Add globally registered timers

README.md

@@ -427,6 +427,55 @@ julia> print_timer(to)
 
 In order to complement the default timer simply call `TimerOutputs.complement!()`.
 
+## Shared Timers
+
+It is sometimes desirable for a timer to be shared across all users of the
+package.  For this purpose, `get_timer` maintains a collection of named timers
+defined in the package.
+
+`get_timer(timer_name::String)` retrieves the timer `timer_name` from the
+collection, creating a new timer if none already exists.
+
+For example:
+```julia
+module UseTimer
+using TimerOutputs: @timeit, get_timer
+
+function foo()
+    to = get_timer("Shared")
+    @timeit get_timer("Shared") "foo" sleep(0.1)
+end
+end
+
+@timeit get_timer("Shared") "section1" begin
+    UseTimer.foo()
+    sleep(0.01)
+end
+```
+
+which prints:
+```julia
+julia> print_timer(get_timer("Shared"))
+ ───────────────────────────────────────────────────────────────────
+                            Time                   Allocations
+                    ──────────────────────   ───────────────────────
+  Tot / % measured:      17.1s / 0.82%           44.0MiB / 2.12%
+
+ Section    ncalls     time   %tot     avg     alloc   %tot      avg
+ ───────────────────────────────────────────────────────────────────
+ section1        1    140ms   100%   140ms    956KiB  100%    956KiB
+   foo           1    102ms  72.7%   102ms      144B  0.01%     144B
+ ───────────────────────────────────────────────────────────────────
+```
+
+Note that the result of `get_timer` should not be called from top-level in a
+package that is getting precompiled since the retrieved timer will no longer be
+shared with other users getting a timer with the same name. Also, this function
+is not recommended to be used extensively by libraries as the namespace is
+shared and collisions are possible if two libraries happen to use the same timer
+name.
+
+
 ## Overhead
 
 There is a small overhead in timing a section (0.25 μs) which means that this package is not suitable for measuring sections that finish very quickly.

src/TimerOutput.jl

@@ -52,6 +52,22 @@ Base.copy(to::TimerOutput) = TimerOutput(copy(to.start_data), copy(to.accumulate
                                          copy(to.timer_stack), to.name, to.flattened, to.enabled, to.totmeasured, "", nothing)
 
 const DEFAULT_TIMER = TimerOutput()
+const _timers = Dict{String, TimerOutput}("Default" => DEFAULT_TIMER)
+const _timers_lock = ReentrantLock() # needed for adding new timers on different threads
+"""
+    get_timer(name::String)
+
+Returns the `TimerOutput` associated with `name`.
+If no timers are associated with `name`, a new `TimerOutput` will be created.
+"""
+function get_timer(name::String)
+    lock(_timers_lock) do
+        if !haskey(_timers, name)
+            _timers[name] = TimerOutput(name)
+        end
+        return _timers[name]
+    end
+end
 
 # push! and pop!
 function Base.push!(to::TimerOutput, label::String)

src/TimerOutputs.jl

@@ -4,7 +4,7 @@ using ExprTools
 
 import Base: show, time_ns
 export TimerOutput, @timeit, @timeit_debug, reset_timer!, print_timer, timeit,
-                    enable_timer!, disable_timer!, @notimeit
+                    enable_timer!, disable_timer!, @notimeit, get_timer
 
 # https://github.com/JuliaLang/julia/pull/33717
 if VERSION < v"1.4.0-DEV.475"

test/runtests.jl

@@ -377,6 +377,27 @@ end
 @test "foo" in keys(DEFAULT_TIMER.inner_timers)
 TimerOutputs.reset_timer!()
 
+# Test sharing timers between modules
+@test !haskey(TimerOutputs._timers, "TestModule2")
+@test !haskey(TimerOutputs._timers, "my_timer")
+
+to = get_timer("my_timer")
+@timeit to "foo" sleep(0.1)
+@test ncalls(get_timer("my_timer")["foo"]) == 1
+
+module TestModule2
+    using TimerOutputs: @timeit, get_timer
+    foo(x) = x
+    @timeit get_timer("TestModule2") "foo" foo(1)
+    @timeit get_timer("my_timer") "foo" foo(1)
+end
+
+# Timer from module is accessible to root
+@test haskey(TimerOutputs._timers, "TestModule2")
+@test ncalls(get_timer("TestModule2")["foo"]) == 1
+# Timer from root is accessible to module
+@test ncalls(get_timer("my_timer")["foo"]) == 2
+
 # Broken
 #=
 # Type inference with @timeit_debug