[Process] Fix potential race condition

nicolas-grekas · nicolas-grekas · commit 41c05549ff4d · 2016-01-06T09:44:17.000+01:00
diff --git a/src/Symfony/Component/Process/Process.php b/src/Symfony/Component/Process/Process.php
@@ -651,8 +651,12 @@ public function stop($timeout = 10, $signal = null)
             }
         }
 
-        $this->updateStatus(false);
-        if ($this->processInformation['running']) {
+        if ($this->isRunning()) {
+            if (isset($this->fallbackStatus['pid'])) {
+                unset($this->fallbackStatus['pid']);
+
+                return $this->stop(0, $signal);
+            }
             $this->close();
         }
 
@@ -1145,7 +1149,7 @@ private function resetProcessData()
      */
     private function doSignal($signal, $throwException)
     {
-        if (!$this->isRunning()) {
+        if (null === $pid = $this->getPid()) {
             if ($throwException) {
                 throw new LogicException('Can not send signal on a non running process.');
             }
@@ -1154,7 +1158,7 @@ private function doSignal($signal, $throwException)
         }
 
         if ('\\' === DIRECTORY_SEPARATOR) {
-            exec(sprintf('taskkill /F /T /PID %d 2>&1', $this->getPid()), $output, $exitCode);
+            exec(sprintf('taskkill /F /T /PID %d 2>&1', $pid), $output, $exitCode);
             if ($exitCode && $this->isRunning()) {
                 if ($throwException) {
                     throw new RuntimeException(sprintf('Unable to kill the process (%s).', implode(' ', $output)));
@@ -1166,8 +1170,8 @@ private function doSignal($signal, $throwException)
             if (!$this->enhanceSigchildCompatibility || !$this->isSigchildEnabled()) {
                 $ok = @proc_terminate($this->process, $signal);
             } elseif (function_exists('posix_kill')) {
-                $ok = @posix_kill($this->getPid(), $signal);
-            } elseif ($ok = proc_open(sprintf('kill -%d %d', $signal, $this->getPid()), array(2 => array('pipe', 'w')), $pipes)) {
+                $ok = @posix_kill($pid, $signal);
+            } elseif ($ok = proc_open(sprintf('kill -%d %d', $signal, $pid), array(2 => array('pipe', 'w')), $pipes)) {
                 $ok = false === fgets($pipes[2]);
             }
             if (!$ok) {

Original file line number	Diff line number	Diff line change
`@@ -651,8 +651,12 @@ public function stop($timeout = 10, $signal = null)`
`651`	`651`	`}`
`652`	`652`	`}`
`653`	`653`
`654`		`- $this->updateStatus(false);`
`655`		`- if ($this->processInformation['running']) {`
	`654`	`+ if ($this->isRunning()) {`
	`655`	`+ if (isset($this->fallbackStatus['pid'])) {`
	`656`	`+ unset($this->fallbackStatus['pid']);`
	`657`	`+`
	`658`	`+ return $this->stop(0, $signal);`
	`659`	`+ }`
`656`	`660`	`$this->close();`
`657`	`661`	`}`
`658`	`662`
`@@ -1145,7 +1149,7 @@ private function resetProcessData()`
`1145`	`1149`	`*/`
`1146`	`1150`	`private function doSignal($signal, $throwException)`
`1147`	`1151`	`{`
`1148`		`- if (!$this->isRunning()) {`
	`1152`	`+ if (null === $pid = $this->getPid()) {`
`1149`	`1153`	`if ($throwException) {`
`1150`	`1154`	`throw new LogicException('Can not send signal on a non running process.');`
`1151`	`1155`	`}`
`@@ -1154,7 +1158,7 @@ private function doSignal($signal, $throwException)`
`1154`	`1158`	`}`
`1155`	`1159`
`1156`	`1160`	`if ('\\' === DIRECTORY_SEPARATOR) {`
`1157`		`- exec(sprintf('taskkill /F /T /PID %d 2>&1', $this->getPid()), $output, $exitCode);`
	`1161`	`+ exec(sprintf('taskkill /F /T /PID %d 2>&1', $pid), $output, $exitCode);`
`1158`	`1162`	`if ($exitCode && $this->isRunning()) {`
`1159`	`1163`	`if ($throwException) {`
`1160`	`1164`	`throw new RuntimeException(sprintf('Unable to kill the process (%s).', implode(' ', $output)));`

`1166`	`1170`	`if (!$this->enhanceSigchildCompatibility \|\| !$this->isSigchildEnabled()) {`
`1167`	`1171`	`$ok = @proc_terminate($this->process, $signal);`
`1168`	`1172`	`} elseif (function_exists('posix_kill')) {`
`1169`		`- $ok = @posix_kill($this->getPid(), $signal);`
`1170`		`- } elseif ($ok = proc_open(sprintf('kill -%d %d', $signal, $this->getPid()), array(2 => array('pipe', 'w')), $pipes)) {`
	`1173`	`+ $ok = @posix_kill($pid, $signal);`
	`1174`	`+ } elseif ($ok = proc_open(sprintf('kill -%d %d', $signal, $pid), array(2 => array('pipe', 'w')), $pipes)) {`
`1171`	`1175`	`$ok = false === fgets($pipes[2]);`
`1172`	`1176`	`}`
`1173`	`1177`	`if (!$ok) {`