teste: Add test-shmem-three-async test

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>

test/Makefile

 SRCS	+= test-counter.c
 SRCS	+= test-rnd-from-file.c
 SRCS	+= test-shmem-async.c
+SRCS	+= test-shmem-three-async.c
 
 OBJS	:= $(patsubst %.c,%.o,$(SRCS))
 PROGS	:= $(patsubst %.c,%,$(SRCS))

test/test-shmem-three-async.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <signal.h>
+#include <string.h>
+
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+
+#include <sched.h>
+
+static void *map1;
+static void *map2;
+
+int main(int argc, char *argv[])
+{
+	pid_t pid;
+
+	printf("%s pid %d\n", argv[0], getpid());
+
+	map1 = mmap(NULL, 1024, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
+	map2 = mmap(NULL, 1024, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
+	if (map1 == MAP_FAILED || map2 == MAP_FAILED) {
+		printf("%6d: mmap failed\n", getpid());
+		return 0;
+	}
+
+	memset(map1, '-', 22);
+	((char *)map1)[22] = 0;
+
+	memset(map2, '+', 22);
+	((char *)map1)[22] = 0;
+
+	printf("%6d: Initial  shmem1 pattern '%s'\n", getpid(), (char *)map1);
+
+	pid = fork();
+	if (pid == -1) {
+		printf("fork1 failed\n");
+		return 1;
+	} else if (pid == 0) {
+		int cnt = 0;
+
+		pid = fork();
+		if (pid == -1) {
+			printf("fork2 failed\n");
+			exit(1);
+		} else if (pid == 0) {
+			int num = 0;
+			while(1) {
+				printf("%6d: Observed shmem2 pattern '%s'\n", getpid(), (char *)map2);
+				sprintf(map2, "shared-mem2-%010d", num);
+				sleep(1);
+				num += 2;
+			}
+		}
+
+		cnt = -1;
+		while(1) {
+			cnt += 2;
+			printf("%6d: Observed shmem1 pattern '%s'\n", getpid(), (char *)map1);
+			sprintf(map1, "shared-mem1-%010d", cnt);
+			sleep(1);
+		}
+	} else {
+		while(1) {
+			printf("%6d: Observed shmem1 pattern '%s'\n", getpid(), (char *)map1);
+			printf("%6d: Observed shmem2 pattern '%s'\n", getpid(), (char *)map2);
+			sleep(1);
+		}
+	}
+
+	return 0;
+}