Re: [Help-smalltalk] [bug] async signal queue can miss events

[Holger Hans Peter Freyther]

Issue status update for 
http://smalltalk.gnu.org/project/issue/651
Post a follow up: 
http://smalltalk.gnu.org/project/comments/add/651

Project:      GNU Smalltalk
Version:      <none>
Component:    VM
Category:     bug reports
Priority:     normal
Assigned to:  Unassigned
Reported by:  zecke
Updated by:   zecke
Status:       fixed

The 23:00 analysis... and hypothesis...

_gst_async_file_polling
1.) check for polling...
                            2.) new data arrives
3.) re-alloc
4.) set_filter_interrupt...

It has been some time bit SIGIO/fasync is just edge triggered? isn't it?

Strace with success:
socket(PF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_TCP) = 4
fcntl64(4, F_GETFL)                     = 0x2 (flags O_RDWR)
fcntl64(4, F_SETFL, O_RDWR|O_NONBLOCK)  = 0
connect(4, {sa_family=AF_INET, sin_port=htons(3002),
sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EINPROGRESS (Operation now in
progress)
poll([{fd=4, events=POLLOUT}], 1, 0)    = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=4, events=POLLOUT}], 1, 0)    = 1 ([{fd=4, revents=POLLOUT}])
getpeername(4, {sa_family=AF_INET, sin_port=htons(3002),
sin_addr=inet_addr("127.0.0.1")}, [16]) = 0
poll([{fd=4, events=POLLIN}], 1, 0)     = 1 ([{fd=4, revents=POLLIN}])
poll([{fd=4, events=POLLIN}], 1, 0)     = 1 ([{fd=4, revents=POLLIN}])
poll([{fd=4, events=POLLIN}], 1, 0)     = 1 ([{fd=4, revents=POLLIN}])
poll([{fd=4, events=POLLIN}], 1, 0)     = 1 ([{fd=4, revents=POLLIN}])
recvfrom(4, "\0\21\376\4\1\10\1\7\1\2\1\3\1\4\1\5\1\1\1\0", 1024, 0,
NULL, NULL) = 20
close(4)

Strace with failure:
socket(PF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_TCP) = 4
fcntl64(4, F_GETFL)                     = 0x2 (flags O_RDWR)
fcntl64(4, F_SETFL, O_RDWR|O_NONBLOCK)  = 0
connect(4, {sa_family=AF_INET, sin_port=htons(3002),
sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EINPROGRESS (Operation now in
progress)
poll([{fd=4, events=POLLOUT}], 1, 0)    = 1 ([{fd=4, revents=POLLOUT}])
poll([{fd=4, events=POLLOUT}], 1, 0)    = 1 ([{fd=4, revents=POLLOUT}])
getpeername(4, {sa_family=AF_INET, sin_port=htons(3002),
sin_addr=inet_addr("127.0.0.1")}, [16]) = 0
poll([{fd=4, events=POLLIN}], 1, 0)     = 0 (Timeout)
fcntl64(4, F_GETFL)                     = 0x802 (flags
O_RDWR|O_NONBLOCK)
fcntl64(4, F_SETFL, O_RDWR|O_NONBLOCK|O_ASYNC) = 0
fcntl64(4, F_SETOWN, 22087)             = 0