diff --git a/src/Symfony/Component/Process/Pipes/UnixPipes.php b/src/Symfony/Component/Process/Pipes/UnixPipes.php
index 73146356d4..2bf669733e 100644
--- a/src/Symfony/Component/Process/Pipes/UnixPipes.php
+++ b/src/Symfony/Component/Process/Pipes/UnixPipes.php
@@ -102,7 +102,7 @@ class UnixPipes extends AbstractPipes
         unset($r[0]);
 
         // let's have a look if something changed in streams
-        if ($r && false === $n = @stream_select($r, $w, $e, 0, $blocking ? Process::TIMEOUT_PRECISION * 1E6 : 0)) {
+        if (($r || $w) && false === $n = @stream_select($r, $w, $e, 0, $blocking ? Process::TIMEOUT_PRECISION * 1E6 : 0)) {
             // if a system call has been interrupted, forget about it, let's try again
             // otherwise, an error occurred, let's reset pipes
             if (!$this->hasSystemCallBeenInterrupted()) {
diff --git a/src/Symfony/Component/Process/Pipes/WindowsPipes.php b/src/Symfony/Component/Process/Pipes/WindowsPipes.php
index bedac8feed..23e412ca3a 100644
--- a/src/Symfony/Component/Process/Pipes/WindowsPipes.php
+++ b/src/Symfony/Component/Process/Pipes/WindowsPipes.php
@@ -106,11 +106,15 @@ class WindowsPipes extends AbstractPipes
     public function readAndWrite($blocking, $close = false)
     {
         $this->unblock();
-        $this->write();
+        $w = $this->write();
+        $read = $r = $e = array();
 
-        $read = array();
-        if ($this->fileHandles && $blocking) {
-            usleep(Process::TIMEOUT_PRECISION * 1E6);
+        if ($blocking) {
+            if ($w) {
+                @stream_select($r, $w, $e, 0, Process::TIMEOUT_PRECISION * 1E6);
+            } elseif ($this->fileHandles) {
+                usleep(Process::TIMEOUT_PRECISION * 1E6);
+            }
         }
         foreach ($this->fileHandles as $type => $fileHandle) {
             $data = stream_get_contents($fileHandle, -1, $this->readBytes[$type]);
diff --git a/src/Symfony/Component/Process/Process.php b/src/Symfony/Component/Process/Process.php
index 32704df3f1..ebaa07ecd5 100644
--- a/src/Symfony/Component/Process/Process.php
+++ b/src/Symfony/Component/Process/Process.php
@@ -360,8 +360,7 @@ class Process
         do {
             $this->checkTimeout();
             $running = '\\' === DIRECTORY_SEPARATOR ? $this->isRunning() : $this->processPipes->areOpen();
-            $close = '\\' !== DIRECTORY_SEPARATOR || !$running;
-            $this->readPipes(true, $close);
+            $this->readPipes($running, '\\' !== DIRECTORY_SEPARATOR || !$running);
         } while ($running);
 
         while ($this->isRunning()) {
@@ -1295,14 +1294,15 @@ class Process
         }
 
         $this->processInformation = proc_get_status($this->process);
+        $running = $this->processInformation['running'];
 
-        $this->readPipes($blocking, '\\' === DIRECTORY_SEPARATOR ? !$this->processInformation['running'] : true);
+        $this->readPipes($running && $blocking, '\\' !== DIRECTORY_SEPARATOR || !$running);
 
         if ($this->fallbackStatus && $this->enhanceSigchildCompatibility && $this->isSigchildEnabled()) {
             $this->processInformation = $this->fallbackStatus + $this->processInformation;
         }
 
-        if (!$this->processInformation['running']) {
+        if (!$running) {
             $this->close();
         }
     }