server-skynet-source-3rd-je.../include/jemalloc/internal/log.h
Kevin Svetlitski 3e2ba7a651 Remove dead stores detected by static analysis
None of these are harmful, and they are almost certainly optimized
away by the compiler. The motivation for fixing them anyway is that
we'd like to enable static analysis as part of CI, and the first step
towards that is resolving the warnings it produces at present.
2023-05-11 20:27:49 -07:00

115 lines
3.6 KiB
C

#ifndef JEMALLOC_INTERNAL_LOG_H
#define JEMALLOC_INTERNAL_LOG_H
#include "jemalloc/internal/atomic.h"
#include "jemalloc/internal/malloc_io.h"
#include "jemalloc/internal/mutex.h"
#ifdef JEMALLOC_LOG
# define JEMALLOC_LOG_VAR_BUFSIZE 1000
#else
# define JEMALLOC_LOG_VAR_BUFSIZE 1
#endif
#define JEMALLOC_LOG_BUFSIZE 4096
/*
* The log malloc_conf option is a '|'-delimited list of log_var name segments
* which should be logged. The names are themselves hierarchical, with '.' as
* the delimiter (a "segment" is just a prefix in the log namespace). So, if
* you have:
*
* log("arena", "log msg for arena"); // 1
* log("arena.a", "log msg for arena.a"); // 2
* log("arena.b", "log msg for arena.b"); // 3
* log("arena.a.a", "log msg for arena.a.a"); // 4
* log("extent.a", "log msg for extent.a"); // 5
* log("extent.b", "log msg for extent.b"); // 6
*
* And your malloc_conf option is "log=arena.a|extent", then lines 2, 4, 5, and
* 6 will print at runtime. You can enable logging from all log vars by
* writing "log=.".
*
* None of this should be regarded as a stable API for right now. It's intended
* as a debugging interface, to let us keep around some of our printf-debugging
* statements.
*/
extern char log_var_names[JEMALLOC_LOG_VAR_BUFSIZE];
extern atomic_b_t log_init_done;
typedef struct log_var_s log_var_t;
struct log_var_s {
/*
* Lowest bit is "inited", second lowest is "enabled". Putting them in
* a single word lets us avoid any fences on weak architectures.
*/
atomic_u_t state;
const char *name;
};
#define LOG_NOT_INITIALIZED 0U
#define LOG_INITIALIZED_NOT_ENABLED 1U
#define LOG_ENABLED 2U
#define LOG_VAR_INIT(name_str) {ATOMIC_INIT(LOG_NOT_INITIALIZED), name_str}
/*
* Returns the value we should assume for state (which is not necessarily
* accurate; if logging is done before logging has finished initializing, then
* we default to doing the safe thing by logging everything).
*/
unsigned log_var_update_state(log_var_t *log_var);
/* We factor out the metadata management to allow us to test more easily. */
#define log_do_begin(log_var) \
if (config_log) { \
unsigned log_state = atomic_load_u(&(log_var).state, \
ATOMIC_RELAXED); \
if (unlikely(log_state == LOG_NOT_INITIALIZED)) { \
log_state = log_var_update_state(&(log_var)); \
assert(log_state != LOG_NOT_INITIALIZED); \
} \
if (log_state == LOG_ENABLED) { \
{
/* User code executes here. */
#define log_do_end(log_var) \
} \
} \
}
/*
* MSVC has some preprocessor bugs in its expansion of __VA_ARGS__ during
* preprocessing. To work around this, we take all potential extra arguments in
* a var-args functions. Since a varargs macro needs at least one argument in
* the "...", we accept the format string there, and require that the first
* argument in this "..." is a const char *.
*/
static inline void
log_impl_varargs(const char *name, ...) {
char buf[JEMALLOC_LOG_BUFSIZE];
va_list ap;
va_start(ap, name);
const char *format = va_arg(ap, const char *);
size_t dst_offset = 0;
dst_offset += malloc_snprintf(buf, JEMALLOC_LOG_BUFSIZE, "%s: ", name);
dst_offset += malloc_vsnprintf(buf + dst_offset,
JEMALLOC_LOG_BUFSIZE - dst_offset, format, ap);
malloc_snprintf(buf + dst_offset, JEMALLOC_LOG_BUFSIZE - dst_offset, "\n");
va_end(ap);
malloc_write(buf);
}
/* Call as log("log.var.str", "format_string %d", arg_for_format_string); */
#define LOG(log_var_str, ...) \
do { \
static log_var_t log_var = LOG_VAR_INIT(log_var_str); \
log_do_begin(log_var) \
log_impl_varargs((log_var).name, __VA_ARGS__); \
log_do_end(log_var) \
} while (0)
#endif /* JEMALLOC_INTERNAL_LOG_H */