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[PATCH v2 3/6] Add a mutex to guarantee single writer to qemu_logfile ha
From: |
Robert Foley |
Subject: |
[PATCH v2 3/6] Add a mutex to guarantee single writer to qemu_logfile handle. |
Date: |
Fri, 15 Nov 2019 08:10:37 -0500 |
Also added qemu_logfile_init() for initializing the logfile mutex.
Signed-off-by: Robert Foley <address@hidden>
---
v2
- In qemu_set_log() moved location of mutex lock/unlock
due to cleanup changes.
---
v1
- changed qemu_logfile_init() to use __constructor__.
---
util/log.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/util/log.c b/util/log.c
index 417d16ec66..91ebb5c924 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 +77,10 @@ void qemu_set_log(int log_flags)
if (qemu_loglevel && (!is_daemonized() || logfilename)) {
need_to_open_file = true;
}
+ g_assert(qemu_logfile_mutex.initialized);
+ 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 +115,7 @@ void qemu_set_log(int log_flags)
#endif
log_append = 1;
}
+ qemu_mutex_unlock(&qemu_logfile_mutex);
}
}
@@ -240,12 +251,15 @@ void qemu_log_flush(void)
/* Close the log file */
void qemu_log_close(void)
{
+ g_assert(qemu_logfile_mutex.initialized);
+ 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[] = {
--
2.17.1
- [PATCH v2 0/6] Make the qemu_logfile handle thread safe., Robert Foley, 2019/11/15
- [PATCH v2 1/6] Fix double free issue in qemu_set_log_filename()., Robert Foley, 2019/11/15
- [PATCH v2 3/6] Add a mutex to guarantee single writer to qemu_logfile handle.,
Robert Foley <=
- [PATCH v2 2/6] Cleaned up flow of code in qemu_set_log(), to simplify and clarify., Robert Foley, 2019/11/15
- [PATCH v2 4/6] qemu_log_lock/unlock now preserves the qemu_logfile handle., Robert Foley, 2019/11/15
- [PATCH v2 5/6] Add use of RCU for qemu_logfile., Robert Foley, 2019/11/15