Update test_ckpt.c

- Rename test_ckpt.C -> test_ckpt.cpp
- Update it so it can be easily used as C code as well.
- Allow it to take in an argument for checkpoint size in MB

These changes will help me with testing in #163.

examples/CMakeLists.txt

@@ -7,7 +7,7 @@ LIST(APPEND example_files
 	test_api_multiple.c
 	test_interpose.c
 	test_interpose_multiple.c
-	test_ckpt.C
+	test_ckpt.cpp
 	test_ckpt.F
 	scr.moab
 	scr_interpose.moab
@@ -70,18 +70,18 @@ ADD_EXECUTABLE(test_interpose_multiple test_common.c test_interpose_multiple.c)
 TARGET_LINK_LIBRARIES(test_interpose_multiple ${SCR_LINK_TO})
 SCR_ADD_TEST(test_interpose_multiple "" "../examplesrank*.ckpt")
 
-ADD_EXECUTABLE(test_ckpt_C test_ckpt.C)
+ADD_EXECUTABLE(test_ckpt test_ckpt.cpp)
 IF(MPI_CXX_FOUND)
-    TARGET_INCLUDE_DIRECTORIES(test_ckpt_C PUBLIC ${CMAKE_CURRENT_SOURCE_DIR} ${MPI_CXX_INCLUDE_PATH})
-    TARGET_LINK_LIBRARIES(test_ckpt_C ${SCR_LINK_TO} ${MPI_CXX_LIBRARIES})
+    TARGET_INCLUDE_DIRECTORIES(test_ckpt PUBLIC ${CMAKE_CURRENT_SOURCE_DIR} ${MPI_CXX_INCLUDE_PATH})
+    TARGET_LINK_LIBRARIES(test_ckpt ${SCR_LINK_TO} ${MPI_CXX_LIBRARIES})
 ELSE(MPI_CXX_FOUND)
-    TARGET_LINK_LIBRARIES(test_ckpt_C ${SCR_LINK_TO})
+    TARGET_LINK_LIBRARIES(test_ckpt ${SCR_LINK_TO})
 ENDIF(MPI_CXX_FOUND)
-SCR_ADD_TEST(test_ckpt_C "" "rank_0.ckpt")
+SCR_ADD_TEST(test_ckpt "" "rank_0.ckpt")
 
 IF(ENABLE_FORTRAN)
         SET_SOURCE_FILES_PROPERTIES(test_ckpt.F PROPERTIES LANGUAGE Fortran)
-	ADD_EXECUTABLE(test_ckpt_F test_ckpt.F)
+	    ADD_EXECUTABLE(test_ckpt_F test_ckpt.F)
         SET_TARGET_PROPERTIES(test_ckpt_F PROPERTIES LINKER_LANGUAGE Fortran)
 
         IF(SCR_LINK_STATIC)

examples/test_ckpt.cpp

@@ -0,0 +1,90 @@
+// mpig++ -g -O0 -I../src -o test_ckpt_C test_ckpt.C -L/usr/local/tools/scr-1.1/lib -lscr
+/*
+ * Usage:
+ *
+ *      ./test_ckpt [megabytes]
+ *
+ * Optionally pass the size of our checkpoint file to write, in megabytes.
+ *
+ * Note: This is compiled as C++ file to verify SCR works with C++.  It only
+ * trivially uses C++ semantics, so that people can use it as example code for
+ * C as well.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <iostream>
+using namespace std;
+
+#include "mpi.h"
+#include "scr.h"
+int checkpoint(int size_mb)
+{
+    int rank;
+    char tmp[256];
+    char file[SCR_MAX_FILENAME];
+    char dir[SCR_MAX_FILENAME];
+    char dname;
+    int rc;
+
+    /* Get our rank */
+    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+
+    /* Inform SCR that we are starting a new checkpoint */
+    SCR_Start_checkpoint();
+
+    /* Build the filename for our checkpoint file */
+    sprintf(tmp, "rank_%d", rank);
+    cout << "In: " << tmp << "\n";
+
+    /* Register our checkpoint file with SCR, and where to write it */
+    SCR_Route_file(tmp, file);
+
+    /* Write our checkpoint file */
+    sprintf(tmp, "truncate -s %dM %s", size_mb, file);
+    system(tmp);
+
+    cout << "Out: " << file << "\n";
+
+    /* Tell SCR whether this process wrote its checkpoint files successfully */
+    SCR_Complete_checkpoint(1);
+
+    return 0;
+}
+
+/*
+ * test_ckpt [megabytes]
+ *
+ * Optionally pass the size of our checkpoint file to write, in megabytes.
+ */
+int main(int argc, char **argv)
+{
+    int size_mb = 1;
+
+    if (argc == 2) {
+        size_mb = atoi(argv[1]);
+    }
+
+    MPI_Init(NULL, NULL);
+
+    /* Initialize the SCR library */
+    SCR_Init();
+
+    /* Ask SCR whether we need to checkpoint */
+    int flag = 0;
+    SCR_Need_checkpoint(&flag);
+    if (flag) {
+        /* Execute the checkpoint code */
+        checkpoint(size_mb);
+    }
+
+    /* Shut down the SCR library */
+    SCR_Finalize();
+
+    MPI_Finalize();
+
+    return 0;
+}