Re: [Xen-cim] Emailing: libxen.diff - Ewan Mellor - com.xensource.lists.xen-cim

8 messages in com.xensource.lists.xen-cimRe: [Xen-cim] Emailing: libxen.diff

From	Sent On	Attachments
Subrahmanian, Raj	22 Dec 2006 19:00	.diff
Ewan Mellor	23 Dec 2006 02:12
Subrahmanian, Raj	23 Dec 2006 23:20
Ewan Mellor	24 Dec 2006 03:50
Gareth S Bestor	24 Dec 2006 13:46
Jim Fehlig	26 Dec 2006 21:49
Subrahmanian, Raj	02 Jan 2007 08:33
Jim Fehlig	02 Jan 2007 09:06

Subject:	Re: [Xen-cim] Emailing: libxen.diff
From:	Ewan Mellor (ew...@xensource.com)
Date:	12/23/2006 02:12:34 AM
List:	com.xensource.lists.xen-cim

On Fri, Dec 22, 2006 at 10:00:49PM -0500, Subrahmanian, Raj wrote:

This will MT-safe the xen_init and xen_fini calls, so that we can do it once for each provider than for each call.

I don't think that this belongs in libxen, as that library shouldn't add a dependency on libpthread unconditionally. Can't you do this inside the provider?

Ewan.

Raj <<libxen.diff>>

diff -r 8348f40ba2b7 tools/libxen/Makefile --- a/tools/libxen/Makefile Thu Dec 21 14:49:19 2006 +0000 +++ b/tools/libxen/Makefile Fri Dec 22 17:32:26 2006 -0500 @@ -27,7 +27,8 @@ CFLAGS = -Iinclude \ -W -Wall -Wmissing-prototypes -Werror -std=c99 -O2 -fPIC

LDFLAGS = $(shell xml2-config --libs) \ - $(shell curl-config --libs) + $(shell curl-config --libs) \ + -lpthread

LIBXENAPI_HDRS = $(wildcard include/*.h) LIBXENAPI_OBJS = $(patsubst %.c, %.o, $(wildcard src/*.c)) diff -r 8348f40ba2b7 tools/libxen/include/xen_common.h --- a/tools/libxen/include/xen_common.h Thu Dec 21 14:49:19 2006 +0000 +++ b/tools/libxen/include/xen_common.h Fri Dec 22 17:32:26 2006 -0500 @@ -24,13 +24,13 @@ #include <stddef.h> #include <stdint.h> #include <time.h> - +// The init and the fini really need to happen only once. +// The mutex will take care of that +#include <pthread.h> #include "xen_host_decl.h" -

typedef bool (*xen_result_func)(const void *data, size_t len, void *result_handle); -

/** * len does not include a terminating \0. diff -r 8348f40ba2b7 tools/libxen/src/xen_common.c --- a/tools/libxen/src/xen_common.c Thu Dec 21 14:49:19 2006 +0000 +++ b/tools/libxen/src/xen_common.c Fri Dec 22 17:32:26 2006 -0500 @@ -43,6 +43,8 @@ #define PERMISSIVE 1

+static pthread_mutex_t mutexUserCount=PTHREAD_MUTEX_INITIALIZER; +static unsigned UserCount=0; static xmlXPathCompExprPtr responsePath = NULL; static xmlXPathCompExprPtr faultPath = NULL;

@@ -111,23 +113,35 @@ void void xen_init(void) { - responsePath = - xmlXPathCompile( - BAD_CAST( - "/methodResponse/params/param/value/struct/member/value")); - faultPath = - xmlXPathCompile( - BAD_CAST("/methodResponse/fault/value/struct/member/value")); + pthread_mutex_lock(&mutexUserCount); + if (UserCount==0) + { + responsePath = + xmlXPathCompile( + BAD_CAST( + "/methodResponse/params/param/value/struct/member/value")); + faultPath = + xmlXPathCompile( + BAD_CAST("/methodResponse/fault/value/struct/member/value")); + } + UserCount++; + pthread_mutex_unlock(&mutexUserCount); }

void xen_fini(void) { - xmlXPathFreeCompExpr(responsePath); - xmlXPathFreeCompExpr(faultPath); - responsePath = NULL; - faultPath = NULL; + pthread_mutex_lock(&mutexUserCount); + UserCount--; + if (UserCount==0) + { + xmlXPathFreeCompExpr(responsePath); + xmlXPathFreeCompExpr(faultPath); + responsePath = NULL; + faultPath = NULL; + } + pthread_mutex_unlock(&mutexUserCount); }