Add new API to find total RAM.

Change-Id: Iad2dff3c44f471515f093e7f0d0d959528881ab9

3 files changed, 31 insertions, 7 deletions

diff --git a/core/java/android/app/ActivityManager.java b/core/java/android/app/ActivityManager.java
index 7746ca9..4e61c3c 100644
--- a/core/java/android/app/ActivityManager.java
+++ b/core/java/android/app/ActivityManager.java
@@ -1078,13 +1078,20 @@ public class ActivityManager {
      */
     public static class MemoryInfo implements Parcelable {
         /**
-         * The total available memory on the system.  This number should not
+         * The available memory on the system.  This number should not
          * be considered absolute: due to the nature of the kernel, a significant
          * portion of this memory is actually in use and needed for the overall
          * system to run well.
          */
         public long availMem;
-        
+
+        /**
+         * The total memory accessible by the kernel.  This is basically the
+         * RAM size of the device, not including below-kernel fixed allocations
+         * like DMA buffers, RAM for the baseband CPU, etc.
+         */
+        public long totalMem;
+
         /**
          * The threshold of {@link #availMem} at which we consider memory to be
          * low and start killing background services and other non-extraneous
@@ -1116,6 +1123,7 @@ public class ActivityManager {
 
         public void writeToParcel(Parcel dest, int flags) {
             dest.writeLong(availMem);
+            dest.writeLong(totalMem);
             dest.writeLong(threshold);
             dest.writeInt(lowMemory ? 1 : 0);
             dest.writeLong(hiddenAppThreshold);
@@ -1126,6 +1134,7 @@ public class ActivityManager {
         
         public void readFromParcel(Parcel source) {
             availMem = source.readLong();
+            totalMem = source.readLong();
             threshold = source.readLong();
             lowMemory = source.readInt() != 0;
             hiddenAppThreshold = source.readLong();
diff --git a/core/java/android/os/Process.java b/core/java/android/os/Process.java
index 1df53e8..18fd3cb 100644
--- a/core/java/android/os/Process.java
+++ b/core/java/android/os/Process.java
@@ -897,6 +897,9 @@ public class Process {
     public static final native long getFreeMemory();
     
     /** @hide */
+    public static final native long getTotalMemory();
+    
+    /** @hide */
     public static final native void readProcLines(String path,
             String[] reqFields, long[] outSizes);
     
diff --git a/core/jni/android_util_Process.cpp b/core/jni/android_util_Process.cpp
index d20cc9e..027ed16 100644
--- a/core/jni/android_util_Process.cpp
+++ b/core/jni/android_util_Process.cpp
@@ -402,7 +402,7 @@ static int pid_compare(const void* v1, const void* v2)
     return *((const jint*)v1) - *((const jint*)v2);
 }
 
-static jlong android_os_Process_getFreeMemory(JNIEnv* env, jobject clazz)
+static jlong getFreeMemoryImpl(const char* const sums[], const int sumsLen[], int num)
 {
     int fd = open("/proc/meminfo", O_RDONLY);
 
@@ -424,11 +424,8 @@ static jlong android_os_Process_getFreeMemory(JNIEnv* env, jobject clazz)
     int numFound = 0;
     jlong mem = 0;
 
-    static const char* const sums[] = { "MemFree:", "Cached:", NULL };
-    static const int sumsLen[] = { strlen("MemFree:"), strlen("Cached:"), 0 };
-
     char* p = buffer;
-    while (*p && numFound < 2) {
+    while (*p && numFound < num) {
         int i = 0;
         while (sums[i]) {
             if (strncmp(p, sums[i], sumsLen[i]) == 0) {
@@ -453,6 +450,20 @@ static jlong android_os_Process_getFreeMemory(JNIEnv* env, jobject clazz)
     return numFound > 0 ? mem : -1;
 }
 
+static jlong android_os_Process_getFreeMemory(JNIEnv* env, jobject clazz)
+{
+    static const char* const sums[] = { "MemFree:", "Cached:", NULL };
+    static const int sumsLen[] = { strlen("MemFree:"), strlen("Cached:"), 0 };
+    return getFreeMemoryImpl(sums, sumsLen, 2);
+}
+
+static jlong android_os_Process_getTotalMemory(JNIEnv* env, jobject clazz)
+{
+    static const char* const sums[] = { "MemTotal:", NULL };
+    static const int sumsLen[] = { strlen("MemTotal:"), 0 };
+    return getFreeMemoryImpl(sums, sumsLen, 1);
+}
+
 void android_os_Process_readProcLines(JNIEnv* env, jobject clazz, jstring fileStr,
                                       jobjectArray reqFields, jlongArray outFields)
 {
@@ -901,6 +912,7 @@ static const JNINativeMethod methods[] = {
     {"sendSignal", "(II)V", (void*)android_os_Process_sendSignal},
     {"sendSignalQuiet", "(II)V", (void*)android_os_Process_sendSignalQuiet},
     {"getFreeMemory", "()J", (void*)android_os_Process_getFreeMemory},
+    {"getTotalMemory", "()J", (void*)android_os_Process_getTotalMemory},
     {"readProcLines", "(Ljava/lang/String;[Ljava/lang/String;[J)V", (void*)android_os_Process_readProcLines},
     {"getPids", "(Ljava/lang/String;[I)[I", (void*)android_os_Process_getPids},
     {"readProcFile", "(Ljava/lang/String;[I[Ljava/lang/String;[J[F)Z", (void*)android_os_Process_readProcFile},