Merge branch 'ma/ts-cleanups'

gitster · gitster · commit a48ce3785850 · 2017-09-10T17:08:22.000+09:00
Assorted bugfixes and clean-ups.

* ma/ts-cleanups:
  ThreadSanitizer: add suppressions
  strbuf_setlen: don't write to strbuf_slopbuf
  pack-objects: take lock before accessing `remaining`
  convert: always initialize attr_action in convert_attrs
diff --git a/.tsan-suppressions b/.tsan-suppressions
@@ -0,0 +1,10 @@
+# Suppressions for ThreadSanitizer (tsan).
+#
+# This file is used by setting the environment variable TSAN_OPTIONS to, e.g.,
+# "suppressions=$(pwd)/.tsan-suppressions". Observe that relative paths such as
+# ".tsan-suppressions" might not work.
+
+# A static variable is written to racily, but we always write the same value, so
+# in practice it (hopefully!) doesn't matter.
+race:^want_color$
+race:^transfer_debug$
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
@@ -2171,7 +2171,10 @@ static void *threaded_find_deltas(void *arg)
 {
 	struct thread_params *me = arg;
 
+	progress_lock();
 	while (me->remaining) {
+		progress_unlock();
+
 		find_deltas(me->list, &me->remaining,
 			    me->window, me->depth, me->processed);
 
@@ -2193,7 +2196,10 @@ static void *threaded_find_deltas(void *arg)
 			pthread_cond_wait(&me->cond, &me->mutex);
 		me->data_ready = 0;
 		pthread_mutex_unlock(&me->mutex);
+
+		progress_lock();
 	}
+	progress_unlock();
 	/* leave ->working 1 so that this doesn't get more work assigned */
 	return NULL;
 }
diff --git a/color.c b/color.c
@@ -338,6 +338,13 @@ static int check_auto_color(void)
 
 int want_color(int var)
 {
+	/*
+	 * NEEDSWORK: This function is sometimes used from multiple threads, and
+	 * we end up using want_auto racily. That "should not matter" since
+	 * we always write the same value, but it's still wrong. This function
+	 * is listed in .tsan-suppressions for the time being.
+	 */
+
 	static int want_auto = -1;
 
 	if (var < 0)
diff --git a/convert.c b/convert.c
@@ -1040,7 +1040,6 @@ static void convert_attrs(struct conv_attrs *ca, const char *path)
 		ca->crlf_action = git_path_check_crlf(ccheck + 4);
 		if (ca->crlf_action == CRLF_UNDEFINED)
 			ca->crlf_action = git_path_check_crlf(ccheck + 0);
-		ca->attr_action = ca->crlf_action;
 		ca->ident = git_path_check_ident(ccheck + 1);
 		ca->drv = git_path_check_convert(ccheck + 2);
 		if (ca->crlf_action != CRLF_BINARY) {
@@ -1054,12 +1053,14 @@ static void convert_attrs(struct conv_attrs *ca, const char *path)
 			else if (eol_attr == EOL_CRLF)
 				ca->crlf_action = CRLF_TEXT_CRLF;
 		}
-		ca->attr_action = ca->crlf_action;
 	} else {
 		ca->drv = NULL;
 		ca->crlf_action = CRLF_UNDEFINED;
 		ca->ident = 0;
 	}
+
+	/* Save attr and make a decision for action */
+	ca->attr_action = ca->crlf_action;
 	if (ca->crlf_action == CRLF_TEXT)
 		ca->crlf_action = text_eol_is_crlf() ? CRLF_TEXT_CRLF : CRLF_TEXT_INPUT;
 	if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_FALSE)
diff --git a/strbuf.h b/strbuf.h
@@ -147,7 +147,10 @@ static inline void strbuf_setlen(struct strbuf *sb, size_t len)
 	if (len > (sb->alloc ? sb->alloc - 1 : 0))
 		die("BUG: strbuf_setlen() beyond buffer");
 	sb->len = len;
-	sb->buf[len] = '\0';
+	if (sb->buf != strbuf_slopbuf)
+		sb->buf[len] = '\0';
+	else
+		assert(!strbuf_slopbuf[0]);
 }
 
 /**
diff --git a/transport-helper.c b/transport-helper.c
@@ -1117,6 +1117,13 @@ int transport_helper_init(struct transport *transport, const char *name)
 __attribute__((format (printf, 1, 2)))
 static void transfer_debug(const char *fmt, ...)
 {
+	/*
+	 * NEEDSWORK: This function is sometimes used from multiple threads, and
+	 * we end up using debug_enabled racily. That "should not matter" since
+	 * we always write the same value, but it's still wrong. This function
+	 * is listed in .tsan-suppressions for the time being.
+	 */
+
 	va_list args;
 	char msgbuf[PBUFFERSIZE];
 	static int debug_enabled = -1;

Original file line number	Diff line number	Diff line change
`@@ -2171,7 +2171,10 @@ static void threaded_find_deltas(void arg)`
`2171`	`2171`	`{`
`2172`	`2172`	`struct thread_params *me = arg;`
`2173`	`2173`
	`2174`	`+ progress_lock();`
`2174`	`2175`	`while (me->remaining) {`
	`2176`	`+ progress_unlock();`
	`2177`	`+`
`2175`	`2178`	`find_deltas(me->list, &me->remaining,`
`2176`	`2179`	`me->window, me->depth, me->processed);`
`2177`	`2180`
`@@ -2193,7 +2196,10 @@ static void threaded_find_deltas(void arg)`
`2193`	`2196`	`pthread_cond_wait(&me->cond, &me->mutex);`
`2194`	`2197`	`me->data_ready = 0;`
`2195`	`2198`	`pthread_mutex_unlock(&me->mutex);`
	`2199`	`+`
	`2200`	`+ progress_lock();`
`2196`	`2201`	`}`
	`2202`	`+ progress_unlock();`
`2197`	`2203`	`/* leave ->working 1 so that this doesn't get more work assigned */`
`2198`	`2204`	`return NULL;`
`2199`	`2205`	`}`