diff options
Diffstat (limited to 'pcap_breakloop.3pcap')
| -rw-r--r-- | pcap_breakloop.3pcap | 41 |
1 files changed, 29 insertions, 12 deletions
diff --git a/pcap_breakloop.3pcap b/pcap_breakloop.3pcap index a395820..cc000d2 100644 --- a/pcap_breakloop.3pcap +++ b/pcap_breakloop.3pcap @@ -17,7 +17,7 @@ .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. .\" -.TH PCAP_BREAKLOOP 3PCAP "5 April 2008" +.TH PCAP_BREAKLOOP 3PCAP "25 July 2018" .SH NAME pcap_breakloop \- force a pcap_dispatch() or pcap_loop() call to return .SH SYNOPSIS @@ -33,12 +33,13 @@ void pcap_breakloop(pcap_t *); .SH DESCRIPTION .B pcap_breakloop() sets a flag that will force -.B pcap_dispatch() +.B pcap_dispatch(3PCAP) or -.B pcap_loop() +.B pcap_loop(3PCAP) to return rather than looping; they will return the number of packets -that have been processed so far, or \-2 if no packets have been -processed so far. +that have been processed so far, or +.B PCAP_ERROR_BREAK +if no packets have been processed so far. .PP This routine is safe to use inside a signal handler on UNIX or a console control handler on Windows, as it merely sets a flag that is checked @@ -60,11 +61,23 @@ packets arrive and the call completes. .PP .ft B Note also that, in a multi-threaded application, if one thread is -blocked in pcap_dispatch(), pcap_loop(), pcap_next(), or pcap_next_ex(), +blocked in pcap_dispatch(), pcap_loop(), pcap_next(3PCAP), or pcap_next_ex(3PCAP), a call to pcap_breakloop() in a different thread will not unblock that -thread; you will need to use whatever mechanism the OS provides for +thread. +.ft R +You will need to use whatever mechanism the OS provides for breaking a thread out of blocking calls in order to unblock the thread, -such as thread cancellation in systems that support POSIX threads. +such as thread cancellation or thread signalling in systems that support +POSIX threads, or +.B SetEvent() +on the result of +.B pcap_getevent() +on a +.B pcap_t +on which the thread is blocked on Windows. Asynchronous procedure calls +will not work on Windows, as a thread blocked on a +.B pcap_t +will not be in an alertable state. .ft R .PP Note that @@ -87,12 +100,16 @@ or .B pcap_loop() after it is called; at most one more packet might be processed. .PP -If \-2 is returned from +If +.B PCAP_ERROR_BREAK +is returned from .B pcap_dispatch() or .BR pcap_loop() , -the flag is cleared, so a subsequent call will resume reading packets. +the flag is cleared, so a subsequent call will resume reading packets. If a positive number is returned, the flag is not cleared, so a -subsequent call will return \-2 and clear the flag. +subsequent call will return +.B PCAP_ERROR_BREAK +and clear the flag. .SH SEE ALSO -pcap(3PCAP), pcap_loop(3PCAP), pcap_next_ex(3PCAP) +pcap(3PCAP) |