Re: [Xenomai-help] :: rt_printf with daemonized task

[oliver.schlenker@domain.hid]

-------- Original Message --------
Subject: Re: :: rt_printf with daemonized task (09-Okt-2009 15:49)
From:    Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
To:      oliver.schlenker@smmotioncontrol.de

> oliver.schlenker@smmotioncontrol.de wrote:
> > +#define RT_PRINT_SYSLOG_STREAM	((FILE *)-9999)
> 
> -9999 may be a valid pointer. Only values between -4096 and 4095 can not
> be valid pointers.
> 
> -- 
>                                           Gilles
> 

ok, did change it to -99.



Oliver



--- rt_print.c.original	2008-09-10 10:36:27.000000000 +0200
+++ rt_print.c	2009-10-09 15:52:07.404908000 +0200
                 
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <syslog.h>
 
 #include <rtdk.h>
 #include <asm/xenomai/system.h>
                  
 
 #define RT_PRINT_LINE_BREAK		256
 
+#define RT_PRINT_SYSLOG_STREAM	((FILE *)-99)
+
 struct entry_head {
 	FILE *dest;
 	uint32_t seq_no;
+	int priority;
 	char text[1];
 } __attribute__((packed));
 
                   
 
 static void cleanup_buffer(struct print_buffer *buffer);
 static void print_buffers(void);
+static void rt_print_reinit_atfork_prepare(void);
+static void rt_print_reinit_atfork_child(void);
 
 /* *** rt_print API *** */
 
-int rt_vfprintf(FILE *stream, const char *format, va_list args)
+static int rt_print_to_buffer(FILE *stream, int priority, const char *format, va_list args)
 {
 	struct print_buffer *buffer = pthread_getspecific(__buffer_key);
 	off_t write_pos, read_pos;
                   
 			/* Write out empty entry */
 			head = buffer->ring + write_pos;
 			head->seq_no = __seq_no;
+			head->priority = 0;
 			head->text[0] = 0;
 
 			/* Forward to the ring buffer start */
                   
 	/* If we were able to write some text, finalise the entry */
 	if (len > 0) {
 		head->seq_no = ++__seq_no;
+		head->priority = priority;
 		head->dest = stream;
 
 		/* Move forward by text and head length */
                   
 		/* An empty entry marks the wrap-around */
 		head = buffer->ring + write_pos;
 		head->seq_no = __seq_no;
+		head->priority = priority;
 		head->text[0] = 0;
 
 		write_pos = 0;
                    
 	return res;
 }
 
+int rt_vfprintf(FILE *stream, const char *format, va_list args)
+{
+	return rt_print_to_buffer( stream, 0, format, args);
+}
+
 int rt_vprintf(const char *format, va_list args)
 {
 	return rt_vfprintf(stdout, format, args);
                    
 	return n;
 }
 
+void rt_syslog(int priority, char *format, ...)
+{
+	va_list args;
+
+	va_start(args, format);
+	rt_print_to_buffer(RT_PRINT_SYSLOG_STREAM, priority, format, args);
+	va_end(args);
+
+	return;
+}
+
+void rt_vsyslog(int priority, char *format, va_list args )
+{
+
+	rt_print_to_buffer(RT_PRINT_SYSLOG_STREAM, priority, format, args);
+
+	return;
+}
+
 static void set_buffer_name(struct print_buffer *buffer, const char *name)
 {
 	int n;
                    
 
 		if (len) {
 			/* Print out non-empty entry and proceed */
-			fprintf(head->dest, "%s", head->text);
+			/* Check if output goes to syslog */
+			if (head->dest == RT_PRINT_SYSLOG_STREAM) {
+			   	syslog( head->priority, "%s", head->text );
+			} else {
+				/* Output goes to specified stream */
+				fprintf(head->dest, "%s", head->text);
+			}
+
 			read_pos += sizeof(*head) + len;
 		} else {
 			/* Emptry entries mark the wrap-around */
                    
 	}
 }
 
+static void rt_print_reinit_atfork_child(void)
+{
+	pthread_attr_t thattr;
+	struct print_buffer *buffer,*next_b;
+
+	/* Clean parent process buffer list -
+	   Shouldn't be necessary because also done at atfork_parent
+	*/
+	buffer = __first_buffer;
+	while (buffer) {
+		next_b = buffer->next;
+		cleanup_buffer(buffer);
+		buffer = next_b;
+	}
+
+	/* Throw new thread with printer loop in child process */
+	pthread_attr_init(&thattr);
+	pthread_attr_setstacksize(&thattr, PTHREAD_STACK_MIN);
+	pthread_create(&__printer_thread, &thattr, printer_loop, NULL);
+	pthread_atfork(rt_print_reinit_atfork_prepare,NULL,rt_print_reinit_atfork_child);
+}
+
+static void rt_print_reinit_atfork_prepare(void)
+{
+	struct print_buffer *buffer,*next_b;
+
+	/* Clean parent process buffer list */
+	buffer = __first_buffer;
+	while (buffer) {
+		next_b = buffer->next;
+		cleanup_buffer(buffer);
+		buffer = next_b;
+	}
+}
+
 void __rt_print_init(void)
 {
 	pthread_attr_t thattr;
                   
 	pthread_attr_init(&thattr);
 	pthread_attr_setstacksize(&thattr, PTHREAD_STACK_MIN);
 	pthread_create(&__printer_thread, &thattr, printer_loop, NULL);
+	pthread_atfork(rt_print_reinit_atfork_prepare,NULL,rt_print_reinit_atfork_child);
 } 

To: gilles.chanteperdrix@xenomai.org
Cc: jan.kiszka@siemens.com
    xenomai-help@gna.org