Attachment 200960 Details for Bug 234442 – atomically increment gMsgId

[patch] atomically increment gMsgId

diff (text/plain), 1.40 KB, created by Mark Johnston on 2019-01-09 16:55:12 UTC

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Creator: Mark Johnston

Created: 2019-01-09 16:55:12 UTC

Size: 1.40 KB

patch

obsolete

>diff --git a/lib/libnetgraph/msg.c b/lib/libnetgraph/msg.c
>index c94645997acb..061bdc233ff5 100644
>--- a/lib/libnetgraph/msg.c
>+++ b/lib/libnetgraph/msg.c
>@@ -44,6 +44,7 @@ __FBSDID("$FreeBSD$");
> #include <sys/types.h>
> #include <sys/socket.h>
> #include <stdarg.h>
>+#include <stdatomic.h>
> #include <netgraph/ng_message.h>
> #include <netgraph/ng_socket.h>
> 
>@@ -51,7 +52,7 @@ __FBSDID("$FreeBSD$");
> #include "internal.h"
> 
> /* Next message token value */
>-static int	gMsgId;
>+static _Atomic(unsigned int) gMsgId;
> 
> /* For delivering both messages and replies */
> static int	NgDeliverMsg(int cs, const char *path,
>@@ -72,9 +73,7 @@ NgSendMsg(int cs, const char *path,
> 	memset(&msg, 0, sizeof(msg));
> 	msg.header.version = NG_VERSION;
> 	msg.header.typecookie = cookie;
>-	if (++gMsgId < 0)
>-		gMsgId = 1;
>-	msg.header.token = gMsgId;
>+	msg.header.token = atomic_fetch_add(&gMsgId, 1) & INT_MAX;
> 	msg.header.flags = NGF_ORIG;
> 	msg.header.cmd = cmd;
> 	snprintf((char *)msg.header.cmdstr, NG_CMDSTRSIZ, "cmd%d", cmd);
>@@ -143,9 +142,7 @@ NgSendAsciiMsg(int cs, const char *path, const char *fmt, ...)
> 
> 	/* Now send binary version */
> 	binary = (struct ng_mesg *)reply->data;
>-	if (++gMsgId < 0)
>-		gMsgId = 1;
>-	binary->header.token = gMsgId;
>+	binary->header.token = atomic_fetch_add(&gMsgId, 1) & INT_MAX;
> 	binary->header.version = NG_VERSION;
> 	if (NgDeliverMsg(cs,
> 	    path, binary, binary->data, binary->header.arglen) < 0) {

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Attachments on bug 234442: 200557 | 200960