[Xcb-commit] xcb
Keith Packard
keithp at kemper.freedesktop.org
Sat Jul 1 00:18:10 PDT 2006
xcb/src/xcb_in.c | 32 ++++++++++++++++++++++++--------
xcb/src/xcb_out.c | 20 +++++++++++++-------
xcb/src/xcbint.h | 2 ++
3 files changed, 39 insertions(+), 15 deletions(-)
New commits:
diff-tree 27cca19cbd0576648c65844ac75d53c122e61cab (from eb47cf7068788ce6986bcea10e7d027e60af0716)
Author: Keith Packard <keithp at neko.keithp.com>
Date: Sat Jul 1 00:16:07 2006 -0700
Switch sequence comparisons to handle 32-bit sequence number wrap.
Create a macro, XCB_SEQUENCE_COMPARE, that accepts two sequence numbers and
a comparison operator and correctly handles 32-bit wrap around.
Rewrite all ordered sequence number comparisons to use this macro.
Also, caught one error where a sequence was stored in a signed int variable.
Push out a GetInputFocus request when the sequence number does wrap at 32
bits so that applications cannot see sequence 0 (as that is an error
indicator).
diff --git a/xcb/src/xcb_in.c b/xcb/src/xcb_in.c
index 3bf54f3..6433f0e 100644
--- a/xcb/src/xcb_in.c
+++ b/xcb/src/xcb_in.c
@@ -91,11 +91,11 @@ static int read_packet(XCBConnection *c)
/* Compute 32-bit sequence number of this packet. */
if((genrep.response_type & 0x7f) != XCBKeymapNotify)
{
- int lastread = c->in.request_read;
+ unsigned int lastread = c->in.request_read;
c->in.request_read = (lastread & 0xffff0000) | genrep.sequence;
- if(c->in.request_read < lastread)
+ if(XCB_SEQUENCE_COMPARE(c->in.request_read, <, lastread))
c->in.request_read += 0x10000;
- if(c->in.request_read > c->in.request_expected)
+ if(XCB_SEQUENCE_COMPARE(c->in.request_read, >, c->in.request_expected))
c->in.request_expected = c->in.request_read;
if(c->in.request_read != lastread)
@@ -111,7 +111,8 @@ static int read_packet(XCBConnection *c)
if(genrep.response_type != XCBReply) /* error or event */
c->in.request_completed = c->in.request_read; /* XXX: does event/error imply no more replies? */
- while(c->in.pending_replies && c->in.pending_replies->request <= c->in.request_completed)
+ while(c->in.pending_replies &&
+ XCB_SEQUENCE_COMPARE (c->in.pending_replies->request, <=, c->in.request_completed))
{
pending_reply *oldpend = c->in.pending_replies;
c->in.pending_replies = oldpend->next;
@@ -168,12 +169,17 @@ static int read_packet(XCBConnection *c)
cur->next = 0;
*c->in.current_reply_tail = cur;
c->in.current_reply_tail = &cur->next;
- for(reader = c->in.readers; reader && reader->request <= c->in.request_read; reader = reader->next)
+ for(reader = c->in.readers;
+ reader &&
+ XCB_SEQUENCE_COMPARE(reader->request, <=, c->in.request_read);
+ reader = reader->next)
+ {
if(reader->request == c->in.request_read)
{
pthread_cond_signal(reader->data);
break;
}
+ }
return 1;
}
@@ -249,7 +255,7 @@ static int poll_for_reply(XCBConnection
head = 0;
/* We've read requests past the one we want, so if it has replies we have
* them all and they're in the replies map. */
- else if(request < c->in.request_read)
+ else if(XCB_SEQUENCE_COMPARE(request, <, c->in.request_read))
{
head = _xcb_map_remove(c->in.replies, request);
if(head && head->next)
@@ -312,8 +318,13 @@ void *XCBWaitForReply(XCBConnection *c,
reader_list reader;
reader_list **prev_reader;
- for(prev_reader = &c->in.readers; *prev_reader && (*prev_reader)->request <= request; prev_reader = &(*prev_reader)->next)
+ for(prev_reader = &c->in.readers;
+ *prev_reader &&
+ XCB_SEQUENCE_COMPARE ((*prev_reader)->request, <=, request);
+ prev_reader = &(*prev_reader)->next)
+ {
/* empty */;
+ }
reader.request = request;
reader.data = &cond;
reader.next = *prev_reader;
@@ -323,12 +334,17 @@ void *XCBWaitForReply(XCBConnection *c,
if(!_xcb_conn_wait(c, &cond, 0, 0))
break;
- for(prev_reader = &c->in.readers; *prev_reader && (*prev_reader)->request <= request; prev_reader = &(*prev_reader)->next)
+ for(prev_reader = &c->in.readers;
+ *prev_reader &&
+ XCB_SEQUENCE_COMPARE((*prev_reader)->request, <=, request);
+ prev_reader = &(*prev_reader)->next)
+ {
if(*prev_reader == &reader)
{
*prev_reader = (*prev_reader)->next;
break;
}
+ }
pthread_cond_destroy(&cond);
}
diff --git a/xcb/src/xcb_out.c b/xcb/src/xcb_out.c
index f12a071..9a67ad2 100644
--- a/xcb/src/xcb_out.c
+++ b/xcb/src/xcb_out.c
@@ -157,16 +157,22 @@ unsigned int XCBSendRequest(XCBConnectio
while(c->out.writing)
pthread_cond_wait(&c->out.cond, &c->iolock);
- if(req->isvoid && c->out.request == c->in.request_expected + (1 << 16) - 2)
+ request = ++c->out.request;
+ /* send GetInputFocus (sync) when 64k-2 requests have been sent without
+ * a reply.
+ * Also send sync (could use NoOp) at 32-bit wrap to avoid having
+ * applications see sequence 0 as that is used to indicate
+ * an error in sending the request */
+ if((req->isvoid &&
+ c->out.request == c->in.request_expected + (1 << 16) - 2) ||
+ request == 0)
{
prefix[0] = sync.packet;
- request = ++c->out.request;
_xcb_in_expect_reply(c, request, WORKAROUND_NONE, XCB_REQUEST_DISCARD_REPLY);
c->in.request_expected = c->out.request;
+ request = ++c->out.request;
}
- request = ++c->out.request;
- assert(request != 0);
if(workaround != WORKAROUND_NONE || flags != 0)
_xcb_in_expect_reply(c, request, workaround, flags);
if(!req->isvoid)
@@ -238,8 +244,8 @@ int _xcb_out_send(XCBConnection *c, stru
int _xcb_out_flush_to(XCBConnection *c, unsigned int request)
{
- assert(request <= c->out.request);
- if(c->out.request_written >= request)
+ assert(XCB_SEQUENCE_COMPARE(request, <=, c->out.request));
+ if(XCB_SEQUENCE_COMPARE(c->out.request_written, >=, request))
return 1;
if(c->out.queue_len)
{
@@ -252,6 +258,6 @@ int _xcb_out_flush_to(XCBConnection *c,
}
while(c->out.writing)
pthread_cond_wait(&c->out.cond, &c->iolock);
- assert(c->out.request_written >= request);
+ assert(XCB_SEQUENCE_COMPARE(c->out.request_written, >=, request));
return 1;
}
diff --git a/xcb/src/xcbint.h b/xcb/src/xcbint.h
index a6d92aa..9048e9d 100644
--- a/xcb/src/xcbint.h
+++ b/xcb/src/xcbint.h
@@ -43,6 +43,8 @@ enum workarounds {
#define XCB_PAD(i) (-(i) & 3)
+#define XCB_SEQUENCE_COMPARE(a,op,b) ((int) ((a) - (b)) op 0)
+
/* xcb_list.c */
typedef void (*XCBListFreeFunc)(void *);
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