Tighten up libc file io code to avoid EINTR problems

diff --git a/vm/image.cpp b/vm/image.cpp
index 68701c47363468047ca183c50bc55b762a7a496b..54bd2f706d843ef558b5e2ed350d937480bf3696 100755 (executable)
--- a/vm/image.cpp
+++ b/vm/image.cpp
@@ -22,7 +22,7 @@ void factor_vm::load_data_heap(FILE *file, image_header *h, vm_parameters *p)
                p->aging_size,
                p->tenured_size);
 
-       fixnum bytes_read = fread((void*)data->tenured->start,1,h->data_size,file);
+       fixnum bytes_read = safe_fread((void*)data->tenured->start,1,h->data_size,file);
 
        if((cell)bytes_read != h->data_size)
        {
@@ -43,7 +43,7 @@ void factor_vm::load_code_heap(FILE *file, image_header *h, vm_parameters *p)
 
        if(h->code_size != 0)
        {
-               size_t bytes_read = fread(code->allocator->first_block(),1,h->code_size,file);
+               size_t bytes_read = safe_fread(code->allocator->first_block(),1,h->code_size,file);
                if(bytes_read != h->code_size)
                {
                        std::cout << "truncated image: " << bytes_read << " bytes read, ";
@@ -241,7 +241,7 @@ void factor_vm::load_image(vm_parameters *p)
        }
 
        image_header h;
-       if(fread(&h,sizeof(image_header),1,file) != 1)
+       if(safe_fread(&h,sizeof(image_header),1,file) != 1)
                fatal_error("Cannot read image header",0);
 
        if(h.magic != image_magic)
@@ -253,7 +253,7 @@ void factor_vm::load_image(vm_parameters *p)
        load_data_heap(file,&h,p);
        load_code_heap(file,&h,p);
 
-       fclose(file);
+       safe_fclose(file);
 
        init_objects(&h);
 
@@ -298,10 +298,10 @@ bool factor_vm::save_image(const vm_char *filename)
 
        bool ok = true;
 
-       if(fwrite(&h,sizeof(image_header),1,file) != 1) ok = false;
-       if(fwrite((void*)data->tenured->start,h.data_size,1,file) != 1) ok = false;
-       if(fwrite(code->allocator->first_block(),h.code_size,1,file) != 1) ok = false;
-       if(fclose(file)) ok = false;
+       if(safe_fwrite(&h,sizeof(image_header),1,file) != 1) ok = false;
+       if(safe_fwrite((void*)data->tenured->start,h.data_size,1,file) != 1) ok = false;
+       if(safe_fwrite(code->allocator->first_block(),h.code_size,1,file) != 1) ok = false;
+       if(safe_fclose(file)) ok = false;
 
        if(!ok)
                std::cout << "save-image failed: " << strerror(errno) << std::endl;

diff --git a/vm/io.cpp b/vm/io.cpp
index a45e1d10ab3701f4ae493e71bb1ad9b242dbaf4c..9722676f315aaea85bb9e866783905c7a0a92aab 100755 (executable)
--- a/vm/io.cpp
+++ b/vm/io.cpp
@@ -31,6 +31,39 @@ void factor_vm::io_error()
        general_error(ERROR_IO,tag_fixnum(errno),false_object,NULL);
 }
 
+size_t safe_fread(void *ptr, size_t size, size_t nitems, FILE *stream)
+{
+    size_t items_read = 0;
+
+    do {
+        items_read += fread((void*)((int*)ptr+items_read*size),size,nitems-items_read,stream);
+    } while(items_read != nitems && errno == EINTR);
+
+    return items_read;
+}
+
+size_t safe_fwrite(void *ptr, size_t size, size_t nitems, FILE *stream)
+{
+    size_t items_written = 0;
+
+    do {
+        items_written += fwrite((void*)((int*)ptr+items_written*size),size,nitems-items_written,stream);
+    } while(items_written != nitems && errno == EINTR);
+
+    return items_written;
+}
+
+int safe_fclose(FILE *stream)
+{
+    int ret = 0;
+
+    do {
+        ret = fclose(stream);
+    } while(ret != 0 && errno == EINTR);
+
+    return ret;
+}
+
 void factor_vm::primitive_fopen()
 {
        data_root<byte_array> mode(ctx->pop(),this);
@@ -38,18 +71,15 @@ void factor_vm::primitive_fopen()
        mode.untag_check(this);
        path.untag_check(this);
 
-       for(;;)
-       {
-               FILE *file = fopen((char *)(path.untagged() + 1),
+       FILE *file;
+       do {
+               file = fopen((char *)(path.untagged() + 1),
                                   (char *)(mode.untagged() + 1));
                if(file == NULL)
                        io_error();
-               else
-               {
-                       ctx->push(allot_alien(file));
-                       break;
-               }
-       }
+       } while(errno == EINTR);
+
+       ctx->push(allot_alien(file));
 }
 
 FILE *factor_vm::pop_file_handle()
@@ -61,8 +91,7 @@ void factor_vm::primitive_fgetc()
 {
        FILE *file = pop_file_handle();
 
-       for(;;)
-       {
+       do {
                int c = fgetc(file);
                if(c == EOF)
                {
@@ -79,7 +108,7 @@ void factor_vm::primitive_fgetc()
                        ctx->push(tag_fixnum(c));
                        break;
                }
-       }
+       } while(errno == EINTR);
 }
 
 void factor_vm::primitive_fread()
@@ -97,8 +126,8 @@ void factor_vm::primitive_fread()
 
        for(;;)
        {
-               int c = fread(buf.untagged() + 1,1,size,file);
-               if(c <= 0)
+               int c = safe_fread(buf.untagged() + 1,1,size,file);
+               if(c == 0)
                {
                        if(feof(file))
                        {
@@ -110,12 +139,13 @@ void factor_vm::primitive_fread()
                }
                else
                {
-                       if(c != size)
+                       if(feof(file))
                        {
                                byte_array *new_buf = allot_byte_array(c);
                                memcpy(new_buf + 1, buf.untagged() + 1,c);
                                buf = new_buf;
                        }
+
                        ctx->push(buf.value());
                        break;
                }
@@ -127,17 +157,12 @@ void factor_vm::primitive_fputc()
        FILE *file = pop_file_handle();
        fixnum ch = to_fixnum(ctx->pop());
 
-       for(;;)
-       {
+       do {
                if(fputc(ch,file) == EOF)
-               {
                        io_error();
-
-                       /* Still here? EINTR */
-               }
                else
                        break;
-       }
+       } while(errno == EINTR);
 }
 
 void factor_vm::primitive_fwrite()
@@ -150,23 +175,9 @@ void factor_vm::primitive_fwrite()
        if(length == 0)
                return;
 
-       for(;;)
-       {
-               size_t written = fwrite(string,1,length,file);
-               if(written == length)
-                       break;
-               else
-               {
-                       if(feof(file))
-                               break;
-                       else
-                               io_error();
-
-                       /* Still here? EINTR */
-                       length -= written;
-                       string += written;
-               }
-       }
+       size_t written = safe_fwrite(string,1,length,file);
+       if(written != length)
+               io_error();
 }
 
 void factor_vm::primitive_ftell()
@@ -174,8 +185,12 @@ void factor_vm::primitive_ftell()
        FILE *file = pop_file_handle();
        off_t offset;
 
-       if((offset = FTELL(file)) == -1)
-               io_error();
+       do {
+               if((offset = FTELL(file)) == -1)
+                       io_error();
+               else
+                       break;
+       } while(errno == EINTR);
 
        ctx->push(from_signed_8(offset));
 }
@@ -196,37 +211,30 @@ void factor_vm::primitive_fseek()
                break;
        }
 
-       if(FSEEK(file,offset,whence) == -1)
-       {
-               io_error();
-
-               /* Still here? EINTR */
-               critical_error("Don't know what to do; EINTR from fseek()?",0);
-       }
+       do {
+               if(FSEEK(file,offset,whence) == -1)
+                       io_error();
+               else
+                       break;
+       } while(errno == EINTR);
 }
 
 void factor_vm::primitive_fflush()
 {
        FILE *file = pop_file_handle();
-       for(;;)
-       {
+       do {
                if(fflush(file) == EOF)
                        io_error();
                else
                        break;
-       }
+       } while(errno == EINTR);
 }
 
 void factor_vm::primitive_fclose()
 {
        FILE *file = pop_file_handle();
-       for(;;)
-       {
-               if(fclose(file) == EOF)
-                       io_error();
-               else
-                       break;
-       }
+       if(safe_fclose(file) == EOF)
+               io_error();
 }
 
 /* This function is used by FFI I/O. Accessing the errno global directly is

diff --git a/vm/io.hpp b/vm/io.hpp
index 7fa43e0006ce10824b9924fbf0b3f41bfd23258a..41e9cec82dba096908b650a182a9b53a0def7335 100755 (executable)
--- a/vm/io.hpp
+++ b/vm/io.hpp
@@ -1,6 +1,10 @@
 namespace factor
 {
 
+size_t safe_fread(void *ptr, size_t size, size_t nitems, FILE *stream);
+size_t safe_fwrite(void *ptr, size_t size, size_t nitems, FILE *stream);
+int safe_fclose(FILE *stream);
+
 /* Platform specific primitives */
 
 VM_C_API int err_no();