test: Ensure child/forked processes produce unique UUIDs

Author: Michael Fero

tests/unit/Cassandra/UuidTest.php

@@ -61,4 +61,70 @@ public function notEqualTypes()
             array(new Uuid('2a5072fa-7da4-4ccd-a9b4-f017a3872304'), new Uuid('3b5072fa-7da4-4ccd-a9b4-f017a3872304')),
         );
     }
+
+    /**
+     * Ensure UUIDs are unique for fork/child processes
+     *
+     * This test will ensure that the PHP driver is producing unique UUIDs for
+     * all child processes that get created during fork() operations in web
+     * servers (e.g. Apache, nginx, ...etc).
+     *
+     * @test
+     * @ticket PHP-115
+     */
+    public function testUniqueInChild() {
+        if (!function_exists("pcntl_fork")) {
+            $this->markTestSkipped("Unable to Execute testUniqueInChild Unit Test: pcntl_fork() does not exists");
+        } else {
+            // Create a PHP script to call within a PHPUnit test (exit call fails test)
+            $script = <<<EOF
+<?php
+// Get and open the file for appending child UUIDs
+\$uuidsFilename = \$_SERVER['argv'][1];
+\$numberOfForks = \$_SERVER['argv'][2];
+
+// Create requested children process; create UUIDs and append to a file
+\$children = array();
+foreach (range(1, \$numberOfForks) as \$i) {
+    // Create the child process
+    \$pid = pcntl_fork();
+
+    // Ensure the child process was create successfully
+    if (\$pid < 0) {
+        die("Unable to Create Fork: Unique UUID test cannot complete");
+    } else if (\$pid === 0) {
+        // Create a UUID and add it to the file
+        \$uuid = new \Cassandra\Uuid();
+        file_put_contents(\$uuidsFilename, \$uuid->uuid() . PHP_EOL, FILE_APPEND);
+
+        // Terminate child process
+        exit(0);
+    } else {
+        // Parent process: Add the process ID to force waiting on children
+        \$children[] = \$pid;
+    }
+}
+
+// Wait on each child process to finish
+foreach (\$children as \$pid) {
+    pcntl_waitpid(\$pid, \$status);
+}
+?>
+EOF;
+
+            // Execute the PHP script passing in the filename for the UUIDs to be stored
+            $uuidsFilename = tempnam(sys_get_temp_dir(), "uuid");
+            $scriptFilename = tempnam(sys_get_temp_dir(), "uuid");
+            file_put_contents($scriptFilename, $script, FILE_APPEND);
+            exec(PHP_BINARY . " {$scriptFilename} {$uuidsFilename} 1024");
+            unlink($scriptFilename);
+
+            // Get the contents of the file
+            $uuids = file($uuidsFilename);
+            unlink($uuidsFilename);
+
+            // Ensure all the UUIDs are unique
+            $this->assertEquals(1024, count(array_unique($uuids)));
+        }
+    }
 }