]> sigrok.org Git - libserialport.git/blobdiff - serialport.c
Add API for waiting on port events.
[libserialport.git] / serialport.c
index b7dd66a3bfad1220d319a75fb141cae588ee47e7..2adf9357a632adf75da56bf52a147bb275fd3bcb 100644 (file)
@@ -39,6 +39,7 @@
 #include <sys/ioctl.h>
 #include <sys/time.h>
 #include <limits.h>
+#include <poll.h>
 #endif
 #ifdef __APPLE__
 #include <IOKit/IOKitLib.h>
@@ -82,6 +83,8 @@ struct sp_port {
        COMMTIMEOUTS timeouts;
        OVERLAPPED write_ovl;
        OVERLAPPED read_ovl;
+       OVERLAPPED wait_ovl;
+       DWORD events;
        BYTE pending_byte;
        BOOL writing;
 #else
@@ -112,6 +115,12 @@ struct port_data {
 #endif
 };
 
+#ifdef _WIN32
+typedef HANDLE event_handle;
+#else
+typedef int event_handle;
+#endif
+
 /* Standard baud rates. */
 #ifdef _WIN32
 #define BAUD_TYPE DWORD
@@ -541,7 +550,7 @@ out:
                *list_ptr = list;
                RETURN_OK();
        case SP_ERR_SUPP:
-               DEBUG_ERROR(SP_ERR_SUPP, "Enumeration not supported on this platform.");
+               DEBUG_ERROR(SP_ERR_SUPP, "Enumeration not supported on this platform");
        default:
                if (list)
                        sp_free_port_list(list);
@@ -608,8 +617,9 @@ enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
        DEBUG("Opening port %s", port->name);
 
 #ifdef _WIN32
-       DWORD desired_access = 0, flags_and_attributes = 0;
+       DWORD desired_access = 0, flags_and_attributes = 0, errors;
        char *escaped_port_name;
+       COMSTAT status;
 
        /* Prefix port name with '\\.\' to work with ports above COM9. */
        if (!(escaped_port_name = malloc(strlen(port->name + 5))))
@@ -644,17 +654,32 @@ enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
        }
 
        /* 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;
@@ -727,6 +752,11 @@ enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
        data.term.c_cflag |= (CLOCAL | CREAD | HUPCL);
 #endif
 
+#ifdef _WIN32
+       if (ClearCommError(port->hdl, &errors, &status) == 0)
+               RETURN_FAIL("ClearCommError() failed");
+#endif
+
        ret = set_config(port, &data, &config);
 
        if (ret < 0) {
@@ -750,12 +780,17 @@ enum sp_return sp_close(struct sp_port *port)
        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)
@@ -1000,20 +1035,27 @@ enum sp_return sp_nonblocking_write(struct sp_port *port, const void *buf, size_
                /* Start asynchronous write. */
                if (WriteFile(port->hdl, &port->pending_byte, 1, NULL, &port->write_ovl) == 0) {
                        if (GetLastError() == ERROR_IO_PENDING) {
-                               DEBUG("Asynchronous write started");
-                               port->writing = 1;
-                               RETURN_VALUE("%d", ++written);
+                               if (HasOverlappedIoCompleted(&port->write_ovl)) {
+                                       DEBUG("Asynchronous write completed immediately");
+                                       port->writing = 0;
+                                       written++;
+                                       continue;
+                               } else {
+                                       DEBUG("Asynchronous write running");
+                                       port->writing = 1;
+                                       RETURN_VALUE("%d", ++written);
+                               }
                        } else {
                                /* Actual failure of some kind. */
                                RETURN_FAIL("WriteFile() failed");
                        }
                } else {
-                       DEBUG("Single byte written immediately.");
+                       DEBUG("Single byte written immediately");
                        written++;
                }
        }
 
-       DEBUG("All bytes written immediately.");
+       DEBUG("All bytes written immediately");
 
        RETURN_VALUE("%d", written);
 #else
@@ -1059,14 +1101,22 @@ enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, u
                        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;
@@ -1158,6 +1208,14 @@ enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, size_t count
        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;
@@ -1188,7 +1246,7 @@ enum sp_return sp_input_waiting(struct sp_port *port)
        COMSTAT comstat;
 
        if (ClearCommError(port->hdl, &errors, &comstat) == 0)
-               RETURN_FAIL("ClearComError() failed");
+               RETURN_FAIL("ClearCommError() failed");
        RETURN_VALUE("%d", comstat.cbInQue);
 #else
        int bytes_waiting;
@@ -1211,7 +1269,7 @@ enum sp_return sp_output_waiting(struct sp_port *port)
        COMSTAT comstat;
 
        if (ClearCommError(port->hdl, &errors, &comstat) == 0)
-               RETURN_FAIL("ClearComError() failed");
+               RETURN_FAIL("ClearCommError() failed");
        RETURN_VALUE("%d", comstat.cbOutQue);
 #else
        int bytes_waiting;
@@ -1221,6 +1279,186 @@ enum sp_return sp_output_waiting(struct sp_port *port)
 #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)
 {
@@ -1575,7 +1813,6 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 
        if (config->parity >= 0) {
                switch (config->parity) {
-               /* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
                case SP_PARITY_NONE:
                        data->dcb.Parity = NOPARITY;
                        break;