keep improving the robsutness of shm creation

src/main/java/io/bioimage/modelrunner/tensor/shm/SharedMemoryArrayLinux.java

@@ -68,14 +68,23 @@
  */
 public class SharedMemoryArrayLinux implements SharedMemoryArray
 {
+	/**
+	 * Instance of the LibRT JNI containing the methods to interact with the Shared memory segments
+	 */
+	private static final LibRt INSTANCE_RT = LibRt.INSTANCE;
 	/**
 	 * Instance of the CLibrary JNI containing the methods to interact with the Shared memory segments
 	 */
-	private static final LibRt INSTANCE = LibRt.INSTANCE;
+	private static final CLibrary INSTANCE_C = CLibrary.INSTANCE;
+	/**
+	 * Depending on the computer, some might work with LibRT or LibC to create SHM segments.
+	 * Thus if true use librt if false, use libc instance
+	 */
+	private boolean useLibRT = true;
 	/**
 	 * File descriptor value of the shared memory segment
 	 */
-	private final int shmFd;
+	private int shmFd;
 	/**
 	 * Pointer referencing the shared memory byte array
 	 */
@@ -148,20 +157,33 @@ protected SharedMemoryArrayLinux(String name, int size, String dtype, long[] sha
     	this.originalDims = shape;
     	this.size = size;
     	this.memoryName = name;
-
-        shmFd = INSTANCE.shm_open(this.memoryName, O_RDWR | O_CREAT, 0700);
+    	try {
+            shmFd = INSTANCE_RT.shm_open(this.memoryName, O_RDWR | O_CREAT, 0700);
+    	} catch (Exception ex) {
+    		this.useLibRT = false;
+            shmFd = INSTANCE_C.shm_open(this.memoryName, O_RDWR | O_CREAT, 0700);
+    	}
         if (shmFd < 0) {
             throw new RuntimeException("shm_open failed, errno: " + Native.getLastError());
         }
 
-        if (INSTANCE.ftruncate(shmFd, this.size) == -1) {
-        	INSTANCE.close(shmFd);
+        if (this.useLibRT && INSTANCE_RT.ftruncate(shmFd, this.size) == -1) {
+        	INSTANCE_RT.close(shmFd);
+            throw new RuntimeException("ftruncate failed, errno: " + Native.getLastError());
+        } else if (!this.useLibRT && INSTANCE_C.ftruncate(shmFd, this.size) == -1) {
+        	INSTANCE_C.close(shmFd);
             throw new RuntimeException("ftruncate failed, errno: " + Native.getLastError());
         }
-
-        pSharedMemory = INSTANCE.mmap(Pointer.NULL, this.size, PROT_READ | PROT_WRITE, MAP_SHARED, shmFd, 0);
-        if (pSharedMemory == Pointer.NULL) {
-        	INSTANCE.close(shmFd);
+        if (this.useLibRT)
+        	pSharedMemory = INSTANCE_RT.mmap(Pointer.NULL, this.size, PROT_READ | PROT_WRITE, MAP_SHARED, shmFd, 0);
+        else
+        	pSharedMemory = INSTANCE_C.mmap(Pointer.NULL, this.size, PROT_READ | PROT_WRITE, MAP_SHARED, shmFd, 0);
+
+        if (this.useLibRT && pSharedMemory == Pointer.NULL) {
+        	INSTANCE_RT.close(shmFd);
+            throw new RuntimeException("mmap failed, errno: " + Native.getLastError());
+        } else if (!this.useLibRT && pSharedMemory == Pointer.NULL) {
+        	INSTANCE_C.close(shmFd);
             throw new RuntimeException("mmap failed, errno: " + Native.getLastError());
         }
     }
@@ -459,25 +481,32 @@ private void buildFloat64(RandomAccessibleInterval<DoubleType> tensor)
 	 */
 	public void close() {
 		if (this.unlinked) return;
+		int checkhmFd;
+		if (this.useLibRT) checkhmFd = INSTANCE_RT.shm_open(this.memoryName, O_RDONLY, 0700);
+		else checkhmFd = INSTANCE_C.shm_open(this.memoryName, O_RDONLY, 0700);
 
-		int checkhmFd = INSTANCE.shm_open(this.memoryName, O_RDONLY, 0700);
         if (checkhmFd < 0) {
             unlinked = true;
             return;
         }
 
         // Unmap the shared memory
-        if (this.pSharedMemory != Pointer.NULL && INSTANCE.munmap(this.pSharedMemory, size) == -1) {
+        if (this.pSharedMemory != Pointer.NULL && this.useLibRT && INSTANCE_RT.munmap(this.pSharedMemory, size) == -1) {
+            throw new RuntimeException("munmap failed. Errno: " + Native.getLastError());
+        } else if (this.pSharedMemory != Pointer.NULL && !this.useLibRT && INSTANCE_C.munmap(this.pSharedMemory, size) == -1) {
             throw new RuntimeException("munmap failed. Errno: " + Native.getLastError());
         }
 
         // Close the file descriptor
-        if (INSTANCE.close(this.shmFd) == -1) {
+        if (this.useLibRT && INSTANCE_RT.close(this.shmFd) == -1) {
+            throw new RuntimeException("close failed. Errno: " + Native.getLastError());
+        } else if (!this.useLibRT && INSTANCE_C.close(this.shmFd) == -1) {
             throw new RuntimeException("close failed. Errno: " + Native.getLastError());
         }
 
         // Unlink the shared memory object
-        INSTANCE.shm_unlink(this.memoryName);
+        if (this.useLibRT) INSTANCE_RT.shm_unlink(memoryName);
+        else INSTANCE_C.shm_unlink(memoryName);
         unlinked = true;
 	}
 
@@ -628,12 +657,19 @@ RandomAccessibleInterval<T> createImgLib2RaiFromSharedMemoryBlock(String memoryN
         }
 		try {
         	RandomAccessibleInterval<T> rai = buildFromSharedMemoryBlock(pSharedMemory, shape, isFortran, dataType);
+        	/** TODO decide
+        	/** TODO decide
+        	/** TODO decide
+        	/** TODO decide
+        	/** TODO decide
+        	/** TODO decide
         	if (pSharedMemory != Pointer.NULL) {
                 INSTANCE.munmap(pSharedMemory, size);
             }
             if (shmFd >= 0) {
             	INSTANCE.close(shmFd);
             }
+            */
         	return rai;
         } catch (Exception ex) {
             if (pSharedMemory != Pointer.NULL) {