[Libguestfs] [PATCH 2/2] Add the thread identifier to various multi-threaded programs and tests.
---
df/parallel.c | 6 ++++++
src/guestfs.pod | 3 +++
tests/mount-local/test-parallel-mount-local.c | 2 ++
tests/parallel/test-parallel.c | 6 ++++++
4 files changed, 17 insertions(+)
diff --git a/df/parallel.c b/df/parallel.c
index 2d1d1d3..114cc27 100644
--- a/df/parallel.c
+++ b/df/parallel.c
@@ -149,6 +149,7 @@ worker_thread (void *thread_data_vp)
size_t output_len = 0;
guestfs_h *g;
int err;
+ char id[64];
/* Take the next domain from the list. */
if (thread_data->verbose)
@@ -191,6 +192,11 @@ worker_thread (void *thread_data_vp)
return &thread_data->r;
}
+ /* Set the handle identifier so we can tell threads apart. */
+ snprintf (id, sizeof id, "thread_%zu_domain_%zu",
+ thread_data->thread_num, i);
+ guestfs_set_identifier (g, id);
+
/* Copy some settings from the options guestfs handle. */
guestfs_set_trace (g, thread_data->trace);
guestfs_set_verbose (g, thread_data->verbose);
diff --git a/src/guestfs.pod b/src/guestfs.pod
index 248a4d0..349aa8d 100644
--- a/src/guestfs.pod
+++ b/src/guestfs.pod
@@ -1328,6 +1328,9 @@ safe to be called from multiple threads without a mutex.
See the graphical program guestfs-browser for one possible
architecture for multithreaded programs using libvirt and libguestfs.
+Use L</guestfs_set_identifier> to make it simpler to identify threads
+in trace output.
+
=head2 PATH
Libguestfs needs a supermin appliance, which it finds by looking along
diff --git a/tests/mount-local/test-parallel-mount-local.c
b/tests/mount-local/test-parallel-mount-local.c
index 0210330..873d20a 100644
--- a/tests/mount-local/test-parallel-mount-local.c
+++ b/tests/mount-local/test-parallel-mount-local.c
@@ -177,6 +177,8 @@ start_thread (void *statevp)
pthread_exit (&state->exit_status);
}
+ guestfs_set_identifier (g, state->mp);
+
if (guestfs_add_drive_scratch (g, 512*1024*1024, -1) == -1)
goto error;
if (guestfs_launch (g) == -1)
diff --git a/tests/parallel/test-parallel.c b/tests/parallel/test-parallel.c
index d018ec7..85182f2 100644
--- a/tests/parallel/test-parallel.c
+++ b/tests/parallel/test-parallel.c
@@ -43,6 +43,7 @@
#define NR_THREADS 5
struct thread_state {
+ size_t thread_num; /* Thread number. */
pthread_t thread; /* Thread handle. */
int exit_status; /* Thread exit status. */
};
@@ -89,6 +90,7 @@ main (int argc, char *argv[])
sigaction (SIGQUIT, &sa, NULL);
for (i = 0; i < NR_THREADS; ++i) {
+ threads[i].thread_num = i;
/* Start the thread. */
r = pthread_create (&threads[i].thread, NULL, start_thread,
&threads[i]);
@@ -117,6 +119,7 @@ start_thread (void *statevp)
struct thread_state *state = statevp;
guestfs_h *g;
time_t start_t, t;
+ char id[64];
time (&start_t);
@@ -133,6 +136,9 @@ start_thread (void *statevp)
pthread_exit (&state->exit_status);
}
+ snprintf (id, sizeof id, "%zu", state->thread_num);
+ guestfs_set_identifier (g, id);
+
if (guestfs_add_drive_opts (g, "/dev/null",
GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw",
GUESTFS_ADD_DRIVE_OPTS_READONLY, 1,
--
2.5.0