Increase file descriptor limit in native AOT executables

[MichalStrehovsky]

Fixes #82719

Cc @dotnet/ilc-contrib

[Copilot]

Pull Request Overview

This PR consolidates file descriptor limit handling across .NET runtime components by moving the descriptor limit increase functionality from individual runtime implementations into the shared minipal library. This ensures consistent behavior across CoreCLR, Mono, and Native AOT executables.

Key changes:

• Creates a unified minipal_increase_descriptor_limit() function in the minipal library
• Removes duplicate descriptor limit code from CoreCLR PAL and Mono runtime
• Adds descriptor limit increase functionality to Native AOT bootstrap

Reviewed Changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/native/minipal/descriptorlimit.h	New header defining the minipal descriptor limit API
src/native/minipal/descriptorlimit.c	New implementation of descriptor limit increase functionality
src/native/minipal/minipalconfig.h.in	Adds HAVE_RESOURCE_H configuration check
src/native/minipal/configure.cmake	Adds sys/resource.h availability check
src/native/minipal/CMakeLists.txt	Includes new descriptor limit source and disables functionality on problematic platforms
src/mono/mono/mini/driver.c	Replaces local descriptor limit function with minipal version
src/mono/CMakeLists.txt	Removes redundant DONT_SET_RLIMIT_NOFILE definition
src/coreclr/pal/src/init/pal.cpp	Replaces local descriptor limit function with minipal version
src/coreclr/pal/src/CMakeLists.txt	Removes redundant DONT_SET_RLIMIT_NOFILE definition
src/coreclr/nativeaot/Bootstrap/main.cpp	Adds descriptor limit increase call to Native AOT bootstrap

[jkotas]

Thanks

[pavelsavara]

Unfortunately we don't run WASI builds on PRs anymore and (I think) this broke the build.

Log

  FAILED: mono/minipal/minipal/CMakeFiles/minipal_objects.dir/descriptorlimit.c.obj 
  D:\a\_work\1\s\src\mono\wasi\wasi-sdk\bin\clang.exe --target=wasm32-wasip2 --sysroot=D:/a/_work/1/s/src/mono/wasi/wasi-sdk/share/wasi-sysroot -DCOMPILER_SUPPORTS_W_RESERVED_IDENTIFIER -DDISABLE_EGD_SOCKET -DDISABLE_EVENTPIPE -DHAVE_CONFIG_H -DHOST_WASI -D_THREAD_SAFE -D_WASI_EMULATED_MMAN -D_WASI_EMULATED_PROCESS_CLOCKS -D_WASI_EMULATED_PTHREAD -D_WASI_EMULATED_SIGNAL -ID:/a/_work/1/s/artifacts/obj -ID:/a/_work/1/s/src/native -ID:/a/_work/1/s/artifacts/obj/mono/wasi.wasm.Release/mono/minipal/minipal "-ID:/a/_work/1/s/src/mono/wasi/include" "-ID:/a/_work/1/s/src/mono/wasi/mono-include" "-ID:/a/_work/1/s/src/native/public" "-ID:/a/_work/1/s/src/mono/mono/eglib" -D_WASI_EMULATED_PROCESS_CLOCKS -D_WASI_EMULATED_SIGNAL -D_WASI_EMULATED_MMAN -D_WASI_EMULATED_PTHREAD -fno-strict-aliasing -fwrapv -Wall -Wunused -Wmissing-declarations -Wpointer-arith -Wno-cast-qual -Wwrite-strings -Wno-switch -Wno-switch-enum -Wno-unused-value -Wno-attributes -Wno-format-zero-length -Wno-unused-function -Qunused-arguments -Wno-tautological-compare -Wno-parentheses-equality -Wno-self-assign -Wno-return-stack-address -Wno-constant-logical-operand -Wno-zero-length-array -Wno-asm-operand-widths -Wmissing-prototypes -Wstrict-prototypes -Wnested-externs -Werror=return-type -Werror=implicit-function-declaration -Werror=incompatible-pointer-types -Wno-incompatible-pointer-types-discards-qualifiers -Werror -O3 -DNDEBUG -std=gnu11   -g -fPIC -fvisibility=hidden -Wno-strict-prototypes -Wno-unused-but-set-variable -Os -ffp-contract=off -MD -MT mono/minipal/minipal/CMakeFiles/minipal_objects.dir/descriptorlimit.c.obj -MF mono\minipal\minipal\CMakeFiles\minipal_objects.dir\descriptorlimit.c.obj.d -o mono/minipal/minipal/CMakeFiles/minipal_objects.dir/descriptorlimit.c.obj -c D:/a/_work/1/s/src/native/minipal/descriptorlimit.c
  D:/a/_work/1/s/src/native/minipal/descriptorlimit.c:21:19: error: variable has incomplete type 'struct rlimit'
     21 |     struct rlimit rlp;
        |                   ^
  D:/a/_work/1/s/src/native/minipal/descriptorlimit.c:21:12: note: forward declaration of 'struct rlimit'
     21 |     struct rlimit rlp;
        |            ^
  D:/a/_work/1/s/src/native/minipal/descriptorlimit.c:24:14: error: call to undeclared function 'getrlimit'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     24 |     result = getrlimit(RLIMIT_NOFILE, &rlp);
        |              ^
  D:/a/_work/1/s/src/native/minipal/descriptorlimit.c:24:24: error: use of undeclared identifier 'RLIMIT_NOFILE'
     24 |     result = getrlimit(RLIMIT_NOFILE, &rlp);
        |                        ^
  D:/a/_work/1/s/src/native/minipal/descriptorlimit.c:40:14: error: call to undeclared function 'setrlimit'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     40 |     result = setrlimit(RLIMIT_NOFILE, &rlp);
        |              ^
  D:/a/_work/1/s/src/native/minipal/descriptorlimit.c:40:24: error: use of undeclared identifier 'RLIMIT_NOFILE'
  
     40 |     result = setrlimit(RLIMIT_NOFILE, &rlp);
  
        |                        ^

I filled #119100

[MichalStrehovsky]

Unfortunately we don't run WASI builds on PRs anymore and (I think) this broke the build.

Sorry about that, I expected this to cover it:

runtime/src/native/minipal/descriptorlimit.c

Lines 16 to 18 in 1d6c600

	#if TARGET_WASM
	// WebAssembly cannot set limits
	#elif TARGET_LINUX_MUSL

But looks like we don't define TARGET_WASM there? Do we need TARGET_WASI instead? (I don't see that one defined in the failing clang command line either though).

[pavelsavara]

@SingleAccretion volunteered to fix it here #116390 (comment)

[MichalStrehovsky]

@SingleAccretion volunteered to fix it here #116390 (comment)

Sorry for the trouble. Should be an easy fix for someone who knows the right ifdef to gate against.

[jkotas]

Unfortunately we don't run WASI builds on PRs anymore

@pavelsavara Is there a reason? It would be ok to run a WASI build in the CI to catch trivial build breaks like this (single flavor, build only, PRs only - no official builds). We do the same for number of other community supported platforms.

[pavelsavara]

@pavelsavara Is there a reason?

The setup we had in Net9 was much broader, library unit tests, workload testing, native builds, there is also our own build of LLVM and ideally WASI-SDK to flow, wasmtime installations to helix ... we didn't have bandwidth to maintain it in Net10.

It would be ok to run a WASI build in the CI to catch trivial build breaks like this (single flavor, build only, PRs only - no official builds). We do the same for number of other community supported platforms.

Yes, we are discussing that with @lewing, perhaps I disabled too much of the above ?