test open with multiple procs

open_multi.c

@@ -0,0 +1,176 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "mpi.h"
+#include "unifyfs.h"
+
+int mpi_sum(int val)
+{
+    int sum;
+    MPI_Allreduce(&val, &sum, 1, MPI_INT, MPI_SUM, MPI_COMM_WORLD);
+    return sum;
+}
+
+off_t getsize(char* file)
+{
+    off_t size = (off_t)-1;
+    struct stat buf;
+    int rc = stat(file, &buf);
+    if (rc == 0) {
+        size = buf.st_size;
+    }
+    return size;
+}
+
+int main(int argc, char* argv[])
+{
+    char mountpoint[] = "/unifyfs";
+
+    MPI_Init(&argc, &argv);
+
+    int rank, ranks;
+    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+    MPI_Comm_size(MPI_COMM_WORLD, &ranks);
+
+    int ret = unifyfs_mount(mountpoint, rank, ranks, 0);
+
+    char file[256];
+    sprintf(file, "%s/testfile", mountpoint);
+
+    size_t bufsize = 1024*1024;
+    char* buf = (char*) malloc(bufsize);
+    memset(buf, rank, bufsize);
+
+    MPI_Barrier(MPI_COMM_WORLD);
+
+    /* create a file in exclusive mode,
+     * one rank should win, all others should get EEXIST */
+    errno = 0;
+    int success = 0;
+    int eexist  = 0;
+    int fd = open(file, O_WRONLY | O_CREAT | O_EXCL);
+    if (fd >= 0) {
+        success = 1;
+        close(fd);
+    } else if (errno == EEXIST) {
+        eexist = 1;
+    }
+
+    /* one rank should win */
+    int sum = mpi_sum(success);
+    if (sum != 1) {
+    }
+
+    /* all others should get EEXIST */
+    sum = mpi_sum(eexist);
+    if (sum != (ranks - 1)) {
+    }
+
+    MPI_Barrier(MPI_COMM_WORLD);
+
+    /* all delete,
+     * one rank should win, all others should get ENOENT */
+    errno = 0;
+    success = 0;
+    int enoent = 0;
+    int rc = unlink(file);
+    if (rc == 0) {
+        success = 1;
+    } else if (errno == ENOENT) {
+        enoent = 1;
+    }
+
+    /* one winner */
+    sum = mpi_sum(success);
+    if (sum != 1) {
+    }
+
+    /* everyone else should get ENOENT */
+    sum = mpi_sum(enoent);
+    if (sum != (ranks - 1)) {
+    }
+
+    MPI_Barrier(MPI_COMM_WORLD);
+
+    /* all create, this time not exclusive */
+    errno = 0;
+    success = 0;
+    fd = open(file, O_WRONLY | O_CREAT | O_TRUNC);
+    if (fd >= 0) {
+        success = 1;
+        close(fd);
+    }
+
+    /* all should succeed */
+    sum = mpi_sum(success);
+    if (sum != ranks) {
+    }
+
+    MPI_Barrier(MPI_COMM_WORLD);
+
+    /* open file for writing */
+    errno = 0;
+    success = 0;
+    fd = open(file, O_WRONLY);
+    if (fd >= 0) {
+        success = 1;
+        close(fd);
+    }
+
+    /* all should succeeed */
+    sum = mpi_sum(success);
+    if (sum != ranks) {
+    }
+
+    MPI_Barrier(MPI_COMM_WORLD);
+
+    unlink(file);
+
+    MPI_Barrier(MPI_COMM_WORLD);
+
+    /* have all ranks write to a different section of the file,
+     * then open file with truncate on one rank to verify size change */
+    fd = open(file, O_WRONLY | O_CREAT);
+    if (fd >= 0) {
+        off_t offset = (off_t) (rank * bufsize);
+        pwrite(fd, buf, bufsize, offset);
+        fsync(fd);
+        close(fd);
+    }
+    MPI_Barrier(MPI_COMM_WORLD);
+    if (rank == 0) {
+        /* all ranks should have written some data */
+        off_t size = getsize(file);
+        if (size != bufsize * ranks) {
+        }
+
+        /* create file with truncate */
+        fd = open(file, O_WRONLY | O_CREAT | O_TRUNC);
+        if (fd >= 0) {
+            close(fd);
+        }
+
+        /* now file should be 0 length again */
+        size = getsize(file);
+        if (size != 0) {
+        }
+    }
+    MPI_Barrier(MPI_COMM_WORLD);
+
+    unlink(file);
+
+    MPI_Barrier(MPI_COMM_WORLD);
+
+    free(buf);
+
+    unifyfs_unmount();
+
+    MPI_Finalize();
+
+    return 0;
+}