Merge pull request #151 from magnusuMET/feature/hdf5-lock

Use hdf5 lock

Cargo.toml

@@ -10,9 +10,9 @@ default-members = ["netcdf", "netcdf-sys"]
 resolver = "2"
 
 [workspace.dependencies]
-netcdf = { path = "netcdf", version = "0.10.0" }
-netcdf-sys = { path = "netcdf-sys", version = "0.7.0" }
+netcdf = { path = "netcdf", version = "0.10.1" }
+netcdf-sys = { path = "netcdf-sys", version = "0.8.0" }
 netcdf-src = { path = "netcdf-src", version = "0.4.0" }
 netcdf-derive = { path = "netcdf-derive", version = "0.1.0" }
-hdf5-sys = { package = "hdf5-metno-sys", version = "0.9.0" }
+hdf5-sys = { package = "hdf5-metno-sys", version = "0.9.1" }
 mpi-sys = { version = "0.2.1" }

README.md

@@ -52,7 +52,7 @@ Some examples of usage can be found in the [tests/lib.rs](netcdf/tests/lib.rs) f
 
 The `netcdf` crate is thread-safe, although the `netcdf-c` library is not itself threadsafe. To render a safe interface, a global mutex is used to serialize access to the underlying library. Consider using a non threadsafe version of `hdf5` to avoid double locking (performance consideration).
 
-Use of `netcdf-sys` is not thread-safe. Users of this library must take care that calls do not interfere with simultaneous use of e.g. `netcdf`. Using the `hdf5-sys` library could also pose a problem, as this library is used throughout `netCDF-c` and internal state may be disrupted.
+Use of `netcdf-sys` is not thread-safe. Users of this library must take care that calls do not interfere with simultaneous use of e.g. `netcdf` or `hdf5-sys`. Use the lock provided by `netcdf-sys` to serialise access to the `hdf5` and `netCDF` libraries.
 
 ## License
 

netcdf-sys/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "netcdf-sys"
-version = "0.7.0"
+version = "0.8.0"
 authors = [
     "Michael Hiley <[email protected]>",
     "Magnus Ulimoen <[email protected]>"
@@ -25,6 +25,7 @@ curl-sys = { version = "0.4.51", optional = true }
 hdf5-sys = { workspace = true }
 netcdf-src = { workspace = true, optional = true }
 mpi-sys = { workspace = true, optional = true }
+parking_lot = "0.12.3"
 
 [dev-dependencies]
 

netcdf-sys/src/lib.rs

@@ -33,12 +33,12 @@ pub use filter::*;
 #[cfg(feature = "mpi")]
 pub mod par;
 
-use std::sync::Mutex;
-
 /// Global netCDF lock for using all functions in the netCDF library
 ///
 /// Per the NetCDF FAQ: "THE C-BASED LIBRARIES ARE NOT THREAD-SAFE"
-pub static libnetcdf_lock: Mutex<()> = Mutex::new(());
+/// This lock is the same as the one in `hdf5`, so the two libraries
+/// can be used at the same time
+pub use hdf5_sys::LOCK as libnetcdf_lock;
 
 #[cfg(test)]
 mod tests {
@@ -57,7 +57,7 @@ mod tests {
 
         let mut ncid: nc_type = -999_999;
         unsafe {
-            let _g = libnetcdf_lock.lock().unwrap();
+            let _g = libnetcdf_lock.lock();
             let err = nc_open(f.as_ptr(), NC_NOWRITE, &mut ncid);
             assert_eq!(err, NC_NOERR);
             let err = nc_close(ncid);
@@ -78,7 +78,7 @@ mod tests {
         let mut varid: nc_type = -999_999;
         let mut nvars: nc_type = -999_999;
         unsafe {
-            let _g = libnetcdf_lock.lock().unwrap();
+            let _g = libnetcdf_lock.lock();
             let err = nc_open(f.as_ptr(), NC_NOWRITE, &mut ncid);
             assert_eq!(err, NC_NOERR);
             let err = nc_inq_nvars(ncid, &mut nvars);
@@ -104,7 +104,7 @@ mod tests {
         let mut varid: nc_type = -999_999;
         let mut buf: Vec<nc_type> = vec![0; 6 * 12];
         unsafe {
-            let _g = libnetcdf_lock.lock().unwrap();
+            let _g = libnetcdf_lock.lock();
             let err = nc_open(f.as_ptr(), NC_NOWRITE, &mut ncid);
             assert_eq!(err, NC_NOERR);
 

netcdf/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "netcdf"
-version = "0.10.0"
+version = "0.10.1"
 authors = [
     "Michael Hiley <[email protected]>",
     "Magnus Ulimoen <[email protected]>"
@@ -30,6 +30,7 @@ netcdf-derive = { workspace = true, optional = true }
 bitflags = "2.4.2"
 libc = "0.2.155"
 mpi-sys = { workspace = true, optional = true }
+parking_lot = "0.12.3"
 
 [dev-dependencies]
 clap = { version = "4.5.1", features = ["derive"] }