Re: [PATCH v2] virthreadpool: create threads from the newly expanded workers
On 3/18/24 14:31, Wei Gong wrote:
when the thread pool is dynamically expanded, threads should
not be created from the existing workers; they should be created
from the newly expanded workers
Signed-off-by: Wei Gong <gongwei833x(a)gmail.com>
---
src/util/virthreadpool.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/src/util/virthreadpool.c b/src/util/virthreadpool.c
index d45fa92061..de8113df81 100644
--- a/src/util/virthreadpool.c
+++ b/src/util/virthreadpool.c
@@ -184,7 +184,8 @@ virThreadPoolExpand(virThreadPool *pool, size_t gain, bool priority)
size_t i = 0;
struct virThreadPoolWorkerData *data = NULL;
- VIR_EXPAND_N(*workers, *curWorkers, gain);
+ VIR_REALLOC_N(*workers, *curWorkers + gain);
+ memset(&(*workers)[*curWorkers], 0, sizeof(virThread) *
gain);
I don't think it's safe to do this ^^^.
Firstly, pthread_t is an opaque type. We don't know if all zeroes are
valid value (that's why there are functions like pthread_equal()) or if
it's a valid init value.
Secondly, since *curWorkers is incremented at only after successful
thread creation, we can no longer get it to point to an uninitialized
array item.
I'll drop this line before pushing.
for (i = 0; i < gain; i++) {
g_autofree char *name = NULL;
@@ -199,7 +200,7 @@ virThreadPoolExpand(virThreadPool *pool, size_t gain, bool priority)
else
name = g_strdup(pool->jobName);
- if (virThreadCreateFull(&(*workers)[i],
+ if (virThreadCreateFull(&(*workers)[*curWorkers],
false,
virThreadPoolWorker,
name,
@@ -207,15 +208,13 @@ virThreadPoolExpand(virThreadPool *pool, size_t gain, bool
priority)
data) < 0) {
VIR_FREE(data);
virReportSystemError(errno, "%s", _("Failed to create
thread"));
- goto error;
+ return -1;
}
+
+ (*curWorkers)++;
}
return 0;
-
- error:
- *curWorkers -= gain - i;
- return -1;
}
virThreadPool *
Reviewed-by: Michal Privoznik <mprivozn(a)redhat.com>
and merged. Congratulations on your first libvirt contribution!
Michal