Fix: Revert of 814b4934e2604a419bcb8eec57c0450dbb47e2c3

author Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>

Wed, 6 Apr 2022 13:17:38 +0000 (09:17 -0400)

committer Jérémie Galarneau <jeremie.galarneau@efficios.com>

Tue, 12 Apr 2022 20:44:55 +0000 (16:44 -0400)
author Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Wed, 6 Apr 2022 13:17:38 +0000 (09:17 -0400)
committer Jérémie Galarneau <jeremie.galarneau@efficios.com>
Tue, 12 Apr 2022 20:44:55 +0000 (16:44 -0400)
diff --git a/src/bin/lttng-sessiond/notification-thread-commands.cpp b/src/bin/lttng-sessiond/notification-thread-commands.cpp

index 568580403abc13039afa6f1b50b47457f83ff805..1de6ff58be3609d1f24690a055cfcfc756709cce 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread-commands.cpp
+++ b/src/bin/lttng-sessiond/notification-thread-commands.cpp
@@ -33,7 +33,7 @@ int run_command_wait(struct notification_thread_handle *handle,
         cds_list_add_tail(&cmd->cmd_list_node,
                         &handle->cmd_queue.list);
         /* Wake-up thread. */
-       ret = lttng_write(lttng_pipe_get_writefd(handle->cmd_queue.event_pipe),
+       ret = lttng_write(handle->cmd_queue.event_fd,
                         &notification_counter, sizeof(notification_counter));
         if (ret != sizeof(notification_counter)) {
                 PERROR("write to notification thread's queue event fd");
@@ -89,7 +89,7 @@ int run_command_no_wait(struct notification_thread_handle *handle,
         cds_list_add_tail(&new_cmd->cmd_list_node,
                         &handle->cmd_queue.list);
         /* Wake-up thread. */
-       ret = lttng_write(lttng_pipe_get_writefd(handle->cmd_queue.event_pipe),
+       ret = lttng_write(handle->cmd_queue.event_fd,
                         &notification_counter, sizeof(notification_counter));
         if (ret != sizeof(notification_counter)) {
                 PERROR("write to notification thread's queue event fd");
diff --git a/src/bin/lttng-sessiond/notification-thread-events.cpp b/src/bin/lttng-sessiond/notification-thread-events.cpp

index 279bc7c5a26aa797c08d800b38b16ae98aa04627..da4f8a4b2ad515f601b90435fe696acde129beb0 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread-events.cpp
+++ b/src/bin/lttng-sessiond/notification-thread-events.cpp
@@ -3123,28 +3123,55 @@ end:
         return 0;
  }
  
+static
+int pop_cmd_queue(struct notification_thread_handle *handle,
+               struct notification_thread_command **cmd)
+{
+       int ret;
+       uint64_t counter;
+
+       pthread_mutex_lock(&handle->cmd_queue.lock);
+       ret = lttng_read(handle->cmd_queue.event_fd, &counter, sizeof(counter));
+       if (ret != sizeof(counter)) {
+               ret = -1;
+               goto error_unlock;
+       }
+
+       /* Simulate behaviour of EFD_SEMAPHORE for older kernels. */
+       counter -= 1;
+       if (counter != 0) {
+               ret = lttng_write(handle->cmd_queue.event_fd, &counter,
+                               sizeof(counter));
+               if (ret != sizeof(counter)) {
+                       PERROR("Failed to write back to event_fd for EFD_SEMAPHORE emulation");
+                       ret = -1;
+                       goto error_unlock;
+               }
+       }
+
+       *cmd = cds_list_first_entry(&handle->cmd_queue.list,
+                       struct notification_thread_command, cmd_list_node);
+       cds_list_del(&((*cmd)->cmd_list_node));
+       ret = 0;
+
+error_unlock:
+       pthread_mutex_unlock(&handle->cmd_queue.lock);
+       return ret;
+}
+
  /* Returns 0 on success, 1 on exit requested, negative value on error. */
  int handle_notification_thread_command(
                 struct notification_thread_handle *handle,
                 struct notification_thread_state *state)
  {
         int ret;
-       uint64_t counter;
         struct notification_thread_command *cmd;
  
-       /* Read the event pipe to put it back into a quiescent state. */
-       ret = lttng_read(lttng_pipe_get_readfd(handle->cmd_queue.event_pipe), &counter,
-                       sizeof(counter));
-       if (ret != sizeof(counter)) {
+       ret = pop_cmd_queue(handle, &cmd);
+       if (ret) {
                 goto error;
         }
  
-       pthread_mutex_lock(&handle->cmd_queue.lock);
-       cmd = cds_list_first_entry(&handle->cmd_queue.list,
-                       struct notification_thread_command, cmd_list_node);
-       cds_list_del(&cmd->cmd_list_node);
-       pthread_mutex_unlock(&handle->cmd_queue.lock);
-
         DBG("Received `%s` command",
                         notification_command_type_str(cmd->type));
         switch (cmd->type) {
diff --git a/src/bin/lttng-sessiond/notification-thread.cpp b/src/bin/lttng-sessiond/notification-thread.cpp

index cd95e68858f58d68521c29e2d752a15f088430dc..17a9956824f6c09dc01a807e112a4a0627fe1c01 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread.cpp
+++ b/src/bin/lttng-sessiond/notification-thread.cpp
@@ -18,6 +18,7 @@
  #include <common/align.hpp>
  #include <common/time.hpp>
  #include <sys/stat.h>
+#include <sys/eventfd.h>
  #include <time.h>
  #include <signal.h>
  
@@ -59,8 +60,11 @@ void notification_thread_handle_destroy(
         pthread_mutex_destroy(&handle->cmd_queue.lock);
         sem_destroy(&handle->ready);
  
-       if (handle->cmd_queue.event_pipe) {
-               lttng_pipe_destroy(handle->cmd_queue.event_pipe);
+       if (handle->cmd_queue.event_fd >= 0) {
+               ret = close(handle->cmd_queue.event_fd);
+               if (ret < 0) {
+                       PERROR("Failed to close notification command queue event fd");
+               }
         }
         if (handle->channel_monitoring_pipes.ust32_consumer >= 0) {
                 ret = close(handle->channel_monitoring_pipes.ust32_consumer);
@@ -92,7 +96,7 @@ struct notification_thread_handle *notification_thread_handle_create(
  {
         int ret;
         struct notification_thread_handle *handle;
-       struct lttng_pipe *event_pipe = NULL;
+       int event_fd = -1;
  
         handle = zmalloc<notification_thread_handle>();
         if (!handle) {
@@ -101,14 +105,13 @@ struct notification_thread_handle *notification_thread_handle_create(
  
         sem_init(&handle->ready, 0, 0);
  
-       event_pipe = lttng_pipe_open(FD_CLOEXEC);
-       if (!event_pipe) {
-               ERR("event_pipe creation");
+       event_fd =  eventfd(0, EFD_CLOEXEC);
+       if (event_fd < 0) {
+               PERROR("event_fd creation");
                 goto error;
         }
  
-       handle->cmd_queue.event_pipe = event_pipe;
-       event_pipe = NULL;
+       handle->cmd_queue.event_fd = event_fd;
  
         CDS_INIT_LIST_HEAD(&handle->cmd_queue.list);
         ret = pthread_mutex_init(&handle->cmd_queue.lock, NULL);
@@ -150,7 +153,6 @@ struct notification_thread_handle *notification_thread_handle_create(
  end:
         return handle;
  error:
-       lttng_pipe_destroy(event_pipe);
         notification_thread_handle_destroy(handle);
         return NULL;
  }
@@ -296,7 +298,7 @@ int init_poll_set(struct lttng_poll_event *poll_set,
                 ERR("Failed to add notification channel socket to pollset");
                 goto error;
         }
-       ret = lttng_poll_add(poll_set, lttng_pipe_get_readfd(handle->cmd_queue.event_pipe),
+       ret = lttng_poll_add(poll_set, handle->cmd_queue.event_fd,
                         LPOLLIN | LPOLLERR);
         if (ret < 0) {
                 ERR("Failed to add notification command queue event fd to pollset");
@@ -711,7 +713,7 @@ void *thread_notification(void *data)
                                         ERR("Unexpected poll events %u for notification socket %i", revents, fd);
                                         goto error;
                                 }
-                       } else if (fd == lttng_pipe_get_readfd(handle->cmd_queue.event_pipe)) {
+                       } else if (fd == handle->cmd_queue.event_fd) {
                                 ret = handle_notification_thread_command(handle,
                                                 &state);
                                 if (ret < 0) {
diff --git a/src/bin/lttng-sessiond/notification-thread.hpp b/src/bin/lttng-sessiond/notification-thread.hpp

index 3444af9c041c24e5570390764bd23a46fd7eb20b..2f77189ad143c7763e9a7ee4fc76280d64d7db2a 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread.hpp
+++ b/src/bin/lttng-sessiond/notification-thread.hpp
@@ -63,7 +63,7 @@ struct notification_thread_handle {
          * has been enqueued.
          */
         struct {
-               struct lttng_pipe *event_pipe;
+               int event_fd;
                 struct cds_list_head list;
                 pthread_mutex_t lock;
         } cmd_queue;
author	Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
	Wed, 6 Apr 2022 13:17:38 +0000 (09:17 -0400)
committer	Jérémie Galarneau <jeremie.galarneau@efficios.com>
	Tue, 12 Apr 2022 20:44:55 +0000 (16:44 -0400)
src/bin/lttng-sessiond/notification-thread-commands.cpp		patch \| blob \| blame \| history
src/bin/lttng-sessiond/notification-thread-events.cpp		patch \| blob \| blame \| history
src/bin/lttng-sessiond/notification-thread.cpp		patch \| blob \| blame \| history
src/bin/lttng-sessiond/notification-thread.hpp		patch \| blob \| blame \| history