diff options
| -rw-r--r-- | libpipe/pipe.c | 28 |
1 files changed, 20 insertions, 8 deletions
diff --git a/libpipe/pipe.c b/libpipe/pipe.c index 73463acd..d0035cbb 100644 --- a/libpipe/pipe.c +++ b/libpipe/pipe.c @@ -19,6 +19,7 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <string.h> /* For bzero() */ +#include <assert.h> #include <mach/time_value.h> #include <mach/mach_host.h> @@ -114,11 +115,16 @@ pipe_send (struct pipe *pipe, void *source, if (pipe->flags & PIPE_BROKEN) return EPIPE; - if (control || ports) + if (control_len > 0 || num_ports > 0) /* Write a control packet. */ { + /* Note that we don't record the source address in control packets, as + it's recorded in the following data packet anyway, and this prevents + it from being dealloc'd twice; this depends on the fact that we + always write a data packet. */ struct packet *control_packet = - pq_queue (pipe->queue, PACKET_TYPE_CONTROL, source); + pq_queue (pipe->queue, PACKET_TYPE_CONTROL, NULL); + if (control_packet == NULL) err = ENOBUFS; else @@ -206,13 +212,19 @@ pipe_recv (struct pipe *pipe, int noblock, unsigned *flags, void **source, packet_read_ports (packet, ports, num_ports); packet_read_source (packet, &control_source); + packet = pq_next (pq, PACKET_TYPE_DATA, control_source); - if (!packet && source) - /* Since there is no data, say where the control data came from. */ - *source = control_source; - else if (control_source) - /* Otherwise be sure to get rid of our reference to the address. */ - pipe_dealloc_addr (control_source); + + /* Control packets should only have a source address if they're not + followed by a data packet. */ + assert (!!packet == !control_source); + + if (!packet) + if (source) + /* Since there is no data, say where the control data came from. */ + *source = control_source; + else + pipe_dealloc_addr (control_source); } else /* No control data... */ |