1
0
mirror of https://github.com/git/git synced 2024-07-02 15:48:44 +00:00
git/trace.h

95 lines
2.7 KiB
C
Raw Normal View History

#ifndef TRACE_H
#define TRACE_H
#include "git-compat-util.h"
#include "strbuf.h"
struct trace_key {
const char * const key;
int fd;
unsigned int initialized : 1;
unsigned int need_close : 1;
};
#define TRACE_KEY_INIT(name) { "GIT_TRACE_" #name, 0, 0, 0 }
extern void trace_repo_setup(const char *prefix);
extern int trace_want(struct trace_key *key);
extern void trace_disable(struct trace_key *key);
trace: add high resolution timer function to debug performance issues Add a getnanotime() function that returns nanoseconds since 01/01/1970 as unsigned 64-bit integer (i.e. overflows in july 2554). This is easier to work with than e.g. struct timeval or struct timespec. Basing the timer on the epoch allows using the results with other time-related APIs. To simplify adaption to different platforms, split the implementation into a common getnanotime() and a platform-specific highres_nanos() function. The common getnanotime() function handles errors, falling back to gettimeofday() if highres_nanos() isn't implemented or doesn't work. getnanotime() is also responsible for normalizing to the epoch. The offset to the system clock is calculated only once on initialization, i.e. manually setting the system clock has no impact on the timer (except if the fallback gettimeofday() is in use). Git processes are typically short lived, so we don't need to handle clock drift. The highres_nanos() function returns monotonically increasing nanoseconds relative to some arbitrary point in time (e.g. system boot), or 0 on failure. Providing platform-specific implementations should be relatively easy, e.g. adapting to clock_gettime() as defined by the POSIX realtime extensions is seven lines of code. This version includes highres_nanos() implementations for: * Linux: using clock_gettime(CLOCK_MONOTONIC) * Windows: using QueryPerformanceCounter() Todo: * enable clock_gettime() on more platforms * add Mac OSX version, e.g. using mach_absolute_time + mach_timebase_info Signed-off-by: Karsten Blees <blees@dcon.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-07-12 00:05:42 +00:00
extern uint64_t getnanotime(void);
#ifndef HAVE_VARIADIC_MACROS
__attribute__((format (printf, 1, 2)))
extern void trace_printf(const char *format, ...);
__attribute__((format (printf, 2, 3)))
extern void trace_printf_key(struct trace_key *key, const char *format, ...);
__attribute__((format (printf, 2, 3)))
extern void trace_argv_printf(const char **argv, const char *format, ...);
extern void trace_strbuf(struct trace_key *key, const struct strbuf *data);
#else
/*
* Macros to add file:line - see above for C-style declarations of how these
* should be used.
*/
/*
* TRACE_CONTEXT may be set to __FUNCTION__ if the compiler supports it. The
* default is __FILE__, as it is consistent with assert(), and static function
* names are not necessarily unique.
*
* __FILE__ ":" __FUNCTION__ doesn't work with GNUC, as __FILE__ is supplied
* by the preprocessor as a string literal, and __FUNCTION__ is filled in by
* the compiler as a string constant.
*/
#ifndef TRACE_CONTEXT
# define TRACE_CONTEXT __FILE__
#endif
/*
* Note: with C99 variadic macros, __VA_ARGS__ must include the last fixed
* parameter ('format' in this case). Otherwise, a call without variable
* arguments will have a surplus ','. E.g.:
*
* #define foo(format, ...) bar(format, __VA_ARGS__)
* foo("test");
*
* will expand to
*
* bar("test",);
*
* which is invalid (note the ',)'). With GNUC, '##__VA_ARGS__' drops the
* comma, but this is non-standard.
*/
#define trace_printf(...) \
trace_printf_key_fl(TRACE_CONTEXT, __LINE__, NULL, __VA_ARGS__)
#define trace_printf_key(key, ...) \
trace_printf_key_fl(TRACE_CONTEXT, __LINE__, key, __VA_ARGS__)
#define trace_argv_printf(argv, ...) \
trace_argv_printf_fl(TRACE_CONTEXT, __LINE__, argv, __VA_ARGS__)
#define trace_strbuf(key, data) \
trace_strbuf_fl(TRACE_CONTEXT, __LINE__, key, data)
/* backend functions, use non-*fl macros instead */
__attribute__((format (printf, 4, 5)))
extern void trace_printf_key_fl(const char *file, int line, struct trace_key *key,
const char *format, ...);
__attribute__((format (printf, 4, 5)))
extern void trace_argv_printf_fl(const char *file, int line, const char **argv,
const char *format, ...);
extern void trace_strbuf_fl(const char *file, int line, struct trace_key *key,
const struct strbuf *data);
#endif /* HAVE_VARIADIC_MACROS */
#endif /* TRACE_H */