
+ size_t memory_map_size,
+ int cpu_fd)
+{
+ int shmfd, ret;
+ struct lttng_counter_shm_object *obj;
+ char *memory_map;
+
+ if (cpu_fd < 0)
+ return NULL;
+ if (table->allocated_len >= table->size)
+ return NULL;
+ obj = &table->objects[table->allocated_len];
+
+ /* create shm */
+
+ shmfd = cpu_fd;
+ ret = zero_file(shmfd, memory_map_size);
+ if (ret) {
+ PERROR("zero_file");
+ goto error_zero_file;
+ }
+ ret = ftruncate(shmfd, memory_map_size);
+ if (ret) {
+ PERROR("ftruncate");
+ goto error_ftruncate;
+ }
+ /*
+ * Also ensure the file metadata is synced with the storage by using
+ * fsync(2).
+ */
+ ret = fsync(shmfd);
+ if (ret) {
+ PERROR("fsync");
+ goto error_fsync;
+ }
+ obj->shm_fd_ownership = 0;
+ obj->shm_fd = shmfd;
+
+ /* memory_map: mmap */
+ memory_map = mmap(NULL, memory_map_size, PROT_READ | PROT_WRITE,
+ MAP_SHARED | LTTNG_MAP_POPULATE, shmfd, 0);
+ if (memory_map == MAP_FAILED) {
+ PERROR("mmap");
+ goto error_mmap;
+ }
+ obj->type = LTTNG_COUNTER_SHM_OBJECT_SHM;
+ obj->memory_map = memory_map;
+ obj->memory_map_size = memory_map_size;
+ obj->allocated_len = 0;
+ obj->index = table->allocated_len++;
+
+ return obj;
+
+error_mmap:
+error_fsync:
+error_ftruncate:
+error_zero_file:
+ return NULL;
+}
+
+static
+struct lttng_counter_shm_object *_lttng_counter_shm_object_table_alloc_mem(struct lttng_counter_shm_object_table *table,
+ size_t memory_map_size)
+{
+ struct lttng_counter_shm_object *obj;
+ void *memory_map;
+
+ if (table->allocated_len >= table->size)
+ return NULL;
+ obj = &table->objects[table->allocated_len];
+
+ memory_map = zmalloc(memory_map_size);
+ if (!memory_map)
+ goto alloc_error;
+
+ /* no shm_fd */
+ obj->shm_fd = -1;
+ obj->shm_fd_ownership = 0;
+
+ obj->type = LTTNG_COUNTER_SHM_OBJECT_MEM;
+ obj->memory_map = memory_map;
+ obj->memory_map_size = memory_map_size;
+ obj->allocated_len = 0;
+ obj->index = table->allocated_len++;
+
+ return obj;
+
+alloc_error:
+ return NULL;
+}
+
+/*
+ * libnuma prints errors on the console even for numa_available().
+ * Work-around this limitation by using get_mempolicy() directly to
+ * check whether the kernel supports mempolicy.
+ */
+#ifdef HAVE_LIBNUMA
+static bool lttng_is_numa_available(void)
+{
+ int ret;
+
+ ret = get_mempolicy(NULL, NULL, 0, NULL, 0);
+ if (ret && errno == ENOSYS) {
+ return false;
+ }
+ return numa_available() > 0;
+}
+#endif
+
+struct lttng_counter_shm_object *lttng_counter_shm_object_table_alloc(struct lttng_counter_shm_object_table *table,
+ size_t memory_map_size,
+ enum lttng_counter_shm_object_type type,
+ int cpu_fd,
+ int cpu)
+{
+ struct lttng_counter_shm_object *shm_object;
+#ifdef HAVE_LIBNUMA
+ int oldnode = 0, node;
+ bool numa_avail;
+
+ numa_avail = lttng_is_numa_available();
+ if (numa_avail) {
+ oldnode = numa_preferred();
+ if (cpu >= 0) {
+ node = numa_node_of_cpu(cpu);
+ if (node >= 0)
+ numa_set_preferred(node);
+ }
+ if (cpu < 0 || node < 0)
+ numa_set_localalloc();
+ }
+#endif /* HAVE_LIBNUMA */
+ switch (type) {
+ case LTTNG_COUNTER_SHM_OBJECT_SHM:
+ shm_object = _lttng_counter_shm_object_table_alloc_shm(table, memory_map_size,
+ cpu_fd);
+ break;
+ case LTTNG_COUNTER_SHM_OBJECT_MEM:
+ shm_object = _lttng_counter_shm_object_table_alloc_mem(table, memory_map_size);
+ break;
+ default:
+ assert(0);
+ }
+#ifdef HAVE_LIBNUMA
+ if (numa_avail)
+ numa_set_preferred(oldnode);
+#endif /* HAVE_LIBNUMA */
+ return shm_object;
+}
+
+struct lttng_counter_shm_object *lttng_counter_shm_object_table_append_shm(struct lttng_counter_shm_object_table *table,
+ int shm_fd,
+ size_t memory_map_size)
+{
+ struct lttng_counter_shm_object *obj;
+ char *memory_map;
+
+ if (table->allocated_len >= table->size)
+ return NULL;
+
+ obj = &table->objects[table->allocated_len];
+
+ obj->shm_fd = shm_fd;
+ obj->shm_fd_ownership = 1;
+
+ /* memory_map: mmap */
+ memory_map = mmap(NULL, memory_map_size, PROT_READ | PROT_WRITE,
+ MAP_SHARED | LTTNG_MAP_POPULATE, shm_fd, 0);
+ if (memory_map == MAP_FAILED) {
+ PERROR("mmap");
+ goto error_mmap;
+ }
+ obj->type = LTTNG_COUNTER_SHM_OBJECT_SHM;
+ obj->memory_map = memory_map;
+ obj->memory_map_size = memory_map_size;
+ obj->allocated_len = memory_map_size;
+ obj->index = table->allocated_len++;
+
+ return obj;
+
+error_mmap:
+ return NULL;
+}
+
+/*
+ * Passing ownership of mem to object.
+ */
+struct lttng_counter_shm_object *lttng_counter_shm_object_table_append_mem(struct lttng_counter_shm_object_table *table,
+ void *mem, size_t memory_map_size)
+{
+ struct lttng_counter_shm_object *obj;
+
+ if (table->allocated_len >= table->size)
+ return NULL;
+ obj = &table->objects[table->allocated_len];
+
+ obj->shm_fd = -1;
+ obj->shm_fd_ownership = 0;
+
+ obj->type = LTTNG_COUNTER_SHM_OBJECT_MEM;
+ obj->memory_map = mem;
+ obj->memory_map_size = memory_map_size;
+ obj->allocated_len = memory_map_size;
+ obj->index = table->allocated_len++;
+
+ return obj;
+
+ return NULL;
+}
+
+static
+void lttng_counter_shmp_object_destroy(struct lttng_counter_shm_object *obj, int consumer)
+{
+ switch (obj->type) {
+ case LTTNG_COUNTER_SHM_OBJECT_SHM:
+ {
+ int ret;
+
+ ret = munmap(obj->memory_map, obj->memory_map_size);
+ if (ret) {
+ PERROR("umnmap");
+ assert(0);
+ }
+
+ if (obj->shm_fd_ownership) {
+ /* Delete FDs only if called from app (not consumer). */
+ if (!consumer) {
+ lttng_ust_lock_fd_tracker();
+ ret = close(obj->shm_fd);
+ if (!ret) {
+ lttng_ust_delete_fd_from_tracker(obj->shm_fd);
+ } else {
+ PERROR("close");
+ assert(0);
+ }
+ lttng_ust_unlock_fd_tracker();
+ } else {
+ ret = close(obj->shm_fd);
+ if (ret) {
+ PERROR("close");
+ assert(0);
+ }
+ }
+ }
+ break;
+ }
+ case LTTNG_COUNTER_SHM_OBJECT_MEM:
+ {
+ free(obj->memory_map);
+ break;
+ }
+ default:
+ assert(0);
+ }
+}
+
+void lttng_counter_shm_object_table_destroy(struct lttng_counter_shm_object_table *table, int consumer)
+{
+ int i;
+
+ for (i = 0; i < table->allocated_len; i++)
+ lttng_counter_shmp_object_destroy(&table->objects[i], consumer);
+ free(table);
+}
+
+/*
+ * lttng_counter_zalloc_shm - allocate memory within a shm object.
+ *
+ * Shared memory is already zeroed by shmget.
+ * *NOT* multithread-safe (should be protected by mutex).
+ * Returns a -1, -1 tuple on error.
+ */
+struct lttng_counter_shm_ref lttng_counter_zalloc_shm(struct lttng_counter_shm_object *obj, size_t len)
+{
+ struct lttng_counter_shm_ref ref;
+ struct lttng_counter_shm_ref shm_ref_error = { -1, -1 };
+
+ if (obj->memory_map_size - obj->allocated_len < len)
+ return shm_ref_error;
+ ref.index = obj->index;
+ ref.offset = obj->allocated_len;
+ obj->allocated_len += len;
+ return ref;
+}
+
+void lttng_counter_align_shm(struct lttng_counter_shm_object *obj, size_t align)
+{
+ size_t offset_len = offset_align(obj->allocated_len, align);
+ obj->allocated_len += offset_len;
+}
projects / deliverable / lttng-ust.git / blobdiff