Add a test for CAS write operation

src/CMakeLists.txt

@@ -200,6 +200,14 @@ target_link_libraries(osd_peering_pg_test tcmalloc_minimal)
 # test_allocator
 add_executable(test_allocator test_allocator.cpp allocator.cpp)
 
+# test_cas
+add_executable(test_cas
+	test_cas.cpp
+)
+target_link_libraries(test_cas
+	vitastor_client
+)
+
 # test_cluster_client
 add_executable(test_cluster_client
 	test_cluster_client.cpp

src/test_cas.cpp

@@ -0,0 +1,135 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "epoll_manager.h"
+#include "cluster_client.h"
+
+void send_read(cluster_client_t *cli, uint64_t inode, std::function<void(int, uint64_t)> cb)
+{
+    cluster_op_t *op = new cluster_op_t();
+    op->opcode = OSD_OP_READ;
+    op->inode = inode;
+    op->offset = 0;
+    op->len = 4096;
+    op->iov.push_back(malloc_or_die(op->len), op->len);
+    op->callback = [cb](cluster_op_t *op)
+    {
+        uint64_t version = op->version;
+        int retval = op->retval;
+        if (retval == op->len)
+            retval = 0;
+        free(op->iov.buf[0].iov_base);
+        delete op;
+        if (cb != NULL)
+            cb(retval, version);
+    };
+    cli->execute(op);
+}
+
+void send_write(cluster_client_t *cli, uint64_t inode, int byte, uint64_t version, std::function<void(int)> cb)
+{
+    cluster_op_t *op = new cluster_op_t();
+    op->opcode = OSD_OP_WRITE;
+    op->inode = inode;
+    op->offset = 0;
+    op->len = 4096;
+    op->version = version;
+    op->iov.push_back(malloc_or_die(op->len), op->len);
+    memset(op->iov.buf[0].iov_base, byte, op->len);
+    op->callback = [cb](cluster_op_t *op)
+    {
+        int retval = op->retval;
+        if (retval == op->len)
+            retval = 0;
+        free(op->iov.buf[0].iov_base);
+        delete op;
+        if (cb != NULL)
+            cb(retval);
+    };
+    cli->execute(op);
+}
+
+int main(int narg, char *args[])
+{
+    json11::Json::object cfgo;
+    for (int i = 1; i < narg; i++)
+    {
+        if (args[i][0] == '-' && args[i][1] == '-')
+        {
+            const char *opt = args[i]+2;
+            cfgo[opt] = i == narg-1 ? "1" : args[++i];
+        }
+    }
+    json11::Json cfg(cfgo);
+    uint64_t inode = (cfg["pool_id"].uint64_value() << (64-POOL_ID_BITS))
+        | cfg["inode_id"].uint64_value();
+    uint64_t base_ver = 0;
+    // Create client
+    auto ringloop = new ring_loop_t(512);
+    auto epmgr = new epoll_manager_t(ringloop);
+    auto cli = new cluster_client_t(ringloop, epmgr->tfd, cfg);
+    cli->on_ready([&]()
+    {
+        send_read(cli, inode, [&](int r, uint64_t v)
+        {
+            if (r < 0)
+            {
+                fprintf(stderr, "Initial read operation failed\n");
+                exit(1);
+            }
+            base_ver = v;
+            // CAS v=1 = compare with zero, non-existing object
+            send_write(cli, inode, 0x01, base_ver+1, [&](int r)
+            {
+                if (r < 0)
+                {
+                    fprintf(stderr, "CAS for non-existing object failed\n");
+                    exit(1);
+                }
+                // Check that read returns the new version
+                send_read(cli, inode, [&](int r, uint64_t v)
+                {
+                    if (r < 0)
+                    {
+                        fprintf(stderr, "Read operation failed after write\n");
+                        exit(1);
+                    }
+                    if (v != base_ver+1)
+                    {
+                        fprintf(stderr, "Read operation failed to return the new version number\n");
+                        exit(1);
+                    }
+                    // CAS v=2 = compare with v=1, existing object
+                    send_write(cli, inode, 0x02, base_ver+2, [&](int r)
+                    {
+                        if (r < 0)
+                        {
+                            fprintf(stderr, "CAS for existing object failed\n");
+                            exit(1);
+                        }
+                        // CAS v=2 again = compare with v=1, but version is 2. Must fail with -EINTR
+                        send_write(cli, inode, 0x03, base_ver+2, [&](int r)
+                        {
+                            if (r != -EINTR)
+                            {
+                                fprintf(stderr, "CAS conflict detection failed\n");
+                                exit(1);
+                            }
+                            printf("Basic CAS test succeeded\n");
+                            exit(0);
+                        });
+                    });
+                });
+            });
+        });
+    });
+    while (1)
+    {
+        ringloop->loop();
+        ringloop->wait();
+    }
+    return 0;
+}

tests/test_cas.sh

@@ -0,0 +1,7 @@
+#!/bin/bash -ex
+
+. `dirname $0`/run_3osds.sh
+
+build/src/test_cas --pool_id 1 --inode_id 1 --etcd_address $ETCD_URL
+
+format_green OK