From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34438) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bou9c-0002tS-94 for qemu-devel@nongnu.org; Tue, 27 Sep 2016 11:18:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bou9b-0000nr-DI for qemu-devel@nongnu.org; Tue, 27 Sep 2016 11:18:44 -0400 From: Stefan Hajnoczi Date: Tue, 27 Sep 2016 16:18:34 +0100 Message-Id: <1474989516-18255-2-git-send-email-stefanha@redhat.com> In-Reply-To: <1474989516-18255-1-git-send-email-stefanha@redhat.com> References: <1474989516-18255-1-git-send-email-stefanha@redhat.com> Subject: [Qemu-devel] [PATCH v2 1/3] coroutine: add qemu_coroutine_entered() function List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , qemu-block@nongnu.org, Roman Pen , Fam Zheng , Stefan Hajnoczi See the doc comments for a description of this new coroutine API. Signed-off-by: Stefan Hajnoczi --- include/qemu/coroutine.h | 13 +++++++++++++ util/qemu-coroutine.c | 5 +++++ 2 files changed, 18 insertions(+) diff --git a/include/qemu/coroutine.h b/include/qemu/coroutine.h index 29a2078..e6a60d5 100644 --- a/include/qemu/coroutine.h +++ b/include/qemu/coroutine.h @@ -92,6 +92,19 @@ Coroutine *coroutine_fn qemu_coroutine_self(void); */ bool qemu_in_coroutine(void); +/** + * Return true if the coroutine is currently entered + * + * A coroutine is "entered" if it has not yielded from the current + * qemu_coroutine_enter() call used to run it. This does not mean that the + * coroutine is currently executing code since it may have transferred control + * to another coroutine using qemu_coroutine_enter(). + * + * When several coroutines enter each other there may be no way to know which + * ones have already been entered. In such situations this function can be + * used to avoid recursively entering coroutines. + */ +bool qemu_coroutine_entered(Coroutine *co); /** diff --git a/util/qemu-coroutine.c b/util/qemu-coroutine.c index 3cbf225..737bffa 100644 --- a/util/qemu-coroutine.c +++ b/util/qemu-coroutine.c @@ -146,3 +146,8 @@ void coroutine_fn qemu_coroutine_yield(void) self->caller = NULL; qemu_coroutine_switch(self, to, COROUTINE_YIELD); } + +bool qemu_coroutine_entered(Coroutine *co) +{ + return co->caller; +} -- 2.7.4