Initial work on tracking memory usage

src/benchmark/benchmark_result.rs

@@ -45,6 +45,10 @@ pub struct BenchmarkResult {
     /// Exit codes of all command invocations
     pub exit_codes: Vec<Option<i32>>,
 
+    /// All max. memory sizes
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub max_rss_byte: Option<Vec<Second>>,
+
     /// Parameter values for this benchmark
     #[serde(skip_serializing_if = "BTreeMap::is_empty")]
     pub parameters: BTreeMap<String, String>,

src/benchmark/executor.rs

@@ -99,6 +99,7 @@ impl<'a> Executor for RawExecutor<'a> {
                 time_real: result.time_real,
                 time_user: result.time_user,
                 time_system: result.time_system,
+                max_rss_byte: Some(result.max_rss_byte),
             },
             result.status,
         ))
@@ -167,6 +168,7 @@ impl<'a> Executor for ShellExecutor<'a> {
                 time_real: result.time_real,
                 time_user: result.time_user,
                 time_system: result.time_system,
+                max_rss_byte: Some(result.max_rss_byte),
             },
             result.status,
         ))
@@ -226,6 +228,7 @@ impl<'a> Executor for ShellExecutor<'a> {
             time_real: mean(&times_real),
             time_user: mean(&times_user),
             time_system: mean(&times_system),
+            max_rss_byte: None,
         });
 
         Ok(())
@@ -279,6 +282,7 @@ impl Executor for MockExecutor {
                 time_real: Self::extract_time(command.get_command_line()),
                 time_user: 0.0,
                 time_system: 0.0,
+                max_rss_byte: None,
             },
             status,
         ))

src/benchmark/timing_result.rs

@@ -11,4 +11,7 @@ pub struct TimingResult {
 
     /// Time spent in kernel mode
     pub time_system: Second,
+
+    /// Amount of memory used
+    pub max_rss_byte: Option<i64>,
 }

src/timer/mod.rs

@@ -32,6 +32,9 @@ struct CPUTimes {
 
     /// Total amount of time spent executing in kernel mode
     pub system_usec: i64,
+
+    /// Total amount of memory used by the process
+    pub max_rss_byte: i64,
 }
 
 /// Used to indicate the result of running a command
@@ -40,7 +43,7 @@ pub struct TimerResult {
     pub time_real: Second,
     pub time_user: Second,
     pub time_system: Second,
-
+    pub max_rss_byte: i64,
     /// The exit status of the process
     pub status: ExitStatus,
 }
@@ -106,12 +109,13 @@ pub fn execute_and_measure(mut command: Command) -> Result<TimerResult> {
     let status = child.wait()?;
 
     let time_real = wallclock_timer.stop();
-    let (time_user, time_system) = cpu_timer.stop();
+    let (time_user, time_system, max_rss_byte) = cpu_timer.stop();
 
     Ok(TimerResult {
         time_real,
         time_user,
         time_system,
+        max_rss_byte,
         status,
     })
 }

src/timer/unix_timer.rs

@@ -25,10 +25,10 @@ impl CPUTimer {
         }
     }
 
-    pub fn stop(&self) -> (Second, Second) {
+    pub fn stop(&self) -> (Second, Second, i64) {
         let end_cpu = get_cpu_times();
         let cpu_interval = cpu_time_interval(&self.start_cpu, &end_cpu);
-        (cpu_interval.user, cpu_interval.system)
+        (cpu_interval.user, cpu_interval.system, end_cpu.max_rss_byte)
     }
 }
 
@@ -45,12 +45,20 @@ fn get_cpu_times() -> CPUTimes {
 
     const MICROSEC_PER_SEC: i64 = 1000 * 1000;
 
+    // Linux and *BSD return the value in KibiBytes, Darwin flavors in bytes
+    let max_rss_byte = if cfg!(target_os = "macos") || cfg!(target_os = "ios") {
+        result.ru_maxrss
+    } else {
+        result.ru_maxrss * 1024
+    };
+
     #[allow(clippy::useless_conversion)]
     CPUTimes {
         user_usec: i64::from(result.ru_utime.tv_sec) * MICROSEC_PER_SEC
             + i64::from(result.ru_utime.tv_usec),
         system_usec: i64::from(result.ru_stime.tv_sec) * MICROSEC_PER_SEC
             + i64::from(result.ru_stime.tv_usec),
+        max_rss_byte,
     }
 }
 
@@ -70,11 +78,13 @@ fn test_cpu_time_interval() {
     let t_a = CPUTimes {
         user_usec: 12345,
         system_usec: 54321,
+        max_rss_byte: 0,
     };
 
     let t_b = CPUTimes {
         user_usec: 20000,
         system_usec: 70000,
+        max_rss_byte: 0,
     };
 
     let t_zero = cpu_time_interval(&t_a, &t_a);