From 3b402b40d669bb6d65eebb91588a2edb8214b7ce Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 27 Sep 2011 20:31:46 -0400 Subject: [PATCH] Add vtid (gettid()) context Signed-off-by: Mathieu Desnoyers --- include/ust/lttng-events.h | 5 +- include/ust/lttng-ust-abi.h | 3 +- libust/Makefile.am | 1 + libust/lttng-context-pthread-id.c | 2 +- libust/lttng-context-vtid.c | 84 +++++++++++++++++++++ libust/lttng-ust-abi.c | 2 + tests/ust-basic-tracing/ust-basic-tracing.c | 5 +- 7 files changed, 94 insertions(+), 8 deletions(-) create mode 100644 libust/lttng-context-vtid.c diff --git a/include/ust/lttng-events.h b/include/ust/lttng-events.h index a7726f0..7a8cf6f 100644 --- a/include/ust/lttng-events.h +++ b/include/ust/lttng-events.h @@ -307,8 +307,6 @@ void ltt_transport_register(struct ltt_transport *transport); void ltt_transport_unregister(struct ltt_transport *transport); void synchronize_trace(void); -//int ltt_debugfs_abi_init(void); -//void ltt_debugfs_abi_exit(void); int ltt_probe_register(struct lttng_probe_desc *desc); void ltt_probe_unregister(struct lttng_probe_desc *desc); @@ -322,8 +320,7 @@ struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p); void lttng_remove_context_field(struct lttng_ctx **ctx_p, struct lttng_ctx_field *field); void lttng_destroy_context(struct lttng_ctx *ctx); +int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx); int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx); -//extern const struct file_operations lttng_tracepoint_list_fops; - #endif /* _UST_LTTNG_EVENTS_H */ diff --git a/include/ust/lttng-ust-abi.h b/include/ust/lttng-ust-abi.h index 0496538..7146579 100644 --- a/include/ust/lttng-ust-abi.h +++ b/include/ust/lttng-ust-abi.h @@ -66,7 +66,8 @@ struct lttng_ust_event { }; enum lttng_ust_context_type { - LTTNG_UST_CONTEXT_PTHREAD_ID = 0, + LTTNG_UST_CONTEXT_VTID = 0, + LTTNG_UST_CONTEXT_PTHREAD_ID = 1, }; struct lttng_ust_context { diff --git a/libust/Makefile.am b/libust/Makefile.am index 66837f5..9857dd2 100644 --- a/libust/Makefile.am +++ b/libust/Makefile.am @@ -19,6 +19,7 @@ libust_la_SOURCES = \ ust-core.c \ probes/lttng-probe-ust.c \ probes/lttng-probe-ust.h \ + lttng-context-vtid.c \ lttng-context-pthread-id.c \ ltt-context.c diff --git a/libust/lttng-context-pthread-id.c b/libust/lttng-context-pthread-id.c index d5ca230..1ad1fb0 100644 --- a/libust/lttng-context-pthread-id.c +++ b/libust/lttng-context-pthread-id.c @@ -49,7 +49,7 @@ int lttng_add_pthread_id_to_ctx(struct lttng_ctx **ctx) field->event_field.type.atype = atype_integer; field->event_field.type.u.basic.integer.size = sizeof(unsigned long) * CHAR_BIT; field->event_field.type.u.basic.integer.alignment = lttng_alignof(unsigned long) * CHAR_BIT; - field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(pid_t); + field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(unsigned long); 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; diff --git a/libust/lttng-context-vtid.c b/libust/lttng-context-vtid.c new file mode 100644 index 0000000..fd1e320 --- /dev/null +++ b/libust/lttng-context-vtid.c @@ -0,0 +1,84 @@ +/* + * (C) Copyright 2009-2011 - + * Mathieu Desnoyers + * + * LTTng UST vtid context. + * + * Dual LGPL v2.1/GPL v2 license. + */ + +#include +#include +#include +#include +#include + +#ifdef __linux__ +#include +#endif + +#if defined(_syscall0) +_syscall0(pid_t, gettid) +#elif defined(__NR_gettid) +static inline pid_t gettid(void) +{ + return syscall(__NR_gettid); +} +#else +#warning "use pid as tid" +static inline pid_t gettid(void) +{ + return getpid(); +} +#endif + +/* + * We cache the result to ensure we don't trigger a system call for + * each event. + */ +static __thread pid_t cached_vtid; + +static +size_t vtid_get_size(size_t offset) +{ + size_t size = 0; + + size += lib_ring_buffer_align(offset, lttng_alignof(pid_t)); + size += sizeof(pid_t); + return size; +} + +static +void vtid_record(struct lttng_ctx_field *field, + struct lib_ring_buffer_ctx *ctx, + struct ltt_channel *chan) +{ + if (unlikely(!cached_vtid)) + cached_vtid = gettid(); + lib_ring_buffer_align_ctx(ctx, lttng_alignof(cached_vtid)); + chan->ops->event_write(ctx, &cached_vtid, sizeof(cached_vtid)); +} + +int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx) +{ + struct lttng_ctx_field *field; + + field = lttng_append_context(ctx); + if (!field) + return -ENOMEM; + if (lttng_find_context(*ctx, "vtid")) { + lttng_remove_context_field(ctx, field); + return -EEXIST; + } + field->event_field.name = "vtid"; + 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->get_size = vtid_get_size; + field->record = vtid_record; + return 0; +} diff --git a/libust/lttng-ust-abi.c b/libust/lttng-ust-abi.c index 924b7af..35c93c9 100644 --- a/libust/lttng-ust-abi.c +++ b/libust/lttng-ust-abi.c @@ -274,6 +274,8 @@ long lttng_abi_add_context(int objd, switch (context_param->ctx) { case LTTNG_UST_CONTEXT_PTHREAD_ID: return lttng_add_pthread_id_to_ctx(ctx); + case LTTNG_UST_CONTEXT_VTID: + return lttng_add_vtid_to_ctx(ctx); default: return -EINVAL; } diff --git a/tests/ust-basic-tracing/ust-basic-tracing.c b/tests/ust-basic-tracing/ust-basic-tracing.c index d0ba413..d200b4f 100644 --- a/tests/ust-basic-tracing/ust-basic-tracing.c +++ b/tests/ust-basic-tracing/ust-basic-tracing.c @@ -565,11 +565,12 @@ int send_app_msgs(int sock, const char *outputpath, printf("received event handle %u\n", event_handle[k]); } - /* Attach pthread_id context */ + /* Attach vtid context */ memset(&lum, 0, sizeof(lum)); lum.handle = channel_data.handle; lum.cmd = LTTNG_UST_CONTEXT; - lum.u.context.ctx = LTTNG_UST_CONTEXT_PTHREAD_ID; + lum.u.context.ctx = LTTNG_UST_CONTEXT_VTID; + //lum.u.context.ctx = LTTNG_UST_CONTEXT_PTHREAD_ID; ret = send_app_cmd(sock, &lum, &lur); if (ret) return ret; -- 2.34.1