Add vtid (gettid()) context

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/include/ust/lttng-events.h b/include/ust/lttng-events.h
index a7726f090fd465b17defa44afb8fe305d4a30372..7a8cf6f839617de14ef7673fc301487ca5f14639 100644 (file)
--- 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 04965387c1c8ad13144569e5c7b14fd41f979031..7146579129006b45995c1a27283881a1be159698 100644 (file)
--- 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 66837f5a8835a02361b512dcbef24e42a8ac96ee..9857dd2d6f4d9ef3b8cd752353552aff2436ad1f 100644 (file)
--- 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 d5ca230939eef0ad88d3b21d4c09a94b10ead1ff..1ad1fb094ea4a52167cdca4f8b07dfdadc6a6ada 100644 (file)
--- 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 (file)
index 0000000..fd1e320
--- /dev/null
+++ b/libust/lttng-context-vtid.c
@@ -0,0 +1,84 @@
+/*
+ * (C) Copyright       2009-2011 -
+ *             Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng UST vtid context.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <ust/lttng-events.h>
+#include <ust/lttng-tracer.h>
+#include <ust/ringbuffer-config.h>
+
+#ifdef __linux__
+#include <syscall.h>
+#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 924b7afaea342684d4510f2f121214a91addc709..35c93c91b5e1b64bb088e3f601853b3353896170 100644 (file)
--- 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 d0ba4137d9899ed760194e749b94626fc8d022b1..d200b4f98f50566eb4bc031d0d749f73e3705cad 100644 (file)
--- 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;