diff options
| -rw-r--r-- | include/sysemu/char.h | 11 | ||||
| -rw-r--r-- | qemu-char.c | 58 |
2 files changed, 53 insertions, 16 deletions
diff --git a/include/sysemu/char.h b/include/sysemu/char.h index bd2b62d21a..c8b15f9729 100644 --- a/include/sysemu/char.h +++ b/include/sysemu/char.h @@ -54,6 +54,7 @@ typedef struct { typedef void IOEventHandler(void *opaque, int event); struct CharDriverState { + QemuMutex chr_write_lock; void (*init)(struct CharDriverState *s); int (*chr_write)(struct CharDriverState *s, const uint8_t *buf, int len); int (*chr_sync_read)(struct CharDriverState *s, @@ -164,6 +165,7 @@ void qemu_chr_fe_event(CharDriverState *s, int event); * @qemu_chr_fe_printf: * * Write to a character backend using a printf style interface. + * This function is thread-safe. * * @fmt see #printf */ @@ -176,8 +178,9 @@ int qemu_chr_fe_add_watch(CharDriverState *s, GIOCondition cond, /** * @qemu_chr_fe_write: * - * Write data to a character backend from the front end. This function will - * send data from the front end to the back end. + * Write data to a character backend from the front end. This function + * will send data from the front end to the back end. This function + * is thread-safe. * * @buf the data * @len the number of bytes to send @@ -192,7 +195,7 @@ int qemu_chr_fe_write(CharDriverState *s, const uint8_t *buf, int len); * Write data to a character backend from the front end. This function will * send data from the front end to the back end. Unlike @qemu_chr_fe_write, * this function will block if the back end cannot consume all of the data - * attempted to be written. + * attempted to be written. This function is thread-safe. * * @buf the data * @len the number of bytes to send @@ -216,7 +219,7 @@ int qemu_chr_fe_read_all(CharDriverState *s, uint8_t *buf, int len); /** * @qemu_chr_fe_ioctl: * - * Issue a device specific ioctl to a backend. + * Issue a device specific ioctl to a backend. This function is thread-safe. * * @cmd see CHR_IOCTL_* * @arg the data associated with @cmd diff --git a/qemu-char.c b/qemu-char.c index 9961b02ce6..a9025e642e 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -121,7 +121,12 @@ void qemu_chr_be_generic_open(CharDriverState *s) int qemu_chr_fe_write(CharDriverState *s, const uint8_t *buf, int len) { - return s->chr_write(s, buf, len); + int ret; + + qemu_mutex_lock(&s->chr_write_lock); + ret = s->chr_write(s, buf, len); + qemu_mutex_unlock(&s->chr_write_lock); + return ret; } int qemu_chr_fe_write_all(CharDriverState *s, const uint8_t *buf, int len) @@ -129,6 +134,7 @@ int qemu_chr_fe_write_all(CharDriverState *s, const uint8_t *buf, int len) int offset = 0; int res; + qemu_mutex_lock(&s->chr_write_lock); while (offset < len) { do { res = s->chr_write(s, buf + offset, len - offset); @@ -137,17 +143,17 @@ int qemu_chr_fe_write_all(CharDriverState *s, const uint8_t *buf, int len) } } while (res == -1 && errno == EAGAIN); - if (res == 0) { + if (res <= 0) { break; } - if (res < 0) { - return res; - } - offset += res; } + qemu_mutex_unlock(&s->chr_write_lock); + if (res < 0) { + return res; + } return offset; } @@ -315,11 +321,14 @@ typedef struct { int prod[MAX_MUX]; int cons[MAX_MUX]; int timestamps; + + /* Protected by the CharDriverState chr_write_lock. */ int linestart; int64_t timestamps_start; } MuxDriver; +/* Called with chr_write_lock held. */ static int mux_chr_write(CharDriverState *chr, const uint8_t *buf, int len) { MuxDriver *d = chr->opaque; @@ -865,6 +874,7 @@ typedef struct FDCharDriver { QTAILQ_ENTRY(FDCharDriver) node; } FDCharDriver; +/* Called with chr_write_lock held. */ static int fd_chr_write(CharDriverState *chr, const uint8_t *buf, int len) { FDCharDriver *s = chr->opaque; @@ -1064,12 +1074,14 @@ static CharDriverState *qemu_chr_open_stdio(ChardevStdio *opts) typedef struct { GIOChannel *fd; - int connected; int read_bytes; + + /* Protected by the CharDriverState chr_write_lock. */ + int connected; guint timer_tag; } PtyCharDriver; -static void pty_chr_update_read_handler(CharDriverState *chr); +static void pty_chr_update_read_handler_locked(CharDriverState *chr); static void pty_chr_state(CharDriverState *chr, int connected); static gboolean pty_chr_timer(gpointer opaque) @@ -1077,14 +1089,17 @@ static gboolean pty_chr_timer(gpointer opaque) struct CharDriverState *chr = opaque; PtyCharDriver *s = chr->opaque; + qemu_mutex_lock(&chr->chr_write_lock); s->timer_tag = 0; if (!s->connected) { /* Next poll ... */ - pty_chr_update_read_handler(chr); + pty_chr_update_read_handler_locked(chr); } + qemu_mutex_unlock(&chr->chr_write_lock); return FALSE; } +/* Called with chr_write_lock held. */ static void pty_chr_rearm_timer(CharDriverState *chr, int ms) { PtyCharDriver *s = chr->opaque; @@ -1101,7 +1116,8 @@ static void pty_chr_rearm_timer(CharDriverState *chr, int ms) } } -static void pty_chr_update_read_handler(CharDriverState *chr) +/* Called with chr_write_lock held. */ +static void pty_chr_update_read_handler_locked(CharDriverState *chr) { PtyCharDriver *s = chr->opaque; GPollFD pfd; @@ -1117,13 +1133,21 @@ static void pty_chr_update_read_handler(CharDriverState *chr) } } +static void pty_chr_update_read_handler(CharDriverState *chr) +{ + qemu_mutex_lock(&chr->chr_write_lock); + pty_chr_update_read_handler_locked(chr); + qemu_mutex_unlock(&chr->chr_write_lock); +} + +/* Called with chr_write_lock held. */ static int pty_chr_write(CharDriverState *chr, const uint8_t *buf, int len) { PtyCharDriver *s = chr->opaque; if (!s->connected) { /* guest sends data, check for (re-)connect */ - pty_chr_update_read_handler(chr); + pty_chr_update_read_handler_locked(chr); return 0; } return io_channel_send(s->fd, buf, len); @@ -1169,6 +1193,7 @@ static gboolean pty_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque) return TRUE; } +/* Called with chr_write_lock held. */ static void pty_chr_state(CharDriverState *chr, int connected) { PtyCharDriver *s = chr->opaque; @@ -1659,9 +1684,12 @@ static CharDriverState *qemu_chr_open_pp_fd(int fd) typedef struct { int max_size; HANDLE hcom, hrecv, hsend; - OVERLAPPED orecv, osend; + OVERLAPPED orecv; BOOL fpipe; DWORD len; + + /* Protected by the CharDriverState chr_write_lock. */ + OVERLAPPED osend; } WinCharState; typedef struct { @@ -1771,6 +1799,7 @@ static int win_chr_init(CharDriverState *chr, const char *filename) return -1; } +/* Called with chr_write_lock held. */ static int win_chr_write(CharDriverState *chr, const uint8_t *buf, int len1) { WinCharState *s = chr->opaque; @@ -2213,6 +2242,7 @@ typedef struct { int max_size; } NetCharDriver; +/* Called with chr_write_lock held. */ static int udp_chr_write(CharDriverState *chr, const uint8_t *buf, int len) { NetCharDriver *s = chr->opaque; @@ -2403,6 +2433,7 @@ static int unix_send_msgfds(CharDriverState *chr, const uint8_t *buf, int len) } #endif +/* Called with chr_write_lock held. */ static int tcp_chr_write(CharDriverState *chr, const uint8_t *buf, int len) { TCPCharDriver *s = chr->opaque; @@ -3000,6 +3031,7 @@ static size_t ringbuf_count(const CharDriverState *chr) return d->prod - d->cons; } +/* Called with chr_write_lock held. */ static int ringbuf_chr_write(CharDriverState *chr, const uint8_t *buf, int len) { RingBufCharDriver *d = chr->opaque; @@ -3024,9 +3056,11 @@ static int ringbuf_chr_read(CharDriverState *chr, uint8_t *buf, int len) RingBufCharDriver *d = chr->opaque; int i; + qemu_mutex_lock(&chr->chr_write_lock); for (i = 0; i < len && d->cons != d->prod; i++) { buf[i] = d->cbuf[d->cons++ & (d->size - 1)]; } + qemu_mutex_unlock(&chr->chr_write_lock); return i; } |