implement a more robust cancelation mechanism of async reader

This commit is contained in:
Dimitri Stolnikov 2012-08-08 21:21:46 +02:00
parent b49a8336ee
commit 22b9d82fb5
1 changed files with 27 additions and 8 deletions

View File

@ -1143,6 +1143,10 @@ int rtlsdr_close(rtlsdr_dev_t *dev)
if (!dev)
return -1;
/* block until all async operations have been completed (if any) */
while (RTLSDR_INACTIVE != dev->async_status)
usleep(10);
rtlsdr_deinit_baseband(dev);
libusb_release_interface(dev->devh, 0);
@ -1183,9 +1187,10 @@ static void LIBUSB_CALL _libusb_callback(struct libusb_transfer *xfer)
dev->cb(xfer->buffer, xfer->actual_length, dev->cb_ctx);
libusb_submit_transfer(xfer); /* resubmit transfer */
} else if (LIBUSB_TRANSFER_CANCELLED == xfer->status) {
/* nothing to do */
} else {
/*fprintf(stderr, "transfer status: %d\n", xfer->status);*/
rtlsdr_cancel_async(dev); /* abort async loop */
}
}
@ -1255,12 +1260,18 @@ int rtlsdr_read_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx,
uint32_t buf_num, uint32_t buf_len)
{
unsigned int i;
int r;
int r = 0;
struct timeval tv = { 1, 0 };
enum rtlsdr_async_status next_status = RTLSDR_INACTIVE;
if (!dev)
return -1;
if (RTLSDR_INACTIVE != dev->async_status)
return -2;
dev->async_status = RTLSDR_RUNNING;
dev->cb = cb;
dev->cb_ctx = ctx;
@ -1289,8 +1300,6 @@ int rtlsdr_read_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx,
libusb_submit_transfer(dev->xfer[i]);
}
dev->async_status = RTLSDR_RUNNING;
while (RTLSDR_INACTIVE != dev->async_status) {
r = libusb_handle_events_timeout(dev->ctx, &tv);
if (r < 0) {
@ -1301,7 +1310,7 @@ int rtlsdr_read_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx,
}
if (RTLSDR_CANCELING == dev->async_status) {
dev->async_status = RTLSDR_INACTIVE;
next_status = RTLSDR_INACTIVE;
if (!dev->xfer)
break;
@ -1310,19 +1319,22 @@ int rtlsdr_read_async(rtlsdr_dev_t *dev, rtlsdr_read_async_cb_t cb, void *ctx,
if (!dev->xfer[i])
continue;
if (dev->xfer[i]->status == LIBUSB_TRANSFER_COMPLETED) {
if (LIBUSB_TRANSFER_CANCELLED !=
dev->xfer[i]->status) {
libusb_cancel_transfer(dev->xfer[i]);
dev->async_status = RTLSDR_CANCELING;
next_status = RTLSDR_CANCELING;
}
}
if (RTLSDR_INACTIVE == dev->async_status)
if (RTLSDR_INACTIVE == next_status)
break;
}
}
_rtlsdr_free_async_buffers(dev);
dev->async_status = next_status;
return r;
}
@ -1331,11 +1343,18 @@ int rtlsdr_cancel_async(rtlsdr_dev_t *dev)
if (!dev)
return -1;
/* if streaming, try to cancel gracefully */
if (RTLSDR_RUNNING == dev->async_status) {
dev->async_status = RTLSDR_CANCELING;
return 0;
}
/* if called while in pending state, change the state forcefully */
if (RTLSDR_INACTIVE != dev->async_status) {
dev->async_status = RTLSDR_INACTIVE;
return 0;
}
return -2;
}