move safe_fork into a standalone method

1 files changed, 44 insertions, 0 deletions

diff --git a/Library/Homebrew/utils/fork.rb b/Library/Homebrew/utils/fork.rb
new file mode 100644
index 000000000..defe1fa79
--- /dev/null
+++ b/Library/Homebrew/utils/fork.rb
@@ -0,0 +1,44 @@
+require "fcntl"
+require "socket"
+
+module Utils
+  def self.safe_fork(&block)
+    socket_path = "#{Dir.mktmpdir("homebrew", HOMEBREW_TEMP)}/socket"
+    server = UNIXServer.new(socket_path)
+    ENV["HOMEBREW_ERROR_PIPE"] = socket_path
+    read, write = IO.pipe
+
+    pid = fork do
+      begin
+        server.close
+        read.close
+        write.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC)
+        yield
+      rescue Exception => e
+        Marshal.dump(e, write)
+        write.close
+        exit! 1
+      end
+    end
+
+    ignore_interrupts(:quietly) do # the child will receive the interrupt and marshal it back
+      begin
+        socket = server.accept_nonblock
+      rescue Errno::EAGAIN, Errno::EWOULDBLOCK, Errno::ECONNABORTED, Errno::EPROTO, Errno::EINTR
+        retry unless Process.waitpid(pid, Process::WNOHANG)
+      else
+        socket.send_io(write)
+      end
+      write.close
+      data = read.read
+      read.close
+      Process.wait(pid) unless socket.nil?
+      raise Marshal.load(data) unless data.nil? or data.empty?
+      raise Interrupt if $?.exitstatus == 130
+      raise "Suspicious failure" unless $?.success?
+    end
+  ensure
+    server.close
+    FileUtils.rm_r File.dirname(socket_path)
+  end
+end