Add emulated thread-creation-related functions

These functions always fail
WebAssembly · Sep 25, 2024 · 87d8ee2 · 87d8ee2
1 parent 01a7f89
commit 87d8ee2
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Showing 4 changed files with 75 additions and 0 deletions.
diff --git a/Makefile b/Makefile
@@ -143,6 +143,8 @@ LIBWASI_EMULATED_SIGNAL_SOURCES = \
 LIBWASI_EMULATED_SIGNAL_MUSL_SOURCES = \
     $(LIBC_TOP_HALF_MUSL_SRC_DIR)/signal/psignal.c \
     $(LIBC_TOP_HALF_MUSL_SRC_DIR)/string/strsignal.c
+LIBWASI_EMULATED_PTHREAD_SOURCES = \
+    $(STUB_PTHREADS_DIR)/stub-pthreads-emulated.c
 LIBDL_SOURCES = $(LIBC_TOP_HALF_MUSL_SRC_DIR)/misc/dl.c
 LIBSETJMP_SOURCES = $(LIBC_TOP_HALF_MUSL_SRC_DIR)/setjmp/wasm32/rt.c
 LIBC_BOTTOM_HALF_CRT_SOURCES = $(wildcard $(LIBC_BOTTOM_HALF_DIR)/crt/*.c)
@@ -500,6 +502,7 @@ LIBWASI_EMULATED_PROCESS_CLOCKS_OBJS = $(call objs,$(LIBWASI_EMULATED_PROCESS_CL
 LIBWASI_EMULATED_GETPID_OBJS = $(call objs,$(LIBWASI_EMULATED_GETPID_SOURCES))
 LIBWASI_EMULATED_SIGNAL_OBJS = $(call objs,$(LIBWASI_EMULATED_SIGNAL_SOURCES))
 LIBWASI_EMULATED_SIGNAL_MUSL_OBJS = $(call objs,$(LIBWASI_EMULATED_SIGNAL_MUSL_SOURCES))
+LIBWASI_EMULATED_PTHREAD_OBJS = $(call objs,$(LIBWASI_EMULATED_PTHREAD_SOURCES))
 LIBDL_OBJS = $(call objs,$(LIBDL_SOURCES))
 LIBSETJMP_OBJS = $(call objs,$(LIBSETJMP_SOURCES))
 LIBC_BOTTOM_HALF_CRT_OBJS = $(call objs,$(LIBC_BOTTOM_HALF_CRT_SOURCES))
@@ -603,6 +606,7 @@ LIBWASI_EMULATED_PROCESS_CLOCKS_SO_OBJS = $(patsubst %.o,%.pic.o,$(LIBWASI_EMULA
 LIBWASI_EMULATED_GETPID_SO_OBJS = $(patsubst %.o,%.pic.o,$(LIBWASI_EMULATED_GETPID_OBJS))
 LIBWASI_EMULATED_SIGNAL_SO_OBJS = $(patsubst %.o,%.pic.o,$(LIBWASI_EMULATED_SIGNAL_OBJS))
 LIBWASI_EMULATED_SIGNAL_MUSL_SO_OBJS = $(patsubst %.o,%.pic.o,$(LIBWASI_EMULATED_SIGNAL_MUSL_OBJS))
+LIBWASI_EMULATED_PTHREAD_SO_OBJS = $(patsubst %.o,%.pic.o,$(LIBWASI_EMULATED_PTHREAD_OBJS))
 LIBDL_SO_OBJS = $(patsubst %.o,%.pic.o,$(LIBDL_OBJS))
 LIBSETJMP_SO_OBJS = $(patsubst %.o,%.pic.o,$(LIBSETJMP_OBJS))
 BULK_MEMORY_SO_OBJS = $(patsubst %.o,%.pic.o,$(BULK_MEMORY_OBJS))
@@ -618,6 +622,7 @@ PIC_OBJS = \
 	$(LIBWASI_EMULATED_GETPID_SO_OBJS) \
 	$(LIBWASI_EMULATED_SIGNAL_SO_OBJS) \
 	$(LIBWASI_EMULATED_SIGNAL_MUSL_SO_OBJS) \
+	$(LIBWASI_EMULATED_PTHREAD_SO_OBJS) \
 	$(LIBDL_SO_OBJS) \
 	$(LIBSETJMP_SO_OBJS) \
 	$(BULK_MEMORY_SO_OBJS) \
@@ -659,6 +664,8 @@ $(OBJDIR)/libwasi-emulated-getpid.so.a: $(LIBWASI_EMULATED_GETPID_SO_OBJS)
 
 $(OBJDIR)/libwasi-emulated-signal.so.a: $(LIBWASI_EMULATED_SIGNAL_SO_OBJS) $(LIBWASI_EMULATED_SIGNAL_MUSL_SO_OBJS)
 
+$(OBJDIR)/libwasi-emulated-pthread.so.a: $(LIBWASI_EMULATED_PTHREAD_SO_OBJS)
+
 $(OBJDIR)/libdl.so.a: $(LIBDL_SO_OBJS)
 
 $(OBJDIR)/libsetjmp.so.a: $(LIBSETJMP_SO_OBJS)
@@ -677,6 +684,8 @@ $(SYSROOT_LIB)/libwasi-emulated-getpid.a: $(LIBWASI_EMULATED_GETPID_OBJS)
 
 $(SYSROOT_LIB)/libwasi-emulated-signal.a: $(LIBWASI_EMULATED_SIGNAL_OBJS) $(LIBWASI_EMULATED_SIGNAL_MUSL_OBJS)
 
+$(SYSROOT_LIB)/libwasi-emulated-pthread.a: $(LIBWASI_EMULATED_PTHREAD_OBJS)
+
 $(SYSROOT_LIB)/libdl.a: $(LIBDL_OBJS)
 
 $(SYSROOT_LIB)/libsetjmp.a: $(LIBSETJMP_OBJS)
@@ -775,6 +784,11 @@ $(LIBC_TOP_HALF_ALL_OBJS) $(LIBC_TOP_HALF_ALL_SO_OBJS) $(MUSL_PRINTSCAN_LONG_DOU
 $(LIBWASI_EMULATED_PROCESS_CLOCKS_OBJS) $(LIBWASI_EMULATED_PROCESS_CLOCKS_SO_OBJS): CFLAGS += \
     -I$(LIBC_BOTTOM_HALF_CLOUDLIBC_SRC)
 
+$(LIBWASI_EMULATED_PTHREAD_OBJS) $(LIBWASI_EMULATED_PTHREAD_SO_OBJS): CFLAGS += \
+    -I$(LIBC_TOP_HALF_MUSL_SRC_DIR)/include \
+    -I$(LIBC_TOP_HALF_MUSL_SRC_DIR)/internal \
+    -I$(LIBC_TOP_HALF_MUSL_DIR)/arch/wasm32
+
 # emmalloc uses a lot of pointer type-punning, which is UB under strict aliasing,
 # and this was found to have real miscompilations in wasi-libc#421.
 $(EMMALLOC_OBJS): CFLAGS += \
@@ -824,6 +838,7 @@ LIBC_SO = \
 	$(SYSROOT_LIB)/libwasi-emulated-process-clocks.so \
 	$(SYSROOT_LIB)/libwasi-emulated-getpid.so \
 	$(SYSROOT_LIB)/libwasi-emulated-signal.so \
+	$(SYSROOT_LIB)/libwasi-emulated-pthread.so \
 	$(SYSROOT_LIB)/libdl.so
 ifeq ($(BUILD_LIBSETJMP),yes)
 LIBC_SO += \
@@ -842,6 +857,10 @@ STATIC_LIBS = \
     $(SYSROOT_LIB)/libwasi-emulated-getpid.a \
     $(SYSROOT_LIB)/libwasi-emulated-signal.a \
     $(SYSROOT_LIB)/libdl.a
+ifneq ($(THREAD_MODEL), posix)
+    STATIC_LIBS += \
+        $(SYSROOT_LIB)/libwasi-emulated-pthread.a
+endif
 ifeq ($(BUILD_LIBSETJMP),yes)
 STATIC_LIBS += \
 	$(SYSROOT_LIB)/libsetjmp.a

diff --git a/expected/wasm32-wasip1/defined-symbols.txt b/expected/wasm32-wasip1/defined-symbols.txt
@@ -181,6 +181,9 @@ __powf_log2_data
 __progname
 __progname_full
 __pthread_cond_timedwait
+__pthread_create
+__pthread_detach
+__pthread_join
 __pthread_key_create
 __pthread_key_delete
 __pthread_mutex_consistent
@@ -980,9 +983,12 @@ pthread_condattr_getpshared
 pthread_condattr_init
 pthread_condattr_setclock
 pthread_condattr_setpshared
+pthread_create
+pthread_detach
 pthread_equal
 pthread_exit
 pthread_getspecific
+pthread_join
 pthread_key_create
 pthread_key_delete
 pthread_mutex_consistent
@@ -1026,6 +1032,8 @@ pthread_spin_lock
 pthread_spin_trylock
 pthread_spin_unlock
 pthread_testcancel
+pthread_timedjoin_np
+pthread_tryjoin_np
 putc
 putc_unlocked
 putchar

diff --git a/expected/wasm32-wasip2/defined-symbols.txt b/expected/wasm32-wasip2/defined-symbols.txt
@@ -184,6 +184,9 @@ __powf_log2_data
 __progname
 __progname_full
 __pthread_cond_timedwait
+__pthread_create
+__pthread_detach
+__pthread_join
 __pthread_key_create
 __pthread_key_delete
 __pthread_mutex_consistent
@@ -1113,9 +1116,12 @@ pthread_condattr_getpshared
 pthread_condattr_init
 pthread_condattr_setclock
 pthread_condattr_setpshared
+pthread_create
+pthread_detach
 pthread_equal
 pthread_exit
 pthread_getspecific
+pthread_join
 pthread_key_create
 pthread_key_delete
 pthread_mutex_consistent
@@ -1159,6 +1165,8 @@ pthread_spin_lock
 pthread_spin_trylock
 pthread_spin_unlock
 pthread_testcancel
+pthread_timedjoin_np
+pthread_tryjoin_np
 putc
 putc_unlocked
 putchar

diff --git a/stub-pthreads/stub-pthreads-emulated.c b/stub-pthreads/stub-pthreads-emulated.c
@@ -0,0 +1,40 @@
+// This file is linked into wasi-emulated-pthread
+
+#include "pthread_impl.h"
+
+int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict attrp, void *(*entry)(void *), void *restrict arg)
+{
+	/*
+		"The system lacked the necessary resources to create another thread,
+		or the system-imposed limit on the total number of threads in a process
+		{PTHREAD_THREADS_MAX} would be exceeded."
+	*/
+	return EAGAIN;
+}
+weak_alias(__pthread_create, pthread_create);
+int __pthread_detach(pthread_t t)
+{
+	/*
+		If we are the only thread, when we exit the whole process exits.
+		So the storage will be reclaimed no matter what.
+	*/
+	return 0;
+}
+weak_alias(__pthread_detach, pthread_detach);
+int __pthread_join(pthread_t t, void **res)
+{
+	/*
+		"The behavior is undefined if the value specified by the thread argument
+		to pthread_join() refers to the calling thread."
+	*/
+	return 0;
+}
+weak_alias(__pthread_join, pthread_join);
+int pthread_tryjoin_np(pthread_t t, void **res)
+{
+	return 0;
+}
+int pthread_timedjoin_np(pthread_t t, void **res, const struct timespec *at)
+{
+	return 0;
+}