1 files changed, 144 insertions, 0 deletions
diff --git a/spec/lib/gitlab/process_management_spec.rb b/spec/lib/gitlab/process_management_spec.rb
new file mode 100644
index 00000000000..a71a476b540
--- /dev/null
+++ b/spec/lib/gitlab/process_management_spec.rb
@@ -0,0 +1,144 @@
+# frozen_string_literal: true
+
+require_relative '../../../lib/gitlab/process_management'
+
+RSpec.describe Gitlab::ProcessManagement do
+  describe '.trap_signals' do
+    it 'traps the given signals' do
+      expect(described_class).to receive(:trap).ordered.with(:INT)
+      expect(described_class).to receive(:trap).ordered.with(:HUP)
+
+      described_class.trap_signals(%i(INT HUP))
+    end
+  end
+
+  describe '.modify_signals' do
+    it 'traps the given signals with the given command' do
+      expect(described_class).to receive(:trap).ordered.with(:INT, 'DEFAULT')
+      expect(described_class).to receive(:trap).ordered.with(:HUP, 'DEFAULT')
+
+      described_class.modify_signals(%i(INT HUP), 'DEFAULT')
+    end
+  end
+
+  describe '.signal_processes' do
+    it 'sends a signal to every given process' do
+      expect(described_class).to receive(:signal).with(1, :INT)
+
+      described_class.signal_processes([1], :INT)
+    end
+  end
+
+  describe '.signal' do
+    it 'sends a signal to the given process' do
+      allow(Process).to receive(:kill).with(:INT, 4)
+      expect(described_class.signal(4, :INT)).to eq(true)
+    end
+
+    it 'returns false when the process does not exist' do
+      allow(Process).to receive(:kill).with(:INT, 4).and_raise(Errno::ESRCH)
+      expect(described_class.signal(4, :INT)).to eq(false)
+    end
+  end
+
+  describe '.wait_async' do
+    it 'waits for a process in a separate thread' do
+      thread = described_class.wait_async(Process.spawn('true'))
+
+      # Upon success Process.wait just returns the PID.
+      expect(thread.value).to be_a_kind_of(Numeric)
+    end
+  end
+
+  # In the X_alive? checks, we check negative PIDs sometimes as a simple way
+  # to be sure the pids are definitely for non-existent processes.
+  # Note that -1 is special, and sends the signal to every process we have permission
+  # for, so we use -2, -3 etc
+  describe '.all_alive?' do
+    it 'returns true if all processes are alive' do
+      processes = [Process.pid]
+
+      expect(described_class.all_alive?(processes)).to eq(true)
+    end
+
+    it 'returns false when a thread was not alive' do
+      processes = [-2]
+
+      expect(described_class.all_alive?(processes)).to eq(false)
+    end
+  end
+
+  describe '.process_alive?' do
+    it 'returns true if the process is alive' do
+      process = Process.pid
+
+      expect(described_class.process_alive?(process)).to eq(true)
+    end
+
+    it 'returns false when a thread was not alive' do
+      process = -2
+
+      expect(described_class.process_alive?(process)).to eq(false)
+    end
+
+    it 'returns false when no pid is given' do
+      process = nil
+
+      expect(described_class.process_alive?(process)).to eq(false)
+    end
+  end
+
+  describe '.process_died?' do
+    it 'returns false if the process is alive' do
+      process = Process.pid
+
+      expect(described_class.process_died?(process)).to eq(false)
+    end
+
+    it 'returns true when a thread was not alive' do
+      process = -2
+
+      expect(described_class.process_died?(process)).to eq(true)
+    end
+
+    it 'returns true when no pid is given' do
+      process = nil
+
+      expect(described_class.process_died?(process)).to eq(true)
+    end
+  end
+
+  describe '.pids_alive' do
+    it 'returns the pids that are alive, from a given array' do
+      pids = [Process.pid, -2]
+
+      expect(described_class.pids_alive(pids)).to match_array([Process.pid])
+    end
+  end
+
+  describe '.any_alive?' do
+    it 'returns true if at least one process is alive' do
+      processes = [Process.pid, -2]
+
+      expect(described_class.any_alive?(processes)).to eq(true)
+    end
+
+    it 'returns false when all threads are dead' do
+      processes = [-2, -3]
+
+      expect(described_class.any_alive?(processes)).to eq(false)
+    end
+  end
+
+  describe '.write_pid' do
+    it 'writes the PID of the current process to the given file' do
+      handle = double(:handle)
+
+      allow(File).to receive(:open).with('/dev/null', 'w').and_yield(handle)
+
+      expect(handle).to receive(:write).with(Process.pid.to_s)
+
+      described_class.write_pid('/dev/null')
+    end
+  end
+end