Add -ust to the name of UST threads of the application

Add the required functions to change the thread name of the UST
threads and add the -ust string at its end. This will help to
identify LTTng-UST processes when analyzing the trace of a process.

Signed-off-by: Raphaël Beamonte <raphael.beamonte@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/configure.ac b/configure.ac
index 569255300a2d99a207bf89d94488a8d8a174355f..de462ffcc67f329a89752737d2fde0934d2fc012 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -135,6 +135,11 @@ AM_CONDITIONAL([LTTNG_UST_BUILD_WITH_LIBDL], [test "x$have_libdl" = "xyes"])
 AM_CONDITIONAL([LTTNG_UST_BUILD_WITH_LIBC_DL], [test "x$have_libc_dl" = "xyes"])
 
 AC_CHECK_LIB([pthread], [pthread_create])
+AC_CHECK_LIB([pthread], [pthread_setname_np],
+       AC_DEFINE([HAVE_PTHREAD_SETNAME_NP], [1], [Define to 1 if pthread_setname_np is available.]),
+       AC_CHECK_LIB([pthread], [pthread_set_name_np],
+               AC_DEFINE([HAVE_PTHREAD_SET_NAME_NP], [1], [Define to 1 if pthread_set_name_np is available.]),
+               AC_MSG_RESULT([pthread setname/set_name not found.])))
 
 # Check for dlfcn.h
 AC_CHECK_HEADER([dlfcn.h])

diff --git a/liblttng-ust/Makefile.am b/liblttng-ust/Makefile.am
index f1801cf59e17f2cedbe9b4a09f65a55e724e9084..05929be71f61640bba27db03a53ac59d68ae2064 100644 (file)
--- a/liblttng-ust/Makefile.am
+++ b/liblttng-ust/Makefile.am
@@ -14,6 +14,7 @@ liblttng_ust_tracepoint_la_SOURCES = \
        error.h
 liblttng_ust_tracepoint_la_LIBADD = \
        -lurcu-bp \
+       -lpthread \
        $(top_builddir)/snprintf/libustsnprintf.la
 liblttng_ust_tracepoint_la_LDFLAGS = -no-undefined -version-info $(LTTNG_UST_LIBRARY_VERSION)
 liblttng_ust_tracepoint_la_CFLAGS = -DUST_COMPONENT="liblttng_ust_tracepoint" -fno-strict-aliasing

diff --git a/liblttng-ust/compat.h b/liblttng-ust/compat.h
index 43b2223e43b84ad5c5dc373a8c327eb365fd32f4..de5e64775004dfefb87fb7e1210016b855eabb88 100644 (file)
--- a/liblttng-ust/compat.h
+++ b/liblttng-ust/compat.h
@@ -3,6 +3,7 @@
 
 /*
  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2016 Raphaël Beamonte <raphael.beamonte@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -34,7 +35,19 @@ void lttng_ust_getprocname(char *name)
        (void) prctl(PR_GET_NAME, (unsigned long) name, 0, 0, 0);
 }
 
+/*
+ * If pthread_setname_np is available.
+ */
+#ifdef HAVE_PTHREAD_SETNAME_NP
+static inline
+int lttng_pthread_setname_np(pthread_t thread, const char *name)
+{
+       return pthread_setname_np(thread, name);
+}
+#endif
+
 #elif defined(__FreeBSD__)
+
 #include <stdlib.h>
 #include <string.h>
 
@@ -59,6 +72,59 @@ void lttng_ust_getprocname(char *name)
                strncpy(name, bsd_name, LTTNG_UST_PROCNAME_LEN - 1);
 }
 
+/*
+ * If pthread_set_name_np is available.
+ */
+#ifdef HAVE_PTHREAD_SET_NAME_NP
+static inline
+int lttng_pthread_setname_np(pthread_t thread, const char *name)
+{
+       return pthread_set_name_np(thread, name);
+}
+#endif
+
+#endif
+
+/*
+ * If a pthread setname/set_name function is available, declare
+ * the setustprocname() function that will add '-ust' to the end
+ * of the current process name, while truncating it if needed.
+ */
+#if defined(HAVE_PTHREAD_SETNAME_NP) || defined(HAVE_PTHREAD_SETNAME_NP)
+#define LTTNG_UST_PROCNAME_SUFFIX "-ust"
+
+#include <pthread.h>
+
+static inline
+int lttng_ust_setustprocname(void)
+{
+       int ret = 0, len;
+       char name[LTTNG_UST_PROCNAME_LEN];
+       int limit = LTTNG_UST_PROCNAME_LEN - strlen(LTTNG_UST_PROCNAME_SUFFIX);
+
+       lttng_ust_getprocname(name);
+
+       len = strlen(name);
+       if (len > limit) {
+               len = limit;
+       }
+
+       ret = sprintf(name + len, LTTNG_UST_PROCNAME_SUFFIX);
+       if (ret) {
+               goto error;
+       }
+
+       ret = lttng_pthread_setname_np(pthread_self(), name);
+
+error:
+       return ret;
+}
+#else
+static inline
+int lttng_ust_setustprocname(void)
+{
+       return 0;
+}
 #endif
 
 #include <errno.h>

diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c
index e00a22ce4cae66dd7161111ba5de342dea7267b5..6105403a25d032b618df9c6202644ff138a0a034 100644 (file)
--- a/liblttng-ust/lttng-ust-comm.c
+++ b/liblttng-ust/lttng-ust-comm.c
@@ -1295,6 +1295,15 @@ void *ust_listener_thread(void *arg)
        int sock, ret, prev_connect_failed = 0, has_waited = 0;
        long timeout;
 
+       /*
+        * If available, add '-ust' to the end of this thread's
+        * process name
+        */
+       ret = lttng_ust_setustprocname();
+       if (ret) {
+               ERR("Unable to set UST process name");
+       }
+
        /* Restart trying to connect to the session daemon */
 restart:
        if (prev_connect_failed) {