This lock will be used to protect data structures which will be hung
off the libxl_ctx in subsequent patches.
Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
---
tools/libxl/libxl.c | 3 +++
tools/libxl/libxl_internal.h | 16 ++++++++++++++++
2 files changed, 19 insertions(+), 0 deletions(-)
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 5d448af..a3c9807 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -40,6 +40,7 @@ int libxl_ctx_alloc(libxl_ctx **pctx, int version,
xentoollog_logger * lg)
{
libxl_ctx *ctx;
struct stat stat_buf;
+ const pthread_mutex_t mutex_value = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
if (version != LIBXL_VERSION)
return ERROR_VERSION;
@@ -53,6 +54,8 @@ int libxl_ctx_alloc(libxl_ctx **pctx, int version,
xentoollog_logger * lg)
memset(ctx, 0, sizeof(libxl_ctx));
ctx->lg = lg;
+ memcpy(&ctx->lock, &mutex_value, sizeof(ctx->lock));
+
if ( stat(XENSTORE_PID_FILE, &stat_buf) != 0 ) {
LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "Is xenstore daemon running?\n"
"failed to stat %s", XENSTORE_PID_FILE);
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 6d9da2c..79a9de4 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -23,6 +23,7 @@
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
+#include <pthread.h>
#include <xs.h>
#include <xenctrl.h>
@@ -95,6 +96,9 @@ struct libxl__ctx {
xc_interface *xch;
struct xs_handle *xsh;
+ pthread_mutex_t lock; /* protects data structures hanging off the ctx */
+ /* always use MUTEX_LOCK and MUTEX_UNLOCK to manipulate this */
+
/* for callers who reap children willy-nilly; caller must only
* set this after libxl_init and before any other call - or
* may leave them untouched */
@@ -577,6 +581,18 @@ _hidden libxl__json_object *libxl__json_parse(libxl__gc
*gc, const char *s);
#define CTX libxl__gc_owner(gc)
+#define MUTEX_LOCK do { \
+ int mutex_r = pthread_mutex_lock(&CTX->lock); \
+ assert(!mutex_r); \
+ } while(0)
+
+#define MUTEX_UNLOCK do { \
+ int mutex_r = pthread_mutex_unlock(&CTX->lock); \
+ assert(!mutex_r); \
+ } while(0)
+
+
+
/*
* Inserts "elm_new" into the sorted list "head".
*
--
1.7.2.5
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