Re sending the patch following Gilles comments

Gilles Chanteperdrix wrote:

On 9/3/07, Ravid Baruch Naali <[EMAIL PROTECTED]> wrote:
Hello again,

Hi,

I'm not sure what is the preferred way to commit my changes, so before I
commit i'm Attaching my patch in order to get you remarks and further
instructions

The synchronization on tasks completion with the semID semaphore seems
broken. The main thread will get the semahore when the first task
completes, not when all the tasks complete.

I see too many comments, for instance:
// Checking for failures
if (error == ERROR)

is useless, it is pretty obvious from reading the code that you are
checking for failure. Comments should tell us things that are not
obvious.

Now, about the style, this is C code, so use C style comments. I would
also prefer that you use the kernel coding style, but this is not
kernel code, so I am not sure the rule is to use the kernel coding
style.


--
Ravid Baruch Naali
[EMAIL PROTECTED]
+972 4 6732729
+972 52 5830021

Index: ksrc/skins/vxworks/demos/sem.c
===================================================================
--- ksrc/skins/vxworks/demos/sem.c	(revision 0)
+++ ksrc/skins/vxworks/demos/sem.c	(revision 0)
@@ -0,0 +1,138 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <vxworks/vxworks.h>
+#include <sys/mman.h>
+
+
+#define TASK_NUM 10
+#define STACK_SIZE 1024
+#define LOOPS 10
+#define xnarch_printf printf
+#define TOP_PRIORITY 25
+
+SEM_ID task_counter_sem;
+SEM_ID task_sync_sem;
+
+static errno_to_messgae(char *failing_func);
+
+/*
+ * A shared main routine for all tasks other then the main
+ * each task waits for the signal from the main task
+ * then it notify it's existing 
+ *
+ * It then loops and prints out LOOPS times it's name and tid
+ * when done it notifies
+ * 
+ * None of the parameters are being used
+ */
+void task_main_routine(long arg1, long arg2, long arg3, long arg4, long arg5, long arg6,
+	long arg7, long arg8, long arg9, long arg10)
+{
+	int localerrno;
+	STATUS result;
+	int priority;
+	int i = LOOPS;
+	int ownID = taskIdSelf();
+
+	/*Waiting to start synchronized with all other spawned tasks*/
+	result = semTake(task_sync_sem, WAIT_FOREVER);
+	if (result == ERROR) {
+		errno_to_messgae("semTake counter");	
+		return;
+	}
+	/*Taking the counting semaphore to indicate task started running stall
+	 * main from exiting */
+	result = semTake(task_counter_sem, WAIT_FOREVER);
+	if (result == ERROR) {
+		errno_to_messgae("semTake counter");	
+		return;
+	}
+	result = taskPriorityGet(ownID, &priority);
+	
+	xnprintf( "Task priority is %d\n", priority);
+	while (i) {
+		xnprintf("Task name is %s tid=%d\n", taskName(ownID), ownID);
+		sleep(1);
+		i--;
+	}
+	/*Signaling this task is done*/
+	semGive(task_counter_sem);
+}
+
+/*
+ * Main task:
+ * spawns TASK_NUM tasks synchronize their operation 
+ * exit and clean up when all tasks are done
+ */
+int main(int argc, char **argv)
+{
+	/*array holding all tasks ids*/
+	int tids[TASK_NUM];
+	int i;
+	mlockall(MCL_CURRENT|MCL_FUTURE);
+	/* counting semaphore inital value set to the number of tasks*/
+	task_counter_sem = semCCreate(SEM_Q_PRIORITY, TASK_NUM);
+	if (!task_counter_sem) {
+		xnprintf( "Failed to create semaphore\n");
+		exit(1);
+	}
+	/* semaphore to synchronize all task operation */
+	task_sync_sem = semBCreate(SEM_Q_PRIORITY, SEM_EMPTY);
+	if (!task_sync_sem) {
+		xnprintf( "Failed to create binary semaphore\n");
+		exit(1);
+	}
+	for (i = 0; i < TASK_NUM; i++) {
+		tids[i] = taskSpawn(NULL, (TOP_PRIORITY - i), 0, STACK_SIZE , 
+				task_main_routine,0,0,0,0,0,0,0,0,0,0);
+		xnprintf( "Spawned task: %d\n", tids[i]);
+	}
+	/* Signaling all tasks to run */
+	semFlush(task_sync_sem);
+	/* Waiting for all task to complete their main routine */
+	for (i = 0; i < TASK_NUM; i++)
+		semTake(task_counter_sem, WAIT_FOREVER);
+	/* Cleanup */
+	for (i = 0; i < TASK_NUM; i++)
+		taskDelete(tids[i]);
+	semDelete(task_counter_sem);
+	semDelete(task_sync_sem);
+}
+
+
+/*
+ * Prints out the meaning of an error with relation to the failing function
+ *
+ * parameter:
+ * a prefix string to the failure reason 
+ */
+static errno_to_messgae(char *failing_func)
+{
+	int localerrno = errnoGet();
+	xnprintf("%s: ", failing_func);
+	switch(localerrno){
+	case S_objLib_OBJ_ID_ERROR:
+		xnprintf( "Semaphore ID is invalid\n");
+		break;
+	case S_objLib_OBJ_UNAVAILABLE:
+		xnprintf( "Semaphore unavailable (NO_WAIT)\n");
+		break;
+	case S_objLib_OBJ_TIMEOUT:
+		xnprintf( "Timeout occured before semaphore was"
+				" released\n");
+		break;
+	case S_semLib_INVALID_OPTION:
+		xnprintf( "Semaphore type is invalid\n");
+		break;
+	case EINTR:
+		xnprintf( "Received interup\n");
+		break;
+	default:
+		break;
+	}
+}
Index: ksrc/skins/vxworks/demos/Makefile
===================================================================
--- ksrc/skins/vxworks/demos/Makefile	(revision 2960)
+++ ksrc/skins/vxworks/demos/Makefile	(working copy)
@@ -7,7 +7,7 @@
 
 STD_CFLAGS  := $(shell $(XENO_CONFIG) --xeno-cflags)
 STD_LDFLAGS := $(shell $(XENO_CONFIG) --xeno-ldflags) -lvxworks
-STD_TARGETS := satch
+STD_TARGETS := satch sem
 
 GCIC := $(prefix)/bin/gcic
 SIM_CFLAGS  := -g
@@ -27,6 +27,9 @@
 satch: satch.c
 	$(CC) -o $@ $< $(STD_CFLAGS) $(STD_LDFLAGS)
 
+sem: sem.c
+	$(CC) -o $@ $< $(STD_CFLAGS) $(STD_LDFLAGS)
+
 satch_sim: satch_sim.o
 	$(GCIC) -o $@ $< $(SIM_LDFLAGS)
 
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