Lock initialization of PRIV_CALL-scoped data.

src/pcre2.c

@@ -26,6 +26,7 @@
  */
 
 #include <locale.h>
+#include <pthread.h>
 
 #include "vmod_pcre2.h"
 
@@ -36,6 +37,9 @@
 			AZ(pcre2_set_##param((ctx), (type)(param)));	\
 	} while(0)
 
+/* Locks initialization of PRIV_CALL-scoped data. */
+static pthread_mutex_t call_lock = PTHREAD_MUTEX_INITIALIZER;
+
 void
 errmsg(VRT_CTX, const char *fmt, ...)
 {
@@ -245,20 +249,28 @@ get_match_opts(VRT_CTX, struct vmod_priv *priv, MATCH_CTX_OPTS, MATCH_FLAGS,
 	struct match_call *match_opts;
 	pcre2_match_context *mctx;
 
+	AZ(pthread_mutex_lock(&call_lock));
+	if (priv->priv != NULL) {
+		/* Someone beat us to it. */
+		AZ(pthread_mutex_unlock(&call_lock));
+		CAST_OBJ(match_opts, priv->priv, VMOD_PCRE2_MATCH_CALL_MAGIC);
+		return match_opts;
+	}
+
 	if (!check_uint32_range(ctx, match_limit, "match_limit", context,
 				caller))
-		return NULL;
+		goto fail;
 	if (!check_uint32_range(ctx, offset_limit, "offset_limit", context,
 				caller))
-		return NULL;
+		goto fail;
 	if (!check_uint32_range(ctx, recursion_limit, "recursion_limit",
 				context, caller))
-		return NULL;
+		goto fail;
 
 	if ((mctx = pcre2_match_context_create(NULL)) == NULL) {
 		VERRNOMEM(ctx, "creating match context in %s%s", context,
 			  caller);
-		return NULL;
+		goto fail;
 	}
 	SET_CTX_PARAM(mctx, match_limit, uint32_t);
 	SET_CTX_PARAM(mctx, offset_limit, uint32_t);
@@ -268,7 +280,7 @@ get_match_opts(VRT_CTX, struct vmod_priv *priv, MATCH_CTX_OPTS, MATCH_FLAGS,
 	if (match_opts == NULL) {
 		VERRNOMEM(ctx, "allocating call-scoped match options in %s%s",
 			  context, caller);
-		return NULL;
+		goto fail;
 	}
 	match_opts->mctx = mctx;
 	set_match_flags(&match_opts->match_options, MATCH_SUB_FLAGS_PARAMS);
@@ -277,5 +289,10 @@ get_match_opts(VRT_CTX, struct vmod_priv *priv, MATCH_CTX_OPTS, MATCH_FLAGS,
 	priv->free = match_call_free;
 	priv->len = sizeof(*match_opts);
 
+	AZ(pthread_mutex_unlock(&call_lock));
 	return match_opts;
+
+ fail:
+	AZ(pthread_mutex_unlock(&call_lock));
+	return NULL;
 }

src/vmod_pcre2.c

@@ -546,7 +546,6 @@ vmod_match(VRT_CTX, struct vmod_priv *call, struct vmod_priv *task,
 	}
 
 	/* Compile and match options saved in PRIV_CALL scope */
-	/* XXX need a lock */
 	if (call->priv != NULL)
 		CAST_OBJ(match_call, call->priv, VMOD_PCRE2_MATCH_CALL_MAGIC);
 	else if ((match_call = get_match_opts(ctx, call, MATCH_CTX_PARAMS,