X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=include%2Flttng%2Fusterr-signal-safe.h;fp=include%2Flttng%2Fusterr-signal-safe.h;h=894149a3464056e5c13ab22a1874649ab96d8b10;hb=4318ae1be57eb7983ab4857a7a8eeb4a030a8216;hp=0000000000000000000000000000000000000000;hpb=d4419b81b243bc3a6bdd4a09b3ca2216d044a1c7;p=ust.git

diff --git a/include/lttng/usterr-signal-safe.h b/include/lttng/usterr-signal-safe.h
new file mode 100644
index 0000000..894149a
--- /dev/null
+++ b/include/lttng/usterr-signal-safe.h
@@ -0,0 +1,159 @@
+#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; 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 <string.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include <lttng/core.h>
+#include <lttng/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
+#endif
+
+/* To stringify the expansion of a define */
+#define UST_XSTR(d) UST_STR(d)
+#define UST_STR(s) #s
+
+#define USTERR_MAX_LEN	512
+
+/* We sometimes print in the tracing path, and tracing can occur in
+ * signal handlers, so we must use a print method which is signal safe.
+ */
+
+extern int ust_safe_snprintf(char *str, size_t n, const char *fmt, ...)
+	__attribute__ ((format (printf, 3, 4)));
+
+static inline void __attribute__ ((format (printf, 1, 2)))
+	__check_ust_safe_fmt(const char *fmt, ...)
+{
+}
+
+#define sigsafe_print_err(fmt, args...)					\
+{									\
+	/* Can't use dynamic allocation. Limit ourselves to USTERR_MAX_LEN chars. */ \
+	char ____buf[USTERR_MAX_LEN];					\
+	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 UST_XSTR(UST_COMPONENT)
+
+#define ERRMSG(fmt, args...)			\
+	do {					\
+		sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_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)
+#else
+# 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)
+#define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
+
+#if (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)
+#define PERROR(call, args...)\
+	do { \
+		char buf[200] = "Error in strerror_r()"; \
+		strerror_r(errno, buf, sizeof(buf)); \
+		ERRMSG("Error: " call ": %s", ## args, buf); \
+	} while(0);
+#else
+#define PERROR(call, args...)\
+	do { \
+		char *buf; \
+		char tmp[200]; \
+		buf = strerror_r(errno, tmp, sizeof(tmp)); \
+		ERRMSG("Error: " call ": %s", ## args, buf); \
+	} while(0);
+#endif
+
+#define BUG_ON(condition)					\
+	do {							\
+		if (caa_unlikely(condition))			\
+			ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__);	\
+	} while(0)
+#define WARN_ON(condition)					\
+	do {							\
+		if (caa_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 */