#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 <signal.h>
#include <dirent.h>
#include <lttng/align.h>
-#include <helper.h>
#include <limits.h>
#include <helper.h>
table = zmalloc(sizeof(struct shm_object_table) +
max_nb_obj * sizeof(table->objects[0]));
+ if (!table)
+ return NULL;
table->size = max_nb_obj;
return table;
}
-struct shm_object *shm_object_table_append(struct shm_object_table *table,
- size_t memory_map_size)
+static
+struct shm_object *_shm_object_table_alloc_shm(struct shm_object_table *table,
+ size_t memory_map_size,
+ int stream_fd)
{
- int shmfd, waitfd[2], ret, i, sigblocked = 0;
+ int shmfd, waitfd[2], ret, i;
struct shm_object *obj;
char *memory_map;
- char tmp_name[NAME_MAX] = "/ust-shm-tmp-XXXXXX";
- sigset_t all_sigs, orig_sigs;
+ if (stream_fd < 0)
+ return NULL;
if (table->allocated_len >= table->size)
return NULL;
obj = &table->objects[table->allocated_len];
}
memcpy(obj->wait_fd, waitfd, sizeof(waitfd));
- /* shm_fd: create shm */
-
- /*
- * Theoretically, we could leak a shm if the application crashes
- * between open and unlink. Disable signals on this thread for
- * increased safety against this scenario.
- */
- sigfillset(&all_sigs);
- ret = pthread_sigmask(SIG_BLOCK, &all_sigs, &orig_sigs);
- if (ret == -1) {
- PERROR("pthread_sigmask");
- goto error_pthread_sigmask;
- }
- sigblocked = 1;
-
- /*
- * Allocate shm, and immediately unlink its shm oject, keeping
- * only the file descriptor as a reference to the object. If it
- * already exists (caused by short race window during which the
- * global object exists in a concurrent shm_open), simply retry.
- * We specifically do _not_ use the / at the beginning of the
- * pathname so that some OS implementations can keep it local to
- * the process (POSIX leaves this implementation-defined).
- */
- do {
- /*
- * Using mktemp filename with O_CREAT | O_EXCL open
- * flags.
- */
- mktemp(tmp_name);
- if (tmp_name[0] == '\0') {
- PERROR("mktemp");
- goto error_shm_open;
- }
- shmfd = shm_open(tmp_name,
- O_CREAT | O_EXCL | O_RDWR, 0700);
- } while (shmfd < 0 && (errno == EEXIST || errno == EACCES));
- if (shmfd < 0) {
- PERROR("shm_open");
- goto error_shm_open;
- }
- ret = shm_unlink(tmp_name);
- if (ret < 0 && errno != ENOENT) {
- PERROR("shm_unlink");
- goto error_shm_release;
- }
- sigblocked = 0;
- ret = pthread_sigmask(SIG_SETMASK, &orig_sigs, NULL);
- if (ret == -1) {
- PERROR("pthread_sigmask");
- goto error_sigmask_release;
- }
+ /* create shm */
+
+ shmfd = stream_fd;
ret = zero_file(shmfd, memory_map_size);
if (ret) {
PERROR("zero_file");
PERROR("ftruncate");
goto error_ftruncate;
}
+ obj->shm_fd_ownership = 0;
obj->shm_fd = shmfd;
/* memory_map: mmap */
PERROR("mmap");
goto error_mmap;
}
+ obj->type = SHM_OBJECT_SHM;
obj->memory_map = memory_map;
obj->memory_map_size = memory_map_size;
obj->allocated_len = 0;
error_mmap:
error_ftruncate:
-error_shm_release:
error_zero_file:
-error_sigmask_release:
- ret = close(shmfd);
- if (ret) {
- PERROR("close");
- assert(0);
+error_fcntl:
+ for (i = 0; i < 2; i++) {
+ ret = close(waitfd[i]);
+ if (ret) {
+ PERROR("close");
+ assert(0);
+ }
+ }
+error_pipe:
+ return NULL;
+}
+
+static
+struct shm_object *_shm_object_table_alloc_mem(struct shm_object_table *table,
+ size_t memory_map_size)
+{
+ struct shm_object *obj;
+ void *memory_map;
+ int waitfd[2], i, ret;
+
+ 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;
+
+ /* wait_fd: create pipe */
+ ret = pipe(waitfd);
+ if (ret < 0) {
+ PERROR("pipe");
+ goto error_pipe;
}
-error_shm_open:
- if (sigblocked) {
- ret = pthread_sigmask(SIG_SETMASK, &orig_sigs, NULL);
- if (ret == -1) {
- PERROR("pthread_sigmask");
+ for (i = 0; i < 2; i++) {
+ ret = fcntl(waitfd[i], F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("fcntl");
+ goto error_fcntl;
}
}
-error_pthread_sigmask:
+ /* The write end of the pipe needs to be non-blocking */
+ ret = fcntl(waitfd[1], F_SETFL, O_NONBLOCK);
+ if (ret < 0) {
+ PERROR("fcntl");
+ goto error_fcntl;
+ }
+ memcpy(obj->wait_fd, waitfd, sizeof(waitfd));
+
+ /* no shm_fd */
+ obj->shm_fd = -1;
+ obj->shm_fd_ownership = 0;
+
+ obj->type = 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;
+
error_fcntl:
for (i = 0; i < 2; i++) {
ret = close(waitfd[i]);
}
}
error_pipe:
+ free(memory_map);
+alloc_error:
+ return NULL;
+}
+
+struct shm_object *shm_object_table_alloc(struct shm_object_table *table,
+ size_t memory_map_size,
+ enum shm_object_type type,
+ int stream_fd)
+{
+ switch (type) {
+ case SHM_OBJECT_SHM:
+ return _shm_object_table_alloc_shm(table, memory_map_size,
+ stream_fd);
+ case SHM_OBJECT_MEM:
+ return _shm_object_table_alloc_mem(table, memory_map_size);
+ default:
+ assert(0);
+ }
return NULL;
-
}
-struct shm_object *shm_object_table_append_shadow(struct shm_object_table *table,
- int shm_fd, int wait_fd, size_t memory_map_size)
+struct shm_object *shm_object_table_append_shm(struct shm_object_table *table,
+ int shm_fd, int wakeup_fd, uint32_t stream_nr,
+ size_t memory_map_size)
{
struct shm_object *obj;
char *memory_map;
+ int ret;
if (table->allocated_len >= table->size)
return NULL;
+ /* streams _must_ be received in sequential order, else fail. */
+ if (stream_nr + 1 != table->allocated_len)
+ return NULL;
+
obj = &table->objects[table->allocated_len];
- /* wait_fd: set read end of the pipe. */
- obj->wait_fd[0] = wait_fd;
- obj->wait_fd[1] = -1; /* write end is unset. */
+ /* wait_fd: set write end of the pipe. */
+ obj->wait_fd[0] = -1; /* read end is unset */
+ obj->wait_fd[1] = wakeup_fd;
obj->shm_fd = shm_fd;
+ obj->shm_fd_ownership = 1;
+
+ ret = fcntl(obj->wait_fd[1], F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("fcntl");
+ goto error_fcntl;
+ }
+ /* The write end of the pipe needs to be non-blocking */
+ ret = fcntl(obj->wait_fd[1], F_SETFL, O_NONBLOCK);
+ if (ret < 0) {
+ PERROR("fcntl");
+ goto error_fcntl;
+ }
/* memory_map: mmap */
memory_map = mmap(NULL, memory_map_size, PROT_READ | PROT_WRITE,
PERROR("mmap");
goto error_mmap;
}
+ obj->type = SHM_OBJECT_SHM;
obj->memory_map = memory_map;
obj->memory_map_size = memory_map_size;
obj->allocated_len = memory_map_size;
return obj;
+error_fcntl:
error_mmap:
return NULL;
}
+/*
+ * Passing ownership of mem to object.
+ */
+struct shm_object *shm_object_table_append_mem(struct shm_object_table *table,
+ void *mem, size_t memory_map_size, int wakeup_fd)
+{
+ struct shm_object *obj;
+ int ret;
+
+ if (table->allocated_len >= table->size)
+ return NULL;
+ obj = &table->objects[table->allocated_len];
+
+ obj->wait_fd[0] = -1; /* read end is unset */
+ obj->wait_fd[1] = wakeup_fd;
+ obj->shm_fd = -1;
+ obj->shm_fd_ownership = 0;
+
+ ret = fcntl(obj->wait_fd[1], F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("fcntl");
+ goto error_fcntl;
+ }
+ /* The write end of the pipe needs to be non-blocking */
+ ret = fcntl(obj->wait_fd[1], F_SETFL, O_NONBLOCK);
+ if (ret < 0) {
+ PERROR("fcntl");
+ goto error_fcntl;
+ }
+
+ obj->type = 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;
+
+error_fcntl:
+ return NULL;
+}
+
static
void shmp_object_destroy(struct shm_object *obj)
{
- int ret, i;
+ switch (obj->type) {
+ case SHM_OBJECT_SHM:
+ {
+ int ret, i;
- if (!obj->is_shadow) {
ret = munmap(obj->memory_map, obj->memory_map_size);
if (ret) {
PERROR("umnmap");
assert(0);
}
- }
- if (obj->shm_fd >= 0) {
- ret = close(obj->shm_fd);
- if (ret) {
- PERROR("close");
- assert(0);
+ if (obj->shm_fd_ownership) {
+ ret = close(obj->shm_fd);
+ if (ret) {
+ PERROR("close");
+ assert(0);
+ }
+ }
+ for (i = 0; i < 2; i++) {
+ if (obj->wait_fd[i] < 0)
+ continue;
+ ret = close(obj->wait_fd[i]);
+ if (ret) {
+ PERROR("close");
+ assert(0);
+ }
}
+ break;
}
- for (i = 0; i < 2; i++) {
- if (obj->wait_fd[i] < 0)
- continue;
- ret = close(obj->wait_fd[i]);
- if (ret) {
- PERROR("close");
- assert(0);
+ case SHM_OBJECT_MEM:
+ {
+ int ret, i;
+
+ for (i = 0; i < 2; i++) {
+ if (obj->wait_fd[i] < 0)
+ continue;
+ ret = close(obj->wait_fd[i]);
+ if (ret) {
+ PERROR("close");
+ assert(0);
+ }
}
+ free(obj->memory_map);
+ break;
+ }
+ default:
+ assert(0);
}
}