Messages in this thread | | | Date | Tue, 23 Jun 2020 16:56:13 +0200 | From | Jiri Olsa <> | Subject | Re: [PATCH v8 03/13] perf evlist: implement control command handling functions |
| |
On Wed, Jun 17, 2020 at 11:36:46AM +0300, Alexey Budankov wrote:
SNIP
> +static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd, > + char *cmd_data, size_t data_size) > +{ > + int err; > + char c; > + size_t bytes_read = 0; > + > + memset(cmd_data, 0, data_size--); > + > + do { > + err = read(evlist->ctl_fd.fd, &c, 1); > + if (err > 0) { > + if (c == '\n' || c == '\0') > + break; > + cmd_data[bytes_read++] = c; > + if (bytes_read == data_size) > + break; > + } else { > + if (err == -1) > + pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd); > + break; > + } > + } while (1); > + > + pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data, > + bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
do you want to display the message above only if (err > 0) ?
> + > + if (err > 0) { > + if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG, > + strlen(EVLIST_CTL_CMD_ENABLE_TAG))) { > + *cmd = EVLIST_CTL_CMD_ENABLE; > + } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG, > + strlen(EVLIST_CTL_CMD_DISABLE_TAG))) { > + *cmd = EVLIST_CTL_CMD_DISABLE; > + } > + } > + > + return err; > +}
SNIP
> + int ctlfd_pos = evlist->ctl_fd.pos; > + struct pollfd *entries = evlist->core.pollfd.entries; > + > + if (ctlfd_pos == -1 || !entries[ctlfd_pos].revents) > + return 0; > + > + if (entries[ctlfd_pos].revents & POLLIN) { > + err = evlist__ctlfd_recv(evlist, cmd, cmd_data, > + EVLIST_CTL_CMD_MAX_LEN); > + if (err > 0) { > + switch (*cmd) { > + case EVLIST_CTL_CMD_ENABLE: > + evlist__enable(evlist); > + break; > + case EVLIST_CTL_CMD_DISABLE: > + evlist__disable(evlist); > + break; > + case EVLIST_CTL_CMD_ACK: > + case EVLIST_CTL_CMD_UNSUPPORTED: > + default: > + pr_debug("ctlfd: unsupported %d\n", *cmd); > + break; > + } > + if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED)) > + evlist__ctlfd_ack(evlist); > + } > + } > + > + if (entries[ctlfd_pos].revents & (POLLHUP | POLLERR)) > + evlist__finalize_ctlfd(evlist);
should this error be propagated via err?
jirka
| |