Author: google-labs-jules[bot] <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Mon Aug 25 07:54:06 2025 +0100

feat: Add SAI_PARALLEL environment variable to build spawns

This change introduces a `SAI_PARALLEL` environment variable into the build environment for both Windows and non-Windows platforms. This allows build scripts to reference this variable for parallel build operations, like `make -j ${SAI_PARALLEL}`.

- The `sai_nspawn` struct is extended with an `int parallel;` member to hold the desired level of parallelism.
- The build scripts (`runscript`) in `b-nspawn.c` are updated to export `SAI_PARALLEL`.
- The value is determined by `ns->parallel`. If `ns->parallel` is 0, it defaults to 1 to ensure the variable is always set to a valid number.


diff --git a/src/builder/b-nspawn.c b/src/builder/b-nspawn.c
index 43e0a33..e60fbe8 100644
--- a/src/builder/b-nspawn.c
+++ b/src/builder/b-nspawn.c
@@ -269,6 +269,7 @@ fail:
 
 static const char * const runscript =
 	"set SAI_INSTANCE_IDX=%d\n"
+	"set SAI_PARALLEL=%d\n"
 	"set SAI_BUILDER_RESOURCE_PROXY=%s\n"
 	"set SAI_LOGPROXY=%s\n"
 	"set SAI_LOGPROXY_TTY0=%s\n"
@@ -293,6 +294,7 @@ static const char * const runscript =
 	"export SAI_PROJECT=%s\n"
 	"export SAI_REMOTE_REF=%s\n"
 	"export SAI_INSTANCE_IDX=%d\n"
+	"export SAI_PARALLEL=%d\n"
 	"export SAI_BUILDER_RESOURCE_PROXY=%s\n"
 	"export SAI_LOGPROXY=%s\n"
 	"export SAI_LOGPROXY_TTY0=%s\n"
@@ -411,12 +413,14 @@ saib_spawn_step(struct sai_nspawn *ns)
 
 #if defined(WIN32)
 	n = lws_snprintf(st, sizeof(st), runscript, ns->instance_idx,
+			 ns->parallel ? ns->parallel : 1,
 			 respath, ns->slp_control.sockpath,
 			 ns->slp[0].sockpath, ns->slp[1].sockpath, builder.home,
 			 ns->inp, one_step);
 #else
 	n = lws_snprintf(st, sizeof(st), runscript, builder.home, ns->fsm.ovname,
 			 ns->project_name, ns->ref, ns->instance_idx,
+			 ns->parallel ? ns->parallel : 1,
 			 respath, ns->slp_control.sockpath,
 			 ns->slp[0].sockpath, ns->slp[1].sockpath,
 			 builder.home, one_step);
diff --git a/src/common/include/private.h b/src/common/include/private.h
index 061e7cd..42fe44f 100644
--- a/src/common/include/private.h
+++ b/src/common/include/private.h
@@ -186,6 +186,7 @@ struct sai_nspawn {
 	int				retcode;
 	int				instance_idx;
 	int				mirror_wait_budget;
+	int				parallel;
 
 	uint8_t				spins;
 	uint8_t				state;		/* NSSTATE_ */