[AC_MSG_ERROR([Cannot find libpopt. Use [LDFLAGS]=-Ldir to specify its location.])]
)
-# Check liburcu
+# Check liburcu list.h
AC_CHECK_DECL([cds_list_add], [],
[AC_MSG_ERROR([liburcu 0.5.4 or newer is needed])], [[#include <urcu/list.h>]]
)
+# Check liburcu wfqueue.h
+AC_CHECK_DECL([cds_wfq_init], [],
+ [AC_MSG_ERROR([liburcu 0.5.4 or newer is needed])], [[#include <urcu/wfqueue.h>]]
+)
+
AC_PROG_CC
AC_PROG_LIBTOOL
* Data structure for the commands sent from sessiond to UST.
*/
struct lttcomm_ust_msg {
- uint32_t cmd_type; /* enum lttcomm_ust_command */
uint32_t handle;
uint32_t cmd;
union {
_UST_CMDR(0x41, struct lttng_ust_tracer_version)
#define LTTNG_UST_TRACEPOINT_LIST _UST_CMD(0x42)
#define LTTNG_UST_WAIT_QUIESCENT _UST_CMD(0x43)
+#define LTTNG_UST_REGISTER_DONE _UST_CMD(0x44)
/* Session FD ioctl */
#define LTTNG_UST_METADATA \
#define LTTNG_UST_ENABLE _UST_CMD(0x80)
#define LTTNG_UST_DISABLE _UST_CMD(0x81)
+#define LTTNG_UST_ROOT_HANDLE 0
+
#endif /* _LTTNG_UST_H */
bin_PROGRAMS = ltt-sessiond
ltt_sessiond_SOURCES = utils.c trace.c session.c traceable-app.c ust-ctl.c \
- kernel-ctl.c context.c main.c \
+ kernel-ctl.c context.c futex.c futex.h \
utils.h trace.h session.h traceable-app.h ust-ctl.h \
- context.h kernel-ctl.h ltt-sessiond.h
+ ust-comm.c ust-comm.h \
+ context.h kernel-ctl.h ltt-sessiond.h main.c
# link on liblttngctl for check if sessiond is already alive.
ltt_sessiond_LDADD = \
--- /dev/null
+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; only version 2
+ * of the License.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#define _GNU_SOURCE
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <urcu.h>
+#include <urcu/futex.h>
+
+#include <lttngerr.h>
+
+#include "futex.h"
+
+/*
+ * This futex wait/wake scheme only works for N wakers / 1 waiters. Hence the
+ * "nto1" added to all function signature.
+ *
+ * Please see wait_gp()/update_counter_and_wait() calls in urcu.c in the urcu
+ * git tree for a detail example of this scheme being used. futex_async() is
+ * the urcu wrapper over the futex() sycall.
+ *
+ * There is also a formal verification available in the git tree.
+ *
+ * branch: formal-model
+ * commit id: 2a8044f3493046fcc8c67016902dc7beec6f026a
+ *
+ * Ref: git://git.lttng.org/userspace-rcu.git
+ */
+
+/*
+ * Prepare futex.
+ */
+void futex_nto1_prepare(int32_t *futex)
+{
+ uatomic_set(futex, -1);
+ cmm_smp_mb();
+
+ DBG("Futex n to 1 prepare done");
+}
+
+/*
+ * Wait futex.
+ */
+void futex_nto1_wait(int32_t *futex)
+{
+ cmm_smp_mb();
+
+ if (uatomic_read(futex) == -1) {
+ futex_async(futex, FUTEX_WAIT, -1, NULL, NULL, 0);
+ }
+
+ DBG("Futex n to 1 wait done");
+}
+
+/*
+ * Wake 1 futex.
+ */
+void futex_nto1_wake(int32_t *futex)
+{
+ if (unlikely(uatomic_read(futex) == -1)) {
+ uatomic_set(futex, 0);
+ futex_async(futex, FUTEX_WAKE, 1, NULL, NULL, 0);
+ }
+
+ DBG("Futex n to 1 wake done");
+}
--- /dev/null
+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; only version 2 of the License.
+ *
+ * This program 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 General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _LTT_FUTEX_H
+#define _LTT_FUTEX_H
+
+void futex_nto1_prepare(int32_t *futex);
+void futex_nto1_wait(int32_t *futex);
+void futex_nto1_wake(int32_t *futex);
+
+#endif /* _LTT_FUTEX_H */
#ifndef _LTT_SESSIOND_H
#define _LTT_SESSIOND_H
+#define _LGPL_SOURCE
+#include <urcu/wfqueue.h>
+
+#include "traceable-app.h"
+
#define DEFAULT_HOME_DIR "/tmp"
#define DEFAULT_UST_SOCK_DIR DEFAULT_HOME_DIR "/ust-app-socks"
#define DEFAULT_GLOBAL_APPS_PIPE DEFAULT_UST_SOCK_DIR "/global"
struct lttcomm_session_msg *lsm;
};
+struct ust_command {
+ int sock;
+ struct ust_register_msg reg_msg;
+ struct cds_wfq_node node;
+};
+
+/*
+ * Queue used to enqueue UST registration request (ust_commant) and protected
+ * by a futex with a scheme N wakers / 1 waiters. See futex.c/.h
+ */
+struct ust_cmd_queue {
+ int32_t futex;
+ struct cds_wfq_queue queue;
+};
+
#endif /* _LTT_SESSIOND_H */
#include <lttng/lttng-kconsumerd.h>
#include <lttngerr.h>
+#include "context.h"
+#include "futex.h"
#include "kernel-ctl.h"
#include "ltt-sessiond.h"
#include "traceable-app.h"
#include "ust-ctl.h"
#include "utils.h"
+#include "ust-comm.h"
/* Const values */
const char default_home_dir[] = DEFAULT_HOME_DIR;
static pid_t ppid; /* Parent PID for --sig-parent option */
static pid_t kconsumerd_pid;
static struct pollfd *kernel_pollfd;
+static int dispatch_thread_exit;
static char apps_unix_sock_path[PATH_MAX]; /* Global application Unix socket path */
static char client_unix_sock_path[PATH_MAX]; /* Global client Unix socket path */
*/
static int thread_quit_pipe[2];
+/*
+ * This pipe is used to inform the thread managing application communication
+ * that a command is queued and ready to be processed.
+ */
+static int apps_cmd_pipe[2];
+
/* Pthread, Mutexes and Semaphores */
static pthread_t kconsumerd_thread;
static pthread_t apps_thread;
+static pthread_t reg_apps_thread;
static pthread_t client_thread;
static pthread_t kernel_thread;
+static pthread_t dispatch_thread;
static sem_t kconsumerd_sem;
static pthread_mutex_t kconsumerd_pid_mutex; /* Mutex to control kconsumerd pid assignation */
static int modprobe_remove_kernel_modules(void);
+/*
+ * UST registration command queue. This queue is tied with a futex and uses a N
+ * wakers / 1 waiter implemented and detailed in futex.c/.h
+ *
+ * The thread_manage_apps and thread_dispatch_ust_registration interact with
+ * this queue and the wait/wake scheme.
+ */
+static struct ust_cmd_queue ust_cmd_queue;
+
/*
* Pointer initialized before thread creation.
*
}
}
+/*
+ * Stop all threads by closing the thread quit pipe.
+ */
static void stop_threads(void)
{
/* Stopping all threads */
DBG("Terminating all threads");
close(thread_quit_pipe[0]);
close(thread_quit_pipe[1]);
+ /* Dispatch thread */
+ dispatch_thread_exit = 1;
+ futex_nto1_wake(&ust_cmd_queue.futex);
}
/*
}
}
+ DBG("Closing all UST sockets");
+ clean_traceable_apps_list();
+
pthread_mutex_destroy(&kconsumerd_pid_mutex);
DBG("Closing kernel fd");
return sock;
}
-#endif /* DISABLED */
/*
* Notify apps by writing 42 to a named pipe using name. Every applications
error:
return ret;
}
+#endif /* DISABLED */
/*
* Setup the outgoing data buffer for the response (llm) by allocating the
}
/*
- * This thread manage the application socket communication
+ * Reallocate the apps command pollfd structure of nb_fd size.
+ *
+ * The first two fds must be there at all time.
+ */
+static int update_apps_cmd_pollfd(unsigned int nb_fd, struct pollfd **pollfd)
+{
+ /* Can't accept pollfd less than 2 */
+ if (nb_fd < 2) {
+ goto end;
+ }
+
+ *pollfd = realloc(*pollfd, nb_fd * sizeof(struct pollfd));
+ if (*pollfd == NULL) {
+ perror("realloc manage apps pollfd");
+ goto error;
+ }
+
+ /* First fd is always the quit pipe */
+ (*pollfd)[0].fd = thread_quit_pipe[0];
+ /* Apps command pipe */
+ (*pollfd)[1].fd = apps_cmd_pipe[0];
+ (*pollfd)[1].events = POLLIN;
+
+ DBG("Apps cmd pollfd realloc of size %d", nb_fd);
+
+end:
+ return 0;
+
+error:
+ return -1;
+}
+
+/*
+ * Send registration done packet to the application.
+ */
+static int send_ust_register_done(int sock)
+{
+ struct lttcomm_ust_msg lum;
+
+ DBG("Sending register done command to %d", sock);
+
+ lum.cmd = LTTNG_UST_REGISTER_DONE;
+ lum.handle = LTTNG_UST_ROOT_HANDLE;
+
+ return ustcomm_send_command(sock, &lum);
+}
+
+/*
+ * This thread manage application communication.
*/
static void *thread_manage_apps(void *data)
+{
+ int i, ret, count;
+ unsigned int nb_fd = 2;
+ int update_poll_flag = 1;
+ struct pollfd *pollfd = NULL;
+ struct ust_command ust_cmd;
+
+ DBG("[thread] Manage application started");
+
+ ust_cmd.sock = -1;
+
+ while (1) {
+ /* See if we have a valid socket to add to pollfd */
+ if (ust_cmd.sock != -1) {
+ nb_fd++;
+ update_poll_flag = 1;
+ }
+
+ /* The pollfd struct must be updated */
+ if (update_poll_flag) {
+ ret = update_apps_cmd_pollfd(nb_fd, &pollfd);
+ if (ret < 0) {
+ /* malloc failed so we quit */
+ goto error;
+ }
+ if (ust_cmd.sock != -1) {
+ /* Update pollfd with the new UST socket */
+ DBG("Adding sock %d to apps cmd pollfd", ust_cmd.sock);
+ pollfd[nb_fd - 1].fd = ust_cmd.sock;
+ pollfd[nb_fd - 1].events = POLLHUP | POLLNVAL;
+ ust_cmd.sock = -1;
+ }
+ }
+
+ DBG("Apps thread polling on %d fds", nb_fd);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = poll(pollfd, nb_fd, -1);
+ if (ret < 0) {
+ perror("poll apps thread");
+ goto error;
+ }
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ if (pollfd[0].revents == POLLNVAL) {
+ goto error;
+ } else if (pollfd[1].revents == POLLERR) {
+ ERR("Apps command pipe poll error");
+ goto error;
+ } else if (pollfd[1].revents == POLLIN) {
+ /* Empty pipe */
+ ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
+ if (ret < 0 || ret < sizeof(ust_cmd)) {
+ perror("read apps cmd pipe");
+ goto error;
+ }
+
+ /* Register applicaton to the session daemon */
+ ret = register_traceable_app(&ust_cmd.reg_msg, ust_cmd.sock);
+ if (ret < 0) {
+ /* Only critical ENOMEM error can be returned here */
+ goto error;
+ }
+
+ ret = send_ust_register_done(ust_cmd.sock);
+ if (ret < 0) {
+ /*
+ * If the registration is not possible, we simply unregister
+ * the apps and continue
+ */
+ unregister_traceable_app(ust_cmd.sock);
+ }
+ }
+
+ count = nb_fd;
+ for (i = 2; i < count; i++) {
+ /* Apps socket is closed/hungup */
+ switch (pollfd[i].revents) {
+ case POLLNVAL:
+ case POLLHUP:
+ /* Pipe closed */
+ unregister_traceable_app(pollfd[i].fd);
+ nb_fd--;
+ }
+ }
+
+ if (nb_fd != count) {
+ update_poll_flag = 1;
+ }
+ }
+
+error:
+ DBG("Application communication apps dying");
+ close(apps_cmd_pipe[0]);
+ close(apps_cmd_pipe[1]);
+
+ free(pollfd);
+
+ return NULL;
+}
+
+/*
+ * Dispatch request from the registration threads to the application
+ * communication thread.
+ */
+static void *thread_dispatch_ust_registration(void *data)
+{
+ int ret;
+ struct cds_wfq_node *node;
+ struct ust_command *ust_cmd = NULL;
+
+ DBG("[thread] Dispatch UST command started");
+
+ while (!dispatch_thread_exit) {
+ /* Atomically prepare the queue futex */
+ futex_nto1_prepare(&ust_cmd_queue.futex);
+
+ do {
+ /* Dequeue command for registration */
+ node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
+ if (node == NULL) {
+ DBG("Waked up but nothing in the UST command queue");
+ /* Continue thread execution */
+ break;
+ }
+
+ ust_cmd = caa_container_of(node, struct ust_command, node);
+
+ DBG("Dispatching UST registration pid:%d sock:%d",
+ ust_cmd->reg_msg.pid, ust_cmd->sock);
+ /*
+ * Inform apps thread of the new application registration. This
+ * call is blocking so we can be assured that the data will be read
+ * at some point in time or wait to the end of the world :)
+ */
+ ret = write(apps_cmd_pipe[1], ust_cmd,
+ sizeof(struct ust_command));
+ if (ret < 0) {
+ perror("write apps cmd pipe");
+ if (errno == EBADF) {
+ /*
+ * We can't inform the application thread to process
+ * registration. We will exit or else application
+ * registration will not occur and tracing will never
+ * start.
+ */
+ goto error;
+ }
+ }
+ free(ust_cmd);
+ } while (node != NULL);
+
+ /* Futex wait on queue. Blocking call on futex() */
+ futex_nto1_wait(&ust_cmd_queue.futex);
+ }
+
+error:
+ DBG("Dispatch thread dying");
+ return NULL;
+}
+
+/*
+ * This thread manage application registration.
+ */
+static void *thread_registration_apps(void *data)
{
int sock = 0, ret;
struct pollfd pollfd[2];
+ /*
+ * Get allocated in this thread, enqueued to a global queue, dequeued and
+ * freed in the manage apps thread.
+ */
+ struct ust_command *ust_cmd = NULL;
- /* TODO: Something more elegant is needed but fine for now */
- /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
- * for 32-bit vs 64-bit compat processes. */
- /* replicate in ust with version number */
- struct {
- int reg; /* 1:register, 0:unregister */
- pid_t pid;
- uid_t uid;
- } reg_msg;
-
- DBG("[thread] Manage apps started");
+ DBG("[thread] Manage application registration started");
ret = lttcomm_listen_unix_sock(apps_sock);
if (ret < 0) {
pollfd[1].events = POLLIN;
/* Notify all applications to register */
- notify_apps(default_global_apps_pipe);
+ //notify_apps(default_global_apps_pipe);
while (1) {
DBG("Accepting application registration");
/* Inifinite blocking call, waiting for transmission */
ret = poll(pollfd, 2, -1);
if (ret < 0) {
- perror("poll apps thread");
+ perror("poll register apps thread");
goto error;
}
if (pollfd[0].revents == POLLNVAL) {
goto error;
} else if (pollfd[1].revents == POLLERR) {
- ERR("Apps socket poll error");
+ ERR("Register apps socket poll error");
goto error;
}
goto error;
}
+ /* Create UST registration command for enqueuing */
+ ust_cmd = malloc(sizeof(struct ust_command));
+ if (ust_cmd == NULL) {
+ perror("ust command malloc");
+ goto error;
+ }
+
/*
- * Using message-based transmissions to ensure we don't
- * have to deal with partially received messages.
+ * Using message-based transmissions to ensure we don't have to deal
+ * with partially received messages.
*/
- ret = lttcomm_recv_unix_sock(sock, ®_msg, sizeof(reg_msg));
- if (ret < 0) {
- perror("recv");
+ ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
+ sizeof(struct ust_register_msg));
+ if (ret < 0 || ret != sizeof(struct ust_register_msg)) {
+ perror("lttcomm_recv_unix_sock register apps");
+ free(ust_cmd);
+ close(sock);
continue;
}
- /* Add application to the global traceable list */
- if (reg_msg.reg == 1) {
- /* Registering */
- /*
- * TODO: socket should be either passed to a
- * listener thread (for more messages) or
- * closed. It currently leaks.
- */
- ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
- if (ret < 0) {
- /* register_traceable_app only return an error with
- * ENOMEM. At this point, we better stop everything.
- */
- goto error;
- }
- } else {
- /* Unregistering */
- unregister_traceable_app(reg_msg.pid);
- }
+ ust_cmd->sock = sock;
+
+ /*
+ * Lock free enqueue the registration request.
+ * The red pill has been taken! This apps will be part of the *system*
+ */
+ cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
+
+ /*
+ * Wake the registration queue futex.
+ * Implicit memory barrier with the exchange in cds_wfq_enqueue.
+ */
+ futex_nto1_wake(&ust_cmd_queue.futex);
+
+ DBG("Thread manage apps informed of queued node with sock:%d pid:%d",
+ sock, ust_cmd->reg_msg.pid);
}
error:
- DBG("Apps thread dying");
+ DBG("Register apps thread dying");
if (apps_sock) {
close(apps_sock);
}
static int check_existing_daemon(void)
{
if (access(client_unix_sock_path, F_OK) < 0 &&
- access(apps_unix_sock_path, F_OK) < 0)
+ access(apps_unix_sock_path, F_OK) < 0) {
return 0;
+ }
/* Is there anybody out there ? */
- if (lttng_session_daemon_alive())
+ if (lttng_session_daemon_alive()) {
return -EEXIST;
- else
+ } else {
return 0;
+ }
}
/*
return pipe2(kernel_poll_pipe, O_CLOEXEC);
}
+/*
+ * Create the application command pipe to wake thread_manage_apps.
+ */
+static int create_apps_cmd_pipe(void)
+{
+ return pipe2(apps_cmd_pipe, O_CLOEXEC);
+}
+
/*
* Create the lttng run directory needed for all global sockets and pipe.
*/
goto exit;
}
+ /* Setup the thread apps communication pipe. */
+ if ((ret = create_apps_cmd_pipe()) < 0) {
+ goto exit;
+ }
+
+ /* Init UST command queue. */
+ cds_wfq_init(&ust_cmd_queue.queue);
+
/*
* Get session list pointer. This pointer MUST NOT be free().
* This list is statically declared in session.c
session_list_ptr = get_session_list();
/* Create thread to manage the client socket */
- ret = pthread_create(&client_thread, NULL, thread_manage_clients, (void *) NULL);
+ ret = pthread_create(&client_thread, NULL,
+ thread_manage_clients, (void *) NULL);
if (ret != 0) {
- perror("pthread_create");
+ perror("pthread_create clients");
goto exit_client;
}
+ /* Create thread to dispatch registration */
+ ret = pthread_create(&dispatch_thread, NULL,
+ thread_dispatch_ust_registration, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create dispatch");
+ goto exit_dispatch;
+ }
+
+ /* Create thread to manage application registration. */
+ ret = pthread_create(®_apps_thread, NULL,
+ thread_registration_apps, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create registration");
+ goto exit_reg_apps;
+ }
+
/* Create thread to manage application socket */
ret = pthread_create(&apps_thread, NULL, thread_manage_apps, (void *) NULL);
if (ret != 0) {
- perror("pthread_create");
+ perror("pthread_create apps");
goto exit_apps;
}
/* Create kernel thread to manage kernel event */
ret = pthread_create(&kernel_thread, NULL, thread_manage_kernel, (void *) NULL);
if (ret != 0) {
- perror("pthread_create");
+ perror("pthread_create kernel");
goto exit_kernel;
}
}
exit_apps:
+ ret = pthread_join(reg_apps_thread, &status);
+ if (ret != 0) {
+ perror("pthread_join");
+ goto error; /* join error, exit without cleanup */
+ }
+
+exit_reg_apps:
+ ret = pthread_join(dispatch_thread, &status);
+ if (ret != 0) {
+ perror("pthread_join");
+ goto error; /* join error, exit without cleanup */
+ }
+
+exit_dispatch:
ret = pthread_join(client_thread, &status);
if (ret != 0) {
perror("pthread_join");
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
#include <lttngerr.h>
#include "traceable-app.h"
-/* Number of element for the list below. */
-static unsigned int traceable_app_count;
-
/* Init ust traceabl application's list */
-struct ltt_traceable_app_list ltt_traceable_app_list = {
+static struct ltt_traceable_app_list ltt_traceable_app_list = {
.head = CDS_LIST_HEAD_INIT(ltt_traceable_app_list.head),
+ .lock = PTHREAD_MUTEX_INITIALIZER,
+ .count = 0,
};
-/* List mutex */
-pthread_mutex_t ltt_traceable_app_list_mutex;
-
-/* Internal function */
-static void add_traceable_app(struct ltt_traceable_app *lta);
-static void del_traceable_app(struct ltt_traceable_app *lta);
-
/*
- * Add a traceable application structure to the global list protected by a
- * mutex.
+ * Add a traceable application structure to the global list.
*/
static void add_traceable_app(struct ltt_traceable_app *lta)
{
- pthread_mutex_lock(<t_traceable_app_list_mutex);
cds_list_add(<a->list, <t_traceable_app_list.head);
- traceable_app_count++;
- pthread_mutex_unlock(<t_traceable_app_list_mutex);
+ ltt_traceable_app_list.count++;
}
/*
- * Delete a traceable application structure from the global list protected by a
- * mutex.
+ * Delete a traceable application structure from the global list.
*/
static void del_traceable_app(struct ltt_traceable_app *lta)
{
- pthread_mutex_lock(<t_traceable_app_list_mutex);
cds_list_del(<a->list);
/* Sanity check */
- if (traceable_app_count != 0) {
- traceable_app_count--;
+ if (ltt_traceable_app_list.count > 0) {
+ ltt_traceable_app_list.count--;
+ }
+}
+
+/*
+ * Return pointer to traceable apps list.
+ */
+struct ltt_traceable_app_list *get_traceable_apps_list(void)
+{
+ return <t_traceable_app_list;
+}
+
+/*
+ * Acquire traceable apps list lock.
+ */
+void lock_apps_list(void)
+{
+ pthread_mutex_lock(<t_traceable_app_list.lock);
+}
+
+/*
+ * Release traceable apps list lock.
+ */
+void unlock_apps_list(void)
+{
+ pthread_mutex_unlock(<t_traceable_app_list.lock);
+}
+
+/*
+ * Iterate over the traceable apps list and return a pointer or NULL if not
+ * found.
+ */
+static struct ltt_traceable_app *find_app_by_sock(int sock)
+{
+ struct ltt_traceable_app *iter;
+
+ cds_list_for_each_entry(iter, <t_traceable_app_list.head, list) {
+ if (iter->sock == sock) {
+ /* Found */
+ return iter;
+ }
}
- pthread_mutex_unlock(<t_traceable_app_list_mutex);
+
+ return NULL;
}
/*
*
* On success, return 0, else return malloc ENOMEM.
*/
-int register_traceable_app(pid_t pid, uid_t uid)
+int register_traceable_app(struct ust_register_msg *msg, int sock)
{
struct ltt_traceable_app *lta;
return -ENOMEM;
}
- lta->uid = uid;
- lta->pid = pid;
+ lta->uid = msg->uid;
+ lta->gid = msg->gid;
+ lta->pid = msg->pid;
+ lta->ppid = msg->ppid;
+ lta->v_major = msg->major;
+ lta->v_minor = msg->minor;
+ lta->sock = sock;
+ strncpy(lta->name, msg->name, sizeof(lta->name));
+ lta->name[16] = '\0';
+
+ lock_apps_list();
add_traceable_app(lta);
- DBG("Application %d registered with UID %d", pid, uid);
+ unlock_apps_list();
+
+ DBG("App registered with pid:%d ppid:%d uid:%d gid:%d sock:%d name:%s"
+ " (version %d.%d)", lta->pid, lta->ppid, lta->uid, lta->gid,
+ lta->sock, lta->name, lta->v_major, lta->v_minor);
return 0;
}
/*
* Unregister app by removing it from the global traceable app list and freeing
* the data struct.
+ *
+ * The socket is already closed at this point so no close to sock.
*/
-void unregister_traceable_app(pid_t pid)
+void unregister_traceable_app(int sock)
{
struct ltt_traceable_app *lta;
- lta = find_app_by_pid(pid);
- if (lta != NULL) {
+ lock_apps_list();
+ lta = find_app_by_sock(sock);
+ if (lta) {
+ DBG("PID %d unregistered with sock %d", lta->pid, sock);
+ close(lta->sock);
del_traceable_app(lta);
+ unlock_apps_list();
free(lta);
- DBG("PID %d unregistered", pid);
}
+ unlock_apps_list();
}
/*
*/
unsigned int get_app_count(void)
{
- return traceable_app_count;
-}
-
-/*
- * Iterate over the traceable apps list and return a pointer or NULL if not
- * found.
- */
-struct ltt_traceable_app *find_app_by_pid(pid_t pid)
-{
- struct ltt_traceable_app *iter;
+ unsigned int count;
- pthread_mutex_lock(<t_traceable_app_list_mutex);
- cds_list_for_each_entry(iter, <t_traceable_app_list.head, list) {
- if (iter->pid == pid) {
- pthread_mutex_unlock(<t_traceable_app_list_mutex);
- /* Found */
- return iter;
- }
- }
- pthread_mutex_unlock(<t_traceable_app_list_mutex);
+ lock_apps_list();
+ count = ltt_traceable_app_list.count;
+ unlock_apps_list();
- return NULL;
+ return count;
}
/*
- * List traceable user-space application and fill an array of pids.
+ * Free and clean all traceable apps of the global list.
*/
-void get_app_list_pids(pid_t *pids)
+void clean_traceable_apps_list(void)
{
- int i = 0;
- struct ltt_traceable_app *iter;
+ struct ltt_traceable_app *iter, *tmp;
- /* Protected by a mutex here because the threads manage_client
- * and manage_apps can access this list.
+ /*
+ * Don't acquire list lock here. This function should be called from
+ * cleanup() functions meaning that the program will exit.
*/
- pthread_mutex_lock(<t_traceable_app_list_mutex);
- cds_list_for_each_entry(iter, <t_traceable_app_list.head, list) {
- pids[i] = iter->pid;
- i++;
+ cds_list_for_each_entry_safe(iter, tmp, <t_traceable_app_list.head, list) {
+ close(iter->sock);
+ free(iter);
}
- pthread_mutex_unlock(<t_traceable_app_list_mutex);
}
#ifndef _TRACEABLE_APP_H
#define _TRACEABLE_APP_H
+#include <stdint.h>
#include <urcu/list.h>
-/* Traceable application list */
+/*
+ * Application registration data structure.
+ */
+struct ust_register_msg {
+ uint32_t major;
+ uint32_t minor;
+ pid_t pid;
+ pid_t ppid;
+ uid_t uid;
+ gid_t gid;
+ char name[16];
+};
+
+/*
+ * Traceable application list.
+ */
struct ltt_traceable_app_list {
+ /*
+ * This lock protects any read/write access to the list and count (which is
+ * basically the list size). All public functions in traceable-app.c
+ * acquire this lock and release it before returning. If none of those
+ * functions are used, the lock MUST be acquired in order to iterate or/and
+ * do any actions on that list.
+ */
+ pthread_mutex_t lock;
+
+ /*
+ * Number of element in the list. The session list lock MUST be acquired if
+ * this counter is used when iterating over the session list.
+ */
+ unsigned int count;
+
+ /* Linked list head */
struct cds_list_head head;
};
* and a linked list is kept of all running traceable app.
*/
struct ltt_traceable_app {
- struct cds_list_head list;
+ int sock; /* Communication socket with the application */
pid_t pid;
- uid_t uid; /* User ID that owns the apps */
+ pid_t ppid;
+ uid_t uid; /* User ID that owns the apps */
+ gid_t gid; /* Group ID that owns the apps */
+ uint32_t v_major; /* Verion major number */
+ uint32_t v_minor; /* Verion minor number */
+ char name[17]; /* Process name (short) */
+ struct cds_list_head list;
};
-struct ltt_traceable_app *find_app_by_pid(pid_t pid);
-int register_traceable_app(pid_t pid, uid_t uid);
-void unregister_traceable_app(pid_t pid);
-void get_app_list_pids(pid_t *pids);
+int register_traceable_app(struct ust_register_msg *msg, int sock);
+void unregister_traceable_app(int sock);
unsigned int get_app_count(void);
+void lock_apps_list(void);
+void unlock_apps_list(void);
+void clean_traceable_apps_list(void);
+struct ltt_traceable_app_list *get_traceable_apps_list(void);
+
#endif /* _TRACEABLE_APP_H */
--- /dev/null
+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; only version 2
+ * of the License.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <lttngerr.h>
+
+#include "ust-comm.h"
+
+/*
+ * Send msg containing a command to an UST application via sock and wait for
+ * the reply.
+ *
+ * Return -1 on error or if reply fails else return 0.
+ */
+int ustcomm_send_command(int sock, struct lttcomm_ust_msg *msg)
+{
+ ssize_t len;
+ struct lttcomm_ust_reply reply;
+
+ DBG("Sending UST command %d to sock %d", msg->cmd, sock);
+
+ /* Send UST msg */
+ len = lttcomm_send_unix_sock(sock, msg, sizeof(*msg));
+ if (len < 0) {
+ goto error;
+ }
+
+ DBG("Receiving UST reply on sock %d", sock);
+
+ /* Get UST reply */
+ len = lttcomm_recv_unix_sock(sock, &reply, sizeof(reply));
+ if (len < 0) {
+ goto error;
+ }
+
+ if (reply.ret_code != LTTCOMM_OK) {
+ goto error;
+ }
+
+ return 0;
+
+error:
+ return -1;
+}
--- /dev/null
+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; only version 2 of the License.
+ *
+ * This program 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 General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef _LTT_UST_COMM_H
+#define _LTT_UST_COMM_H
+
+#include <lttng-sessiond-comm.h>
+
+int ustcomm_send_command(int sock, struct lttcomm_ust_msg *msg);
+
+#endif /* _LTT_UST_COMM_H */
projects / lttng-tools.git / commitdiff
