log: passing user-defined log

Signed-off-by: zkhatami88 <z.khatami88@gmail.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/456407 (master)

(cherry picked from commit 46523f33e016ac36b998873041a1ca89528c4dbb)
Change-Id: I993e15a6e75029b0717960d5da31325e7f3522c1
Signed-off-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/458450
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

include/spdk/event.h

@@ -132,6 +132,19 @@ struct spdk_app_opts {
 
 	/** Opaque context for use of the env implementation. */
 	void			*env_context;
+
+	/**
+	 * for passing user-provided log call
+	 *
+	 * \param level Log level threshold.
+	 * \param file Name of the current source file.
+	 * \param line Current source file line.
+	 * \param func Current source function name.
+	 * \param format Format string to the message.
+	 */
+	void (* log)(int level, const char *file, const int line,
+		     const char *func, const char *format);
+
 };
 
 /**

include/spdk/log.h

@@ -45,11 +45,14 @@
 extern "C" {
 #endif
 
+typedef void logfunc(int level, const char *file, const int line,
+		     const char *func, const char *format);
+
 /**
  * Initialize the logging module. Messages prior
  * to this call will be dropped.
  */
-void spdk_log_open(void);
+void spdk_log_open(logfunc *logf);
 
 /**
  * Close the currently active log. Messages after this call

lib/event/app.c

@@ -623,7 +623,7 @@ spdk_app_start(struct spdk_app_opts *opts, spdk_msg_fn start_fn,
 		goto app_start_setup_conf_err;
 	}
 
-	spdk_log_open();
+	spdk_log_open(opts->log);
 	SPDK_NOTICELOG("Total cores available: %d\n", spdk_env_get_core_count());
 
 	/*

lib/log/log.c

@@ -50,16 +50,24 @@ static const char *const spdk_level_names[] = {
 
 #define MAX_TMPBUF 1024
 
+static logfunc *g_log = NULL;
+
 void
-spdk_log_open(void)
+spdk_log_open(logfunc *logf)
 {
-	openlog("spdk", LOG_PID, LOG_LOCAL7);
+	if (logf) {
+		g_log = logf;
+	} else {
+		openlog("spdk", LOG_PID, LOG_LOCAL7);
+	}
 }
 
 void
 spdk_log_close(void)
 {
-	closelog();
+	if (!g_log) {
+		closelog();
+	}
 }
 
 #ifdef SPDK_LOG_BACKTRACE_LVL
@@ -126,20 +134,25 @@ spdk_log(enum spdk_log_level level, const char *file, const int line, const char
 		return;
 	}
 
-	va_start(ap, format);
+	if (g_log) {
+		g_log(level, file, line, func, format);
 
-	vsnprintf(buf, sizeof(buf), format, ap);
+	} else {
+		va_start(ap, format);
 
-	if (level <= g_spdk_log_print_level) {
-		fprintf(stderr, "%s:%4d:%s: *%s*: %s", file, line, func, spdk_level_names[level], buf);
-		spdk_log_unwind_stack(stderr, level);
+		vsnprintf(buf, sizeof(buf), format, ap);
+
+		if (level <= g_spdk_log_print_level) {
+			fprintf(stderr, "%s:%4d:%s: *%s*: %s", file, line, func, spdk_level_names[level], buf);
+			spdk_log_unwind_stack(stderr, level);
+		}
+
+		if (level <= g_spdk_log_level) {
+			syslog(severity, "%s:%4d:%s: *%s*: %s", file, line, func, spdk_level_names[level], buf);
+		}
+
+		va_end(ap);
 	}
-
-	if (level <= g_spdk_log_level) {
-		syslog(severity, "%s:%4d:%s: *%s*: %s", file, line, func, spdk_level_names[level], buf);
-	}
-
-	va_end(ap);
 }
 
 static void

test/unit/lib/log/log.c/log_ut.c

@@ -74,7 +74,7 @@ log_test(void)
 	CU_ASSERT(spdk_log_get_flag("log") == false);
 #endif
 
-	spdk_log_open();
+	spdk_log_open(NULL);
 	spdk_log_set_flag("log");
 	SPDK_WARNLOG("log warning unit test\n");
 	SPDK_DEBUGLOG(SPDK_LOG_LOG, "log test\n");