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Merged
shai-almog merged 2 commits into from
Dec 25, 2025
Merged

Handle volatile fields with C atomics #4354

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8661c24
Handle volatile fields with C atomics
shai-almog Dec 25, 2025
59e76be
Fix pointer casts for volatile field accessors
shai-almog Dec 25, 2025
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1 change: 1 addition & 0 deletions vm/ByteCodeTranslator/src/cn1_globals.h
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@
#include <pthread.h>
#include <setjmp.h>
#include <math.h>
#include <stdatomic.h>

//#define DEBUG_GC_ALLOCATIONS

Expand Down
143 changes: 96 additions & 47 deletions vm/ByteCodeTranslator/src/com/codename1/tools/translator/ByteCodeClass.java
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Original file line number Diff line number Diff line change
Expand Up @@ -694,28 +694,36 @@ public String generateCCode(List<ByteCodeClass> allClasses) {
}
b.append(";\n}\n\n");
} else {
b.append(bf.getCDefinition());
b.append(bf.getCStorageDefinition());
b.append(" STATIC_FIELD_");
b.append(clsName);
b.append("_");
b.append(bf.getFieldName());
b.append(" = 0;\n");

// static getter
// static getter
b.append(bf.getCDefinition());
b.append(" get_static_");
b.append(clsName);
b.append("_");
b.append(bf.getFieldName().replace('$', '_'));
b.append("(CODENAME_ONE_THREAD_STATE) {\n __STATIC_INITIALIZER_");
b.append(bf.getClsName());
b.append("(threadStateData);\n return STATIC_FIELD_");
b.append(bf.getClsName());
b.append("_");
b.append(bf.getFieldName());
b.append(";\n}\n\n");
if (bf.isVolatile()) {
b.append("(threadStateData);\n return atomic_load(&STATIC_FIELD_");
b.append(bf.getClsName());
b.append("_");
b.append(bf.getFieldName());
b.append(");\n}\n\n");
} else {
b.append("(threadStateData);\n return STATIC_FIELD_");
b.append(bf.getClsName());
b.append("_");
b.append(bf.getFieldName());
b.append(";\n}\n\n");
}

// static setter
// static setter
b.append("void set_static_");
b.append(clsName);
b.append("_");
Expand All @@ -724,30 +732,31 @@ public String generateCCode(List<ByteCodeClass> allClasses) {
b.append(bf.getCDefinition());
b.append(" __cn1StaticVal) {\n __STATIC_INITIALIZER_");
b.append(bf.getClsName());
if(bf.isObjectType()) {
if(bf.isFinal()) {
b.append("(threadStateData);\n STATIC_FIELD_");
} else {
b.append("(threadStateData);\n STATIC_FIELD_");
}
if (bf.isVolatile()) {
b.append("(threadStateData);\n atomic_store(&STATIC_FIELD_");
b.append(bf.getClsName());
b.append("_");
b.append(bf.getFieldName());
b.append(", __cn1StaticVal);");
} else {
b.append("(threadStateData);\n STATIC_FIELD_");
b.append(bf.getClsName());
b.append("_");
b.append(bf.getFieldName());
b.append(" = __cn1StaticVal;");
}
b.append(bf.getClsName());
b.append("_");
b.append(bf.getFieldName());
if(bf.shouldRemoveFromHeapCollection()) {
if(bf.getType() != null && bf.getType().endsWith("String")) {
b.append(" = __cn1StaticVal;\n removeObjectFromHeapCollection(threadStateData, __cn1StaticVal);\n if(__cn1StaticVal != 0) {\n removeObjectFromHeapCollection(threadStateData, ((struct obj__java_lang_String*)__cn1StaticVal)->java_lang_String_value);\n }\n}\n\n");
b.append("\n removeObjectFromHeapCollection(threadStateData, __cn1StaticVal);\n if(__cn1StaticVal != 0) {\n removeObjectFromHeapCollection(threadStateData, ((struct obj__java_lang_String*)__cn1StaticVal)->java_lang_String_value);\n }\n}\n\n");
} else {
b.append(" = __cn1StaticVal;\n removeObjectFromHeapCollection(threadStateData, __cn1StaticVal);\n}\n\n");
b.append("\n removeObjectFromHeapCollection(threadStateData, __cn1StaticVal);\n}\n\n");
}
} else {
b.append(" = __cn1StaticVal;\n}\n\n");
b.append("\n}\n\n");
}
}
}
}
}

if(isInterface) {
b.append("int **classToInterfaceMap_");
Expand All @@ -768,13 +777,24 @@ public String generateCCode(List<ByteCodeClass> allClasses) {
b.append(clsName);
b.append("_");
b.append(fld.getFieldName());
b.append("(JAVA_OBJECT __cn1T) {\n ").append(nullCheck).append(" return (*(struct obj__");
b.append(clsName);
b.append("*)__cn1T).");
b.append(fld.getClsName());
b.append("_");
b.append(fld.getFieldName());
b.append(";\n}\n\n");
b.append("(JAVA_OBJECT __cn1T) {\n ").append(nullCheck).append(" ");
if (fld.isVolatile()) {
b.append("return atomic_load(&((struct obj__");
b.append(clsName);
b.append("*)__cn1T)->");
b.append(fld.getClsName());
b.append("_");
b.append(fld.getFieldName());
b.append(");\n}\n\n");
} else {
b.append("return ((struct obj__");
b.append(clsName);
b.append("*)__cn1T)->");
b.append(fld.getClsName());
b.append("_");
b.append(fld.getFieldName());
b.append(";\n}\n\n");
}

b.append("void set_field_");
b.append(clsName);
Expand All @@ -783,16 +803,27 @@ public String generateCCode(List<ByteCodeClass> allClasses) {
b.append("(CODENAME_ONE_THREAD_STATE, ");
b.append(fld.getCDefinition());
if(fld.isObjectType()) {
b.append(" __cn1Val, JAVA_OBJECT __cn1T) {\n ").append(nullCheck).append(" (*(struct obj__");
b.append(" __cn1Val, JAVA_OBJECT __cn1T) {\n ").append(nullCheck).append(" ");
} else {
b.append(" __cn1Val, JAVA_OBJECT __cn1T) {\n ").append(nullCheck).append(" (*(struct obj__");
b.append(" __cn1Val, JAVA_OBJECT __cn1T) {\n ").append(nullCheck).append(" ");
}
if (fld.isVolatile()) {
b.append("atomic_store(&((struct obj__");
b.append(clsName);
b.append("*)__cn1T)->");
b.append(fld.getClsName());
b.append("_");
b.append(fld.getFieldName());
b.append(", __cn1Val);\n}\n\n");
} else {
b.append("((struct obj__");
b.append(clsName);
b.append("*)__cn1T)->");
b.append(fld.getClsName());
b.append("_");
b.append(fld.getFieldName());
b.append(" = __cn1Val;\n}\n\n");
}
b.append(clsName);
b.append("*)__cn1T).");
b.append(fld.getClsName());
b.append("_");
b.append(fld.getFieldName());
b.append(" = __cn1Val;\n}\n\n");
}


Expand Down Expand Up @@ -824,10 +855,19 @@ public String generateCCode(List<ByteCodeClass> allClasses) {
b.append("*)objToMark;\n");
for(ByteCodeField fld : fullFieldList) {
if(!fld.isStaticField() && fld.isObjectType() && fld.getClsName().equals(clsName)) {
b.append(" gcMarkObject(threadStateData, objInstance->");
b.append(fld.getClsName());
b.append("_");
b.append(fld.getFieldName());
b.append(" gcMarkObject(threadStateData, ");
if (fld.isVolatile()) {
b.append("atomic_load(&objInstance->");
b.append(fld.getClsName());
b.append("_");
b.append(fld.getFieldName());
b.append(")");
} else {
b.append("objInstance->");
b.append(fld.getClsName());
b.append("_");
b.append(fld.getFieldName());
}
b.append(", force);\n");
}
}
Expand Down Expand Up @@ -1196,7 +1236,7 @@ private void addFields(StringBuilder b) {
for(ByteCodeField bf : fields) {
if(!bf.isStaticField()) {
b.append(" ");
b.append(bf.getCDefinition());
b.append(bf.getCStorageDefinition());
b.append(" ");
b.append(clsName);
b.append("_");
Expand Down Expand Up @@ -1335,7 +1375,7 @@ public String generateCHeader() {
b.append("();\n");
if(!(bf.isFinal() && bf.getValue() != null && !writableFields.contains(bf.getFieldName()))) {
b.append("extern ");
b.append(bf.getCDefinition());
b.append(bf.getCStorageDefinition());
b.append(" STATIC_FIELD_");
b.append(clsName);
b.append("_");
Expand Down Expand Up @@ -1741,7 +1781,7 @@ public void appendStaticFieldsExtern(StringBuilder b) {
for(ByteCodeField bf : fields) {
if(bf.isStaticField() && bf.isObjectType() && !bf.shouldRemoveFromHeapCollection()) {
b.append("extern ");
b.append(bf.getCDefinition());
b.append(bf.getCStorageDefinition());
b.append(" STATIC_FIELD_");
b.append(clsName);
b.append("_");
Expand All @@ -1767,10 +1807,19 @@ private boolean isTrulyFinal(ByteCodeField bf) {
public void appendStaticFieldsMark(StringBuilder b) {
for(ByteCodeField bf : fields) {
if(bf.isStaticField() && bf.isObjectType() && !bf.shouldRemoveFromHeapCollection()) {
b.append(" gcMarkObject(threadStateData, STATIC_FIELD_");
b.append(clsName);
b.append("_");
b.append(bf.getFieldName());
b.append(" gcMarkObject(threadStateData, ");
if (bf.isVolatile()) {
b.append("atomic_load(&STATIC_FIELD_");
b.append(clsName);
b.append("_");
b.append(bf.getFieldName());
b.append(")");
} else {
b.append("STATIC_FIELD_");
b.append(clsName);
b.append("_");
b.append(bf.getFieldName());
}
b.append(", JAVA_TRUE);\n");
}
}
Expand Down
13 changes: 13 additions & 0 deletions vm/ByteCodeTranslator/src/com/codename1/tools/translator/ByteCodeField.java
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Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,7 @@ public class ByteCodeField {
private boolean finalField;
private Object value;
private boolean privateField;
private final boolean volatileField;

public ByteCodeField(String clsName, int access, String name, String desc, String signature, Object value) {
this.clsName = clsName;
Expand All @@ -55,6 +56,7 @@ public ByteCodeField(String clsName, int access, String name, String desc, Strin
}
staticField = (access & Opcodes.ACC_STATIC) == Opcodes.ACC_STATIC;
finalField = (access & Opcodes.ACC_FINAL) == Opcodes.ACC_FINAL;
volatileField = (access & Opcodes.ACC_VOLATILE) == Opcodes.ACC_VOLATILE;
fieldName = name.replace('$', '_');

arrayDimensions = 0;
Expand Down Expand Up @@ -115,6 +117,13 @@ public String getCDefinition() {
}
return Util.getCType(primitiveType);
}

public String getCStorageDefinition() {
if (volatileField) {
return "_Atomic " + getCDefinition();
}
return getCDefinition();
}

public List<String> getDependentClasses() {
return dependentClasses;
Expand Down Expand Up @@ -150,6 +159,10 @@ public String getClsName() {
public boolean isObjectType() {
return arrayDimensions > 0 || primitiveType == null;
}

public boolean isVolatile() {
return volatileField;
}

public boolean isFinal() {
return finalField;
Expand Down
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