chore: combine thread locals into struct

runtime/compiletime/memory/64bit_nix.c

@@ -1,5 +1,5 @@
 /* https://github.com/gwsystems/silverfish/blob/master/runtime/memory/64bit_nix.c */
-#include <types.h>
+#include "types.h"
 
 #ifdef USE_MEM_VM
 
@@ -7,7 +7,7 @@
 INLINE float
 get_f32(i32 offset)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	return *(float *)address;
@@ -16,7 +16,7 @@ get_f32(i32 offset)
 INLINE double
 get_f64(i32 offset)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	return *(double *)address;
@@ -25,7 +25,7 @@ get_f64(i32 offset)
 INLINE i8
 get_i8(i32 offset)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	return *(i8 *)address;
@@ -34,7 +34,7 @@ get_i8(i32 offset)
 INLINE i16
 get_i16(i32 offset)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	return *(i16 *)address;
@@ -43,7 +43,7 @@ get_i16(i32 offset)
 INLINE i32
 get_i32(i32 offset)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	return *(i32 *)address;
@@ -52,7 +52,7 @@ get_i32(i32 offset)
 INLINE i64
 get_i64(i32 offset)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	return *(i64 *)address;
@@ -61,7 +61,7 @@ get_i64(i32 offset)
 INLINE i32
 get_global_i32(i32 offset)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	return *(i32 *)address;
@@ -70,7 +70,7 @@ get_global_i32(i32 offset)
 INLINE i64
 get_global_i64(i32 offset)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	return *(i64 *)address;
@@ -80,7 +80,7 @@ get_global_i64(i32 offset)
 INLINE void
 set_f32(i32 offset, float v)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	*(float *)address = v;
@@ -89,7 +89,7 @@ set_f32(i32 offset, float v)
 INLINE void
 set_f64(i32 offset, double v)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	*(double *)address = v;
@@ -98,7 +98,7 @@ set_f64(i32 offset, double v)
 INLINE void
 set_i8(i32 offset, i8 v)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	*(i8 *)address = v;
@@ -107,7 +107,7 @@ set_i8(i32 offset, i8 v)
 INLINE void
 set_i16(i32 offset, i16 v)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	*(i16 *)address = v;
@@ -116,7 +116,7 @@ set_i16(i32 offset, i16 v)
 INLINE void
 set_i32(i32 offset, i32 v)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	*(i32 *)address = v;
@@ -125,7 +125,7 @@ set_i32(i32 offset, i32 v)
 INLINE void
 set_i64(i32 offset, i64 v)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	*(i64 *)address = v;
@@ -134,7 +134,7 @@ set_i64(i32 offset, i64 v)
 INLINE void
 set_global_i32(i32 offset, i32 v)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	*(i32 *)address = v;
@@ -143,7 +143,7 @@ set_global_i32(i32 offset, i32 v)
 INLINE void
 set_global_i64(i32 offset, i64 v)
 {
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	void *address      = &mem_as_chars[offset];
 
 	*(i64 *)address = v;
@@ -155,7 +155,7 @@ get_function_from_table(u32 idx, u32 type_id)
 {
 	assert(idx < INDIRECT_TABLE_SIZE);
 
-	struct indirect_table_entry f = module_indirect_table[idx];
+	struct indirect_table_entry f = local_sandbox_member_cache.module_indirect_table[idx];
 
 	//	assert(f.type_id == type_id);
 	assert(f.func_pointer);

runtime/include/types.h

@@ -73,11 +73,14 @@ struct indirect_table_entry {
 	void *func_pointer;
 };
 
-extern __thread struct indirect_table_entry *module_indirect_table;
+/* Cache of Frequently Accessed Members used to avoid pointer chasing */
+struct sandbox_member_cache {
+	struct indirect_table_entry *module_indirect_table;
+	void *                       linear_memory_start;
+	u32                          linear_memory_size;
+};
 
-/* for sandbox linear memory isolation */
-extern __thread void *sandbox_lmbase;
-extern __thread u32   sandbox_lmbound;
+extern __thread struct sandbox_member_cache local_sandbox_member_cache;
 
 /* TODO: LOG_TO_FILE logic is untested */
 extern i32 runtime_log_file_descriptor;

runtime/src/current_sandbox.c

@@ -1,8 +1,15 @@
 #include "current_sandbox.h"
+#include "types.h"
 
 /* current sandbox that is active.. */
 static __thread sandbox_t *worker_thread_current_sandbox = NULL;
 
+__thread struct sandbox_member_cache local_sandbox_member_cache = {
+	.linear_memory_start   = NULL,
+	.linear_memory_size    = 0,
+	.module_indirect_table = NULL,
+};
+
 /**
  * Getter for the current sandbox executing on this thread
  * @returns the current sandbox executing on this thread
@@ -22,15 +29,19 @@ current_sandbox_set(struct sandbox *sandbox)
 {
 	/* Unpack hierarchy to avoid pointer chasing */
 	if (sandbox == NULL) {
+		local_sandbox_member_cache = (struct sandbox_member_cache){
+			.linear_memory_start   = NULL,
+			.linear_memory_size    = 0,
+			.module_indirect_table = NULL,
+		};
 		worker_thread_current_sandbox = NULL;
-		sandbox_lmbase                = NULL;
-		sandbox_lmbound               = 0;
-		module_indirect_table         = NULL;
 	} else {
+		local_sandbox_member_cache = (struct sandbox_member_cache){
+			.linear_memory_start   = sandbox->linear_memory_start,
+			.linear_memory_size    = sandbox->linear_memory_size,
+			.module_indirect_table = sandbox->module->indirect_table,
+		};
 		worker_thread_current_sandbox = sandbox;
-		sandbox_lmbase                = sandbox->linear_memory_start;
-		sandbox_lmbound               = sandbox->linear_memory_size;
-		module_indirect_table         = sandbox->module->indirect_table;
 	}
 }
 

runtime/src/libc/uvio.c

@@ -1,9 +1,11 @@
-#include <runtime.h>
-#include <worker_thread.h>
-#include <sandbox.h>
 #include <uv.h>
-#include <http_request.h>
-#include <current_sandbox.h>
+
+#include "current_sandbox.h"
+#include "http_request.h"
+#include "runtime.h"
+#include "sandbox.h"
+#include "types.h"
+#include "worker_thread.h"
 
 // What should we tell the child program its UID and GID are?
 #define UID 0xFF
@@ -462,7 +464,7 @@ wasm_mmap(i32 addr, i32 len, i32 prot, i32 flags, i32 file_descriptor, i32 offse
 
 	assert(len % WASM_PAGE_SIZE == 0);
 
-	i32 result = sandbox_lmbound;
+	i32 result = local_sandbox_member_cache.linear_memory_size;
 	for (int i = 0; i < len / WASM_PAGE_SIZE; i++) { expand_memory(); }
 
 	return result;

runtime/src/memory/64bit_nix.c

@@ -1,7 +1,8 @@
 /* Code from https://github.com/gwsystems/silverfish/blob/master/runtime/memory/64bit_nix.c */
-#include <runtime.h>
-#include <sandbox.h>
-#include <current_sandbox.h>
+#include "current_sandbox.h"
+#include "runtime.h"
+#include "sandbox.h"
+#include "types.h"
 
 #ifdef USE_MEM_VM
 
@@ -27,10 +28,11 @@ expand_memory(void)
 	struct sandbox *sandbox = current_sandbox_get();
 
 	// max_pages = 0 => no limit: FIXME
-	assert((sandbox->sandbox_size + sandbox_lmbound) / WASM_PAGE_SIZE < WASM_MAX_PAGES);
+	assert((sandbox->sandbox_size + local_sandbox_member_cache.linear_memory_size) / WASM_PAGE_SIZE
+	       < WASM_MAX_PAGES);
 	// Remap the relevant wasm page to readable
-	char *mem_as_chars = sandbox_lmbase;
-	char *page_address = &mem_as_chars[sandbox_lmbound];
+	char *mem_as_chars = local_sandbox_member_cache.linear_memory_start;
+	char *page_address = &mem_as_chars[local_sandbox_member_cache.linear_memory_size];
 
 	void *map_result = mmap(page_address, WASM_PAGE_SIZE, PROT_READ | PROT_WRITE,
 	                        MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
@@ -40,12 +42,13 @@ expand_memory(void)
 	}
 
 	// TODO: check sandbox->linear_memory_max_size
-	if (sandbox_lmbound > sandbox->linear_memory_max_size) {
+	if (local_sandbox_member_cache.linear_memory_size > sandbox->linear_memory_max_size) {
 		printf("expand_memory - Out of Memory!\n");
 		exit(EXIT_FAILURE);
 	}
-	sandbox_lmbound += WASM_PAGE_SIZE;
-	sandbox->linear_memory_size = sandbox_lmbound;
+	local_sandbox_member_cache.linear_memory_size += WASM_PAGE_SIZE;
+	// local_sandbox_member_cache is "forked state", so update authoritative member
+	sandbox->linear_memory_size = local_sandbox_member_cache.linear_memory_size;
 }
 
 INLINE char *
@@ -54,9 +57,10 @@ get_memory_ptr_for_runtime(u32 offset, u32 bounds_check)
 	// Due to how we setup memory for x86, the virtual memory mechanism will catch the error, if bounds <
 	// WASM_PAGE_SIZE
 	assert(bounds_check < WASM_PAGE_SIZE
-	       || (sandbox_lmbound > bounds_check && offset <= sandbox_lmbound - bounds_check));
+	       || (local_sandbox_member_cache.linear_memory_size > bounds_check
+	           && offset <= local_sandbox_member_cache.linear_memory_size - bounds_check));
 
-	char *mem_as_chars = (char *)sandbox_lmbase;
+	char *mem_as_chars = (char *)local_sandbox_member_cache.linear_memory_start;
 	char *address      = &mem_as_chars[offset];
 
 	return address;

runtime/src/memory/common.c

@@ -1,15 +1,12 @@
-#include <runtime.h>
-
-__thread struct indirect_table_entry *module_indirect_table = NULL;
-__thread void *                       sandbox_lmbase        = NULL;
-__thread u32                          sandbox_lmbound       = 0;
+#include "runtime.h"
+#include "types.h"
 
 /* Region initialization helper function */
 EXPORT void
 initialize_region(u32 offset, u32 data_count, char *data)
 {
-	assert(sandbox_lmbound >= data_count);
-	assert(offset < sandbox_lmbound - data_count);
+	assert(local_sandbox_member_cache.linear_memory_size >= data_count);
+	assert(offset < local_sandbox_member_cache.linear_memory_size - data_count);
 
 	/* FIXME: Hack around segmented and unsegmented access */
 	memcpy(get_memory_ptr_for_runtime(offset, data_count), data, data_count);
@@ -19,11 +16,16 @@ void
 add_function_to_table(u32 idx, u32 type_id, char *pointer)
 {
 	assert(idx < INDIRECT_TABLE_SIZE);
+	assert(local_sandbox_member_cache.module_indirect_table != NULL);
 
 	/* TODO: atomic for multiple concurrent invocations? */
-	if (module_indirect_table[idx].type_id == type_id && module_indirect_table[idx].func_pointer == pointer) return;
+	if (local_sandbox_member_cache.module_indirect_table[idx].type_id == type_id
+	    && local_sandbox_member_cache.module_indirect_table[idx].func_pointer == pointer)
+		return;
 
-	module_indirect_table[idx] = (struct indirect_table_entry){ .type_id = type_id, .func_pointer = pointer };
+	local_sandbox_member_cache.module_indirect_table[idx] = (struct indirect_table_entry){
+		.type_id = type_id, .func_pointer = pointer
+	};
 }
 
 /* If we are using runtime globals, we need to populate them */

runtime/src/module.c

@@ -4,9 +4,10 @@
 #include <stdlib.h>
 #include <uv.h>
 
-#include <module.h>
-#include <module_database.h>
-#include <runtime.h>
+#include "types.h"
+#include "module.h"
+#include "module_database.h"
+#include "runtime.h"
 
 /*************************
  * Private Static Inline *
@@ -148,20 +149,22 @@ module_new(char *name, char *path, i32 argument_count, u32 stack_size, u32 max_m
 		module->max_request_or_response_size = round_up_to_page(response_size);
 	}
 
-	/* module_indirect_table is a thread-local struct */
-	struct indirect_table_entry *cache_tbl = module_indirect_table;
-
-	/* assumption: All modules are created at program start before we enable preemption or enable the execution
-	   of any worker threads We are checking that thread-local module_indirect_table is NULL to prove that we aren't
-	   yet preempting If we want to be able to do this later, we can possibly defer module_initialize_table until
-	   the first invocation */
-	assert(cache_tbl == NULL);
-
-	/* TODO: determine why we have to set the module_indirect_table state before calling table init and then
-	 * restore the existing value. What is the relationship between these things? */
-	module_indirect_table = module->indirect_table;
+	/* Table initialization calls a function that runs within the sandbox. Rather than setting the current sandbox,
+	 * we partially fake this out by only setting the module_indirect_table and then clearing after table
+	 * initialization is complete.
+	 *
+	 * assumption: This approach depends on module_new only being invoked at program start before preemption is
+	 * enabled. We are check that local_sandbox_member_cache.module_indirect_table is NULL to gain confidence that
+	 * we are not invoking this in a way that clobbers a current module.
+	 *
+	 * If we want to be able to do this later, we can possibly defer module_initialize_table until the first
+	 * invocation
+	 */
+
+	assert(local_sandbox_member_cache.module_indirect_table == NULL);
+	local_sandbox_member_cache.module_indirect_table = module->indirect_table;
 	module_initialize_table(module);
-	module_indirect_table = cache_tbl;
+	local_sandbox_member_cache.module_indirect_table = NULL;
 
 	/* Add the module to the in-memory module DB */
 	module_database_add(module);

runtime/src/sandbox.c

@@ -1,14 +1,16 @@
 #include <assert.h>
-#include <runtime.h>
-#include <worker_thread.h>
-#include <sandbox.h>
 #include <sys/mman.h>
 #include <pthread.h>
 #include <signal.h>
 #include <uv.h>
-#include <libuv_callbacks.h>
-#include <current_sandbox.h>
-#include <http_parser_settings.h>
+
+#include "current_sandbox.h"
+#include "http_parser_settings.h"
+#include "libuv_callbacks.h"
+#include "runtime.h"
+#include "sandbox.h"
+#include "types.h"
+#include "worker_thread.h"
 
 /**
  * Takes the arguments from the sandbox struct and writes them into the WebAssembly linear memory
@@ -21,8 +23,8 @@ sandbox_setup_arguments(struct sandbox *sandbox)
 	i32   argument_count = module_get_argument_count(sandbox->module);
 
 	/* whatever gregor has, to be able to pass arguments to a module! */
-	sandbox->arguments_offset = sandbox_lmbound;
-	assert(sandbox_lmbase == sandbox->linear_memory_start);
+	sandbox->arguments_offset = local_sandbox_member_cache.linear_memory_size;
+	assert(local_sandbox_member_cache.linear_memory_start == sandbox->linear_memory_start);
 	expand_memory();
 
 	i32 *array_ptr  = worker_thread_get_memory_ptr_void(sandbox->arguments_offset, argument_count * sizeof(i32));