Refactor julia initialization by finding and loading the sysimage earlier (#58231)

This changes the order of initialization slightly. The goal is to be
able to initialize executables and share libraries without having to
explicitly call init functions.

This still doesn't address the thread safety

Author: topolarity

doc/src/manual/embedding.md

@@ -54,7 +54,7 @@ linking against `libjulia`.
 The first thing that must be done before calling any other Julia C function is to
 initialize Julia. This is done by calling `jl_init`, which tries to automatically determine
 Julia's install location. If you need to specify a custom location, or specify which system
-image to load, use `jl_init_with_image` instead.
+image to load, use `jl_init_with_image_file` or `jl_init_with_image_handle` instead.
 
 The second statement in the test program evaluates a Julia statement using a call to `jl_eval_string`.
 

src/init.c

@@ -534,169 +534,6 @@ int jl_isabspath(const char *in) JL_NOTSAFEPOINT
     return 0; // relative path
 }
 
-static char *absrealpath(const char *in, int nprefix)
-{ // compute an absolute realpath location, so that chdir doesn't change the file reference
-  // ignores (copies directly over) nprefix characters at the start of abspath
-#ifndef _OS_WINDOWS_
-    char *out = realpath(in + nprefix, NULL);
-    if (out) {
-        if (nprefix > 0) {
-            size_t sz = strlen(out) + 1;
-            char *cpy = (char*)malloc_s(sz + nprefix);
-            memcpy(cpy, in, nprefix);
-            memcpy(cpy + nprefix, out, sz);
-            free(out);
-            out = cpy;
-        }
-    }
-    else {
-        size_t sz = strlen(in + nprefix) + 1;
-        if (in[nprefix] == PATHSEPSTRING[0]) {
-            out = (char*)malloc_s(sz + nprefix);
-            memcpy(out, in, sz + nprefix);
-        }
-        else {
-            size_t path_size = JL_PATH_MAX;
-            char *path = (char*)malloc_s(JL_PATH_MAX);
-            if (uv_cwd(path, &path_size)) {
-                jl_error("fatal error: unexpected error while retrieving current working directory");
-            }
-            out = (char*)malloc_s(path_size + 1 + sz + nprefix);
-            memcpy(out, in, nprefix);
-            memcpy(out + nprefix, path, path_size);
-            out[nprefix + path_size] = PATHSEPSTRING[0];
-            memcpy(out + nprefix + path_size + 1, in + nprefix, sz);
-            free(path);
-        }
-    }
-#else
-    // GetFullPathName intentionally errors if given an empty string so manually insert `.` to invoke cwd
-    char *in2 = (char*)malloc_s(JL_PATH_MAX);
-    if (strlen(in) - nprefix == 0) {
-        memcpy(in2, in, nprefix);
-        in2[nprefix] = '.';
-        in2[nprefix+1] = '\0';
-        in = in2;
-    }
-    DWORD n = GetFullPathName(in + nprefix, 0, NULL, NULL);
-    if (n <= 0) {
-        jl_error("fatal error: jl_options.image_file path too long or GetFullPathName failed");
-    }
-    char *out = (char*)malloc_s(n + nprefix);
-    DWORD m = GetFullPathName(in + nprefix, n, out + nprefix, NULL);
-    if (n != m + 1) {
-        jl_error("fatal error: jl_options.image_file path too long or GetFullPathName failed");
-    }
-    memcpy(out, in, nprefix);
-    free(in2);
-#endif
-    return out;
-}
-
-// create an absolute-path copy of the input path format string
-// formed as `joinpath(replace(pwd(), "%" => "%%"), in)`
-// unless `in` starts with `%`
-static const char *absformat(const char *in)
-{
-    if (in[0] == '%' || jl_isabspath(in))
-        return in;
-    // get an escaped copy of cwd
-    size_t path_size = JL_PATH_MAX;
-    char path[JL_PATH_MAX];
-    if (uv_cwd(path, &path_size)) {
-        jl_error("fatal error: unexpected error while retrieving current working directory");
-    }
-    size_t sz = strlen(in) + 1;
-    size_t i, fmt_size = 0;
-    for (i = 0; i < path_size; i++)
-        fmt_size += (path[i] == '%' ? 2 : 1);
-    char *out = (char*)malloc_s(fmt_size + 1 + sz);
-    fmt_size = 0;
-    for (i = 0; i < path_size; i++) { // copy-replace pwd portion
-        char c = path[i];
-        out[fmt_size++] = c;
-        if (c == '%')
-            out[fmt_size++] = '%';
-    }
-    out[fmt_size++] = PATHSEPSTRING[0]; // path sep
-    memcpy(out + fmt_size, in, sz); // copy over format, including nul
-    return out;
-}
-
-static void jl_resolve_sysimg_location(JL_IMAGE_SEARCH rel)
-{
-    // this function resolves the paths in jl_options to absolute file locations as needed
-    // and it replaces the pointers to `julia_bindir`, `julia_bin`, `image_file`, and output file paths
-    // it may fail, print an error, and exit(1) if any of these paths are longer than JL_PATH_MAX
-    //
-    // note: if you care about lost memory, you should call the appropriate `free()` function
-    // on the original pointer for each `char*` you've inserted into `jl_options`, after
-    // calling `julia_init()`
-    char *free_path = (char*)malloc_s(JL_PATH_MAX);
-    size_t path_size = JL_PATH_MAX;
-    if (uv_exepath(free_path, &path_size)) {
-        jl_error("fatal error: unexpected error while retrieving exepath");
-    }
-    if (path_size >= JL_PATH_MAX) {
-        jl_error("fatal error: jl_options.julia_bin path too long");
-    }
-    jl_options.julia_bin = (char*)malloc_s(path_size + 1);
-    memcpy((char*)jl_options.julia_bin, free_path, path_size);
-    ((char*)jl_options.julia_bin)[path_size] = '\0';
-    if (!jl_options.julia_bindir) {
-        jl_options.julia_bindir = getenv("JULIA_BINDIR");
-        if (!jl_options.julia_bindir) {
-            jl_options.julia_bindir = dirname(free_path);
-        }
-    }
-    if (jl_options.julia_bindir)
-        jl_options.julia_bindir = absrealpath(jl_options.julia_bindir, 0);
-    free(free_path);
-    free_path = NULL;
-    if (jl_options.image_file) {
-        if (rel == JL_IMAGE_JULIA_HOME && !jl_isabspath(jl_options.image_file)) {
-            // build time path, relative to JULIA_BINDIR
-            free_path = (char*)malloc_s(JL_PATH_MAX);
-            int n = snprintf(free_path, JL_PATH_MAX, "%s" PATHSEPSTRING "%s",
-                             jl_options.julia_bindir, jl_options.image_file);
-            if (n >= JL_PATH_MAX || n < 0) {
-                jl_error("fatal error: jl_options.image_file path too long");
-            }
-            jl_options.image_file = free_path;
-        }
-        if (jl_options.image_file)
-            jl_options.image_file = absrealpath(jl_options.image_file, 0);
-        if (free_path) {
-            free(free_path);
-            free_path = NULL;
-        }
-    }
-    if (jl_options.outputo)
-        jl_options.outputo = absrealpath(jl_options.outputo, 0);
-    if (jl_options.outputji)
-        jl_options.outputji = absrealpath(jl_options.outputji, 0);
-    if (jl_options.outputbc)
-        jl_options.outputbc = absrealpath(jl_options.outputbc, 0);
-    if (jl_options.outputasm)
-        jl_options.outputasm = absrealpath(jl_options.outputasm, 0);
-    if (jl_options.machine_file)
-        jl_options.machine_file = absrealpath(jl_options.machine_file, 0);
-    if (jl_options.output_code_coverage)
-        jl_options.output_code_coverage = absformat(jl_options.output_code_coverage);
-    if (jl_options.tracked_path)
-        jl_options.tracked_path = absrealpath(jl_options.tracked_path, 0);
-
-    const char **cmdp = jl_options.cmds;
-    if (cmdp) {
-        for (; *cmdp; cmdp++) {
-            const char *cmd = *cmdp;
-            if (cmd[0] == 'L') {
-                *cmdp = absrealpath(cmd, 1);
-            }
-        }
-    }
-}
-
 JL_DLLEXPORT int jl_is_file_tracked(jl_sym_t *path)
 {
     const char* path_ = jl_symbol_name(path);
@@ -722,8 +559,85 @@ static void restore_fp_env(void)
         jl_error("Failed to configure floating point environment");
     }
 }
+static NOINLINE void _finish_jl_init_(jl_image_buf_t sysimage, jl_ptls_t ptls, jl_task_t *ct)
+{
+    JL_TIMING(JULIA_INIT, JULIA_INIT);
+
+    if (sysimage.kind == JL_IMAGE_KIND_SO)
+        jl_gc_notify_image_load(sysimage.data, sysimage.size);
+
+    if (jl_options.cpu_target == NULL)
+        jl_options.cpu_target = "native";
+
+    // Parse image, perform relocations, and init JIT targets, etc.
+    jl_image_t parsed_image = jl_init_processor_sysimg(sysimage, jl_options.cpu_target);
+
+    jl_init_codegen();
+    jl_init_common_symbols();
+
+    if (sysimage.kind != JL_IMAGE_KIND_NONE) {
+        // Load the .ji or .so sysimage
+        jl_restore_system_image(&parsed_image, sysimage);
+    } else {
+        // No sysimage provided, init a minimal environment
+        jl_init_types();
+        jl_global_roots_list = (jl_genericmemory_t*)jl_an_empty_memory_any;
+        jl_global_roots_keyset = (jl_genericmemory_t*)jl_an_empty_memory_any;
+    }
+
+    jl_init_flisp();
+    jl_init_serializer();
+
+    if (sysimage.kind == JL_IMAGE_KIND_NONE) {
+        jl_top_module = jl_core_module;
+        jl_init_intrinsic_functions();
+        jl_init_primitives();
+        jl_init_main_module();
+        jl_load(jl_core_module, "boot.jl");
+        jl_current_task->world_age = jl_atomic_load_acquire(&jl_world_counter);
+        post_boot_hooks();
+    }
+
+    if (jl_base_module == NULL) {
+        // nthreads > 1 requires code in Base
+        jl_atomic_store_relaxed(&jl_n_threads, 1);
+        jl_n_markthreads = 0;
+        jl_n_sweepthreads = 0;
+        jl_n_gcthreads = 0;
+        jl_n_threads_per_pool[JL_THREADPOOL_ID_INTERACTIVE] = 0;
+        jl_n_threads_per_pool[JL_THREADPOOL_ID_DEFAULT] = 1;
+    } else {
+        jl_current_task->world_age = jl_atomic_load_acquire(&jl_world_counter);
+        post_image_load_hooks();
+    }
+    jl_start_threads();
+    jl_start_gc_threads();
+    uv_barrier_wait(&thread_init_done);
+
+    jl_gc_enable(1);
+
+    if ((sysimage.kind != JL_IMAGE_KIND_NONE) &&
+            (!jl_generating_output() || jl_options.incremental) && jl_module_init_order) {
+        jl_array_t *init_order = jl_module_init_order;
+        JL_GC_PUSH1(&init_order);
+        jl_module_init_order = NULL;
+        int i, l = jl_array_nrows(init_order);
+        for (i = 0; i < l; i++) {
+            jl_value_t *mod = jl_array_ptr_ref(init_order, i);
+            jl_module_run_initializer((jl_module_t*)mod);
+        }
+        JL_GC_POP();
+    }
+
+    if (jl_options.trim) {
+        jl_entrypoint_mis = (arraylist_t *)malloc_s(sizeof(arraylist_t));
+        arraylist_new(jl_entrypoint_mis, 0);
+    }
+
+    if (jl_options.handle_signals == JL_OPTIONS_HANDLE_SIGNALS_ON)
+        jl_install_sigint_handler();
+}
 
-static NOINLINE void _finish_julia_init(JL_IMAGE_SEARCH rel, jl_ptls_t ptls, jl_task_t *ct);
 
 JL_DLLEXPORT int jl_default_debug_info_kind;
 JL_DLLEXPORT jl_cgparams_t jl_default_cgparams = {
@@ -751,12 +665,12 @@ static void init_global_mutexes(void) {
     JL_MUTEX_INIT(&profile_show_peek_cond_lock, "profile_show_peek_cond_lock");
 }
 
-JL_DLLEXPORT void julia_init(JL_IMAGE_SEARCH rel)
+JL_DLLEXPORT void jl_init_(jl_image_buf_t sysimage)
 {
     // initialize many things, in no particular order
     // but generally running from simple platform things to optional
     // configuration features
-    jl_init_timing();
+
     // Make sure we finalize the tls callback before starting any threads.
     (void)jl_get_pgcstack();
 
@@ -861,96 +775,7 @@ JL_DLLEXPORT void julia_init(JL_IMAGE_SEARCH rel)
     jl_task_t *ct = jl_init_root_task(ptls, stack_lo, stack_hi);
 #pragma GCC diagnostic pop
     JL_GC_PROMISE_ROOTED(ct);
-    _finish_julia_init(rel, ptls, ct);
-}
-
-static NOINLINE void _finish_julia_init(JL_IMAGE_SEARCH rel, jl_ptls_t ptls, jl_task_t *ct)
-{
-    JL_TIMING(JULIA_INIT, JULIA_INIT);
-    jl_resolve_sysimg_location(rel);
-
-    // loads sysimg if available, and conditionally sets jl_options.cpu_target
-    jl_image_buf_t sysimage = { JL_IMAGE_KIND_NONE };
-    if (rel == JL_IMAGE_IN_MEMORY) {
-        sysimage = jl_set_sysimg_so(jl_exe_handle);
-        jl_options.image_file = jl_options.julia_bin;
-    }
-    else if (jl_options.image_file)
-        sysimage = jl_preload_sysimg(jl_options.image_file);
-
-    if (sysimage.kind == JL_IMAGE_KIND_SO)
-        jl_gc_notify_image_load(sysimage.data, sysimage.size);
-
-    if (jl_options.cpu_target == NULL)
-        jl_options.cpu_target = "native";
-
-    // Parse image, perform relocations, and init JIT targets, etc.
-    jl_image_t parsed_image = jl_init_processor_sysimg(sysimage, jl_options.cpu_target);
-
-    jl_init_codegen();
-    jl_init_common_symbols();
-
-    if (sysimage.kind != JL_IMAGE_KIND_NONE) {
-        // Load the .ji or .so sysimage
-        jl_restore_system_image(&parsed_image, sysimage);
-    } else {
-        // No sysimage provided, init a minimal environment
-        jl_init_types();
-        jl_global_roots_list = (jl_genericmemory_t*)jl_an_empty_memory_any;
-        jl_global_roots_keyset = (jl_genericmemory_t*)jl_an_empty_memory_any;
-    }
-
-    jl_init_flisp();
-    jl_init_serializer();
-
-    if (sysimage.kind == JL_IMAGE_KIND_NONE) {
-        jl_top_module = jl_core_module;
-        jl_init_intrinsic_functions();
-        jl_init_primitives();
-        jl_init_main_module();
-        jl_load(jl_core_module, "boot.jl");
-        jl_current_task->world_age = jl_atomic_load_acquire(&jl_world_counter);
-        post_boot_hooks();
-    }
-
-    if (jl_base_module == NULL) {
-        // nthreads > 1 requires code in Base
-        jl_atomic_store_relaxed(&jl_n_threads, 1);
-        jl_n_markthreads = 0;
-        jl_n_sweepthreads = 0;
-        jl_n_gcthreads = 0;
-        jl_n_threads_per_pool[JL_THREADPOOL_ID_INTERACTIVE] = 0;
-        jl_n_threads_per_pool[JL_THREADPOOL_ID_DEFAULT] = 1;
-    } else {
-        jl_current_task->world_age = jl_atomic_load_acquire(&jl_world_counter);
-        post_image_load_hooks();
-    }
-    jl_start_threads();
-    jl_start_gc_threads();
-    uv_barrier_wait(&thread_init_done);
-
-    jl_gc_enable(1);
-
-    if ((sysimage.kind != JL_IMAGE_KIND_NONE) &&
-            (!jl_generating_output() || jl_options.incremental) && jl_module_init_order) {
-        jl_array_t *init_order = jl_module_init_order;
-        JL_GC_PUSH1(&init_order);
-        jl_module_init_order = NULL;
-        int i, l = jl_array_nrows(init_order);
-        for (i = 0; i < l; i++) {
-            jl_value_t *mod = jl_array_ptr_ref(init_order, i);
-            jl_module_run_initializer((jl_module_t*)mod);
-        }
-        JL_GC_POP();
-    }
-
-    if (jl_options.trim) {
-        jl_entrypoint_mis = (arraylist_t *)malloc_s(sizeof(arraylist_t));
-        arraylist_new(jl_entrypoint_mis, 0);
-    }
-
-    if (jl_options.handle_signals == JL_OPTIONS_HANDLE_SIGNALS_ON)
-        jl_install_sigint_handler();
+    _finish_jl_init_(sysimage, ptls, ct);
 }
 
 #ifdef __cplusplus

src/jl_exported_funcs.inc

@@ -240,9 +240,11 @@
     XX(jl_hrtime) \
     XX(jl_idtable_rehash) \
     XX(jl_init) \
+    XX(jl_init_) \
     XX(jl_init_options) \
     XX(jl_init_restored_module) \
-    XX(jl_init_with_image) \
+    XX(jl_init_with_image_file) \
+    XX(jl_init_with_image_handle) \
     XX(jl_install_sigint_handler) \
     XX(jl_instantiate_type_in_env) \
     XX(jl_instantiate_unionall) \