From: Nick Mathewson <nickm@torproject.org>
Date: Wed, 6 Jan 2010 23:42:59 +0000 (-0500)
Subject: Fix byte counts when mixing deferred and non-deferred evbuffer callbacks.
X-Git-Tag: release-2.0.4-alpha~92
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=29151e65b754eb254e6cc3596f006a2de85fd2fb;p=libevent

Fix byte counts when mixing deferred and non-deferred evbuffer callbacks.

This patch finishes 390e0561, which was somehow committed in a half-finished
state.  It solves a failing unit test on windows.
---

diff --git a/buffer.c b/buffer.c
index 8bcd48a5..f6c5bca9 100644
--- a/buffer.c
+++ b/buffer.c
@@ -341,7 +341,8 @@ evbuffer_run_callbacks(struct evbuffer *buffer, int running_deferred)
 	} else if (buffer->deferred_cbs) {
 		mask = EVBUFFER_CB_NODEFER|EVBUFFER_CB_ENABLED;
 		masked_val = EVBUFFER_CB_NODEFER|EVBUFFER_CB_ENABLED;
-/* Don't zero-out n_add/n_del, since */
+		/* Don't zero-out n_add/n_del, since the deferred callbacks
+		   will want to see them. */
 		clear = 0;
 	} else {
 		mask = EVBUFFER_CB_ENABLED;
@@ -361,9 +362,10 @@ evbuffer_run_callbacks(struct evbuffer *buffer, int running_deferred)
         info.orig_size = new_size + buffer->n_del_for_cb - buffer->n_add_for_cb;
         info.n_added = buffer->n_add_for_cb;
         info.n_deleted = buffer->n_del_for_cb;
-        buffer->n_add_for_cb = 0;
-        buffer->n_del_for_cb = 0;
-
+	if (clear) {
+		buffer->n_add_for_cb = 0;
+		buffer->n_del_for_cb = 0;
+	}
 	for (cbent = TAILQ_FIRST(&buffer->callbacks);
 	     cbent != TAILQ_END(&buffer->callbacks);
 	     cbent = next) {
diff --git a/evbuffer-internal.h b/evbuffer-internal.h
index 99dde3ce..0852d59e 100644
--- a/evbuffer-internal.h
+++ b/evbuffer-internal.h
@@ -36,7 +36,9 @@ extern "C" {
 #include "util-internal.h"
 #include "defer-internal.h"
 
-/* Experimental cb flag: "never deferred" */
+/* Experimental cb flag: "never deferred."  Implementation note:
+ * these callbacks may get an inaccurate view of n_del/n_added in their
+ * arguments. */
 #define EVBUFFER_CB_NODEFER 2
 
 #ifdef WIN32