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davidwang200099 · Jul 13, 2020 · 275e044 · 275e044
1 parent b1bcaa4
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diff --git a/Bonus-1-daemon/daemon/jni/Android.mk b/Bonus-1-daemon/daemon/jni/Android.mk
@@ -0,0 +1,9 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+LOCAL_SRC_FILES := daemon.c 
+LOCAL_MODULE := daemon
+LOCAL_CFLAGS += -pie -fPIE 
+LOCAL_LDFLAGS += -pie -fPIE 
+LOCAL_FORCE_STATIC_EXECUTABLE := true
+include $(BUILD_EXECUTABLE)
diff --git a/Bonus-1-daemon/daemon/jni/daemon.c b/Bonus-1-daemon/daemon/jni/daemon.c
@@ -0,0 +1,32 @@
+/*this program create a daemon process, 
+which will make OOM_killer awaken periodically for some pre-set period T
+*/
+#include <unistd.h>  
+#include <sys/types.h>  
+#include <sys/stat.h>  
+#include <stdlib.h>  
+#include <stdio.h>  
+#include <signal.h>
+#define T 2
+
+
+int main(void)
+{
+    if(daemon(0,0) == -1)
+    {
+        printf("fail to create daemon process\n");
+        exit(EXIT_FAILURE);
+    }
+
+    while(1)
+    {
+        //use system call 384, which is oom_killer to check 
+        //if a user has run out its memory quota.
+        //If that, then it will kill the process that has the highest RSS 
+        //among all processes belonging to the user. 
+        //syscall(383,10070,100000000);
+        syscall(378);
+        sleep(T);
+    }
+    return 0;
+}