diff options
| author | Robert Foley <robert.foley@linaro.org> | 2019-11-18 16:15:25 -0500 |
|---|---|---|
| committer | Alex Bennée <alex.bennee@linaro.org> | 2019-12-18 20:18:02 +0000 |
| commit | b8121fe7c005dc3d56e82a0a5ce00563a5fd49d0 (patch) | |
| tree | dea1643897c884bced66717121925c30f901f71a /util | |
| parent | 045e8861df8ec0922b1c47929d23dd61d8b75f8c (diff) | |
Add a mutex to guarantee single writer to qemu_logfile handle.
Also added qemu_logfile_init() for initializing the logfile mutex.
Note that inside qemu_set_log() we needed to add a pair of
qemu_mutex_unlock() calls in order to avoid a double lock in
qemu_log_close(). This unavoidable temporary ugliness will be
cleaned up in a later patch in this series.
Signed-off-by: Robert Foley <robert.foley@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20191118211528.3221-4-robert.foley@linaro.org>
Diffstat (limited to 'util')
| -rw-r--r-- | util/log.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/util/log.c b/util/log.c index 417d16ec66..953a66b5a8 100644 --- a/util/log.c +++ b/util/log.c @@ -24,8 +24,10 @@ #include "qapi/error.h" #include "qemu/cutils.h" #include "trace/control.h" +#include "qemu/thread.h" static char *logfilename; +static QemuMutex qemu_logfile_mutex; FILE *qemu_logfile; int qemu_loglevel; static int log_append = 0; @@ -49,6 +51,11 @@ int qemu_log(const char *fmt, ...) return ret; } +static void __attribute__((__constructor__)) qemu_logfile_init(void) +{ + qemu_mutex_init(&qemu_logfile_mutex); +} + static bool log_uses_own_buffers; /* enable or disable low levels log */ @@ -70,7 +77,9 @@ void qemu_set_log(int log_flags) if (qemu_loglevel && (!is_daemonized() || logfilename)) { need_to_open_file = true; } + qemu_mutex_lock(&qemu_logfile_mutex); if (qemu_logfile && !need_to_open_file) { + qemu_mutex_unlock(&qemu_logfile_mutex); qemu_log_close(); } else if (!qemu_logfile && need_to_open_file) { if (logfilename) { @@ -105,6 +114,7 @@ void qemu_set_log(int log_flags) #endif log_append = 1; } + qemu_mutex_unlock(&qemu_logfile_mutex); } } @@ -240,12 +250,14 @@ void qemu_log_flush(void) /* Close the log file */ void qemu_log_close(void) { + qemu_mutex_lock(&qemu_logfile_mutex); if (qemu_logfile) { if (qemu_logfile != stderr) { fclose(qemu_logfile); } qemu_logfile = NULL; } + qemu_mutex_unlock(&qemu_logfile_mutex); } const QEMULogItem qemu_log_items[] = { |