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Resolving a racing condition while adding ports on the app's side.

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An earlier attempt (ad6265786871) to resolve this condition on the
router's side added a new issue: the app could get a request before
acquiring a port.
This commit is contained in:
Max Romanov
2020-04-10 16:21:58 +03:00
parent c7f5c1c664
commit 58cc13ab29
5 changed files with 48 additions and 13 deletions
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28
src/nxt_unit.c
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@@ -4282,16 +4282,38 @@ nxt_unit_add_port(nxt_unit_ctx_t *ctx, nxt_unit_port_t *port)
int rc;
nxt_unit_impl_t *lib;
nxt_unit_process_t *process;
nxt_unit_port_impl_t *new_port;
nxt_unit_port_impl_t *new_port, *old_port;
lib = nxt_container_of(ctx->unit, nxt_unit_impl_t, unit);
pthread_mutex_lock(&lib->mutex);
old_port = nxt_unit_port_hash_find(&lib->ports, &port->id, 0);
if (nxt_slow_path(old_port != NULL)) {
nxt_unit_debug(ctx, "add_port: duplicate %d,%d in_fd %d out_fd %d",
port->id.pid, port->id.id,
port->in_fd, port->out_fd);
if (port->in_fd != -1) {
close(port->in_fd);
port->in_fd = -1;
}
if (port->out_fd != -1) {
close(port->out_fd);
port->out_fd = -1;
}
pthread_mutex_unlock(&lib->mutex);
return NXT_UNIT_OK;
}
nxt_unit_debug(ctx, "add_port: %d,%d in_fd %d out_fd %d",
port->id.pid, port->id.id,
port->in_fd, port->out_fd);
pthread_mutex_lock(&lib->mutex);
process = nxt_unit_process_get(ctx, port->id.pid);
if (nxt_slow_path(process == NULL)) {
rc = NXT_UNIT_ERROR;