X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-vtid.c;fp=liblttng-ust%2Flttng-context-vtid.c;h=0000000000000000000000000000000000000000;hb=9d4c8b2d907edb9ebc9bfde55602598e7ba0832e;hp=3530d2668757269d6139369bbae19b0a14912c1f;hpb=6ba6fd60507f8e045bdc4f1be14e9d99c6a15f7f;p=lttng-ust.git diff --git a/liblttng-ust/lttng-context-vtid.c b/liblttng-ust/lttng-context-vtid.c deleted file mode 100644 index 3530d266..00000000 --- a/liblttng-ust/lttng-context-vtid.c +++ /dev/null @@ -1,115 +0,0 @@ -/* - * SPDX-License-Identifier: LGPL-2.1-only - * - * Copyright (C) 2009-2012 Mathieu Desnoyers - * - * LTTng UST vtid context. - */ - -#define _LGPL_SOURCE -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "context-internal.h" -#include "lttng-tracer-core.h" - -/* - * We cache the result to ensure we don't trigger a system call for - * each event. - */ -static DEFINE_URCU_TLS(pid_t, cached_vtid); - -/* - * Upon fork or clone, the TID assigned to our thread is not the same as - * we kept in cache. Luckily, we are the only thread surviving in the - * child process, so we can simply clear our cached version. - */ -void lttng_context_vtid_reset(void) -{ - CMM_STORE_SHARED(URCU_TLS(cached_vtid), 0); -} - -static -size_t vtid_get_size(void *priv __attribute__((unused)), - size_t offset) -{ - size_t size = 0; - - size += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(pid_t)); - size += sizeof(pid_t); - return size; -} - -static inline -pid_t wrapper_getvtid(void) -{ - pid_t vtid; - - vtid = CMM_LOAD_SHARED(URCU_TLS(cached_vtid)); - if (caa_unlikely(!vtid)) { - vtid = lttng_gettid(); - CMM_STORE_SHARED(URCU_TLS(cached_vtid), vtid); - } - return vtid; -} - -static -void vtid_record(void *priv __attribute__((unused)), - struct lttng_ust_lib_ring_buffer_ctx *ctx, - struct lttng_ust_channel_buffer *chan) -{ - pid_t vtid = wrapper_getvtid(); - - chan->ops->event_write(ctx, &vtid, sizeof(vtid), lttng_ust_rb_alignof(vtid)); -} - -static -void vtid_get_value(void *priv __attribute__((unused)), - struct lttng_ust_ctx_value *value) -{ - value->u.s64 = wrapper_getvtid(); -} - -static const struct lttng_ust_ctx_field *ctx_field = lttng_ust_static_ctx_field( - lttng_ust_static_event_field("vtid", - lttng_ust_static_type_integer(sizeof(pid_t) * CHAR_BIT, - lttng_ust_rb_alignof(pid_t) * CHAR_BIT, - lttng_ust_is_signed_type(pid_t), - BYTE_ORDER, 10), - false, false), - vtid_get_size, - vtid_record, - vtid_get_value, - NULL, NULL); - -int lttng_add_vtid_to_ctx(struct lttng_ust_ctx **ctx) -{ - int ret; - - if (lttng_find_context(*ctx, ctx_field->event_field->name)) { - ret = -EEXIST; - goto error_find_context; - } - ret = lttng_ust_context_append(ctx, ctx_field); - if (ret) - return ret; - return 0; - -error_find_context: - return ret; -} - -/* - * Force a read (imply TLS fixup for dlopen) of TLS variables. - */ -void lttng_fixup_vtid_tls(void) -{ - asm volatile ("" : : "m" (URCU_TLS(cached_vtid))); -}