Add UST_DEBUG env. var. support
authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Tue, 9 Aug 2011 13:46:51 +0000 (09:46 -0400)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Tue, 9 Aug 2011 13:46:51 +0000 (09:46 -0400)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
README
include/usterr.h
include/usterr_signal_safe.h
libust/Makefile.am
libust/buffers.c
libust/lttng-ust-abi.c
libust/tracepoint.c
libust/ust-core.c [new file with mode: 0644]

diff --git a/README b/README
index a2d115b19c52eb0ebc40a754b80c3a5cd5bbb853..3d7e18e3de27f59a124de7ecbf0a9d4f64f5ec9c 100644 (file)
--- a/README
+++ b/README
@@ -38,6 +38,19 @@ INSTALLATION INSTRUCTIONS:
   the configure script, to generate it.
 
 
+USAGE:
+
+  - Create an instrumentation header following the tracepoint examples.
+    (see tracepoint.h and tests/hello/tp.h).
+  - Link application with -lust.
+  - (TODO: start tracing with the "lttng" command from lttng-tools)
+
+  Note: libust debug can be activated by either of the following means:
+    - Setting the environment variable "UST_DEBUG" when launching the
+      application.
+    - Compiling libust with -DUST_DEBUG.
+
+
 TRACE VIEWER:
 
   LTTV is used for viewing UST traces. LTTV may be obtained at
index dc51d840b42879d6e8f11e1f7567a9f05dc2edad..cab65407dca9c0c5740e038008b884d9480ac3d3 100644 (file)
@@ -1,9 +1,14 @@
-/* Copyright (C) 2009  Pierre-Marc Fournier
+#ifndef _USTERR_H
+#define _USTERR_H
+
+/*
+ * Copyright (C) 2009  Pierre-Marc Fournier
+ * Copyright (C) 2011  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
+ * License as published by the Free Software Foundation; version 2.1 of
+ * the License.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -15,9 +20,6 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
-#ifndef _USTERR_H
-#define _USTERR_H
-
 #include <string.h>
 #include <sys/types.h>
 #include <sys/syscall.h>
 
 #include "share.h"
 
+enum ust_loglevel {
+       UST_LOGLEVEL_UNKNOWN = 0,
+       UST_LOGLEVEL_NORMAL,
+       UST_LOGLEVEL_DEBUG,
+};
+
+extern volatile enum ust_loglevel ust_loglevel;
+void init_usterr(void);
+
+static inline int ust_debug(void)
+{
+       return ust_loglevel == UST_LOGLEVEL_DEBUG;
+}
+
 #ifndef UST_COMPONENT
 #define UST_COMPONENT libust
 #endif
 #define XSTR(d) STR(d)
 #define STR(s) #s
 
-/* A dummy function to force format checking */
-static inline void __attribute__ ((format (printf, 1, 2)))
-       __check_ust_safe_fmt(const char *fmt, ...)
-{
-}
-
 #define UST_STR_COMPONENT XSTR(UST_COMPONENT)
 
-#define ERRMSG(fmt, args...) do { fprintf(stderr, UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" XSTR(__LINE__) ")\n", (long) getpid(), (long) syscall(SYS_gettid), ## args, __func__); } while(0)
+#define ERRMSG(fmt, args...)                                   \
+       do {                                                    \
+               fprintf(stderr, UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" XSTR(__LINE__) ")\n",                          \
+                       (long) getpid(),                        \
+                       (long) syscall(SYS_gettid),             \
+                       ## args,                                \
+                       __func__);                              \
+       } while(0)
 
 #ifdef UST_DEBUG
-# define DBG(fmt, args...) ERRMSG(fmt, ## args)
-# define DBG_raw(fmt, args...) do { fprintf(stderr, fmt, ## args); } while(0)
+# define DBG(fmt, args...)             ERRMSG(fmt, ## args)
+# define DBG_raw(fmt, args...)                                 \
+       do {                                                    \
+                fprintf(stderr, fmt, ## args);                 \
+       } while(0)
 #else
-# define DBG(fmt, args...) __check_ust_safe_fmt(fmt, ## args)
-# define DBG_raw(fmt, args...) __check_ust_safe_fmt(fmt, ## args)
+# define DBG(fmt, args...)                                     \
+       do {                                                    \
+               if (ust_debug())                                \
+                       ERRMSG(fmt, ## args);                   \
+       } while (0)
+# define DBG_raw(fmt, args...)                                 \
+       do {                                                    \
+               if (ust_debug()) {                              \
+                       fprintf(stderr, fmt, ## args);          \
+               }                                               \
+       } while(0)
 #endif
+
 #define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
 #define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
 #define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
@@ -75,8 +105,16 @@ static inline void __attribute__ ((format (printf, 1, 2)))
        } while(0);
 #endif
 
-#define BUG_ON(condition) do { if (unlikely(condition)) ERR("condition not respected (BUG)"); } while(0)
-#define WARN_ON(condition) do { if (unlikely(condition)) WARN("condition not respected on line %s:%d", __FILE__, __LINE__); } while(0)
+#define BUG_ON(condition)                                      \
+       do {                                                    \
+               if (unlikely(condition))                        \
+                       ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
+       } while(0)
+#define WARN_ON(condition)                                     \
+       do {                                                    \
+               if (unlikely(condition))                        \
+                       WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
+       } while(0)
 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 
 #endif /* _USTERR_H */
index 10355dcba849aac3682d162fcdf1051dccdc5da1..77f9d5fc5f69d2db333426e0f41ecc1188f5ed6e 100644 (file)
@@ -1,9 +1,14 @@
-/* Copyright (C) 2009  Pierre-Marc Fournier
+#ifndef _USTERR_SIGNAL_SAFE_H
+#define _USTERR_SIGNAL_SAFE_H
+
+/*
+ * Copyright (C) 2009  Pierre-Marc Fournier
+ * Copyright (C) 2011  Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
+ * License as published by the Free Software Foundation; version 2.1 of
+ * the License.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -15,9 +20,6 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
-#ifndef _USTERR_SIGNAL_SAFE_H
-#define _USTERR_SIGNAL_SAFE_H
-
 #include <string.h>
 #include <sys/types.h>
 #include <sys/syscall.h>
 
 #include "share.h"
 
+enum ust_loglevel {
+       UST_LOGLEVEL_UNKNOWN = 0,
+       UST_LOGLEVEL_NORMAL,
+       UST_LOGLEVEL_DEBUG,
+};
+
+extern volatile enum ust_loglevel ust_loglevel;
+void init_usterr(void);
+
+static inline int ust_debug(void)
+{
+       return ust_loglevel == UST_LOGLEVEL_DEBUG;
+}
+
 #ifndef UST_COMPONENT
 //#error UST_COMPONENT is undefined
 #define UST_COMPONENT libust
@@ -50,37 +66,61 @@ static inline void __attribute__ ((format (printf, 1, 2)))
 {
 }
 
-#define sigsafe_print_err(fmt, args...) \
-{ \
+#define sigsafe_print_err(fmt, args...)                                        \
+{                                                                      \
        /* Can't use dynamic allocation. Limit ourselves to 250 chars. */ \
-       char ____buf[250]; \
-       int ____saved_errno; \
-\
-       /* Save the errno. */ \
-       ____saved_errno = errno; \
-\
-       ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
-\
-       /* Add end of string in case of buffer overflow. */ \
-       ____buf[sizeof(____buf) - 1] = 0; \
-\
-       patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
-       /* Can't print errors because we are in the error printing code path. */ \
-\
-       /* Restore errno, in order to be async-signal safe. */ \
-       errno = ____saved_errno; \
+       char ____buf[250];                                              \
+       int ____saved_errno;                                            \
+                                                                       \
+       /* Save the errno. */                                           \
+       ____saved_errno = errno;                                        \
+                                                                       \
+       ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args);      \
+                                                                       \
+       /* Add end of string in case of buffer overflow. */             \
+       ____buf[sizeof(____buf) - 1] = 0;                               \
+                                                                       \
+       patient_write(STDERR_FILENO, ____buf, strlen(____buf));         \
+       /*                                                              \
+        * Can't print errors because we are in the error printing code \
+        * path.                                                        \
+        */                                                             \
+                                                                       \
+       /* Restore errno, in order to be async-signal safe. */          \
+       errno = ____saved_errno;                                        \
 }
 
 #define UST_STR_COMPONENT XSTR(UST_COMPONENT)
 
-#define ERRMSG(fmt, args...) do { sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" XSTR(__LINE__) ")\n", (long) getpid(), (long) syscall(SYS_gettid), ## args, __func__); fflush(stderr); } while(0)
+#define ERRMSG(fmt, args...)                   \
+       do {                                    \
+               sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" XSTR(__LINE__) ")\n",        \
+               (long) getpid(),                \
+               (long) syscall(SYS_gettid),     \
+               ## args, __func__);             \
+               fflush(stderr);                 \
+       } while(0)
 
 #ifdef UST_DEBUG
-# define DBG(fmt, args...) ERRMSG(fmt, ## args)
-# define DBG_raw(fmt, args...) do { sigsafe_print_err(fmt, ## args); fflush(stderr); } while(0)
+# define DBG(fmt, args...)                     ERRMSG(fmt, ## args)
+# define DBG_raw(fmt, args...)                                 \
+       do {                                                    \
+               sigsafe_print_err(fmt, ## args);                \
+               fflush(stderr);                                 \
+       } while(0)
 #else
-# define DBG(fmt, args...) __check_ust_safe_fmt(fmt, ## args)
-# define DBG_raw(fmt, args...) __check_ust_safe_fmt(fmt, ## args)
+# define DBG(fmt, args...)                                     \
+       do {                                                    \
+               if (ust_debug())                                \
+                       ERRMSG(fmt, ## args);                   \
+       } while (0)
+# define DBG_raw(fmt, args...)                                 \
+       do {                                                    \
+               if (ust_debug()) {                              \
+                       sigsafe_print_err(fmt, ## args);        \
+                       fflush(stderr);                         \
+               }                                               \
+       } while(0)
 #endif
 #define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
 #define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
@@ -103,8 +143,17 @@ static inline void __attribute__ ((format (printf, 1, 2)))
        } while(0);
 #endif
 
-#define BUG_ON(condition) do { if (unlikely(condition)) ERR("condition not respected (BUG)"); } while(0)
-#define WARN_ON(condition) do { if (unlikely(condition)) WARN("condition not respected on line %s:%d", __FILE__, __LINE__); } while(0)
+#define BUG_ON(condition)                                      \
+       do {                                                    \
+               if (unlikely(condition))                        \
+                       ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
+       } while(0)
+#define WARN_ON(condition)                                     \
+       do {                                                    \
+               if (unlikely(condition))                        \
+                       WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
+       } while(0)
 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 
+
 #endif /* _USTERR_SIGNAL_SAFE_H */
index 957565d0a5cb97f83668a544549a820edab1e1ff..0fa4a2b56a83f24e940cbc2c2e004c29be49ca7c 100644 (file)
@@ -16,7 +16,8 @@ libust_la_SOURCES = \
        ltt-context.c \
        ltt-probes.c \
        lttng-ust-abi.c \
-       lttng-ust-comm.c
+       lttng-ust-comm.c \
+       ust-core.c
 
 #removed: buffers.c buffers.h
 
index 9f06ae2d1b690cfdc08b67665aff1ddb86fde70b..c4eddb068cdb72d0ba4855b1eafcbd350c91913b 100644 (file)
@@ -1056,6 +1056,7 @@ static char initialized = 0;
 
 void __attribute__((constructor)) init_ustrelay_transport(void)
 {
+       init_usterr();
        if(!initialized) {
                ltt_transport_register(&ust_relay_transport);
                initialized = 1;
index 31eaa2a7cfc701b11a2f8ce6d2223cd43e707adb..ad582c055bb1f31e036612f8a45a9af60eaeffdc 100644 (file)
@@ -706,6 +706,7 @@ static const struct objd_ops lttng_event_ops = {
 
 void __attribute__((constructor)) lttng_ust_abi_init(void)
 {
+       init_usterr();
        /* TODO: initialize socket */
 }
 
index 3bc5795afc17ce2f811e69015ac338b62ecd5519..67619a85d8e36933af87d57035fb3671452fe406 100644 (file)
@@ -690,6 +690,7 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start)
 
 void __attribute__((constructor)) init_tracepoint(void)
 {
+       init_usterr();
        if (!initialized) {
                tracepoint_register_lib(__start___tracepoints_ptrs,
                        __stop___tracepoints_ptrs
diff --git a/libust/ust-core.c b/libust/ust-core.c
new file mode 100644 (file)
index 0000000..7791ffb
--- /dev/null
@@ -0,0 +1,37 @@
+/*
+ * ust-core.c
+ *
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <usterr_signal_safe.h>
+#include <stdlib.h>
+
+volatile enum ust_loglevel ust_loglevel;
+
+void init_usterr(void)
+{
+       char *ust_debug;
+
+       if (ust_loglevel == UST_LOGLEVEL_UNKNOWN) {
+               ust_debug = getenv("UST_DEBUG");
+               if (ust_debug)
+                       ust_loglevel = UST_LOGLEVEL_DEBUG;
+               else
+                       ust_loglevel = UST_LOGLEVEL_NORMAL;
+       }
+}
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