From 7163d7a40e438b34f36f27f749f7d327f15214c1 Mon Sep 17 00:00:00 2001
From: Ronan Pelliard <ronan.pelliard@datadoghq.com>
Date: Mon, 18 Mar 2024 13:51:17 +0100
Subject: [PATCH] make functions unsafe

---
 src/opts.rs | 54 +++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 42 insertions(+), 12 deletions(-)

diff --git a/src/opts.rs b/src/opts.rs
index acac9a5083..5170c900aa 100644
--- a/src/opts.rs
+++ b/src/opts.rs
@@ -234,7 +234,11 @@ where
 }
 
 /// Get the maximum mmap window size
-pub fn get_mwindow_size() -> Result<libc::size_t, Error> {
+///
+/// # Safety
+/// This function is reading a C global without synchronization, so it is not
+/// thread safe, and should only be called before any thread is spawned.
+pub unsafe fn get_mwindow_size() -> Result<libc::size_t, Error> {
     crate::init();
 
     let mut size = 0;
@@ -250,7 +254,11 @@ pub fn get_mwindow_size() -> Result<libc::size_t, Error> {
 }
 
 /// Set the maximum mmap window size
-pub fn set_mwindow_size(size: libc::size_t) -> Result<(), Error> {
+///
+/// # Safety
+/// This function is modifying a C global without synchronization, so it is not
+/// thread safe, and should only be called before any thread is spawned.
+pub unsafe fn set_mwindow_size(size: libc::size_t) -> Result<(), Error> {
     crate::init();
 
     unsafe {
@@ -264,7 +272,11 @@ pub fn set_mwindow_size(size: libc::size_t) -> Result<(), Error> {
 }
 
 /// Get the maximum memory that will be mapped in total by the library
-pub fn get_mwindow_mapped_limit() -> Result<libc::size_t, Error> {
+///
+/// # Safety
+/// This function is reading a C global without synchronization, so it is not
+/// thread safe, and should only be called before any thread is spawned.
+pub unsafe fn get_mwindow_mapped_limit() -> Result<libc::size_t, Error> {
     crate::init();
 
     let mut limit = 0;
@@ -281,7 +293,11 @@ pub fn get_mwindow_mapped_limit() -> Result<libc::size_t, Error> {
 
 /// Set the maximum amount of memory that can be mapped at any time
 /// by the library.
-pub fn set_mwindow_mapped_limit(limit: libc::size_t) -> Result<(), Error> {
+///
+/// # Safety
+/// This function is modifying a C global without synchronization, so it is not
+/// thread safe, and should only be called before any thread is spawned.
+pub unsafe fn set_mwindow_mapped_limit(limit: libc::size_t) -> Result<(), Error> {
     crate::init();
 
     unsafe {
@@ -296,7 +312,11 @@ pub fn set_mwindow_mapped_limit(limit: libc::size_t) -> Result<(), Error> {
 
 /// Get the maximum number of files that will be mapped at any time by the
 /// library.
-pub fn get_mwindow_file_limit() -> Result<libc::size_t, Error> {
+///
+/// # Safety
+/// This function is reading a C global without synchronization, so it is not
+/// thread safe, and should only be called before any thread is spawned.
+pub unsafe fn get_mwindow_file_limit() -> Result<libc::size_t, Error> {
     crate::init();
 
     let mut limit = 0;
@@ -313,7 +333,11 @@ pub fn get_mwindow_file_limit() -> Result<libc::size_t, Error> {
 
 /// Set the maximum number of files that can be mapped at any time
 /// by the library. The default (0) is unlimited.
-pub fn set_mwindow_file_limit(limit: libc::size_t) -> Result<(), Error> {
+///
+/// # Safety
+/// This function is modifying a C global without synchronization, so it is not
+/// thread safe, and should only be called before any thread is spawned.
+pub unsafe fn set_mwindow_file_limit(limit: libc::size_t) -> Result<(), Error> {
     crate::init();
 
     unsafe {
@@ -337,19 +361,25 @@ mod test {
 
     #[test]
     fn mwindow_size() {
-        assert!(set_mwindow_size(1024).is_ok());
-        assert!(get_mwindow_size().unwrap() == 1024);
+        unsafe {
+            assert!(set_mwindow_size(1024).is_ok());
+            assert!(get_mwindow_size().unwrap() == 1024);
+        }
     }
 
     #[test]
     fn mwindow_mapped_limit() {
-        assert!(set_mwindow_mapped_limit(1024).is_ok());
-        assert!(get_mwindow_mapped_limit().unwrap() == 1024);
+        unsafe {
+            assert!(set_mwindow_mapped_limit(1024).is_ok());
+            assert!(get_mwindow_mapped_limit().unwrap() == 1024);
+        }
     }
 
     #[test]
     fn mwindow_file_limit() {
-        assert!(set_mwindow_file_limit(1024).is_ok());
-        assert!(get_mwindow_file_limit().unwrap() == 1024);
+        unsafe {
+            assert!(set_mwindow_file_limit(1024).is_ok());
+            assert!(get_mwindow_file_limit().unwrap() == 1024);
+        }
     }
 }