perf tools: Add writen function

Adding 'writen' function as a synchronous wrapper for write syscall with
following prototype:

  ssize_t writen(int fd, void *buf, size_t n)

Returns the number of bytes written on success or -1 in case of err.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Requested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1385634619-8129-5-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2013-11-28 11:30:16 +01:00 committed by Arnaldo Carvalho de Melo
parent 838d145202
commit bc3a502bc2
2 changed files with 20 additions and 5 deletions

View File

@ -152,16 +152,14 @@ unsigned long convert_unit(unsigned long value, char *unit)
return value;
}
/*
* Read exactly 'n' bytes or return an error.
*/
ssize_t readn(int fd, void *buf, size_t n)
static ssize_t ion(bool is_read, int fd, void *buf, size_t n)
{
void *buf_start = buf;
size_t left = n;
while (left) {
ssize_t ret = read(fd, buf, left);
ssize_t ret = is_read ? read(fd, buf, left) :
write(fd, buf, left);
if (ret <= 0)
return ret;
@ -174,6 +172,22 @@ ssize_t readn(int fd, void *buf, size_t n)
return n;
}
/*
* Read exactly 'n' bytes or return an error.
*/
ssize_t readn(int fd, void *buf, size_t n)
{
return ion(true, fd, buf, n);
}
/*
* Write exactly 'n' bytes or return an error.
*/
ssize_t writen(int fd, void *buf, size_t n)
{
return ion(false, fd, buf, n);
}
size_t hex_width(u64 v)
{
size_t n = 1;

View File

@ -254,6 +254,7 @@ int strtailcmp(const char *s1, const char *s2);
char *strxfrchar(char *s, char from, char to);
unsigned long convert_unit(unsigned long value, char *unit);
ssize_t readn(int fd, void *buf, size_t n);
ssize_t writen(int fd, void *buf, size_t n);
struct perf_event_attr;