X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-procname.c;h=c6d02cf60d3b0692dd449e5f12f08a32b08307bf;hb=HEAD;hp=96a1b2ca2c36083b9d921220f1173f551256025d;hpb=4e48b5d2debaf6c0c598489c183cc6cb2125c8a3;p=lttng-ust.git diff --git a/liblttng-ust/lttng-context-procname.c b/liblttng-ust/lttng-context-procname.c deleted file mode 100644 index 96a1b2ca..00000000 --- a/liblttng-ust/lttng-context-procname.c +++ /dev/null @@ -1,125 +0,0 @@ -/* - * SPDX-License-Identifier: LGPL-2.1-only - * - * Copyright (C) 2009-2012 Mathieu Desnoyers - * - * LTTng UST procname context. - */ - -#define _LGPL_SOURCE -#include -#include -#include -#include -#include -#include -#include "compat.h" -#include "lttng-tracer-core.h" - -#include "context-internal.h" - -/* Maximum number of nesting levels for the procname cache. */ -#define PROCNAME_NESTING_MAX 2 - -/* - * We cache the result to ensure we don't trigger a system call for - * each event. - * Upon exec, procname changes, but exec takes care of throwing away - * this cached version. - * The procname can also change by calling prctl(). The procname should - * be set for a thread before the first event is logged within this - * thread. - */ -typedef char procname_array[PROCNAME_NESTING_MAX][17]; - -static DEFINE_URCU_TLS(procname_array, cached_procname); - -static DEFINE_URCU_TLS(int, procname_nesting); - -static inline -const char *wrapper_getprocname(void) -{ - int nesting = CMM_LOAD_SHARED(URCU_TLS(procname_nesting)); - - if (caa_unlikely(nesting >= PROCNAME_NESTING_MAX)) - return ""; - if (caa_unlikely(!URCU_TLS(cached_procname)[nesting][0])) { - CMM_STORE_SHARED(URCU_TLS(procname_nesting), nesting + 1); - /* Increment nesting before updating cache. */ - cmm_barrier(); - lttng_pthread_getname_np(URCU_TLS(cached_procname)[nesting], LTTNG_UST_ABI_PROCNAME_LEN); - URCU_TLS(cached_procname)[nesting][LTTNG_UST_ABI_PROCNAME_LEN - 1] = '\0'; - /* Decrement nesting after updating cache. */ - cmm_barrier(); - CMM_STORE_SHARED(URCU_TLS(procname_nesting), nesting); - } - return URCU_TLS(cached_procname)[nesting]; -} - -/* Reset should not be called from a signal handler. */ -void lttng_ust_context_procname_reset(void) -{ - CMM_STORE_SHARED(URCU_TLS(cached_procname)[1][0], '\0'); - CMM_STORE_SHARED(URCU_TLS(procname_nesting), 1); - CMM_STORE_SHARED(URCU_TLS(cached_procname)[0][0], '\0'); - CMM_STORE_SHARED(URCU_TLS(procname_nesting), 0); -} - -static -size_t procname_get_size(void *priv __attribute__((unused)), - size_t offset __attribute__((unused))) -{ - return LTTNG_UST_ABI_PROCNAME_LEN; -} - -static -void procname_record(void *priv __attribute__((unused)), - struct lttng_ust_lib_ring_buffer_ctx *ctx, - struct lttng_ust_channel_buffer *chan) -{ - const char *procname; - - procname = wrapper_getprocname(); - chan->ops->event_write(ctx, procname, LTTNG_UST_ABI_PROCNAME_LEN, 1); -} - -static -void procname_get_value(void *priv __attribute__((unused)), - struct lttng_ust_ctx_value *value) -{ - value->u.str = wrapper_getprocname(); -} - -static const struct lttng_ust_ctx_field *ctx_field = lttng_ust_static_ctx_field( - lttng_ust_static_event_field("procname", - lttng_ust_static_type_array_text(LTTNG_UST_ABI_PROCNAME_LEN), - false, false), - procname_get_size, - procname_record, - procname_get_value, - NULL, NULL); - -int lttng_add_procname_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_procname_tls(void) -{ - asm volatile ("" : : "m" (URCU_TLS(cached_procname)[0])); -}