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#ifndef _PRINT_C_ /* -*- linux-c -*- */
#define _PRINT_C_
#include <linux/config.h>
#include "io.c"
/** @file print.c
* @addtogroup print Print Buffer
* Print Buffer Functions.
* The print buffer is for collecting output to send to the user daemon.
* This is a per-cpu static buffer. The buffer is sent when
* _stp_print_flush() is called.
*
* The reason to do this is to allow multiple small prints to be combined then
* timestamped and sent together to stpd. It could flush automatically on newlines,
* but what about stack traces which span many lines? So try this and see how it works for us.
* @{
*/
/** Size of buffer, not including terminating NULL */
#define STP_PRINT_BUF_LEN 8000
static int _stp_pbuf_len[NR_CPUS];
/* size of timestamp, in bytes, including space */
#define TIMESTAMP_SIZE 19
#define STP_PRINT_BUF_START (TIMESTAMP_SIZE + 1)
static char _stp_pbuf[NR_CPUS][STP_PRINT_BUF_LEN + STP_PRINT_BUF_START + 1];
/** Send the print buffer now.
* Output accumulates in the print buffer until this is called.
* Size is limited by length of print buffer, #STP_PRINT_BUF_LEN.
*/
void _stp_print_flush (void)
{
int cpu = smp_processor_id();
char *buf = &_stp_pbuf[cpu][0];
char *ptr = buf + STP_PRINT_BUF_START;
struct timeval tv;
if (_stp_pbuf_len[cpu] == 0)
return;
/* enforce newline at end */
if (ptr[_stp_pbuf_len[cpu]-1] != '\n') {
ptr[_stp_pbuf_len[cpu]++] = '\n';
ptr[_stp_pbuf_len[cpu]] = '\0';
}
do_gettimeofday(&tv);
scnprintf (buf, TIMESTAMP_SIZE+1, "[%li.%06li] ", tv.tv_sec, tv.tv_usec);
buf[TIMESTAMP_SIZE] = ' ';
_stp_transport_write(t, buf, _stp_pbuf_len[cpu] + TIMESTAMP_SIZE + 2);
_stp_pbuf_len[cpu] = 0;
}
/** Print into the print buffer.
* Like printf, except output goes to the print buffer.
* Safe because overflowing the buffer is not allowed.
* Size is limited by length of print buffer, #STP_PRINT_BUF_LEN.
*
* @param fmt A printf-style format string followed by a
* variable number of args.
* @sa _stp_print_flush()
*/
void _stp_printf (const char *fmt, ...)
{
int num;
va_list args;
int cpu = smp_processor_id();
char *buf = &_stp_pbuf[cpu][STP_PRINT_BUF_START] + _stp_pbuf_len[cpu];
va_start(args, fmt);
num = vscnprintf(buf, STP_PRINT_BUF_LEN - _stp_pbuf_len[cpu], fmt, args);
va_end(args);
if (num > 0)
_stp_pbuf_len[cpu] += num;
}
/** Print into the print buffer.
* Use this if your function already has a va_list.
* You probably want _stp_printf().
*/
void _stp_vprintf (const char *fmt, va_list args)
{
int num;
int cpu = smp_processor_id();
char *buf = &_stp_pbuf[cpu][STP_PRINT_BUF_START] + _stp_pbuf_len[cpu];
num = vscnprintf(buf, STP_PRINT_BUF_LEN -_stp_pbuf_len[cpu], fmt, args);
if (num > 0)
_stp_pbuf_len[cpu] += num;
}
/** Write a C string into the print buffer.
* Copies a string into a print buffer.
* Safe because overflowing the buffer is not allowed.
* Size is limited by length of print buffer, #STP_PRINT_BUF_LEN.
* This is more efficient than using _stp_printf() if you don't
* need fancy formatting.
*
* @param str A C string.
* @sa _stp_print
*/
void _stp_print_cstr (const char *str)
{
int cpu = smp_processor_id();
char *buf = &_stp_pbuf[cpu][STP_PRINT_BUF_START] + _stp_pbuf_len[cpu];
int num = strlen (str);
if (num > STP_PRINT_BUF_LEN - _stp_pbuf_len[cpu])
num = STP_PRINT_BUF_LEN - _stp_pbuf_len[cpu];
strncpy (buf, str, num+1);
_stp_pbuf_len[cpu] += num;
}
/** Clear the scratch buffer.
* This function should be called before anything is written to
* the scratch buffer. Output will accumulate in the buffer
* until this function is called again.
* @returns A pointer to the buffer.
*/
char *_stp_print_clear (void)
{
int cpu = smp_processor_id();
_stp_pbuf_len[cpu] = 0;
return &_stp_pbuf[cpu][STP_PRINT_BUF_START];
}
#include "string.c"
/** Write a String into the print buffer.
* Copies a String into a print buffer.
* Safe because overflowing the buffer is not allowed.
* Size is limited by length of print buffer, #STP_PRINT_BUF_LEN.
* This is more efficient than using _stp_printf() if you don't
* need fancy formatting.
*
* @param str A String.
* @sa _stp_print
*/
void _stp_print_string (String str)
{
if (str->len)
_stp_print_cstr (str->buf);
}
/** Write a String or C string into the print buffer.
* This macro selects the proper function to call.
* @param str A String or C string (char *)
* @sa _stp_print_cstr _stp_print_string
*/
#define _stp_print(str) \
({ \
if (__builtin_types_compatible_p (typeof (str), char[])) { \
char *x = (char *)str; \
_stp_print_cstr(x); \
} else { \
String x = (String)str; \
_stp_print_string(x); \
} \
})
/** @} */
#endif /* _PRINT_C_ */
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