Timeout should reset SIGALRM handler to SIG_DFL

This was the documented behaviour, but tests confirming that were
missing. After implementing the tests, it turned out that the
implementation violated that contract.

src/util/PcntlTimeout.php

@@ -71,8 +71,11 @@ public function timeBoxed(callable $code)
             return call_user_func($code);
         } finally {
             pcntl_alarm(0);
-            pcntl_signal_dispatch();
-            pcntl_signal(SIGALRM, SIG_DFL);
+            try {
+                pcntl_signal_dispatch();
+            } finally {
+                pcntl_signal(SIGALRM, SIG_DFL);
+            }
         }
     }
 

tests/util/PcntlTimeoutTest.php

@@ -2,6 +2,8 @@
 
 namespace malkusch\lock\util;
 
+use malkusch\lock\exception\TimeoutException;
+
 /**
  * Tests for PcntlTimeout
  *
@@ -29,6 +31,23 @@ public function shouldTimeout()
         });
     }
 
+    /**
+     * A long running system call should be interrupted,
+     * any thrown exception should be ignored.
+     *
+     * @test
+     * @expectedException malkusch\lock\exception\TimeoutException
+     */
+    public function shouldTimeoutAndIgnoreException()
+    {
+        $timeout = new PcntlTimeout(1);
+
+        $timeout->timeBoxed(function () {
+            sleep(2);
+            throw new \DomainException("Swallow me");
+        });
+    }
+
     /**
      * A short running system call should complete its execution
      *
@@ -45,6 +64,21 @@ public function shouldNotTimeout()
         $this->assertEquals(42, $result);
     }
 
+    /**
+     * Thrown exceptions from the subject code should be rethrown
+     *
+     * @test
+     * @expectedException \DomainException
+     */
+    public function shouldThrowException()
+    {
+        $timeout = new PcntlTimeout(1);
+
+        $timeout->timeBoxed(function () {
+            throw new \DomainException();
+        });
+    }
+
     /**
      * When a previous scheduled alarm exists, it should fail
      *
@@ -79,4 +113,107 @@ public function shouldResetAlarmWhenNotTimeout()
 
         $this->assertEquals(0, pcntl_alarm(0));
     }
+
+    /**
+     * After not timing out and throwing an exception, there should be no alarm scheduled
+     *
+     * @test
+     */
+    public function shouldResetAlarmWhenNotTimeoutAndException()
+    {
+        $timeout = new PcntlTimeout(3);
+
+        try {
+            $timeout->timeBoxed(function () {
+                throw new \DomainException();
+            });
+        } catch (\DomainException $e) {
+            // expected
+        }
+
+        $this->assertEquals(0, pcntl_alarm(0));
+    }
+
+    /**
+     * After a timeout, the default signal handler should be installed
+     *
+     * @test
+     */
+    public function shouldResetToDefaultHandlerAfterTimeout()
+    {
+        $pid = pcntl_fork();
+        if ($pid == -1) {
+            $this->fail('could not fork');
+        } elseif ($pid === 0) {
+            try {
+                $timeout = new PcntlTimeout(1);
+                $timeout->timeBoxed(function () {
+                    sleep(3);
+                });
+            } catch (TimeoutException $e) {
+                // expected
+            }
+
+            pcntl_alarm(1);
+            sleep(3);
+            exit;
+        }
+        pcntl_wait($status);
+
+        $this->assertEquals(SIGALRM, pcntl_wtermsig($status));
+    }
+
+    /**
+     * After no timeout, the default signal handler should be installed
+     *
+     * @test
+     */
+    public function shouldResetToDefaultHandlerAfterNoTimeout()
+    {
+        $pid = pcntl_fork();
+        if ($pid == -1) {
+            $this->fail('could not fork');
+        } elseif ($pid === 0) {
+            $timeout = new PcntlTimeout(3);
+            $timeout->timeBoxed(function () {
+                return 42;
+            });
+
+            pcntl_alarm(1);
+            sleep(3);
+            exit;
+        }
+        pcntl_wait($status);
+
+        $this->assertEquals(SIGALRM, pcntl_wtermsig($status));
+    }
+
+    /**
+     * After no timeout and throwing an exception, the default signal handler should be installed
+     *
+     * @test
+     */
+    public function shouldResetToDefaultHandlerAfterNoTimeoutAndException()
+    {
+        $pid = pcntl_fork();
+        if ($pid == -1) {
+            $this->fail('could not fork');
+        } elseif ($pid === 0) {
+            try {
+                $timeout = new PcntlTimeout(3);
+                $timeout->timeBoxed(function () {
+                    throw new \DomainException();
+                });
+            } catch (\DomainException $e) {
+                // expected
+            }
+
+            pcntl_alarm(1);
+            sleep(3);
+            exit;
+        }
+        pcntl_wait($status);
+
+        $this->assertEquals(SIGALRM, pcntl_wtermsig($status));
+    }
 }