From patchwork Mon Dec 19 04:19:09 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sam Mendoza-Jonas X-Patchwork-Id: 706932 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3thnmP5h7Nz9t0v for ; Mon, 19 Dec 2016 15:21:25 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=mendozajonas.com header.i=@mendozajonas.com header.b="eFFsesg8"; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3thnmP4PT1zDwHM for ; Mon, 19 Dec 2016 15:21:25 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=mendozajonas.com header.i=@mendozajonas.com header.b="eFFsesg8"; dkim-atps=neutral X-Original-To: petitboot@lists.ozlabs.org Delivered-To: petitboot@lists.ozlabs.org Received: from mendozajonas.com (mendozajonas.com [188.166.185.233]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3thnks3Zk3zDwHV for ; Mon, 19 Dec 2016 15:20:05 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=mendozajonas.com header.i=@mendozajonas.com header.b="eFFsesg8"; dkim-atps=neutral Received: from skellige.ozlabs.ibm.com (unknown [122.99.82.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: sam@mendozajonas.com) by mendozajonas.com (Postfix) with ESMTPSA id E18E0143FB8; Mon, 19 Dec 2016 12:20:01 +0800 (SGT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mendozajonas.com; s=mail; t=1482121202; bh=rwWwwOHARA8EdTNm2SD+uUdqnVPrVGQ+deY4HEwnnMY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eFFsesg8gJMzVZEZaWzjP0OzyH1s6bSdwkVNuMElzm2LybQSG7JXFjt/Hk/Zu2Z+k V92PMB1UjFL19X0jJ/5jNu/sr0mwcu2Mfrsp9dJ0t/yQuKUcLM7TdheZK/xqS78J9Q 7jBDvg+buvd1PbvsC8y6qds5RYRzszPavR8IGUM0= From: Samuel Mendoza-Jonas To: petitboot@lists.ozlabs.org Subject: [PATCH 23/29] lib/process: Allow process output to be retrieved on each event Date: Mon, 19 Dec 2016 15:19:09 +1100 Message-Id: <20161219041915.30497-24-sam@mendozajonas.com> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161219041915.30497-1-sam@mendozajonas.com> References: <20161219041915.30497-1-sam@mendozajonas.com> X-BeenThere: petitboot@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Petitboot bootloader development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Samuel Mendoza-Jonas MIME-Version: 1.0 Errors-To: petitboot-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Petitboot" Allow a custom callback function to be set when registering the IO waiter for asynchronous processes. To allow output from processes to be parsed as it is received, add process_stdout_custom() which passes a new "line" parameter to process_read_stdout_once() in order to consume output as it appears. Users of a custom IO callback will only have access to the process_info struct which is internal to lib/process; the function procinfo_get_process() is added to allow these callers to access process information. Signed-off-by: Samuel Mendoza-Jonas --- lib/process/process.c | 41 ++++++++++++++++++++++++++++++++++++----- lib/process/process.h | 7 +++++++ 2 files changed, 43 insertions(+), 5 deletions(-) diff --git a/lib/process/process.c b/lib/process/process.c index 6e143e0..93fd9c9 100644 --- a/lib/process/process.c +++ b/lib/process/process.c @@ -60,15 +60,22 @@ static struct process_info *get_info(struct process *process) return container_of(process, struct process_info, process); } +struct process *procinfo_get_process(struct process_info *procinfo) +{ + return &procinfo->process; +} + /* Read as much as possible into the currently-allocated stdout buffer, and * possibly realloc it for the next read + * If the line pointer is not NULL, it is set to the start of the latest + * output. * * Returns: * > 0 on success (even though no bytes may have been read) * 0 on EOF (no error, but no more reads can be performed) * < 0 on error **/ -static int process_read_stdout_once(struct process_info *procinfo) +static int process_read_stdout_once(struct process_info *procinfo, char **line) { struct process *process = &procinfo->process; int rc, fd, max_len; @@ -89,6 +96,9 @@ static int process_read_stdout_once(struct process_info *procinfo) return rc; } + if (line) + *line = process->stdout_buf + process->stdout_len; + process->stdout_len += rc; if (process->stdout_len == procinfo->stdout_buf_len - 1) { procinfo->stdout_buf_len *= 2; @@ -157,7 +167,7 @@ static int process_read_stdout(struct process_info *procinfo) return 0; do { - rc = process_read_stdout_once(procinfo); + rc = process_read_stdout_once(procinfo, NULL); } while (rc > 0); process_finish_stdout(procinfo); @@ -170,7 +180,27 @@ static int process_stdout_cb(void *arg) struct process_info *procinfo = arg; int rc; - rc = process_read_stdout_once(procinfo); + rc = process_read_stdout_once(procinfo, NULL); + + /* if we're going to signal to the waitset that we're done (ie, non-zero + * return value), then the waiters will remove us, so we drop the + * reference */ + if (rc < 0) { + talloc_unlink(procset, procinfo); + procinfo->stdout_waiter = NULL; + rc = -1; + } else { + rc = 0; + } + + return rc; +} + +int process_stdout_custom(struct process_info *procinfo, char **line) +{ + int rc; + + rc = process_read_stdout_once(procinfo, line); /* if we're going to signal to the waitset that we're done (ie, non-zero * return value), then the waiters will remove us, so we drop the @@ -387,6 +417,7 @@ int process_run_sync(struct process *process) int process_run_async(struct process *process) { struct process_info *procinfo = get_info(process); + waiter_cb stdout_cb; int rc; rc = process_run_common(procinfo); @@ -394,10 +425,10 @@ int process_run_async(struct process *process) return rc; if (process->keep_stdout) { + stdout_cb = process->stdout_cb ?: process_stdout_cb; procinfo->stdout_waiter = waiter_register_io(procset->waitset, procinfo->stdout_pipe[0], - WAIT_IN, process_stdout_cb, - procinfo); + WAIT_IN, stdout_cb, procinfo); talloc_reference(procset, procinfo); } diff --git a/lib/process/process.h b/lib/process/process.h index f75f197..65fdba8 100644 --- a/lib/process/process.h +++ b/lib/process/process.h @@ -23,6 +23,7 @@ struct process; struct procset; +struct process_info; typedef void (*process_exit_cb)(struct process *); @@ -34,6 +35,8 @@ struct process { bool add_stderr; process_exit_cb exit_cb; void *data; + waiter_cb stdout_cb; + void *stdout_data; /* runtime data */ pid_t pid; @@ -79,4 +82,8 @@ void process_stop_async(struct process *process); * exit status */ bool process_exit_ok(struct process *process); +/* Functions to assist callers using a custom stdout callback */ +struct process *procinfo_get_process(struct process_info *procinfo); +int process_stdout_custom(struct process_info *procinfo, char **line); + #endif /* PROCESS_H */