X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-vpid.c;h=ddcfb8ad3bcf25ed98f15557945d65c4a73c14f2;hb=daacdbfc04fe07ecff0a0d1878b4f48d38912c78;hp=53fb314b8c0da1bdf353f00c59c953879b4ed150;hpb=6d9b54d845b08d54d3f483f1130b499516588db3;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-context-vpid.c b/liblttng-ust/lttng-context-vpid.c
index 53fb314b..ddcfb8ad 100644
--- a/liblttng-ust/lttng-context-vpid.c
+++ b/liblttng-ust/lttng-context-vpid.c
@@ -1,32 +1,21 @@
 /*
- * lttng-context-vpid.c
- *
- * LTTng UST vpid context.
+ * SPDX-License-Identifier: LGPL-2.1-only
  *
  * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; only
- * version 2.1 of the License.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * LTTng UST vpid context.
  */
 
 #define _LGPL_SOURCE
+#include <stddef.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <lttng/ust-events.h>
 #include <lttng/ust-tracer.h>
 #include <lttng/ringbuffer-config.h>
 
+#include "context-internal.h"
+
 /*
  * We cache the result to ensure we don't trigger a system call for
  * each event.
@@ -34,11 +23,16 @@
 static pid_t cached_vpid;
 
 static inline
-pid_t wrapper_getpid(void)
+pid_t wrapper_getvpid(void)
 {
-	if (caa_unlikely(!cached_vpid))
-		cached_vpid = getpid();
-	return cached_vpid;
+	pid_t vpid;
+
+	vpid = CMM_LOAD_SHARED(cached_vpid);
+	if (caa_unlikely(!vpid)) {
+		vpid = getpid();
+		CMM_STORE_SHARED(cached_vpid, vpid);
+	}
+	return vpid;
 }
 
 /*
@@ -47,11 +41,11 @@ pid_t wrapper_getpid(void)
  */
 void lttng_context_vpid_reset(void)
 {
-	cached_vpid = 0;
+	CMM_STORE_SHARED(cached_vpid, 0);
 }
 
 static
-size_t vpid_get_size(struct lttng_ctx_field *field, size_t offset)
+size_t vpid_get_size(struct lttng_ust_ctx_field *field, size_t offset)
 {
 	size_t size = 0;
 
@@ -61,30 +55,26 @@ size_t vpid_get_size(struct lttng_ctx_field *field, size_t offset)
 }
 
 static
-void vpid_record(struct lttng_ctx_field *field,
+void vpid_record(struct lttng_ust_ctx_field *field,
 		 struct lttng_ust_lib_ring_buffer_ctx *ctx,
 		 struct lttng_channel *chan)
 {
-	pid_t pid;
+	pid_t vpid = wrapper_getvpid();
 
-	pid = wrapper_getpid();
-	lib_ring_buffer_align_ctx(ctx, lttng_alignof(pid));
-	chan->ops->event_write(ctx, &pid, sizeof(pid));
+	lib_ring_buffer_align_ctx(ctx, lttng_alignof(vpid));
+	chan->ops->event_write(ctx, &vpid, sizeof(vpid));
 }
 
 static
-void vpid_get_value(struct lttng_ctx_field *field,
-		struct lttng_ctx_value *value)
+void vpid_get_value(struct lttng_ust_ctx_field *field,
+		struct lttng_ust_ctx_value *value)
 {
-	pid_t pid;
-
-	pid = wrapper_getpid();
-	value->u.s64 = pid;
+	value->u.s64 = wrapper_getvpid();
 }
 
-int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx)
+int lttng_add_vpid_to_ctx(struct lttng_ust_ctx **ctx)
 {
-	struct lttng_ctx_field *field;
+	struct lttng_ust_ctx_field *field;
 
 	field = lttng_append_context(ctx);
 	if (!field)
@@ -93,14 +83,14 @@ int lttng_add_vpid_to_ctx(struct lttng_ctx **ctx)
 		lttng_remove_context_field(ctx, field);
 		return -EEXIST;
 	}
-	field->event_field.name = "vpid";
-	field->event_field.type.atype = atype_integer;
-	field->event_field.type.u.basic.integer.size = sizeof(pid_t) * CHAR_BIT;
-	field->event_field.type.u.basic.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
-	field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t);
-	field->event_field.type.u.basic.integer.reverse_byte_order = 0;
-	field->event_field.type.u.basic.integer.base = 10;
-	field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
+	field->event_field->name = "vpid";
+	field->event_field->type.atype = atype_integer;
+	field->event_field->type.u.integer.size = sizeof(pid_t) * CHAR_BIT;
+	field->event_field->type.u.integer.alignment = lttng_alignof(pid_t) * CHAR_BIT;
+	field->event_field->type.u.integer.signedness = lttng_is_signed_type(pid_t);
+	field->event_field->type.u.integer.reverse_byte_order = 0;
+	field->event_field->type.u.integer.base = 10;
+	field->event_field->type.u.integer.encoding = lttng_encode_none;
 	field->get_size = vpid_get_size;
 	field->record = vpid_record;
 	field->get_value = vpid_get_value;