X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftdb%2Ftest%2Flock-tracking.c;h=8e8bb999c52df90ce01a444b4d987b511b2c2e16;hp=bc4be14759211f6718bfda34d124652329d3544a;hb=100444225380d3f5ca29424ea54703d308c7c651;hpb=c4a9fd1b01822e75da853d3f3229de5d35409e31

diff --git a/ccan/tdb/test/lock-tracking.c b/ccan/tdb/test/lock-tracking.c
index bc4be147..8e8bb999 100644
--- a/ccan/tdb/test/lock-tracking.c
+++ b/ccan/tdb/test/lock-tracking.c
@@ -4,6 +4,8 @@
 #include <stdarg.h>
 #include <stdlib.h>
 #include <ccan/tap/tap.h>
+#include <ccan/tdb/tdb_private.h>
+#include "lock-tracking.h"
 
 struct lock {
 	struct lock *next;
@@ -13,6 +15,9 @@ struct lock {
 };
 static struct lock *locks;
 int locking_errors = 0;
+bool suppress_lockcheck = false;
+bool nonblocking_locks;
+int locking_would_block = 0;
 void (*unlock_callback)(int fd);
 
 int fcntl_with_lockcheck(int fd, int cmd, ... /* arg */ )
@@ -20,6 +25,7 @@ int fcntl_with_lockcheck(int fd, int cmd, ... /* arg */ )
 	va_list ap;
 	int ret, arg3;
 	struct flock *fl;
+	bool may_block = false;
 
 	if (cmd != F_SETLK && cmd != F_SETLKW) {
 		/* This may be totally bogus, but we don't know in general. */
@@ -34,6 +40,17 @@ int fcntl_with_lockcheck(int fd, int cmd, ... /* arg */ )
 	fl = va_arg(ap, struct flock *);
 	va_end(ap);
 
+	if (cmd == F_SETLKW && nonblocking_locks) {
+		cmd = F_SETLK;
+		may_block = true;
+	}
+	ret = fcntl(fd, cmd, fl);
+
+	/* Detect when we failed, but might have been OK if we waited. */
+	if (may_block && ret == -1 && (errno == EAGAIN || errno == EACCES)) {
+		locking_would_block++;
+	}
+
 	if (fl->l_type == F_UNLCK) {
 		struct lock **l;
 		struct lock *old = NULL;
@@ -41,15 +58,17 @@ int fcntl_with_lockcheck(int fd, int cmd, ... /* arg */ )
 		for (l = &locks; *l; l = &(*l)->next) {
 			if ((*l)->off == fl->l_start
 			    && (*l)->len == fl->l_len) {
-				old = *l;
-				*l = (*l)->next;
-				free(old);
+				if (ret == 0) {
+					old = *l;
+					*l = (*l)->next;
+					free(old);
+				}
 				break;
 			}
 		}
-		if (!old) {
-			diag("Unknown unlock %u@%u",
-			     (int)fl->l_len, (int)fl->l_start);
+		if (!old && !suppress_lockcheck) {
+			diag("Unknown unlock %u@%u - %i",
+			     (int)fl->l_len, (int)fl->l_start, ret);
 			locking_errors++;
 		}
 	} else {
@@ -68,29 +87,53 @@ int fcntl_with_lockcheck(int fd, int cmd, ... /* arg */ )
 				break;
 			if (fl_end >= i->off && fl_end < i_end)
 				break;
+
+			/* tdb_allrecord_lock does this, handle adjacent: */
+			if (fl->l_start == i_end && fl->l_type == i->type) {
+				if (ret == 0) {
+					i->len = fl->l_len 
+						? i->len + fl->l_len
+						: 0;
+				}
+				goto done;
+			}
 		}
 		if (i) {
-			diag("%s lock %u@%u overlaps %u@%u",
-			     fl->l_type == F_WRLCK ? "write" : "read",
-			     (int)fl->l_len, (int)fl->l_start,
-			     i->len, (int)i->off);
-			locking_errors++;
+			/* Special case: upgrade of allrecord lock. */
+			if (i->type == F_RDLCK && fl->l_type == F_WRLCK
+			    && i->off == FREELIST_TOP
+			    && fl->l_start == FREELIST_TOP
+			    && i->len == 0
+			    && fl->l_len == 0) {
+				if (ret == 0)
+					i->type = F_WRLCK;
+				goto done;
+			}
+			if (!suppress_lockcheck) {
+				diag("%s lock %u@%u overlaps %u@%u",
+				     fl->l_type == F_WRLCK ? "write" : "read",
+				     (int)fl->l_len, (int)fl->l_start,
+				     i->len, (int)i->off);
+				locking_errors++;
+			}
 		}
-		new = malloc(sizeof *new);
-		new->off = fl->l_start;
-		new->len = fl->l_len;
-		new->type = fl->l_type;
-		new->next = locks;
-		locks = new;
-	}
 
-	ret = fcntl(fd, cmd, fl);
+		if (ret == 0) {
+			new = malloc(sizeof *new);
+			new->off = fl->l_start;
+			new->len = fl->l_len;
+			new->type = fl->l_type;
+			new->next = locks;
+			locks = new;
+		}
+	}
+done:
 	if (ret == 0 && fl->l_type == F_UNLCK && unlock_callback)
 		unlock_callback(fd);
 	return ret;
 }
 
-int forget_locking(void)
+unsigned int forget_locking(void)
 {
 	unsigned int num = 0;
 	while (locks) {