From 2e243bc99b2a6940acde0fb55221217c0eba6f40 Mon Sep 17 00:00:00 2001
From: Tim Besard <tim.besard@gmail.com>
Date: Mon, 9 Sep 2024 17:56:02 +0200
Subject: [PATCH] Preserve buffers from GC collection when doing unsafe things.
 (#219)

---
 lib/device.jl     | 4 ++--
 lib/kernel.jl     | 4 ++--
 lib/platform.jl   | 4 ++--
 lib/program.jl    | 4 ++--
 test/behaviour.jl | 2 +-
 5 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/lib/device.jl b/lib/device.jl
index 302b8d7b..243f2fdc 100644
--- a/lib/device.jl
+++ b/lib/device.jl
@@ -24,7 +24,7 @@ end
         clGetDeviceInfo(d, prop, 0, C_NULL, sz)
         chars = Vector{Cchar}(undef, sz[])
         clGetDeviceInfo(d, prop, sz[], chars, C_NULL)
-        return unsafe_string(pointer(chars))
+        return GC.@preserve chars unsafe_string(pointer(chars))
     end
     if s === :profile
         return get_string(CL_DEVICE_PROFILE)
@@ -123,7 +123,7 @@ end
         clGetDeviceInfo(d, CL_DEVICE_EXTENSIONS, 0, C_NULL, size)
         result = Vector{Cchar}(undef, size[])
         clGetDeviceInfo(d, CL_DEVICE_EXTENSIONS, size[], result, C_NULL)
-        bs = unsafe_string(pointer(result))
+        bs = GC.@preserve result unsafe_string(pointer(result))
         return String[string(s) for s in split(bs)]
     end
 
diff --git a/lib/kernel.jl b/lib/kernel.jl
index f9d5bfbb..29656fef 100644
--- a/lib/kernel.jl
+++ b/lib/kernel.jl
@@ -337,7 +337,7 @@ function Base.getproperty(k::Kernel, s::Symbol)
         clGetKernelInfo(k, CL_KERNEL_FUNCTION_NAME, 0, C_NULL, size)
         result = Vector{Cchar}(undef, size[])
         clGetKernelInfo(k, CL_KERNEL_FUNCTION_NAME, size[], result, C_NULL)
-        return unsafe_string(pointer(result))
+        return GC.@preserve result unsafe_string(pointer(result))
     elseif s == :num_args
         result = Ref{Cuint}()
         clGetKernelInfo(k, CL_KERNEL_NUM_ARGS, sizeof(Cuint), result, C_NULL)
@@ -360,7 +360,7 @@ function Base.getproperty(k::Kernel, s::Symbol)
         if err == CL_SUCCESS && size[] > 1
             result = Vector{Cchar}(undef, size[])
             clGetKernelInfo(k, CL_KERNEL_ATTRIBUTES, size[], result, C_NULL)
-            return unsafe_string(pointer(result))
+            return GC.@preserve result unsafe_string(pointer(result))
         else
             return ""
         end
diff --git a/lib/platform.jl b/lib/platform.jl
index 7113dd68..61891e36 100644
--- a/lib/platform.jl
+++ b/lib/platform.jl
@@ -21,7 +21,7 @@ function Base.getproperty(p::Platform, s::Symbol)
         clGetPlatformInfo(p, string_properties[s], 0, C_NULL, size)
         result = Vector{Cchar}(undef, size[])
         clGetPlatformInfo(p, string_properties[s], size[], result, C_NULL)
-        return unsafe_string(pointer(result))
+        return GC.@preserve result unsafe_string(pointer(result))
     end
 
     if s == :extensions
@@ -29,7 +29,7 @@ function Base.getproperty(p::Platform, s::Symbol)
         clGetPlatformInfo(p, CL_PLATFORM_EXTENSIONS, 0, C_NULL, size)
         result = Vector{Cchar}(undef, size[])
         clGetPlatformInfo(p, CL_PLATFORM_EXTENSIONS, size[], result, C_NULL)
-        return split(unsafe_string(pointer(result)))
+        return GC.@preserve result split(unsafe_string(pointer(result)))
     end
 
     return getfield(p, s)
diff --git a/lib/program.jl b/lib/program.jl
index 2b6c30a4..ec5b99ec 100644
--- a/lib/program.jl
+++ b/lib/program.jl
@@ -128,7 +128,7 @@ function Base.getproperty(p::Program, s::Symbol)
         src_len[] <= 1 && return nothing
         src = Vector{Cchar}(undef, src_len[])
         clGetProgramInfo(p, CL_PROGRAM_SOURCE, src_len[], src, C_NULL)
-        return unsafe_string(pointer(src))
+        return GC.@preserve src unsafe_string(pointer(src))
     elseif s == :binary_sizes
         sizes = Vector{Csize_t}(undef, p.num_devices)
         clGetProgramInfo(p, CL_PROGRAM_BINARY_SIZES, sizeof(sizes), sizes, C_NULL)
@@ -180,7 +180,7 @@ function Base.getproperty(p::Program, s::Symbol)
             clGetProgramBuildInfo(p, device, CL_PROGRAM_BUILD_LOG, 0, C_NULL, size)
             log = Vector{Cchar}(undef, size[])
             clGetProgramBuildInfo(p, device, CL_PROGRAM_BUILD_LOG, size[], log, C_NULL)
-            log_dict[device] = unsafe_string(pointer(log))
+            log_dict[device] = GC.@preserve log unsafe_string(pointer(log))
         end
         return log_dict
     else
diff --git a/test/behaviour.jl b/test/behaviour.jl
index 9ec9e7d1..a76ae63c 100644
--- a/test/behaviour.jl
+++ b/test/behaviour.jl
@@ -21,7 +21,7 @@
     cl.launch(kern, str_len, nothing, out_buf)
     h = cl.read(out_buf)
 
-    @test unsafe_string(pointer(h)) == hello_world_str
+    @test hello_world_str == GC.@preserve h unsafe_string(pointer(h))
 end
 
 @testset "Low Level API Test" begin