From b920f03a0259d1e1abb90ae4fcf4af0d291a0d4e Mon Sep 17 00:00:00 2001
From: Oscar Dowson <odow@users.noreply.github.com>
Date: Tue, 20 Aug 2024 16:13:32 +1200
Subject: [PATCH] Remove global nlopt_exception (#230)

---
 src/NLopt.jl  | 33 +++++++++++++++------------------
 test/C_API.jl |  6 +++---
 2 files changed, 18 insertions(+), 21 deletions(-)

diff --git a/src/NLopt.jl b/src/NLopt.jl
index f491d7a..ee18101 100644
--- a/src/NLopt.jl
+++ b/src/NLopt.jl
@@ -116,8 +116,10 @@ mutable struct Opt
     # Opt so that they aren't garbage-collected.  cb[1] is the objective.
     cb::Vector{Callback_Data}
 
+    exception::Any
+
     function Opt(p::Ptr{Cvoid})
-        opt = new(p, Array{Callback_Data}(undef, 1))
+        opt = new(p, Array{Callback_Data}(undef, 1), nothing)
         finalizer(destroy, opt)
         return opt
     end
@@ -205,9 +207,6 @@ end
 
 struct ForcedStop <: Exception end
 
-# cache current exception for forced stop
-global nlopt_exception = nothing
-
 function errmsg(o::Opt)
     msg = nlopt_get_errmsg(o)
     return msg == C_NULL ? nothing : unsafe_string(msg)
@@ -232,11 +231,10 @@ function chk(o::Opt, result::Result)
     elseif result == OUT_OF_MEMORY
         throw(OutOfMemoryError())
     elseif result == FORCED_STOP
-        global nlopt_exception
-        e = nlopt_exception
-        nlopt_exception = nothing
-        if e !== nothing && !isa(e, ForcedStop)
-            throw(e)
+        exception = getfield(o, :exception)
+        setfield!(o, :exception, nothing)
+        if exception !== nothing && !isa(exception, ForcedStop)
+            throw(exception)
         end
     else
         error("nlopt failure $result", _errmsg(o))
@@ -440,9 +438,9 @@ function nlopt_callback_wrapper(
         return d.f(x, p_grad == C_NULL ? Cdouble[] : grad)
     catch e
         if e isa ForcedStop
-            global nlopt_exception = e
+            setfield!(d.o, :exception, e)
         else
-            global nlopt_exception = CapturedException(e, catch_backtrace())
+            setfield!(d.o, :exception, CapturedException(e, catch_backtrace()))
         end
         force_stop!(d.o::Opt)
         return NaN
@@ -524,9 +522,9 @@ function nlopt_vcallback_wrapper(
         d.f(res, x, grad)
     catch e
         if e isa ForcedStop
-            global nlopt_exception = e
+            d.o.exception = e
         else
-            global nlopt_exception = CapturedException(e, catch_backtrace())
+            d.o.exception = CapturedException(e, catch_backtrace())
         end
         force_stop!(d.o::Opt)
     end
@@ -763,11 +761,10 @@ function optimize!(o::Opt, x::Vector{Cdouble})
     # We do not need to check the value of `ret`, except if it is a FORCED_STOP
     # with a Julia-related exception from a callback
     if ret == FORCED_STOP
-        global nlopt_exception
-        e = nlopt_exception
-        nlopt_exception = nothing
-        if e !== nothing && !(e isa ForcedStop)
-            throw(e)
+        exception = getfield(o, :exception)
+        setfield!(o, :exception, nothing)
+        if exception !== nothing && !(exception isa ForcedStop)
+            throw(exception)
         end
     end
     return opt_f[], x, Symbol(ret)
diff --git a/test/C_API.jl b/test/C_API.jl
index 3b6e4dc..6227f2b 100644
--- a/test/C_API.jl
+++ b/test/C_API.jl
@@ -44,7 +44,7 @@ function test_issue_156_CapturedException()
     opt = Opt(:LN_SBPLX, 1)
     opt.min_objective = f
     @test_throws CapturedException optimize(opt, [0.1234])
-    @test NLopt.nlopt_exception === nothing
+    @test getfield(opt, :exception) === nothing
     try
         optimize(opt, [0.1234])
     catch e
@@ -60,7 +60,7 @@ function test_issue_156_ForcedStop()
     opt.min_objective = f
     fmin, xmin, ret = optimize(opt, [0.1234])
     @test ret == :FORCED_STOP
-    @test NLopt.nlopt_exception === nothing
+    @test getfield(opt, :exception) === nothing
     return
 end
 
@@ -70,7 +70,7 @@ function test_issue_156_no_error()
     opt.min_objective = f
     fmin, xmin, ret = optimize(opt, [0.1234])
     @test ret ∈ (:SUCCESS, :FTOL_REACHED, :XTOL_REACHED)
-    @test NLopt.nlopt_exception === nothing
+    @test getfield(opt, :exception) === nothing
     return
 end