atomicio: provide atomic read and write functions.

These functions keep trying to read and write until all data has been
transferred, or an error occurrs.  In the case where an end of file
hasn't been reached, but all of the bytes have not been read/written,
try again.  On EINTR, try again.

1 files changed, 14 insertions, 15 deletions

diff --git a/src/base/circlebuf.cc b/src/base/circlebuf.cc
index a0c015671..d42bb11c3 100644
--- a/src/base/circlebuf.cc
+++ b/src/base/circlebuf.cc
@@ -29,12 +29,11 @@
  */
 
 #include <algorithm>
+#include <cstdio>
+#include <cstring>
 #include <string>
 
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
-
+#include "base/atomicio.hh"
 #include "base/circlebuf.hh"
 #include "base/cprintf.hh"
 #include "base/intmath.hh"
@@ -59,8 +58,8 @@ CircleBuf::dump()
     cprintf("start = %10d, stop = %10d, buflen = %10d\n",
             _start, _stop, _buflen);
     fflush(stdout);
-    ::write(STDOUT_FILENO, _buf, _buflen);
-    ::write(STDOUT_FILENO, "<\n", 2);
+    atomic_write(STDOUT_FILENO, _buf, _buflen);
+    atomic_write(STDOUT_FILENO, "<\n", 2);
 }
 
 void
@@ -106,19 +105,19 @@ CircleBuf::read(int fd, int len)
 
     if (_stop > _start) {
         len = min(len, _stop - _start);
-        ::write(fd, _buf + _start, len);
+        atomic_write(fd, _buf + _start, len);
         _start += len;
     }
     else {
         int endlen = _buflen - _start;
         if (endlen > len) {
-            ::write(fd, _buf + _start, len);
+            atomic_write(fd, _buf + _start, len);
             _start += len;
         }
         else {
-            ::write(fd, _buf + _start, endlen);
+            atomic_write(fd, _buf + _start, endlen);
             _start = min(len - endlen, _stop);
-            ::write(fd, _buf, _start);
+            atomic_write(fd, _buf, _start);
         }
     }
 }
@@ -129,11 +128,11 @@ CircleBuf::read(int fd)
     _size = 0;
 
     if (_stop > _start) {
-        ::write(fd, _buf + _start, _stop - _start);
+        atomic_write(fd, _buf + _start, _stop - _start);
     }
     else {
-        ::write(fd, _buf + _start, _buflen - _start);
-        ::write(fd, _buf, _stop);
+        atomic_write(fd, _buf + _start, _buflen - _start);
+        atomic_write(fd, _buf, _stop);
     }
 
     _start = _stop;
@@ -159,9 +158,9 @@ void
 CircleBuf::readall(int fd)
 {
     if (_rollover)
-        ::write(fd, _buf + _stop, _buflen - _stop);
+        atomic_write(fd, _buf + _stop, _buflen - _stop);
 
-    ::write(fd, _buf, _stop);
+    atomic_write(fd, _buf, _stop);
     _start = _stop;
 }