1 files changed, 158 insertions, 0 deletions
diff --git a/src/components/util/memory.rs b/src/components/util/memory.rs
new file mode 100644
index 00000000000..7b29c07ef0c
--- /dev/null
+++ b/src/components/util/memory.rs
@@ -0,0 +1,158 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! Memory profiling functions.
+
+use std::io::timer::sleep;
+#[cfg(target_os="linux")]
+use std::io::File;
+#[cfg(target_os="linux")]
+use std::os::page_size;
+use task::spawn_named;
+
+pub struct MemoryProfilerChan(pub Sender<MemoryProfilerMsg>);
+
+impl MemoryProfilerChan {
+    pub fn send(&self, msg: MemoryProfilerMsg) {
+        let MemoryProfilerChan(ref c) = *self;
+        c.send(msg);
+    }
+}
+
+pub enum MemoryProfilerMsg {
+    /// Message used to force print the memory profiling metrics.
+    PrintMsg,
+    /// Tells the memory profiler to shut down.
+    ExitMsg,
+}
+
+pub struct MemoryProfiler {
+    pub port: Receiver<MemoryProfilerMsg>,
+}
+
+impl MemoryProfiler {
+    pub fn create(period: Option<f64>) -> MemoryProfilerChan {
+        let (chan, port) = channel();
+        match period {
+            Some(period) => {
+                let period = (period * 1000f64) as u64;
+                let chan = chan.clone();
+                spawn_named("Memory profiler timer", proc() {
+                    loop {
+                        sleep(period);
+                        if chan.send_opt(PrintMsg).is_err() {
+                            break;
+                        }
+                    }
+                });
+                // Spawn the memory profiler.
+                spawn_named("Memory profiler", proc() {
+                    let memory_profiler = MemoryProfiler::new(port);
+                    memory_profiler.start();
+                });
+            }
+            None => {
+                // No-op to handle profiler messages when the memory profiler
+                // is inactive.
+                spawn_named("Memory profiler", proc() {
+                    loop {
+                        match port.recv_opt() {
+                            Err(_) | Ok(ExitMsg) => break,
+                            _ => {}
+                        }
+                    }
+                });
+            }
+        }
+
+        MemoryProfilerChan(chan)
+    }
+
+    pub fn new(port: Receiver<MemoryProfilerMsg>) -> MemoryProfiler {
+        MemoryProfiler {
+            port: port
+        }
+    }
+
+    pub fn start(&self) {
+        loop {
+            match self.port.recv_opt() {
+               Ok(msg) => {
+                   if !self.handle_msg(msg) {
+                       break
+                   }
+               }
+               _ => break
+            }
+        }
+    }
+
+    fn handle_msg(&self, msg: MemoryProfilerMsg) -> bool {
+        match msg {
+            PrintMsg => {
+                self.handle_print_msg();
+                true
+            },
+            ExitMsg => false
+        }
+    }
+
+    fn print_measurement(path: &str, nbytes: Option<i64>) {
+        match nbytes {
+            Some(nbytes) => {
+                let mebi = 1024f64 * 1024f64;
+                println!("{:12s}: {:12.2f}", path, (nbytes as f64) / mebi);
+            }
+            None => {
+                println!("{:12s}: {:>12s}", path, "???");
+            }
+        }
+    }
+
+    fn handle_print_msg(&self) {
+        println!("{:12s}: {:12s}", "_category_", "_size (MiB)_");
+        MemoryProfiler::print_measurement("vsize",    get_vsize());
+        MemoryProfiler::print_measurement("resident", get_resident());
+        println!("");
+    }
+}
+
+// Like std::macros::try!, but for Option<>.
+macro_rules! option_try(
+    ($e:expr) => (match $e { Some(e) => e, None => return None })
+)
+
+#[cfg(target_os="linux")]
+fn get_proc_self_statm_field(field: uint) -> Option<i64> {
+    let mut f = File::open(&Path::new("/proc/self/statm"));
+    match f.read_to_str() {
+        Ok(contents) => {
+            let s = option_try!(contents.as_slice().words().nth(field));
+            let npages: i64 = option_try!(from_str(s));
+            Some(npages * (page_size() as i64))
+        }
+        Err(_) => None
+    }
+}
+
+#[cfg(target_os="linux")]
+fn get_vsize() -> Option<i64> {
+    get_proc_self_statm_field(0)
+}
+
+#[cfg(not(target_os="linux"))]
+fn get_vsize() -> Option<i64> {
+    None
+}
+
+#[cfg(target_os="linux")]
+fn get_resident() -> Option<i64> {
+    get_proc_self_statm_field(1)
+}
+
+#[cfg(not(target_os="linux"))]
+fn get_resident() -> Option<i64> {
+    None
+}
+