commit 86ff40274b4403e0cf29225ece7f28a7f6934184
Author: Christopher Vagnetoft <cvagnetoft@gmail.com>
Date:   Sun Apr 15 16:41:46 2018 +0200

    Initial commit

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..4fbb073
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+/vendor/
+/composer.lock
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..a2261e8
--- /dev/null
+++ b/README.md
@@ -0,0 +1,27 @@
+noccylabs/ipc
+=============
+
+This is a one-size-fits-all IPC library to facilitate communication between
+threads and processes. It contains the following features:
+
+**Core:**
+
+ - [ ] Semaphore
+ - [ ] Mutex
+ - [x] Queue
+ - [x] SharedMemory key-value store
+ - [ ] SharedMemory blocks
+ - [x] Signals
+ - [x] Locks
+
+**High-Level:**
+
+ - [ ] EventBridge
+ - [ ] EventDispatcher
+ - [ ] InterOp/Marshalling
+ - [x] Asynchronous timers
+
+**Transports:**
+
+ - [x] Stream channels
+ 
\ No newline at end of file
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..3d626d7
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,27 @@
+{
+    "name": "noccylabs/ipc",
+    "description": "A complete set of IPC facilities",
+    "type": "library",
+    "license": "GPL-3.0",
+    "authors": [
+        {
+            "name": "Christopher Vagnetoft",
+            "email": "cvagnetoft@gmail.com"
+        }
+    ],
+    "require": {},
+    "repositories": [
+        {
+            "type": "composer",
+            "url": "https://packages.noccylabs.info/composer/"
+        }
+    ],
+    "autoload": {
+        "files": [
+            "src/signals.stub.php"
+        ],
+        "psr-4": {
+            "NoccyLabs\\Ipc\\": "src/"
+        }
+    }
+}
\ No newline at end of file
diff --git a/examples/timers.php b/examples/timers.php
new file mode 100644
index 0000000..5b52991
--- /dev/null
+++ b/examples/timers.php
@@ -0,0 +1,15 @@
+<?php
+
+require_once __DIR__."/../vendor/autoload.php";
+
+use NoccyLabs\Ipc\Interop\Async\Timer;
+
+$timer1 = new Timer(function () { echo "Hello "; });
+$timer2 = new Timer(function () { echo "World! "; });
+
+for ($n = 0; $n < 1000; $n++) {
+  if ($n == 500) {
+    unset($timer2);
+  }
+  usleep(10000);
+}
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..f3b710c
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/5.4/phpunit.xsd"
+         bootstrap="vendor/autoload.php"
+         backupGlobals="false"
+         beStrictAboutCoversAnnotation="true"
+         beStrictAboutOutputDuringTests="true"
+         beStrictAboutTestsThatDoNotTestAnything="true"
+         beStrictAboutTodoAnnotatedTests="true"
+         verbose="true">
+    <testsuite>
+        <directory suffix="Test.php">tests</directory>
+    </testsuite>
+
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">src</directory>
+        </whitelist>
+    </filter>
+</phpunit>
diff --git a/src/Interop/Async/Timer.php b/src/Interop/Async/Timer.php
new file mode 100644
index 0000000..4f34a5f
--- /dev/null
+++ b/src/Interop/Async/Timer.php
@@ -0,0 +1,80 @@
+<?php
+
+namespace NoccyLabs\Ipc\Interop\Async;
+
+use NoccyLabs\Ipc\Signal\SignalHandler;
+
+
+/**
+ * Simple second-granularity timer for asynchronous events
+ * 
+ */
+class Timer
+{
+    private static $timers = null;
+
+    private $callback;
+
+    /**
+     * Constructor
+     *
+     * @param callable $callback
+     */
+    public function __construct(callable $callback)
+    {
+        $this->callback = $callback;
+        $this->seconds = $seconds;
+        self::registerTimer($this->callback);
+    }
+
+    /**
+     * Destructor
+     */
+    public function __destruct()
+    {
+        self::clearTimer($this->callback);
+    }
+
+    /**
+     * Register a timer callback function
+     *
+     * @param callable $timer
+     * @return void
+     */
+    private static function registerTimer(callable $timer)
+    {
+        if (self::$timers === null) {
+            $handler = new SignalHandler(SIGALRM, [ __CLASS__."::onSignal" ]);
+            pcntl_alarm(1);
+        }
+        self::$timers[] = $timer;
+    }
+
+    /**
+     * Remove a timer callback function
+     *
+     * @param callable $timer
+     * @return void
+     */
+    private static function clearTimer(callable $timer)
+    {
+        self::$timers = array_filter(self::$timers, function ($t) use ($timer) {
+            return $t !== $timer;
+        });
+    }
+
+    /**
+     * Handle signals when the alarm fires
+     *
+     * @return void
+     */
+    public static function onSignal()
+    {
+        foreach (self::$timers as $timer) {
+            call_user_func($timer);
+        }
+        pcntl_alarm(1);
+    }
+
+}
+
diff --git a/src/Interop/Channel/ChannelInterface.php b/src/Interop/Channel/ChannelInterface.php
new file mode 100644
index 0000000..0f09313
--- /dev/null
+++ b/src/Interop/Channel/ChannelInterface.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace NoccyLabs\Ipc\Interop\Channel;
+
+
+interface ChannelInterface
+{
+    public function isOpen():bool;
+
+    public function receive();
+
+    public function send($data);
+}
\ No newline at end of file
diff --git a/src/Interop/Channel/StreamChannel.php b/src/Interop/Channel/StreamChannel.php
new file mode 100644
index 0000000..e3b3fed
--- /dev/null
+++ b/src/Interop/Channel/StreamChannel.php
@@ -0,0 +1,54 @@
+<?php
+
+namespace NoccyLabs\Ipc\Interop\Channel;
+
+
+class StreamChannel implements ChannelInterface
+{
+    protected $stream;
+
+    public function __construct($stream)
+    {
+        if (!is_resource($stream)) {
+            if (!is_string($stream)) {
+                throw new \LogicException("Invalid stream");
+            }
+            $stream = stream_socket_client($stream, $errno, $errstr);
+            if (!$stream) {
+                throw new \RuntimeException(sprintf("%d %s", $errno, $errstr));
+            }
+        }
+        
+        $this->stream = $stream;
+
+        $this->isOpen();
+    }
+    
+    public function send($data)
+    {
+        fwrite($this->stream, json_encode($data)."\0");
+    }
+
+    public function receive()
+    {
+        $buf = fread($this->stream, 8192);
+
+        return json_decode(rtrim($buf, "\0"));
+    }
+
+    public function isOpen(): bool
+    {
+        return is_resource($this->stream);
+    }
+
+    public static function createPair()
+    {
+        $fd = stream_socket_pair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP);
+
+        return [
+            new StreamChannel($fd[0]),
+            new StreamChannel($fd[1])
+        ];
+    }
+
+}
\ No newline at end of file
diff --git a/src/Key/FileKey.php b/src/Key/FileKey.php
new file mode 100644
index 0000000..f8181d4
--- /dev/null
+++ b/src/Key/FileKey.php
@@ -0,0 +1,84 @@
+<?php
+
+namespace NoccyLabs\Ipc\Key;
+
+class FileKey implements KeyInterface
+{
+    private $proj;
+
+    private $pathname;
+
+    /**
+     * Constructor
+     *
+     * @param string $pathname
+     * @param string $proj
+     * @param boolean $create
+     */
+    public function __construct(string $pathname, $proj="\0", bool $create=false)
+    {
+        if (!file_exists($pathname)) {
+            if (!$create) {
+                throw new \RuntimeException("Path does not exist: {$pathname}");
+            }
+            if (!is_dir(dirname($pathname))) {
+                throw new \RuntimeException("The directory ".dirname($pathname)." does not exist");
+            }
+            touch($pathname);
+        }
+
+        $this->pathname = $pathname;
+        $this->proj = substr($proj,0,1);
+    }
+
+    /**
+     * Get the pathname used to generate the key
+     *
+     * @return string
+     */
+    public function getPathname():string
+    {
+        return $this->pathname;
+    }
+
+    /**
+     * Get the project identifier. Not guaranteed to be printable
+     *
+     * @return string
+     */
+    public function getProjectIdentifier():string
+    {
+        return $this->proj;
+    }
+
+    /**
+     * Get the key value
+     *
+     * @return int
+     */
+    public function getKey():int
+    {
+        return ftok($this->pathname, $this->proj);
+    }
+
+    /**
+     * Clone the FileKey, increasing the project identifier to create a new key for the
+     * same file
+     *
+     * @return void
+     */
+    public function __clone()
+    {
+        $this->proj = chr(ord($this->proj) + 1);
+    }
+
+    /**
+     * Create printable representation of the key
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return $this->getKey();
+    }
+}
\ No newline at end of file
diff --git a/src/Key/KeyInterface.php b/src/Key/KeyInterface.php
new file mode 100644
index 0000000..2b9cbb6
--- /dev/null
+++ b/src/Key/KeyInterface.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace NoccyLabs\Ipc\Key;
+
+interface KeyInterface
+{
+    public function getKey():int;
+    public function __toString();
+}
\ No newline at end of file
diff --git a/src/Lock/FileLock.php b/src/Lock/FileLock.php
new file mode 100644
index 0000000..1f6b1d6
--- /dev/null
+++ b/src/Lock/FileLock.php
@@ -0,0 +1,88 @@
+<?php
+
+namespace NoccyLabs\Ipc\Lock;
+
+/**
+ * Simple filesystem-based lock
+ * 
+ * 
+ */
+class FileLock
+{
+    const DEFAULT_TIMEOUT = 5;
+
+    protected $pathname;
+
+    protected $resource;
+
+    protected $locked = false;
+
+    /**
+     * Constructor
+     *
+     * @param string $pathname
+     */
+    public function __construct(string $pathname)
+    {
+        if (!file_exists($pathname)) {
+            throw new \RuntimeException(sprintf(
+                "The file %s does not exist",
+                $pathname
+            ));
+        }
+
+        $this->pathname = $pathname;
+        $this->resource = fopen($pathname, "r");
+    }
+
+    public function __destruct()
+    {
+        $this->release();
+        fclose($this->resource);
+    }
+
+    /**
+     * Acquire an exclusive lock
+     *
+     * @param float $timeout
+     * @return boolean
+     */
+    public function acquire(float $timeout = self::DEFAULT_TIMEOUT):bool
+    {
+        if ($this->locked) {
+            return true;
+        }
+
+        $expire = microtime(true) + $timeout;
+        while (!flock($this->resource, LOCK_EX|LOCK_NB)) {
+            if (microtime(true)>$expire) {
+                return false;
+            }
+            usleep(1000);
+        }
+
+        $this->locked = true;
+        return true;
+    }
+
+    /**
+     * Release an acquired lock
+     *
+     * @return void
+     */
+    public function release()
+    {
+        flock($this->resource, LOCK_UN);
+        $this->locked = false;
+    }
+
+    /**
+     * Check if the lock is acquired
+     *
+     * @return boolean
+     */
+    public function isLocked():bool
+    {
+        return $this->locked;
+    }
+}
\ No newline at end of file
diff --git a/src/Msg/Queue.php b/src/Msg/Queue.php
new file mode 100644
index 0000000..078e365
--- /dev/null
+++ b/src/Msg/Queue.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace NoccyLabs\Ipc\Msg;
+
+use NoccyLabs\Ipc\Key\KeyInterface;
+
+
+/**
+ * Message queue wrapper
+ * 
+ */
+class Queue
+{
+    protected $resource;
+
+    /**
+     * Constructor
+     *
+     * @param KeyInterface $key
+     * @param integer $perms
+     */
+    public function __construct(KeyInterface $key, int $perms = 0666)
+    {
+        $this->resource = msg_get_queue($key->getKey(), $perms);
+    }
+
+    /**
+     * Destructor
+     */
+    public function __destruct()
+    {
+
+    }
+
+    /**
+     * Send to the queue
+     *
+     * @param integer $msgtype
+     * @param mixed $message
+     * @param boolean $blocking
+     * @throws RuntimeException on error
+     */
+    public function send(int $msgtype, $message, bool $blocking = true)
+    {
+        $ret = msg_send($this->resource, $msgtype, $message, true, $blocking, $errno);
+        
+        if ($ret === false) {
+            throw new \RuntimeException(sprintf(
+                "msg_send error %d",
+                $errno
+            ));
+        }
+    }
+
+    /**
+     * Receive from the queue
+     *
+     * @param integer $desiredmsgtype
+     * @param integer $msgtype
+     * @param integer $maxsize
+     * @param boolean $blocking
+     * @return mixed
+     * @throws RuntimeException on error
+     */
+    public function receive(int $desiredmsgtype, &$msgtype, int $maxsize=4096, bool $blocking = true)
+    {
+        $ret = msg_receive(
+            $this->resource, 
+            $desiredmsgtype, 
+            $msgtype, 
+            $maxsize, 
+            $message, 
+            true, 
+            $blocking?MSG_IPC_NOWAIT:0, 
+            $errno
+        );
+
+        if ($ret === false) {
+            throw new \RuntimeException(sprintf(
+                "msg_receive error %d",
+                $errno
+            ));
+        }
+
+        return $message;
+    }
+}
\ No newline at end of file
diff --git a/src/Sem/Mutex.php b/src/Sem/Mutex.php
new file mode 100644
index 0000000..943524d
--- /dev/null
+++ b/src/Sem/Mutex.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace NoccyLabs\Ipc\Sem;
+
+use NoccyLabs\Ipc\Key\KeyInterface;
+
+
+
+class Mutex extends Semaphore
+{
+    public function __construct(KeyInterface $key)
+    {
+        parent::__construct($key, 1);
+    }
+}
\ No newline at end of file
diff --git a/src/Sem/Semaphore.php b/src/Sem/Semaphore.php
new file mode 100644
index 0000000..18a94cd
--- /dev/null
+++ b/src/Sem/Semaphore.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace NoccyLabs\Ipc\Sem;
+
+use NoccyLabs\Ipc\Key\KeyInterface;
+
+
+
+class Semaphore
+{
+    public function __construct(KeyInterface $key, int $max)
+    {
+
+    }
+
+    public function acquire(float $timeout)
+    {
+        
+    }
+
+    public function release()
+    {
+        
+    }
+}
\ No newline at end of file
diff --git a/src/Shm/SharedData.php b/src/Shm/SharedData.php
new file mode 100644
index 0000000..fb4bc5b
--- /dev/null
+++ b/src/Shm/SharedData.php
@@ -0,0 +1,133 @@
+<?php
+
+namespace NoccyLabs\Ipc\Shm;
+
+/**
+ * Shared data storage with a key-value interface
+ * 
+ */
+class SharedData extends SharedMemory
+{
+    private const IDX_LOCK = 0;
+    private const IDX_MAP = 1;
+    private const IDX_DATA = 2;
+
+    private $checks = [];
+
+    /**
+     * Acquire a lock
+     *
+     * @return void
+     */
+    private function lock()
+    {
+        $expire = microtime(true) + 1;
+        while ($this[self::IDX_LOCK] !== null) {
+            usleep(1000);
+            // Forcefully continue after 1 second
+            if (microtime(true)>$expire) {
+                break;
+            }
+        }
+        $this[self::IDX_LOCK] = 1;
+    }
+
+    /**
+     * Release the lock
+     *
+     * @return void
+     */
+    private function unlock()
+    {
+        $this[self::IDX_LOCK] = null;
+    }
+
+    /**
+     * Get the value of a key
+     *
+     * @param string $key
+     * @return mixed
+     */
+    public function get(string $key)
+    {
+        $map = (array)$this[self::IDX_MAP];
+        
+        // If the key doesn't exist, return null
+        if (!array_key_exists($key, $map)) {
+            return null;
+        }
+
+        $index = $map[$key];
+        $keyvar = $this[self::IDX_DATA + $index];
+
+        // If for some reason we don't get anything back, return null
+        if (!$keyvar) {
+            return null;
+        }
+        
+        // Save the checksum for later and return the value
+        $this->checks[$key] = $keyvar[0];
+        return $keyvar[1];
+
+    }
+
+    /**
+     * Set a key to a specific value
+     *
+     * @param string $key
+     * @param mixed $value
+     * @param boolean $check
+     * @return boolean
+     */
+    public function set(string $key, $value, $check=false):bool
+    {
+        // Acquire a lock and fetch the map
+        $this->lock();
+        $map = (array)$this[self::IDX_MAP];
+
+        // If the key doesn't exist in the map, we need to set it up
+        if (!array_key_exists($key, $map)) {
+            $free = 0;
+            // Find first free index
+            foreach ($map as $map_key=>$index) {
+                if ($index != $free) { break; }
+                $free++;
+            }
+            // Store the index in the map, and sort it by index.
+            $map[$key] = $free;
+            asort($map);
+            $this[self::IDX_MAP] = $map;
+        }
+
+        // Look up the key and fetch the data
+        $index = $map[$key];
+        $keyvar = $this[self::IDX_DATA + $index];
+
+        // Check the data to make sure the data hasn't changed since last read
+        if ($check && $keyvar && array_key_exists($key, $this->checks)) {
+            if ($keyvar[0] != $this->checks[$key]) {
+                $this->unlock();
+                return false;
+            }
+        }
+
+        // Update the data
+        $this[self::IDX_DATA + $index] = [ md5($value), $value ];
+        $this->unlock();
+        return true;
+    }
+
+    /**
+     * Check if the map contains the key. This method doesn't acquire a lock
+     *
+     * @param string $key
+     * @return bool
+     */
+    public function contains(string $key):bool
+    {
+        $map = (array)$this[self::IDX_MAP];
+
+        return array_key_exists($key, $map);
+    }
+
+}
\ No newline at end of file
diff --git a/src/Shm/SharedMemory.php b/src/Shm/SharedMemory.php
new file mode 100644
index 0000000..6ccbaf8
--- /dev/null
+++ b/src/Shm/SharedMemory.php
@@ -0,0 +1,94 @@
+<?php
+
+namespace NoccyLabs\Ipc\Shm;
+
+use NoccyLabs\Ipc\Key\KeyInterface;
+
+/**
+ * Shared memory segment
+ */
+class SharedMemory implements \ArrayAccess
+{
+
+    protected $resource;
+
+    /**
+     * Constructor
+     *
+     * @param KeyInterface $key
+     * @param integer $memsize
+     * @param integer $perm
+     */
+    public function __construct(KeyInterface $key, int $memsize = 64000, int $perm = 0666)
+    {
+        if (!($shm_resource = shm_attach($key->getKey(), $memsize, $perm))) {
+            throw new \RuntimeException("Unable to attach shm resource {$key}");
+        }
+        
+        $this->resource = $shm_resource;
+    }
+
+    /**
+     * Destructor
+     */
+    public function __destruct()
+    {
+        shm_detach($this->resource);
+        
+    }
+
+    /**
+     * Destroy the shm segment
+     *
+     * @return void
+     */
+    public function destroy()
+    {
+        shm_remove($this->resource);
+    }
+    
+    /**
+     * {@inheritDoc}
+     *
+     * @param int $offset
+     * @return void
+     */
+    public function offsetExists($offset)
+    {
+        return shm_has_var($this->resource, $offset);
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @param int $offset
+     * @return mixed
+     */
+    public function offsetGet($offset)
+    {
+        return shm_has_var($this->resource, $offset)?shm_get_var($this->resource, $offset):null;
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @param int $offset
+     * @param mixed $value
+     * @return void
+     */
+    public function offsetSet($offset, $value)
+    {
+        shm_put_var($this->resource, $offset, $value);
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @param int $offset
+     * @return void
+     */
+    public function offsetUnset($offset)
+    {
+        shm_remove_var($this->resource, $offset);
+    }
+}
\ No newline at end of file
diff --git a/src/Shm/SharedMemoryBlock.php b/src/Shm/SharedMemoryBlock.php
new file mode 100644
index 0000000..ec23762
--- /dev/null
+++ b/src/Shm/SharedMemoryBlock.php
@@ -0,0 +1,99 @@
+<?php
+
+namespace NoccyLabs\Ipc\Shm;
+
+use NoccyLabs\Ipc\Key\KeyInterface;
+
+/**
+ * A block of shared memory that can be read and write like a string buffer
+ * 
+ * 
+ */
+class SharedMemoryBlock 
+{
+
+    const FLAG_ACCESS = "a";
+    const FLAG_CREATE = "c";
+    const FLAG_WRITE = "w";
+    const FLAG_NEW = "n";
+
+    protected $resource;
+
+    /**
+     * Constructor
+     *
+     * @param KeyInterface $key
+     * @param string $flags
+     * @param integer $memsize
+     * @param integer $perm
+     */
+    public function __construct(KeyInterface $key, string $flags, int $memsize, int $perm = 0666)
+    {
+        if (!($shm_resource = shmop_open($key->getKey(), $memsize, $perm))) {
+            throw new \RuntimeException("Unable to attach shm resource {$key}");
+        }
+        
+        $this->resource = $shm_resource;
+    }
+
+    /**
+     * Destructor
+     */
+    public function __destruct()
+    {
+        if (!$this->resource) {
+            return;
+        }
+        shmop_close($this->resource);
+    }
+
+    /**
+     * Destroy the memory block
+     *
+     * @return void
+     */
+    public function destroy()
+    {
+        shmop_delete($this->resource);
+        shmop_close($this->resource);
+        $this->resource = null;
+    }
+
+    /**
+     * Read bytes from the shared block
+     *
+     * @param integer $length
+     * @param integer $offset
+     * @return mixed
+     */
+    public function read($length=0, $offset=0)
+    {
+        if ($length == 0) {
+            $length = shmop_size($this->resource) - $offset;
+        }
+        return shmop_read($this->resource, $offset, $length);
+    }
+
+    /**
+     * Write bytes to the shared block
+     *
+     * @param mixed $data
+     * @param integer $offset
+     * @return integer
+     */
+    public function write($data, $offset=0):int
+    {
+        return shmop_write($this->resource, $data, $offset);
+    }
+
+    /**
+     * Get the size of the memory block
+     *
+     * @return integer
+     */
+    public function getSize():int
+    {
+        return shmop_size($this->resource);
+    }
+
+}
\ No newline at end of file
diff --git a/src/Signal/Signal.php b/src/Signal/Signal.php
new file mode 100644
index 0000000..ee35363
--- /dev/null
+++ b/src/Signal/Signal.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace NoccyLabs\Ipc\Signal;
+
+
+class Signal
+{
+    private $signo;
+
+    public function __construct(int $signo)
+    {
+        $this->signo = $signo;
+    }
+
+    public function setHandler(callable $handler):void
+    {
+        pcntl_signal($this->signo, $handler);
+    }
+
+    public function dispatch($pid):bool
+    {
+        return posix_kill($pid, $this->signo);
+    }
+}
\ No newline at end of file
diff --git a/src/Signal/SignalHandler.php b/src/Signal/SignalHandler.php
new file mode 100644
index 0000000..d5545e0
--- /dev/null
+++ b/src/Signal/SignalHandler.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace NoccyLabs\Ipc\Signal;
+
+
+class SignalHandler
+{
+    private $signo;
+
+    private $callbacks;
+
+    public function __construct(int $signo, array $callbacks=[])
+    {
+        $this->signo = $signo;
+        $this->callbacks = $callbacks;
+        pcntl_signal($this->signo, [ $this, "onSignal" ]);
+    }
+
+    public function __destruct()
+    {
+
+    }
+
+    public function addHandler(callable $handler):void
+    {
+        $this->callbacks[] = $handler;
+    }
+
+    public function onSignal($signo)
+    {
+        foreach ($this->callbacks as $callback) {
+            if (call_user_func($callback) === true)
+                return;
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/src/Signal/SignalTrap.php b/src/Signal/SignalTrap.php
new file mode 100644
index 0000000..8846999
--- /dev/null
+++ b/src/Signal/SignalTrap.php
@@ -0,0 +1,32 @@
+<?php
+
+namespace NoccyLabs\Ipc\Signal;
+
+
+class SignalTrap
+{
+    protected $signal;
+
+    protected $trapped = false;
+
+    public function __construct(int $signo)
+    {
+        $this->signal = new Signal($signo);
+        $this->signal->setHandler([ $this, "onSignal" ]);
+    }
+
+    public function onSignal()
+    {
+        $this->trapped = true;
+    }
+
+    public function isTrapped($reset=true):bool
+    {
+        if ($this->trapped) {
+            $reset && ($this->trapped = false);
+            return true;
+        }
+        return false;
+    }
+
+}
\ No newline at end of file
diff --git a/src/signals.stub.php b/src/signals.stub.php
new file mode 100644
index 0000000..e49f268
--- /dev/null
+++ b/src/signals.stub.php
@@ -0,0 +1,41 @@
+<?php
+
+if (function_exists('pcntl_async_signals')) {
+    define("SIGNALS_ASYNC", true);
+    pcntl_async_signals(true);
+} else {
+    define("SIGNALS_ASYNC", false);
+}
+
+// Signal shims
+defined("SIGHUP")    || define("SIGHUP",    1);  // Hangup (POSIX)
+defined("SIGINT")    || define("SIGINT",    2);  // Terminal interrupt (ANSI)
+defined("SIGQUIT")   || define("SIGQUIT",   3);  // Terminal quit (POSIX)
+defined("SIGILL")    || define("SIGILL",    4);  // Illegal instruction (ANSI)
+defined("SIGTRAP")   || define("SIGTRAP",   5);  // Trace trap (POSIX)
+defined("SIGIOT")    || define("SIGIOT",    6);  // IOT Trap (4.2 BSD)
+defined("SIGBUS")    || define("SIGBUS",    7);  // BUS error (4.2 BSD)
+defined("SIGFPE")    || define("SIGFPE",    8);  // Floating point exception (ANSI)
+defined("SIGKILL")   || define("SIGKILL",   9);  // Kill(can't be caught or ignored) (POSIX)
+defined("SIGUSR1")   || define("SIGUSR1",   10); // User defined signal 1 (POSIX)
+defined("SIGSEGV")   || define("SIGSEGV",   11); // Invalid memory segment access (ANSI)
+defined("SIGUSR2")   || define("SIGUSR2",   12); // User defined signal 2 (POSIX)
+defined("SIGPIPE")   || define("SIGPIPE",   13); // Write on a pipe with no reader, Broken pipe (POSIX)
+defined("SIGALRM")   || define("SIGALRM",   14); // Alarm clock (POSIX)
+defined("SIGTERM")   || define("SIGTERM",   15); // Termination (ANSI)
+defined("SIGSTKFLT") || define("SIGSTKFLT", 16); // Stack fault
+defined("SIGCHLD")   || define("SIGCHLD",   17); // Child process has stopped or exited, changed (POSIX)
+defined("SIGCONT")   || define("SIGCONT",   18); // Continue executing, if stopped (POSIX)
+defined("SIGSTOP")   || define("SIGSTOP",   19); // Stop executing(can't be caught or ignored) (POSIX)
+defined("SIGTSTP")   || define("SIGTSTP",   20); // Terminal stop signal (POSIX)
+defined("SIGTTIN")   || define("SIGTTIN",   21); // Background process trying to read, from TTY (POSIX)
+defined("SIGTTOU")   || define("SIGTTOU",   22); // Background process trying to write, to TTY (POSIX)
+defined("SIGURG")    || define("SIGURG",    23); // Urgent condition on socket (4.2 BSD)
+defined("SIGXCPU")   || define("SIGXCPU",   24); // CPU limit exceeded (4.2 BSD)
+defined("SIGXFSZ")   || define("SIGXFSZ",   25); // File size limit exceeded (4.2 BSD)
+defined("SIGVTALRM") || define("SIGVTALRM", 26); // Virtual alarm clock (4.2 BSD)
+defined("SIGPROF")   || define("SIGPROF",   27); // Profiling alarm clock (4.2 BSD)
+defined("SIGWINCH")  || define("SIGWINCH",  28); // Window size change (4.3 BSD, Sun)
+defined("SIGIO")     || define("SIGIO",     29); // I/O now possible (4.2 BSD)
+defined("SIGPWR")    || define("SIGPWR",    30); // Power failure restart (System V)
+
diff --git a/tests/Interop/Channel/StreamChannelTest.php b/tests/Interop/Channel/StreamChannelTest.php
new file mode 100644
index 0000000..bb6e5a1
--- /dev/null
+++ b/tests/Interop/Channel/StreamChannelTest.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace NoccyLabs\Ipc\Interop\Channel;
+
+
+
+class StreamChannelTest extends \PhpUnit\Framework\TestCase
+{
+
+    public function testCreatingFromStreams()
+    {
+        $fd = stream_socket_pair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP);
+
+        $sc1 = new StreamChannel($fd[0]);
+        $sc2 = new StreamChannel($fd[1]);
+
+        $frame = "Hello World";
+
+        $sc1->send($frame);
+        $rcvd = $sc2->receive();
+
+        $this->assertEquals($frame, $rcvd);
+    }
+
+    public function testCreatingPair()
+    {
+        [ $sc1, $sc2 ] = StreamChannel::createPair();
+
+        $frame = "Hello World";
+
+        $sc1->send($frame);
+        $rcvd = $sc2->receive();
+
+        $this->assertEquals($frame, $rcvd);
+    }
+
+}
\ No newline at end of file
diff --git a/tests/Key/FileKeyTest.php b/tests/Key/FileKeyTest.php
new file mode 100644
index 0000000..6186045
--- /dev/null
+++ b/tests/Key/FileKeyTest.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace NoccyLabs\Ipc\Key;
+
+class FileKeyTest extends \PhpUnit\Framework\TestCase
+{
+    public function testKeyGenerationFromExistingFile()
+    {
+        $keyfile = new FileKey(__FILE__);
+
+        $key = $keyfile->getKey();
+
+        $this->assertGreaterThan(0, $key);
+    }
+
+    public function testKeyGenerationFromTemporaryFile()
+    {
+        $tempfile = "/tmp/key.tmp";
+        file_exists($tempfile) && unlink($tempfile);
+
+        $keyfile = new FileKey($tempfile, "a", true);
+
+        $key = $keyfile->getKey();
+
+        $this->assertGreaterThan(0, $key);
+
+    }
+
+    public function testCloningShouldIncreaseProject()
+    {
+        $keyfile = new FileKey(__FILE__, "a");
+
+        $this->assertEquals("a", $keyfile->getProjectIdentifier());
+
+        $keyfile2 = clone $keyfile;
+
+        $this->assertEquals("b", $keyfile2->getProjectIdentifier());
+    }
+}
\ No newline at end of file
diff --git a/tests/Lock/FileLockTest.php b/tests/Lock/FileLockTest.php
new file mode 100644
index 0000000..91c7dbc
--- /dev/null
+++ b/tests/Lock/FileLockTest.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace NoccyLabs\Ipc\Lock;
+
+
+class FileLockTest extends \PhpUnit\Framework\TestCase
+{
+
+    public function testTheLockingShouldBeExclusive()
+    {
+        $lock1 = new FileLock(__FILE__);
+        $lock2 = new FileLock(__FILE__);
+
+        $this->assertEquals(true, $lock1->acquire(0));
+        $this->assertEquals(false, $lock2->acquire(0));
+
+    }
+}
\ No newline at end of file
diff --git a/tests/Msg/QueueTest.php b/tests/Msg/QueueTest.php
new file mode 100644
index 0000000..28069f4
--- /dev/null
+++ b/tests/Msg/QueueTest.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace NoccyLabs\Ipc\Msg;
+
+use NoccyLabs\Ipc\Key\FileKey;
+
+
+
+
+class QueueTest extends \PhpUnit\Framework\TestCase
+{
+
+
+    public function testSendingAndReceiving()
+    {
+        $key = new FileKey(__FILE__);
+
+        $queue = new Queue($key);
+
+        $queue->send(1, "Hello World");
+
+        $ret = $queue->receive(1, $type);
+        $this->assertEquals("Hello World", $ret);
+        $this->assertEquals(1, $type);
+    }
+
+    public function testSendingAndReceivingWithTypes()
+    {
+        $key = new FileKey(__FILE__);
+
+        $queue = new Queue($key);
+
+        $queue->send(1, "Hello World");
+        $queue->send(2, "Hello World");
+        $queue->send(3, "Hello World");
+
+        $ret = $queue->receive(1, $type);
+        $this->assertEquals(1, $type);
+        
+        $ret = $queue->receive(2, $type);
+        $this->assertEquals(2, $type);
+        
+        $ret = $queue->receive(3, $type);
+        $this->assertEquals(3, $type);
+
+    }
+
+    public function testReceivingFromFront()
+    {
+        $key = new FileKey(__FILE__);
+
+        $queue = new Queue($key);
+
+        $queue->send(1, "Hello World");
+        $queue->send(2, "Hello World");
+        $queue->send(3, "Hello World");
+
+        $ret = $queue->receive(0, $type);
+        $this->assertEquals(1, $type);
+        
+        $ret = $queue->receive(0, $type);
+        $this->assertEquals(2, $type);
+        
+        $ret = $queue->receive(0, $type);
+        $this->assertEquals(3, $type);
+
+    }
+
+
+}
\ No newline at end of file
diff --git a/tests/Shm/SharedDataTest.php b/tests/Shm/SharedDataTest.php
new file mode 100644
index 0000000..544aabd
--- /dev/null
+++ b/tests/Shm/SharedDataTest.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace NoccyLabs\Ipc\Shm;
+
+use NoccyLabs\Ipc\Key\FileKey;
+
+
+
+
+
+class SharedDataTest extends \PhpUnit\Framework\TestCase
+{
+    public function testOpeningSharedData()
+    {
+        $key = new FileKey(__DIR__);
+        $shm = new SharedData($key);
+
+        $this->assertNull($shm->get("foo"));
+        
+        $this->assertTrue($shm->set("foo", "hello"));
+        $this->assertEquals("hello", $shm->get("foo"));
+
+        $this->assertNull($shm->get("bar"));
+        
+        $this->assertTrue($shm->set("bar", "world"));
+        $this->assertEquals("hello", $shm->get("foo"));
+        $this->assertEquals("world", $shm->get("bar"));
+
+        $shm->destroy();
+    }
+}
\ No newline at end of file
diff --git a/tests/Signal/SignalHandlerTest.php b/tests/Signal/SignalHandlerTest.php
new file mode 100644
index 0000000..d82d4a0
--- /dev/null
+++ b/tests/Signal/SignalHandlerTest.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace NoccyLabs\Ipc\Signal;
+
+
+
+
+
+class SignalHandlerTest extends \PhpUnit\Framework\TestCase
+{
+
+    public function testSignalHandlerWithSingleHandlerInConstructor()
+    {
+        $callbacks = [
+            function () use (&$handler1) { $handler1 = true; }
+        ];
+
+        $handler = new SignalHandler(SIGUSR1, $callbacks);
+
+        posix_kill(posix_getpid(), SIGUSR1);
+
+        usleep(1000);
+
+        $this->assertEquals(true, $handler1);
+    }
+
+    public function testSignalHandlerWithMultipleHandlersInConstructor()
+    {
+        $callbacks = [
+            function () use (&$handler1) { $handler1 = true; },
+            function () use (&$handler2) { $handler2 = true; },
+            function () use (&$handler3) { $handler3 = true; }
+        ];
+
+        $handler = new SignalHandler(SIGUSR1, $callbacks);
+
+        posix_kill(posix_getpid(), SIGUSR1);
+
+        usleep(1000);
+
+        $this->assertEquals(true, $handler1);
+        $this->assertEquals(true, $handler2);
+        $this->assertEquals(true, $handler3);
+    }
+
+    public function testSignalHandlerWithAddedHandlers()
+    {
+        $callbacks = [
+            function () use (&$handler1) { $handler1 = true; },
+            function () use (&$handler2) { $handler2 = true; }
+        ];
+
+        $handler = new SignalHandler(SIGUSR1, $callbacks);
+
+        $handler->addHandler(function () use (&$handler3) { $handler3 = true; });
+
+        posix_kill(posix_getpid(), SIGUSR1);
+
+        usleep(1000);
+
+        $this->assertEquals(true, $handler1);
+        $this->assertEquals(true, $handler2);
+        $this->assertEquals(true, $handler3);
+    }
+
+    public function testSignalHandlerWithBlockingHandler()
+    {
+        $callbacks = [
+            function () use (&$handler1) { $handler1 = true; return true; },
+            function () use (&$handler2) { $handler2 = true; },
+            function () use (&$handler3) { $handler3 = true; }
+        ];
+
+        $handler = new SignalHandler(SIGUSR1, $callbacks);
+
+        posix_kill(posix_getpid(), SIGUSR1);
+
+        usleep(1000);
+
+        $this->assertEquals(true, $handler1);
+        $this->assertEquals(false, $handler2);
+        $this->assertEquals(false, $handler3);
+    }
+    
+}
\ No newline at end of file
diff --git a/tests/Signal/SignalTest.php b/tests/Signal/SignalTest.php
new file mode 100644
index 0000000..0eed1d5
--- /dev/null
+++ b/tests/Signal/SignalTest.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace NoccyLabs\Ipc\Signal;
+
+
+
+
+
+class SignalTest extends \PhpUnit\Framework\TestCase
+{
+
+    public function testSimpleSignalHandler()
+    {
+        $callback = function () use (&$handler1) { $handler1 = true; };
+
+        $handler = new Signal(SIGUSR1);
+        $handler->setHandler($callback);
+
+        posix_kill(posix_getpid(), SIGUSR1);
+
+        usleep(1000);
+
+        $this->assertEquals(true, $handler1);
+    }
+
+    public function testSimpleSignalDispatcher()
+    {
+        $callback = function () use (&$handler1) { $handler1 = true; };
+
+        $handler = new Signal(SIGUSR1);
+        $handler->setHandler($callback);
+
+        $handler->dispatch(posix_getpid());
+
+        usleep(1000);
+
+        $this->assertEquals(true, $handler1);
+    }
+    
+}
\ No newline at end of file
diff --git a/tests/Signal/SignalTrapTest.php b/tests/Signal/SignalTrapTest.php
new file mode 100644
index 0000000..f406378
--- /dev/null
+++ b/tests/Signal/SignalTrapTest.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace NoccyLabs\Ipc\Signal;
+
+
+
+
+
+class SignalTrapTest extends \PhpUnit\Framework\TestCase
+{
+
+    public function testSignalTrap()
+    {
+        $trap = new SignalTrap(SIGUSR1);
+
+        $this->assertEquals(false, $trap->isTrapped());
+
+        posix_kill(posix_getpid(), SIGUSR1);
+
+        usleep(1000);
+
+        $this->assertEquals(true, $trap->isTrapped());
+
+        $this->assertEquals(false, $trap->isTrapped());
+    }
+
+    public function testSignalTrapWithoutResetting()
+    {
+        $trap = new SignalTrap(SIGUSR1);
+
+        $this->assertEquals(false, $trap->isTrapped());
+
+        posix_kill(posix_getpid(), SIGUSR1);
+
+        usleep(1000);
+
+        $this->assertEquals(true, $trap->isTrapped(false));
+
+        $this->assertEquals(true, $trap->isTrapped());
+    }
+
+}
\ No newline at end of file