From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 162E86896 for ; Wed, 24 Sep 2014 13:32:46 +0200 (CEST) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP; 24 Sep 2014 04:29:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="390900902" Received: from irsmsx102.ger.corp.intel.com ([163.33.3.155]) by FMSMGA003.fm.intel.com with ESMTP; 24 Sep 2014 04:32:59 -0700 Received: from irsmsx105.ger.corp.intel.com (163.33.3.28) by IRSMSX102.ger.corp.intel.com (163.33.3.155) with Microsoft SMTP Server (TLS) id 14.3.195.1; Wed, 24 Sep 2014 12:38:53 +0100 Received: from irsmsx109.ger.corp.intel.com ([169.254.13.200]) by IRSMSX105.ger.corp.intel.com ([169.254.7.158]) with mapi id 14.03.0195.001; Wed, 24 Sep 2014 12:38:53 +0100 From: "Jastrzebski, MichalX K" To: "dev@dpdk.org" Thread-Topic: [PATCH] Change alarm cancel function to thread-safe. Thread-Index: AQHP1z+gNpYWcLJ780a2XEwi95k/LJwQKTow Date: Wed, 24 Sep 2014 11:38:52 +0000 Message-ID: <60ABE07DBB3A454EB7FAD707B4BB1582138971EC@IRSMSX109.ger.corp.intel.com> References: <1411484549-711-1-git-send-email-michalx.k.jastrzebski@intel.com> In-Reply-To: <1411484549-711-1-git-send-email-michalx.k.jastrzebski@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [163.33.239.181] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH] Change alarm cancel function to thread-safe. X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Sep 2014 11:32:48 -0000 This patch is related to discussion from mode 4 link bonding patch set. Best regards Michal -----Original Message----- From: Jastrzebski, MichalX K=20 Sent: Tuesday, September 23, 2014 5:02 PM To: dev@dpdk.org Cc: Jastrzebski, MichalX K; Wodkowski, PawelX Subject: [PATCH] Change alarm cancel function to thread-safe. It eliminates a race between threads using rte_alarm_cancel and rte_alarm_s= et. Signed-off-by: Pawel Wodkowski Reviewed-by: Michal Jastrzebski --- lib/librte_eal/common/include/rte_alarm.h | 3 +- lib/librte_eal/linuxapp/eal/eal_alarm.c | 68 +++++++++++++++++++------= ---- 2 files changed, 46 insertions(+), 25 deletions(-) diff --git a/lib/librte_eal/common/include/rte_alarm.h b/lib/librte_eal/com= mon/include/rte_alarm.h index d451522..f5f7de4 100644 --- a/lib/librte_eal/common/include/rte_alarm.h +++ b/lib/librte_eal/common/include/rte_alarm.h @@ -76,7 +76,8 @@ typedef void (*rte_eal_alarm_callback)(void *arg); int r= te_eal_alarm_set(uint64_t us, rte_eal_alarm_callback cb, void *cb_arg); =20 /** - * Function to cancel an alarm callback which has been registered before. + * Function to cancel an alarm callback which has been registered=20 + before. If + * used ouside alarm callback it wait for all callbacks to finish its exec= ution. * * @param cb_fn * alarm callback diff --git a/lib/librte_eal/linuxapp/eal/eal_alarm.c b/lib/librte_eal/linux= app/eal/eal_alarm.c index 480f0cb..0561dbf 100644 --- a/lib/librte_eal/linuxapp/eal/eal_alarm.c +++ b/lib/librte_eal/linuxapp/eal/eal_alarm.c @@ -69,12 +69,14 @@ struct alarm_entry { struct timeval time; rte_eal_alarm_callback cb_fn; void *cb_arg; - volatile int executing; + volatile uint8_t executing; + volatile pthread_t executing_id; }; =20 static LIST_HEAD(alarm_list, alarm_entry) alarm_list =3D LIST_HEAD_INITIAL= IZER(); static rte_spinlock_t alarm_list_lk =3D RTE_SPINLOCK_INITIALIZER; =20 + static struct rte_intr_handle intr_handle =3D {.fd =3D -1 }; static int h= andler_registered =3D 0; static void eal_alarm_callback(struct rte_intr_ha= ndle *hdl, void *arg); @@ -108,11 +110,14 @@ eal_alarm_callback(struct rte_= intr_handle *hdl __rte_unused, (ap->time.tv_sec < now.tv_sec || (ap->time.tv_sec =3D=3D now.tv_sec && ap->time.tv_usec <=3D now.tv_usec))){ ap->executing =3D 1; + ap->executing_id =3D pthread_self(); rte_spinlock_unlock(&alarm_list_lk); =20 ap->cb_fn(ap->cb_arg); =20 rte_spinlock_lock(&alarm_list_lk); + ap->executing =3D 0; + LIST_REMOVE(ap, next); rte_free(ap); } @@ -156,7 +161,6 @@ rte_eal_alarm_set(uint64_t us, rte_eal_alarm_callback c= b_fn, void *cb_arg) new_alarm->cb_arg =3D cb_arg; new_alarm->time.tv_usec =3D (now.tv_usec + us) % US_PER_S; new_alarm->time.tv_sec =3D now.tv_sec + ((now.tv_usec + us) / US_PER_S); - new_alarm->executing =3D 0; =20 rte_spinlock_lock(&alarm_list_lk); if (!handler_registered) { @@ -202,34 +206,50 @@ rte_eal_alarm_cancel(rte_eal_alarm_callback cb_fn, vo= id *cb_arg) { struct alarm_entry *ap, *ap_prev; int count =3D 0; + int executing; =20 if (!cb_fn) return -1; =20 - rte_spinlock_lock(&alarm_list_lk); - /* remove any matches at the start of the list */ - while ((ap =3D LIST_FIRST(&alarm_list)) !=3D NULL && - cb_fn =3D=3D ap->cb_fn && ap->executing =3D=3D 0 && - (cb_arg =3D=3D (void *)-1 || cb_arg =3D=3D ap->cb_arg)) { - LIST_REMOVE(ap, next); - rte_free(ap); - count++; - } - ap_prev =3D ap; - - /* now go through list, removing entries not at start */ - LIST_FOREACH(ap, &alarm_list, next) { - /* this won't be true first time through */ - if (cb_fn =3D=3D ap->cb_fn && ap->executing =3D=3D 0 && + do { + executing =3D 0; + rte_spinlock_lock(&alarm_list_lk); + /* remove any matches at the start of the list */ + while ((ap =3D LIST_FIRST(&alarm_list)) !=3D NULL && + cb_fn =3D=3D ap->cb_fn && (cb_arg =3D=3D (void *)-1 || cb_arg =3D=3D ap->cb_arg)) { - LIST_REMOVE(ap,next); - rte_free(ap); - count++; - ap =3D ap_prev; + + if (ap->executing =3D=3D 0) { + LIST_REMOVE(ap, next); + rte_free(ap); + count++; + } else { + if (pthread_equal(ap->executing_id, pthread_self()) =3D=3D 0) + executing++; + + break; + } } ap_prev =3D ap; - } - rte_spinlock_unlock(&alarm_list_lk); + + /* now go through list, removing entries not at start */ + LIST_FOREACH(ap, &alarm_list, next) { + /* this won't be true first time through */ + if (cb_fn =3D=3D ap->cb_fn && + (cb_arg =3D=3D (void *)-1 || cb_arg =3D=3D ap->cb_arg)) { + + if (ap->executing =3D=3D 0) { + LIST_REMOVE(ap, next); + rte_free(ap); + count++; + ap =3D ap_prev; + } else if (pthread_equal(ap->executing_id, pthread_self()) =3D=3D 0) + executing++; + } + ap_prev =3D ap; + } + rte_spinlock_unlock(&alarm_list_lk); + } while (executing !=3D 0); + return count; } - -- 1.7.9.5