Move the ProcessWatcher methods out of content/common/process_watcher into base/process_util, alo...

base/process_util_posix.cc

Index: base/process_util_posix.cc
===================================================================
--- base/process_util_posix.cc	(revision 111236)
+++ base/process_util_posix.cc	(working copy)
@@ -1210,4 +1210,101 @@
   return exited_cleanly;
 }
 
+#if !defined(OS_MACOSX)
+
+namespace {
+
+// Return true if the given child is dead. This will also reap the process.
+// Doesn't block.
+static bool IsChildDead(pid_t child) {
+  const pid_t result = HANDLE_EINTR(waitpid(child, NULL, WNOHANG));
+  if (result == -1) {
+    DPLOG(ERROR) << "waitpid(" << child << ")";
+    NOTREACHED();
+  } else if (result > 0) {
+    // The child has died.
+    return true;
+  }
+
+  return false;
+}
+
+// A thread class which waits for the given child to exit and reaps it.
+// If the child doesn't exit within a couple of seconds, kill it.
+class BackgroundReaper : public PlatformThread::Delegate {
+ public:
+  BackgroundReaper(pid_t child, unsigned timeout)
+      : child_(child),
+        timeout_(timeout) {
+  }
+
+  void ThreadMain() {
+    WaitForChildToDie();
+    delete this;
+  }
+
+  void WaitForChildToDie() {
+    // Wait forever case.
+    if (timeout_ == 0) {
+      pid_t r = HANDLE_EINTR(waitpid(child_, NULL, 0));
+      if (r != child_) {
+        DPLOG(ERROR) << "While waiting for " << child_
+                     << " to terminate, we got the following result: " << r;
+      }
+      return;
+    }
+
+    // There's no good way to wait for a specific child to exit in a timed
+    // fashion. (No kqueue on Linux), so we just loop and sleep.
+
+    // Wait for 2 * timeout_ 500 milliseconds intervals.
+    for (unsigned i = 0; i < 2 * timeout_; ++i) {
+      PlatformThread::Sleep(500);  // 0.5 seconds
+      if (IsChildDead(child_))
+        return;
+    }
+
+    if (kill(child_, SIGKILL) == 0) {
+      // SIGKILL is uncatchable. Since the signal was delivered, we can
+      // just wait for the process to die now in a blocking manner.
+      if (HANDLE_EINTR(waitpid(child_, NULL, 0)) < 0)
+        DPLOG(WARNING) << "waitpid";
+    } else {
+      DLOG(ERROR) << "While waiting for " << child_ << " to terminate we"
+                  << " failed to deliver a SIGKILL signal (" << errno << ").";
+    }
+  }
+
+ private:
+  const pid_t child_;
+  // Number of seconds to wait, if 0 then wait forever and do not attempt to
+  // kill |child_|.
+  const unsigned timeout_;
+
+  DISALLOW_COPY_AND_ASSIGN(BackgroundReaper);
+};
+
+}  // namespace
+
+void EnsureProcessTerminated(ProcessHandle process) {
+  // If the child is already dead, then there's nothing to do.
+  if (IsChildDead(process))
+    return;
+
+  const unsigned timeout = 2;  // seconds
+  BackgroundReaper* reaper = new BackgroundReaper(process, timeout);
+  PlatformThread::CreateNonJoinable(0, reaper);
+}
+
+void EnsureProcessGetsReaped(ProcessHandle process) {
+  // If the child is already dead, then there's nothing to do.
+  if (IsChildDead(process))
+    return;
+
+  BackgroundReaper* reaper = new BackgroundReaper(process, 0);
+  PlatformThread::CreateNonJoinable(0, reaper);
+}
+
+#endif

[willchan no longer on Chromium, 2011/11/23 17:46:37]

Up to you, but it's my personal preference to terminate lengthy #if/#endif
blocks with a // !defined(OS_MACOSX) or something.

[jam, 2011/11/23 17:48:33]

Done.

+
 }  // namespace base