From 2cb4d347d04242be04383433771626bd8ca26129 Mon Sep 17 00:00:00 2001
From: Cedric Roux <cedric.roux@eurecom.fr>
Date: Wed, 1 Jun 2016 17:44:53 +0200
Subject: [PATCH] make the local tracer more robust
if a read from the remote tracer's socket fails, let's smash
the socket and wait for another remote tracer
---
common/utils/T/local_tracer.c | 58 +++++++++++++++++++++++++++--------
1 file changed, 46 insertions(+), 12 deletions(-)
diff --git a/common/utils/T/local_tracer.c b/common/utils/T/local_tracer.c
index fb4cbd9a3e..c7247e980b 100644
--- a/common/utils/T/local_tracer.c
+++ b/common/utils/T/local_tracer.c
@@ -131,35 +131,69 @@ process:
static void *forward_remote_messages(void *_f)
{
+#define PUT(x) do { \
+ if (bufsize == bufmaxsize) { \
+ bufmaxsize += 4096; \
+ buf = realloc(buf, bufmaxsize); \
+ if (buf == NULL) abort(); \
+ } \
+ buf[bufsize] = x; \
+ bufsize++; \
+ } while (0)
+#define PUT_BUF(x, l) do { \
+ char *zz = (char *)(x); \
+ int len = l; \
+ while (len) { PUT(*zz); zz++; len--; } \
+ } while (0)
+
forward_data *f = _f;
int from;
int to;
int l, len;
char *b;
- char buf[1024];
+ char *buf = NULL;
+ int bufsize = 0;
+ int bufmaxsize = 0;
+ char t;
again:
- /* Note: if the remote socket dies while a transfer is running
- * then the state of the tracer will be totally messed up.
- * If that ever happens, things are messed up anyway, so no big
- * deal... (TODO: to be refined at some point, maybe)
- */
while (1) {
from = f->socket_remote;
to = f->socket_local;
- len = read(from, buf, 1024);
- if (len <= 0) break;
- b = buf;
- while (len) {
- l = write(to, b, len);
+ bufsize = 0;
+
+ /* let's read and process messages */
+ len = read(from, &t, 1); if (len <= 0) goto dead;
+ PUT(t);
+
+ switch (t) {
+ case 0:
+ case 1:
+ /* message 0 and 1: get a length and then 'length' numbers */
+ if (read(from, &len, sizeof(int)) != sizeof(int)) goto dead;
+ PUT_BUF(&len, 4);
+ while (len) {
+ if (read(from, &l, sizeof(int)) != sizeof(int)) goto dead;
+ PUT_BUF(&l, 4);
+ len--;
+ }
+ break;
+
+ case 2: break;
+ }
+
+ b = buf;
+ while (bufsize) {
+ l = write(to, b, bufsize);
if (l <= 0) abort();
- len -= l;
+ bufsize -= l;
b += l;
}
}
+dead:
/* socket died, let's stop all traces and wait for another tracer */
buf[0] = 1;
if (write(to, buf, 1) != 1) abort();
--
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