* - @ref Configuration (baud rate, parity, etc.)
* - @ref Signals (modem control lines, breaks, etc.)
* - @ref Data
+ * - @ref Waiting
* - @ref Errors
*
* libserialport is an open source project released under the LGPL3+ license.
SP_MODE_WRITE = 2,
};
+/** Port events. */
+enum sp_event {
+ /* Data received and ready to read. */
+ SP_EVENT_RX_READY = 1,
+ /* Ready to transmit new data. */
+ SP_EVENT_TX_READY = 2,
+ /* Error occured. */
+ SP_EVENT_ERROR = 4,
+};
+
/** Buffer selection. */
enum sp_buffer {
/** Input buffer. */
*/
struct sp_port_config;
+/**
+ * @struct sp_event_set
+ * A set of handles to wait on for events.
+ */
+struct sp_event_set {
+ /** Array of OS-specific handles. */
+ void *handles;
+ /** Array of bitmasks indicating which events apply for each handle. */
+ enum sp_event *masks;
+ /** Number of handles. */
+ unsigned int count;
+};
+
/**
@defgroup Enumeration Port enumeration
@{
*/
enum sp_return sp_drain(struct sp_port *port);
+/**
+ * @}
+ * @defgroup Waiting Waiting for events
+ * @{
+ */
+
+/**
+ * Allocate storage for a set of events.
+ *
+ * The user should allocate a variable of type struct sp_event_set *,
+ * then pass a pointer to this variable to receive the result.
+ *
+ * The result should be freed after use by calling sp_free_event_set().
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ */
+enum sp_return sp_new_event_set(struct sp_event_set **result_ptr);
+
+/**
+ * Add events to a struct sp_event_set for a given port.
+ *
+ * The port must first be opened by calling sp_open() using the same port
+ * structure.
+ *
+ * After the port is closed or the port structure freed, the results may
+ * no longer be valid.
+ *
+ * @param event_set Event set to update.
+ * @param port Pointer to port structure.
+ * @param mask Bitmask of events to be waited for.
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ */
+enum sp_return sp_add_port_events(struct sp_event_set *event_set,
+ const struct sp_port *port, enum sp_event mask);
+
+/**
+ * Wait for any of a set of events to occur.
+ *
+ * @param handles Event set to wait on.
+ * @param timeout Timeout in milliseconds, or zero to wait indefinitely.
+ *
+ * @return SP_OK upon success, a negative error code otherwise.
+ */
+enum sp_return sp_wait(struct sp_event_set *event_set, unsigned int timeout);
+
+/**
+ * Free a structure allocated by sp_new_event_set().
+ */
+void sp_free_event_set(struct sp_event_set *event_set);
+
/**
* @}
* @defgroup Signals Port signalling operations
#include <sys/ioctl.h>
#include <sys/time.h>
#include <limits.h>
+#include <poll.h>
#endif
#ifdef __APPLE__
#include <IOKit/IOKitLib.h>
COMMTIMEOUTS timeouts;
OVERLAPPED write_ovl;
OVERLAPPED read_ovl;
+ OVERLAPPED wait_ovl;
+ DWORD events;
BYTE pending_byte;
BOOL writing;
#else
#endif
};
+#ifdef _WIN32
+typedef HANDLE event_handle;
+#else
+typedef int event_handle;
+#endif
+
/* Standard baud rates. */
#ifdef _WIN32
#define BAUD_TYPE DWORD
}
/* Prepare OVERLAPPED structures. */
- memset(&port->read_ovl, 0, sizeof(port->read_ovl));
- memset(&port->write_ovl, 0, sizeof(port->write_ovl));
- port->read_ovl.hEvent = INVALID_HANDLE_VALUE;
- port->write_ovl.hEvent = INVALID_HANDLE_VALUE;
- if ((port->read_ovl.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL)) == INVALID_HANDLE_VALUE) {
+#define INIT_OVERLAPPED(ovl) do { \
+ memset(&port->ovl, 0, sizeof(port->ovl)); \
+ port->ovl.hEvent = INVALID_HANDLE_VALUE; \
+ if ((port->ovl.hEvent = CreateEvent(NULL, TRUE, TRUE, NULL)) \
+ == INVALID_HANDLE_VALUE) { \
+ sp_close(port); \
+ RETURN_FAIL(#ovl "CreateEvent() failed"); \
+ } \
+} while (0)
+
+ INIT_OVERLAPPED(read_ovl);
+ INIT_OVERLAPPED(write_ovl);
+ INIT_OVERLAPPED(wait_ovl);
+
+ /* Set event mask for RX and error events. */
+ if (SetCommMask(port->hdl, EV_RXCHAR | EV_ERR) == 0) {
sp_close(port);
- RETURN_FAIL("read event CreateEvent() failed");
+ RETURN_FAIL("SetCommMask() failed");
}
- if ((port->write_ovl.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL)) == INVALID_HANDLE_VALUE) {
- sp_close(port);
- RETURN_FAIL("write event CreateEvent() failed");
+
+ /* Start background operation for RX and error events. */
+ if (WaitCommEvent(port->hdl, &port->events, &port->wait_ovl) == 0) {
+ if (GetLastError() != ERROR_IO_PENDING) {
+ sp_close(port);
+ RETURN_FAIL("WaitCommEvent() failed");
+ }
}
port->writing = FALSE;
if (CloseHandle(port->hdl) == 0)
RETURN_FAIL("port CloseHandle() failed");
port->hdl = INVALID_HANDLE_VALUE;
- /* Close event handle created for overlapped reads. */
- if (port->read_ovl.hEvent != INVALID_HANDLE_VALUE && CloseHandle(port->read_ovl.hEvent) == 0)
- RETURN_FAIL("read event CloseHandle() failed");
- /* Close event handle created for overlapped writes. */
- if (port->write_ovl.hEvent != INVALID_HANDLE_VALUE && CloseHandle(port->write_ovl.hEvent) == 0)
- RETURN_FAIL("write event CloseHandle() failed");
+
+ /* Close event handles for overlapped structures. */
+#define CLOSE_OVERLAPPED(ovl) do { \
+ if (port->ovl.hEvent != INVALID_HANDLE_VALUE && \
+ CloseHandle(port->ovl.hEvent) == 0) \
+ RETURN_FAIL(# ovl "event CloseHandle() failed"); \
+} while (0)
+ CLOSE_OVERLAPPED(read_ovl);
+ CLOSE_OVERLAPPED(write_ovl);
+ CLOSE_OVERLAPPED(wait_ovl);
+
#else
/* Returns 0 upon success, -1 upon failure. */
if (close(port->fd) == -1)
DEBUG("Waiting for read to complete");
GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE);
DEBUG("Read completed, %d/%d bytes read", bytes_read, count);
- RETURN_VALUE("%d", bytes_read);
} else {
RETURN_FAIL("ReadFile() failed");
}
} else {
DEBUG("Read completed immediately");
- RETURN_VALUE("%d", count);
+ bytes_read = count;
}
+
+ /* Start background operation for subsequent events. */
+ if (WaitCommEvent(port->hdl, &port->events, &port->wait_ovl) == 0) {
+ if (GetLastError() != ERROR_IO_PENDING)
+ RETURN_FAIL("WaitCommEvent() failed");
+ }
+
+ RETURN_VALUE("%d", bytes_read);
+
#else
size_t bytes_read = 0;
unsigned char *ptr = (unsigned char *) buf;
if (GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE) == 0)
RETURN_FAIL("GetOverlappedResult() failed");
+ if (bytes_read > 0) {
+ /* Start background operation for subsequent events. */
+ if (WaitCommEvent(port->hdl, &port->events, &port->wait_ovl) == 0) {
+ if (GetLastError() != ERROR_IO_PENDING)
+ RETURN_FAIL("WaitCommEvent() failed");
+ }
+ }
+
RETURN_VALUE("%d", bytes_read);
#else
ssize_t bytes_read;
#endif
}
+enum sp_return sp_new_event_set(struct sp_event_set **result_ptr)
+{
+ struct sp_event_set *result;
+
+ TRACE("%p", result_ptr);
+
+ if (!result_ptr)
+ RETURN_ERROR(SP_ERR_ARG, "Null result");
+
+ *result_ptr = NULL;
+
+ if (!(result = malloc(sizeof(struct sp_event_set))))
+ RETURN_ERROR(SP_ERR_MEM, "sp_event_set malloc() failed");
+
+ memset(result, 0, sizeof(struct sp_event_set));
+
+ *result_ptr = result;
+
+ RETURN_OK();
+}
+
+static enum sp_return add_handle(struct sp_event_set *event_set,
+ event_handle handle, enum sp_event mask)
+{
+ void *new_handles;
+ enum sp_event *new_masks;
+
+ TRACE("%p, %d, %d", event_set, handle, mask);
+
+ if (!(new_handles = realloc(event_set->handles,
+ sizeof(event_handle) * (event_set->count + 1))))
+ RETURN_ERROR(SP_ERR_MEM, "handle array realloc() failed");
+
+ if (!(new_masks = realloc(event_set->masks,
+ sizeof(enum sp_event) * (event_set->count + 1))))
+ RETURN_ERROR(SP_ERR_MEM, "mask array realloc() failed");
+
+ event_set->handles = new_handles;
+ event_set->masks = new_masks;
+
+ ((event_handle *) event_set->handles)[event_set->count] = handle;
+ event_set->masks[event_set->count] = mask;
+
+ event_set->count++;
+
+ RETURN_OK();
+}
+
+enum sp_return sp_add_port_events(struct sp_event_set *event_set,
+ const struct sp_port *port, enum sp_event mask)
+{
+ TRACE("%p, %p, %d", event_set, port, mask);
+
+ if (!event_set)
+ RETURN_ERROR(SP_ERR_ARG, "Null event set");
+
+ if (!port)
+ RETURN_ERROR(SP_ERR_ARG, "Null port");
+
+ if (mask > (SP_EVENT_RX_READY | SP_EVENT_TX_READY | SP_EVENT_ERROR))
+ RETURN_ERROR(SP_ERR_ARG, "Invalid event mask");
+
+ if (!mask)
+ RETURN_OK();
+
+#ifdef _WIN32
+ enum sp_event handle_mask;
+ if ((handle_mask = mask & SP_EVENT_TX_READY))
+ TRY(add_handle(event_set, port->write_ovl.hEvent, handle_mask));
+ if ((handle_mask = mask & (SP_EVENT_RX_READY | SP_EVENT_ERROR)))
+ TRY(add_handle(event_set, port->wait_ovl.hEvent, handle_mask));
+#else
+ TRY(add_handle(event_set, port->fd, mask));
+#endif
+
+ RETURN_OK();
+}
+
+void sp_free_event_set(struct sp_event_set *event_set)
+{
+ TRACE("%p", event_set);
+
+ if (!event_set) {
+ DEBUG("Null event set");
+ RETURN();
+ }
+
+ DEBUG("Freeing event set");
+
+ if (event_set->handles)
+ free(event_set->handles);
+ if (event_set->masks)
+ free(event_set->masks);
+
+ free(event_set);
+
+ RETURN();
+}
+
+enum sp_return sp_wait(struct sp_event_set *event_set, unsigned int timeout)
+{
+ TRACE("%p, %d", event_set, timeout);
+
+ if (!event_set)
+ RETURN_ERROR(SP_ERR_ARG, "Null event set");
+
+#ifdef _WIN32
+ if (WaitForMultipleObjects(event_set->count, event_set->handles, FALSE,
+ timeout ? timeout : INFINITE) == WAIT_FAILED)
+ RETURN_FAIL("WaitForMultipleObjects() failed");
+
+ RETURN_OK();
+#else
+ struct timeval start, delta, now, end = {0, 0};
+ int result, timeout_remaining;
+ struct pollfd *pollfds;
+ unsigned int i;
+
+ if (!(pollfds = malloc(sizeof(struct pollfd) * event_set->count)))
+ RETURN_ERROR(SP_ERR_MEM, "pollfds malloc() failed");
+
+ for (i = 0; i < event_set->count; i++) {
+ pollfds[i].fd = ((int *) event_set->handles)[i];
+ pollfds[i].events = 0;
+ pollfds[i].revents = 0;
+ if (event_set->masks[i] & SP_EVENT_RX_READY)
+ pollfds[i].events |= POLLIN;
+ if (event_set->masks[i] & SP_EVENT_TX_READY)
+ pollfds[i].events |= POLLOUT;
+ if (event_set->masks[i] & SP_EVENT_ERROR)
+ pollfds[i].events |= POLLERR;
+ }
+
+ if (timeout) {
+ /* Get time at start of operation. */
+ gettimeofday(&start, NULL);
+ /* Define duration of timeout. */
+ delta.tv_sec = timeout / 1000;
+ delta.tv_usec = (timeout % 1000) * 1000;
+ /* Calculate time at which we should give up. */
+ timeradd(&start, &delta, &end);
+ }
+
+ /* Loop until an event occurs. */
+ while (1)
+ {
+ if (timeout) {
+ gettimeofday(&now, NULL);
+ if (timercmp(&now, &end, >)) {
+ DEBUG("wait timed out");
+ break;
+ }
+ timersub(&end, &now, &delta);
+ timeout_remaining = delta.tv_sec * 1000 + delta.tv_usec / 1000;
+ }
+
+ result = poll(pollfds, event_set->count, timeout ? timeout_remaining : -1);
+
+ if (result < 0) {
+ if (errno == EINTR) {
+ DEBUG("poll() call was interrupted, repeating");
+ continue;
+ } else {
+ free(pollfds);
+ RETURN_FAIL("poll() failed");
+ }
+ } else if (result == 0) {
+ DEBUG("poll() timed out");
+ break;
+ } else {
+ DEBUG("poll() completed");
+ break;
+ }
+ }
+
+ free(pollfds);
+ RETURN_OK();
+#endif
+}
+
#ifdef __linux__
static enum sp_return get_baudrate(int fd, int *baudrate)
{
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