Commit 94a40fc5 authored by Marc-André Lureau's avatar Marc-André Lureau Committed by Paolo Bonzini
Browse files

char: introduce CharBackend 



This new structure is meant to keep the details associated with a char
driver usage. On initialization, it gets a tag from the mux backend.
It can change its handlers thanks to qemu_chr_fe_set_handlers().

This structure is introduced so that all frontend will be moved to hold
and use a CharBackend. This will allow to better track char usage and
allocation, and help prevent some memory leaks or corruption.

Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20161022095318.17775-10-marcandre.lureau@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6dfa8298

include/sysemu/char.h

+50 −0
Original line number Diff line number Diff line
@@ -72,6 +72,12 @@ typedef enum { 
    QEMU_CHAR_FEATURE_LAST,

} CharDriverFeature;



/* This is the backend as seen by frontend, the actual backend is

 * CharDriverState */

typedef struct CharBackend {

    CharDriverState *chr;

    int tag;

} CharBackend;



struct CharDriverState {

    QemuMutex chr_write_lock;
@@ -156,6 +162,8 @@ void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend); 
 * Returns: a new character backend

 */

CharDriverState *qemu_chr_new(const char *label, const char *filename);





/**

 * @qemu_chr_disconnect:

 *
@@ -425,6 +433,48 @@ void qemu_chr_be_write_impl(CharDriverState *s, uint8_t *buf, int len); 
 */

void qemu_chr_be_event(CharDriverState *s, int event);



/**

 * @qemu_chr_fe_init:

 *

 * Initializes a front end for the given CharBackend and CharDriver.

 *

 * Returns: false on error.

 */

bool qemu_chr_fe_init(CharBackend *b, CharDriverState *s, Error **errp);



/**

 * @qemu_chr_fe_get_driver:

 *

 * Returns the driver associated with a CharBackend or NULL.

 */

CharDriverState *qemu_chr_fe_get_driver(CharBackend *be);



/**

 * @qemu_chr_fe_set_handlers:

 * @b: a CharBackend

 * @fd_can_read: callback to get the amount of data the frontend may

 *               receive

 * @fd_read: callback to receive data from char

 * @fd_event: event callback

 * @opaque: an opaque pointer for the callbacks

 * @context: a main loop context or NULL for the default

 *

 * Set the front end char handlers.

 */

void qemu_chr_fe_set_handlers(CharBackend *b,

                              IOCanReadHandler *fd_can_read,

                              IOReadHandler *fd_read,

                              IOEventHandler *fd_event,

                              void *opaque,

                              GMainContext *context);



/**

 * @qemu_chr_fe_take_focus:

 *

 * Take the focus (if the front end is muxed)

 */

void qemu_chr_fe_take_focus(CharBackend *b);



void qemu_chr_add_handlers(CharDriverState *s,

                           IOCanReadHandler *fd_can_read,

                           IOReadHandler *fd_read,

qemu-char.c

+50 −0
Original line number Diff line number Diff line
@@ -910,6 +910,53 @@ static CharDriverState *qemu_chr_open_mux(const char *id, 
    return chr;

}



CharDriverState *qemu_chr_fe_get_driver(CharBackend *be)

{

    return be->chr;

}



bool qemu_chr_fe_init(CharBackend *b, CharDriverState *s, Error **errp)

{

    int tag = 0;



    if (s->is_mux) {

        tag = mux_chr_new_handler_tag(s, errp);

        if (tag < 0) {

            return false;

        }

    }



    b->tag = tag;

    b->chr = s;



    return true;

}



void qemu_chr_fe_set_handlers(CharBackend *b,

                              IOCanReadHandler *fd_can_read,

                              IOReadHandler *fd_read,

                              IOEventHandler *fd_event,

                              void *opaque,

                              GMainContext *context)

{

    if (!b->chr) {

        return;

    }



    qemu_chr_set_handlers(b->chr, fd_can_read, fd_read,

                          fd_event, opaque, context, b->tag);



    if (b->chr->is_mux) {

        mux_chr_set_handlers(b->chr, context);

    }

}



void qemu_chr_fe_take_focus(CharBackend *b)

{

    if (b->chr->is_mux) {

        mux_set_focus(b->chr->opaque, b->tag);

    }

}



typedef struct IOWatchPoll

{
@@ -4184,6 +4231,9 @@ void qemu_chr_disconnect(CharDriverState *chr) 


static void qemu_chr_free_common(CharDriverState *chr)

{

    if (chr->be) {

        chr->be->chr = NULL;

    }

    g_free(chr->filename);

    g_free(chr->label);

    if (chr->logfd != -1) {