2 * SPDX-License-Identifier: LGPL-2.1-only
4 * Copyright (C) 2009 Pierre-Marc Fournier
5 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 #ifndef _UST_COMMON_LOGGING_H
9 #define _UST_COMMON_LOGGING_H
12 #include <sys/types.h>
18 #include <lttng/ust-utils.h>
19 #include <urcu/compiler.h>
20 #include <urcu/system.h>
22 #include "common/patient.h"
23 #include "common/compat/tid.h"
24 #include "common/safe-snprintf.h"
26 enum lttng_ust_log_level
{
27 LTTNG_UST_LOG_LEVEL_UNKNOWN
= 0,
28 LTTNG_UST_LOG_LEVEL_SILENT
,
29 LTTNG_UST_LOG_LEVEL_DEBUG
,
32 enum lttng_ust_log_critical_action
{
33 LTTNG_UST_LOG_CRITICAL_ACTION_UNKNOWN
= 0,
34 LTTNG_UST_LOG_CRITICAL_ACTION_NONE
,
35 LTTNG_UST_LOG_CRITICAL_ACTION_ABORT
,
38 extern int lttng_ust_log_level
/* enum lttng_ust_log_level */
39 __attribute__((visibility("hidden")));
41 extern int lttng_ust_log_critical_action
/* enum lttng_ust_log_critical_action */
42 __attribute__((visibility("hidden")));
45 * Initialize the global log level from the "LTTNG_UST_DEBUG" environment
46 * variable and the global log critical action from "LTTNG_UST_ABORT_ON_CRITICAL".
48 * This could end up being called concurrently by multiple threads but doesn't
49 * require a mutex since the input is invariant across threads and the result
52 void lttng_ust_logging_init(void)
53 __attribute__((visibility("hidden")));
55 #ifdef LTTNG_UST_DEBUG
57 bool lttng_ust_logging_debug_enabled(void)
61 #else /* #ifdef LTTNG_UST_DEBUG */
63 bool lttng_ust_logging_debug_enabled(void)
65 int current_log_level
;
67 current_log_level
= CMM_LOAD_SHARED(lttng_ust_log_level
);
69 /* If the global log level is unknown, lazy-initialize it. */
70 if (caa_unlikely(current_log_level
== LTTNG_UST_LOG_LEVEL_UNKNOWN
)) {
71 lttng_ust_logging_init();
72 current_log_level
= CMM_LOAD_SHARED(lttng_ust_log_level
);
75 return current_log_level
== LTTNG_UST_LOG_LEVEL_DEBUG
;
77 #endif /* #ifdef LTTNG_UST_DEBUG */
79 #ifdef LTTNG_UST_ABORT_ON_CRITICAL
81 bool lttng_ust_logging_abort_on_critical_enabled(void)
85 #else /* #ifdef LTTNG_UST_ABORT_ON_CRITICAL */
87 bool lttng_ust_logging_abort_on_critical_enabled(void)
89 int current_log_critical_action
;
91 current_log_critical_action
= CMM_LOAD_SHARED(lttng_ust_log_critical_action
);
93 /* If the global log critical action is unknown, lazy-initialize it. */
94 if (caa_unlikely(current_log_critical_action
== LTTNG_UST_LOG_CRITICAL_ACTION_UNKNOWN
)) {
95 lttng_ust_logging_init();
96 current_log_critical_action
= CMM_LOAD_SHARED(lttng_ust_log_critical_action
);
99 return current_log_critical_action
== LTTNG_UST_LOG_CRITICAL_ACTION_ABORT
;
101 #endif /* #ifdef LTTNG_UST_ABORT_ON_CRITICAL */
104 * The default component for log statements.
106 #ifndef UST_COMPONENT
107 #define UST_COMPONENT libust
110 #define LTTNG_UST_LOG_MAX_LEN 512
113 * We sometimes print in the tracing path, and tracing can occur in
114 * signal handlers, so we must use a print method which is signal safe.
116 /* Can't use dynamic allocation. Limit ourselves to LTTNG_UST_LOG_MAX_LEN chars. */
117 /* Add end of string in case of buffer overflow. */
118 #define sigsafe_print_err(fmt, args...) \
120 if (lttng_ust_logging_debug_enabled()) { \
121 char ____buf[LTTNG_UST_LOG_MAX_LEN]; \
122 int ____saved_errno; \
124 ____saved_errno = errno; /* signal-safety */ \
125 ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
126 ____buf[sizeof(____buf) - 1] = 0; \
127 ust_patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
128 errno = ____saved_errno; /* signal-safety */ \
133 #define LTTNG_UST_STR_COMPONENT lttng_ust_stringify(UST_COMPONENT)
135 #define ERRMSG(fmt, args...) \
137 sigsafe_print_err(LTTNG_UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" lttng_ust_stringify(__LINE__) ")\n", \
139 (long) lttng_gettid(), \
140 ## args, __func__); \
144 #define DBG(fmt, args...) ERRMSG(fmt, ## args)
145 #define DBG_raw(fmt, args...) sigsafe_print_err(fmt, ## args)
146 #define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
147 #define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
148 #define CRIT(fmt, args...) \
150 ERRMSG("Critical: " fmt, ## args); \
151 if (lttng_ust_logging_abort_on_critical_enabled()) { \
156 #if !defined(__GLIBC__) || ((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
158 * Version using XSI strerror_r.
160 #define PERROR(call, args...) \
162 if (lttng_ust_logging_debug_enabled()) { \
163 char perror_buf[200] = "Error in strerror_r()"; \
164 strerror_r(errno, perror_buf, \
165 sizeof(perror_buf)); \
166 ERRMSG("Error: " call ": %s", ## args, \
172 * Version using GNU strerror_r, for linux with appropriate defines.
174 #define PERROR(call, args...) \
176 if (lttng_ust_logging_debug_enabled()) { \
178 char perror_tmp[200]; \
179 perror_buf = strerror_r(errno, perror_tmp, \
180 sizeof(perror_tmp)); \
181 ERRMSG("Error: " call ": %s", ## args, \
187 #define BUG_ON(condition) \
189 if (caa_unlikely(condition)) \
190 ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
192 #define WARN_ON(condition) \
194 if (caa_unlikely(condition)) \
195 WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
197 #define WARN_ON_ONCE(condition) WARN_ON(condition)
199 #endif /* _UST_COMMON_LOGGING_H */