dt_subr.c

来自「Sun Solaris 10 中的 DTrace 组件的源代码。请参看: htt」· C语言 代码 · 共 729 行 · 第 1/2 页

			return (-1);
	}

	if (n[0] > DT_VERSION_MAJMAX ||
	    n[1] > DT_VERSION_MINMAX ||
	    n[2] > DT_VERSION_MICMAX)
		return (-1);

	if (vp != NULL)
		*vp = DT_VERSION_NUMBER(n[0], n[1], n[2]);

	return (0);
}

int
dt_version_defined(dt_version_t v)
{
	int i;

	for (i = 0; _dtrace_versions[i] != 0; i++) {
		if (_dtrace_versions[i] == v)
			return (1);
	}

	return (0);
}

char *
dt_cpp_add_arg(dtrace_hdl_t *dtp, const char *str)
{
	char *arg;

	if (dtp->dt_cpp_argc == dtp->dt_cpp_args) {
		int olds = dtp->dt_cpp_args;
		int news = olds * 2;
		char **argv = realloc(dtp->dt_cpp_argv, sizeof (char *) * news);

		if (argv == NULL)
			return (NULL);

		bzero(&argv[olds], sizeof (char *) * olds);
		dtp->dt_cpp_argv = argv;
		dtp->dt_cpp_args = news;
	}

	if ((arg = strdup(str)) == NULL)
		return (NULL);

	assert(dtp->dt_cpp_argc < dtp->dt_cpp_args);
	dtp->dt_cpp_argv[dtp->dt_cpp_argc++] = arg;
	return (arg);
}

char *
dt_cpp_pop_arg(dtrace_hdl_t *dtp)
{
	char *arg;

	if (dtp->dt_cpp_argc <= 1)
		return (NULL); /* dt_cpp_argv[0] cannot be popped */

	arg = dtp->dt_cpp_argv[--dtp->dt_cpp_argc];
	dtp->dt_cpp_argv[dtp->dt_cpp_argc] = NULL;

	return (arg);
}

/*PRINTFLIKE1*/
void
dt_dprintf(const char *format, ...)
{
	if (_dtrace_debug) {
		va_list alist;

		va_start(alist, format);
		(void) fputs("libdtrace DEBUG: ", stderr);
		(void) vfprintf(stderr, format, alist);
		va_end(alist);
	}
}

int
dt_ioctl(dtrace_hdl_t *dtp, int val, void *arg)
{
	const dtrace_vector_t *v = dtp->dt_vector;

	if (v == NULL)
		return (ioctl(dtp->dt_fd, val, arg));

	return (v->dtv_ioctl(dtp->dt_varg, val, arg));
}

int
dt_status(dtrace_hdl_t *dtp, processorid_t cpu)
{
	const dtrace_vector_t *v = dtp->dt_vector;

	if (v == NULL)
		return (p_online(cpu, P_STATUS));

	return (v->dtv_status(dtp->dt_varg, cpu));
}

long
dt_sysconf(dtrace_hdl_t *dtp, int name)
{
	const dtrace_vector_t *v = dtp->dt_vector;

	if (v == NULL)
		return (sysconf(name));

	return (v->dtv_sysconf(dtp->dt_varg, name));
}

/*
 * Wrapper around write(2) to handle partial writes.  For maximum safety of
 * output files and proper error reporting, we continuing writing in the
 * face of partial writes until write(2) fails or 'buf' is completely written.
 * We also record any errno in the specified dtrace_hdl_t as well as 'errno'.
 */
ssize_t
dt_write(dtrace_hdl_t *dtp, int fd, const void *buf, size_t n)
{
	ssize_t resid = n;
	ssize_t len;

	while (resid != 0) {
		if ((len = write(fd, buf, resid)) <= 0)
			break;

		resid -= len;
		buf = (char *)buf + len;
	}

	if (resid == n && n != 0)
		return (dt_set_errno(dtp, errno));

	return (n - resid);
}

/*
 * This function handles all output from libdtrace, as well as the
 * dtrace_sprintf() case.  If we're here due to dtrace_sprintf(), then
 * dt_sprintf_buflen will be non-zero; in this case, we sprintf into the
 * specified buffer and return.  Otherwise, if output is buffered (denoted by
 * a NULL fp), we sprintf the desired output into the buffered buffer
 * (expanding the buffer if required).  If we don't satisfy either of these
 * conditions (that is, if we are to actually generate output), then we call
 * fprintf with the specified fp.  In this case, we need to deal with one of
 * the more annoying peculiarities of libc's printf routines:  any failed
 * write persistently sets an error flag inside the FILE causing every
 * subsequent write to fail, but only the caller that initiated the error gets
 * the errno.  Since libdtrace clients often intercept SIGINT, this case is
 * particularly frustrating since we don't want the EINTR on one attempt to
 * write to the output file to preclude later attempts to write.  This
 * function therefore does a clearerr() if any error occurred, and saves the
 * errno for the caller inside the specified dtrace_hdl_t.
 */
/*PRINTFLIKE3*/
int
dt_printf(dtrace_hdl_t *dtp, FILE *fp, const char *format, ...)
{
	va_list ap;
	int n;

	va_start(ap, format);

	if (dtp->dt_sprintf_buflen != 0) {
		int len;
		char *buf;

		assert(dtp->dt_sprintf_buf != NULL);

		buf = &dtp->dt_sprintf_buf[len = strlen(dtp->dt_sprintf_buf)];
		len = dtp->dt_sprintf_buflen - len;
		assert(len >= 0);

		if ((n = vsnprintf(buf, len, format, ap)) < 0)
			n = dt_set_errno(dtp, errno);

		va_end(ap);

		return (n);
	}

	if (fp == NULL) {
		int needed, rval;
		size_t avail;

		/*
		 * It's not legal to use buffered ouput if there is not a
		 * handler for buffered output.
		 */
		if (dtp->dt_bufhdlr == NULL) {
			va_end(ap);
			return (dt_set_errno(dtp, EDT_NOBUFFERED));
		}

		if (dtp->dt_buffered_buf == NULL) {
			assert(dtp->dt_buffered_size == 0);
			dtp->dt_buffered_size = 1;
			dtp->dt_buffered_buf = malloc(dtp->dt_buffered_size);

			if (dtp->dt_buffered_buf == NULL) {
				va_end(ap);
				return (dt_set_errno(dtp, EDT_NOMEM));
			}

			dtp->dt_buffered_offs = 0;
			dtp->dt_buffered_buf[0] = '\0';
		}

		if ((needed = vsnprintf(NULL, 0, format, ap)) < 0) {
			rval = dt_set_errno(dtp, errno);
			va_end(ap);
			return (rval);
		}

		if (needed == 0) {
			va_end(ap);
			return (0);
		}

		for (;;) {
			char *newbuf;

			assert(dtp->dt_buffered_offs < dtp->dt_buffered_size);
			avail = dtp->dt_buffered_size - dtp->dt_buffered_offs;

			if (needed + 1 < avail)
				break;

			if ((newbuf = realloc(dtp->dt_buffered_buf,
			    dtp->dt_buffered_size << 1)) == NULL) {
				va_end(ap);
				return (dt_set_errno(dtp, EDT_NOMEM));
			}

			dtp->dt_buffered_buf = newbuf;
			dtp->dt_buffered_size <<= 1;
		}

		if (vsnprintf(&dtp->dt_buffered_buf[dtp->dt_buffered_offs],
		    avail, format, ap) < 0) {
			rval = dt_set_errno(dtp, errno);
			va_end(ap);
			return (rval);
		}

		dtp->dt_buffered_offs += needed;
		assert(dtp->dt_buffered_buf[dtp->dt_buffered_offs] == '\0');
		return (0);
	}

	n = vfprintf(fp, format, ap);
	va_end(ap);

	if (n < 0) {
		clearerr(fp);
		return (dt_set_errno(dtp, errno));
	}

	return (n);
}

int
dt_buffered_flush(dtrace_hdl_t *dtp, dtrace_probedata_t *pdata,
    dtrace_recdesc_t *rec, dtrace_aggdata_t *agg)
{
	dtrace_bufdata_t data;

	if (dtp->dt_buffered_offs == 0)
		return (0);

	data.dtbda_handle = dtp;
	data.dtbda_buffered = dtp->dt_buffered_buf;
	data.dtbda_probe = pdata;
	data.dtbda_recdesc = rec;
	data.dtbda_aggdata = agg;

	if ((*dtp->dt_bufhdlr)(&data, dtp->dt_bufarg) == DTRACE_HANDLE_ABORT)
		return (dt_set_errno(dtp, EDT_DIRABORT));

	dtp->dt_buffered_offs = 0;
	dtp->dt_buffered_buf[0] = '\0';

	return (0);
}

void
dt_buffered_destroy(dtrace_hdl_t *dtp)
{
	free(dtp->dt_buffered_buf);
	dtp->dt_buffered_buf = NULL;
	dtp->dt_buffered_offs = 0;
	dtp->dt_buffered_size = 0;
}

void *
dt_zalloc(dtrace_hdl_t *dtp, size_t size)
{
	void *data;

	if ((data = malloc(size)) == NULL)
		(void) dt_set_errno(dtp, EDT_NOMEM);
	else
		bzero(data, size);

	return (data);
}

void *
dt_alloc(dtrace_hdl_t *dtp, size_t size)
{
	void *data;

	if ((data = malloc(size)) == NULL)
		(void) dt_set_errno(dtp, EDT_NOMEM);

	return (data);
}

/*ARGSUSED*/
void
dt_free(dtrace_hdl_t *dtp, void *data)
{
	free(data);
}

char *
dt_basename(char *str)
{
	char *last = strrchr(str, '/');

	if (last == NULL)
		return (str);

	return (last + 1);
}

struct _rwlock;
struct _lwp_mutex;

int
dt_rw_read_held(pthread_rwlock_t *lock)
{
	extern int _rw_read_held(struct _rwlock *);
	return (_rw_read_held((struct _rwlock *)lock));
}

int
dt_rw_write_held(pthread_rwlock_t *lock)
{
	extern int _rw_write_held(struct _rwlock *);
	return (_rw_write_held((struct _rwlock *)lock));
}

int
dt_mutex_held(pthread_mutex_t *lock)
{
	extern int _mutex_held(struct _lwp_mutex *);
	return (_mutex_held((struct _lwp_mutex *)lock));
}