Commit c55510b7 authored by Cornelia Huck's avatar Cornelia Huck Committed by Markus Armbruster
Browse files

qemu-error: add {error, warn}_report_once_cond 



Add two functions to print an error/warning report once depending
on a passed-in condition variable and flip it if printed. This is
useful if you want to print a message not once-globally, but e.g.
once-per-device.

Inspired by warn_once() in hw/vfio/ccw.c, which has been replaced
with warn_report_once_cond().

Signed-off-by: default avatarCornelia Huck <cohuck@redhat.com>
Message-Id: <20180830145902.27376-2-cohuck@redhat.com>
Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
[Function comments reworded]
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
parent d6f71af6

hw/vfio/ccw.c

+3 −15
Original line number Diff line number Diff line
@@ -37,23 +37,11 @@ typedef struct VFIOCCWDevice { 
    bool warned_orb_pfch;

} VFIOCCWDevice;



static inline void warn_once(bool *warned, const char *fmt, ...)

{

    va_list ap;



    if (!warned || *warned) {

        return;

    }

    *warned = true;

    va_start(ap, fmt);

    warn_vreport(fmt, ap);

    va_end(ap);

}



static inline void warn_once_pfch(VFIOCCWDevice *vcdev, SubchDev *sch,

                                  const char *msg)

{

    warn_once(&vcdev->warned_orb_pfch, "vfio-ccw (devno %x.%x.%04x): %s",

    warn_report_once_cond(&vcdev->warned_orb_pfch,

                          "vfio-ccw (devno %x.%x.%04x): %s",

                          sch->cssid, sch->ssid, sch->devno, msg);

}

include/qemu/error-report.h

+5 −0
Original line number Diff line number Diff line
@@ -44,6 +44,11 @@ void error_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2); 
void warn_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2);

void info_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2);



bool error_report_once_cond(bool *printed, const char *fmt, ...)

    GCC_FMT_ATTR(2, 3);

bool warn_report_once_cond(bool *printed, const char *fmt, ...)

    GCC_FMT_ATTR(2, 3);



/*

 * Similar to error_report(), except it prints the message just once.

 * Return true when it prints, false otherwise.

util/qemu-error.c

+40 −0
Original line number Diff line number Diff line
@@ -310,3 +310,43 @@ void info_report(const char *fmt, ...) 
    vreport(REPORT_TYPE_INFO, fmt, ap);

    va_end(ap);

}



/*

 * Like error_report(), except print just once.

 * If *printed is false, print the message, and flip *printed to true.

 * Return whether the message was printed.

 */

bool error_report_once_cond(bool *printed, const char *fmt, ...)

{

    va_list ap;



    assert(printed);

    if (*printed) {

        return false;

    }

    *printed = true;

    va_start(ap, fmt);

    vreport(REPORT_TYPE_ERROR, fmt, ap);

    va_end(ap);

    return true;

}



/*

 * Like warn_report(), except print just once.

 * If *printed is false, print the message, and flip *printed to true.

 * Return whether the message was printed.

 */

bool warn_report_once_cond(bool *printed, const char *fmt, ...)

{

    va_list ap;



    assert(printed);

    if (*printed) {

        return false;

    }

    *printed = true;

    va_start(ap, fmt);

    vreport(REPORT_TYPE_WARNING, fmt, ap);

    va_end(ap);

    return true;

}