[Qemu-devel] [PATCH][RFC] Add stdio char device on windows

[Fabien Chouteau]

Simple implementation of an stdio char device on Windows.

Signed-off-by: Fabien Chouteau <address@hidden>
---
 qemu-char.c |  171 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 171 insertions(+), 0 deletions(-)

diff --git a/qemu-char.c b/qemu-char.c
index edc9ad6..c18e668 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -1436,6 +1436,11 @@ static CharDriverState *qemu_chr_open_pp(QemuOpts *opts)
 
 #else /* _WIN32 */
 
+#define STDIO_MAX_CLIENTS 2
+
+static int stdio_nb_clients;
+static CharDriverState *stdio_clients[STDIO_MAX_CLIENTS];
+
 typedef struct {
     int max_size;
     HANDLE hcom, hrecv, hsend;
@@ -1788,6 +1793,171 @@ static CharDriverState 
*qemu_chr_open_win_file_out(QemuOpts *opts)
 
     return qemu_chr_open_win_file(fd_out);
 }
+
+static int win_stdio_write(CharDriverState *chr, const uint8_t *buf, int len)
+{
+    HANDLE *Output = GetStdHandle(STD_OUTPUT_HANDLE);
+    DWORD   size;
+    int     len1;
+
+    len1 = len;
+
+    while (len1 > 0) {
+        if (!WriteFile(Output, buf, len1, &size, NULL)) {
+            break;
+        }
+        buf  += size;
+        len1 -= size;
+    }
+
+    return len - len1;
+}
+
+static HANDLE *Input;
+
+static void win_stdio_wait_func(void *opaque)
+{
+    CharDriverState *chr = opaque;
+    INPUT_RECORD     buf[4];
+    int              ret;
+    DWORD            size;
+    int              i;
+
+    ret = ReadConsoleInput(Input, buf, sizeof(buf)/sizeof(*buf), &size);
+
+    if (!ret) {
+        /* Avoid error storm */
+        qemu_del_wait_object(Input, NULL, NULL);
+        return;
+    }
+
+    for (i = 0; i < size; i++) {
+        KEY_EVENT_RECORD *kev = &buf[i].Event.KeyEvent;
+
+        if (buf[i].EventType == KEY_EVENT && kev->bKeyDown) {
+            int j;
+            if (kev->uChar.AsciiChar != 0) {
+                for (j = 0; j < kev->wRepeatCount; j++)
+                    if (qemu_chr_can_read(chr)) {
+                        uint8_t c = kev->uChar.AsciiChar;
+                        qemu_chr_read(chr, &c, 1);
+                    }
+            }
+        }
+    }
+}
+
+static HANDLE  InputReadyEvent;
+static HANDLE  InputDoneEvent;
+static uint8_t InputBuf;
+
+static DWORD WINAPI win_stdio_thread(LPVOID param)
+{
+    int   ret;
+    DWORD size;
+
+    while (1) {
+
+        /* Wait for one byte */
+        ret = ReadFile(Input, &InputBuf, 1, &size, NULL);
+
+        /* Exit in case of error, continue if nothing read */
+        if (!ret) {
+            break;
+        }
+        if (!size) {
+            continue;
+        }
+
+        /* Some terminal emulator returns \r\n for Enter, just pass \n */
+        if (InputBuf == '\r') {
+            continue;
+        }
+
+        /* Signal the main thread and wait until the byte was eaten */
+        if (!SetEvent(InputReadyEvent)) {
+            break;
+        }
+        if (WaitForSingleObject(InputDoneEvent, INFINITE) != WAIT_OBJECT_0) {
+            break;
+        }
+    }
+
+    qemu_del_wait_object(InputReadyEvent, NULL, NULL);
+    return 0;
+}
+
+static void win_stdio_thread_wait_func(void *opaque)
+{
+    CharDriverState *chr = opaque;
+
+    if (qemu_chr_can_read(chr)) {
+        qemu_chr_read(chr, &InputBuf, 1);
+    }
+
+    SetEvent(InputDoneEvent);
+}
+
+static CharDriverState *qemu_chr_open_win_stdio(QemuOpts *opts)
+{
+    CharDriverState *chr;
+    DWORD            mode;
+    int              is_console = 0;
+
+    Input = GetStdHandle(STD_INPUT_HANDLE);
+    if (Input == INVALID_HANDLE_VALUE) {
+        fprintf(stderr, "cannot open stdio: invalid handle\n");
+        exit(1);
+    }
+
+    is_console = GetConsoleMode(Input, &mode) != 0;
+
+    if (stdio_nb_clients >= STDIO_MAX_CLIENTS
+        || ((display_type != DT_NOGRAPHIC) && (stdio_nb_clients != 0))) {
+        return NULL;
+    }
+
+    chr = qemu_mallocz(sizeof(CharDriverState));
+    if (!chr) {
+        return NULL;
+    }
+
+    chr->chr_write = win_stdio_write;
+
+    if (stdio_nb_clients == 0) {
+        if (is_console) {
+            if (qemu_add_wait_object(InputReadyEvent,
+                                     win_stdio_thread_wait_func, chr)) {
+                fprintf(stderr, "qemu_add_wait_object: failed\n");
+            }
+        } else {
+            DWORD   id;
+            HANDLE *InputThread;
+
+            InputReadyEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
+            InputDoneEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
+            InputThread = CreateThread(NULL, 0, win_stdio_thread, chr, 0, &id);
+
+            if (InputThread == INVALID_HANDLE_VALUE
+                || InputReadyEvent == INVALID_HANDLE_VALUE
+                || InputDoneEvent == INVALID_HANDLE_VALUE) {
+                fprintf(stderr, "cannot create stdio thread or event\n");
+                exit(1);
+            }
+            if (qemu_add_wait_object(Input, win_stdio_thread_wait_func, chr)) {
+                fprintf(stderr, "qemu_add_wait_object: failed\n");
+            }
+        }
+    }
+
+    stdio_clients[stdio_nb_clients++] = chr;
+    if (stdio_nb_clients == 1 && is_console) {
+        /* set the terminal in raw mode */
+        /* ENABLE_QUICK_EDIT_MODE | ENABLE_EXTENDED_FLAGS */
+        SetConsoleMode(Input, ENABLE_PROCESSED_INPUT);
+    }
+    return chr;
+}
 #endif /* !_WIN32 */
 
 /***********************************************************/
@@ -2477,6 +2647,7 @@ static const struct {
     { .name = "pipe",      .open = qemu_chr_open_win_pipe },
     { .name = "console",   .open = qemu_chr_open_win_con },
     { .name = "serial",    .open = qemu_chr_open_win },
+    { .name = "stdio",     .open = qemu_chr_open_win_stdio },
 #else
     { .name = "file",      .open = qemu_chr_open_file_out },
     { .name = "pipe",      .open = qemu_chr_open_pipe },
-- 
1.7.1