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Fix another deadlock between IMMS and TSMS

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Bug 31247871 and Bug 31273203 are the same in terms of that both can be
triggered by calling TSM##getCurrentSpellCheckerSubtype() but different
in terms of what lock objects are involved.

To summarize

 Bug 31273203: between IMMS#mMethodMap and IMM#H
  A. OnClickListener.onClick() running in the IMMS locks IMMS#mMethodMap
     then does some View operations, which can be blocked until
     IMM#H is unlocked (e.g. IMM#onViewDetachedFromWindow()).
  B. TSMS#getCurrentSpellCheckerSubtype() internally calls
     IMM#getCurrentInputMethodSubtype(), which locks IMM#H then can be
     blocked until IMMS#mMethodMap is unlocked.
  The tricky point here is that IMMS and TSMS are running in the same
  process hence IMM#H are actually shared between them.

 Bug 31247871: between IMMS#mMethodMap and TSMS#mSpellCheckerMap
  C. IMMS locks IMMS#mMethodMap then calls
     InputMethodUtils#setNonSelectedSystemImesDisabledUntilUsed(), which
     can be blocked until TSMS#mSpellCheckerMap is unlocked.
  D. TSMS#getCurrentSpellCheckerSubtype() locks TSMS#mSpellCheckerMap
     then may call IMM#getCurrentInputMethodSubtype(), which can be
     blocked until IMMS#mMethodMap is released.

This CL aims to remove the layered lock in D to close Bug 31247871,
while the previous CL [1] took care of B to close Bug 31273203.

Note that A and C are still concerning and should also be taken care of
as a part of Bug 31273203.

 [1]: I20cf2c20f49b1b02c0f7a18257b49d4bcc081b5d
      fa1886feea

Bug: 31247871
Bug: 31273203
Change-Id: I26479e7aa306e0df91d9911891d5625dd5f99678
This commit is contained in:
Yohei Yukawa
2016-09-20 06:43:03 -07:00
parent 564fc8f833
commit e3e31a8801
1 changed files with 63 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

122
services/core/java/com/android/server/TextServicesManagerService.java
View File

@@ -459,71 +459,75 @@ public class TextServicesManagerService extends ITextServicesManager.Stub {
if (!calledFromValidUser()) {
return null;
}
final int subtypeHashCode;
final SpellCheckerInfo sci;
final Locale systemLocale;
synchronized (mSpellCheckerMap) {
final int subtypeHashCode =
subtypeHashCode =
mSettings.getSelectedSpellCheckerSubtype(SpellCheckerSubtype.SUBTYPE_ID_NONE);
if (DBG) {
Slog.w(TAG, "getCurrentSpellCheckerSubtype: " + subtypeHashCode);
}
final SpellCheckerInfo sci = getCurrentSpellChecker(null);
if (sci == null || sci.getSubtypeCount() == 0) {
if (DBG) {
Slog.w(TAG, "Subtype not found.");
}
return null;
}
if (subtypeHashCode == SpellCheckerSubtype.SUBTYPE_ID_NONE
&& !allowImplicitlySelectedSubtype) {
return null;
}
String candidateLocale = null;
if (subtypeHashCode == 0) {
// Spell checker language settings == "auto"
final InputMethodManager imm = mContext.getSystemService(InputMethodManager.class);
if (imm != null) {
final InputMethodSubtype currentInputMethodSubtype =
imm.getCurrentInputMethodSubtype();
if (currentInputMethodSubtype != null) {
final String localeString = currentInputMethodSubtype.getLocale();
if (!TextUtils.isEmpty(localeString)) {
// 1. Use keyboard locale if available in the spell checker
candidateLocale = localeString;
}
}
}
if (candidateLocale == null) {
// 2. Use System locale if available in the spell checker
candidateLocale = mContext.getResources().getConfiguration().locale.toString();
}
}
SpellCheckerSubtype candidate = null;
for (int i = 0; i < sci.getSubtypeCount(); ++i) {
final SpellCheckerSubtype scs = sci.getSubtypeAt(i);
if (subtypeHashCode == 0) {
final String scsLocale = scs.getLocale();
if (candidateLocale.equals(scsLocale)) {
return scs;
} else if (candidate == null) {
if (candidateLocale.length() >= 2 && scsLocale.length() >= 2
&& candidateLocale.startsWith(scsLocale)) {
// Fall back to the applicable language
candidate = scs;
}
}
} else if (scs.hashCode() == subtypeHashCode) {
if (DBG) {
Slog.w(TAG, "Return subtype " + scs.hashCode() + ", input= " + locale
+ ", " + scs.getLocale());
}
// 3. Use the user specified spell check language
return scs;
}
}
// 4. Fall back to the applicable language and return it if not null
// 5. Simply just return it even if it's null which means we could find no suitable
// spell check languages
return candidate;
sci = getCurrentSpellChecker(null);
systemLocale = mContext.getResources().getConfiguration().locale;
}
if (sci == null || sci.getSubtypeCount() == 0) {
if (DBG) {
Slog.w(TAG, "Subtype not found.");
}
return null;
}
if (subtypeHashCode == SpellCheckerSubtype.SUBTYPE_ID_NONE
&& !allowImplicitlySelectedSubtype) {
return null;
}
String candidateLocale = null;
if (subtypeHashCode == 0) {
// Spell checker language settings == "auto"
final InputMethodManager imm = mContext.getSystemService(InputMethodManager.class);
if (imm != null) {
final InputMethodSubtype currentInputMethodSubtype =
imm.getCurrentInputMethodSubtype();
if (currentInputMethodSubtype != null) {
final String localeString = currentInputMethodSubtype.getLocale();
if (!TextUtils.isEmpty(localeString)) {
// 1. Use keyboard locale if available in the spell checker
candidateLocale = localeString;
}
}
}
if (candidateLocale == null) {
// 2. Use System locale if available in the spell checker
candidateLocale = systemLocale.toString();
}
}
SpellCheckerSubtype candidate = null;
for (int i = 0; i < sci.getSubtypeCount(); ++i) {
final SpellCheckerSubtype scs = sci.getSubtypeAt(i);
if (subtypeHashCode == 0) {
final String scsLocale = scs.getLocale();
if (candidateLocale.equals(scsLocale)) {
return scs;
} else if (candidate == null) {
if (candidateLocale.length() >= 2 && scsLocale.length() >= 2
&& candidateLocale.startsWith(scsLocale)) {
// Fall back to the applicable language
candidate = scs;
}
}
} else if (scs.hashCode() == subtypeHashCode) {
if (DBG) {
Slog.w(TAG, "Return subtype " + scs.hashCode() + ", input= " + locale
+ ", " + scs.getLocale());
}
// 3. Use the user specified spell check language
return scs;
}
}
// 4. Fall back to the applicable language and return it if not null
// 5. Simply just return it even if it's null which means we could find no suitable
// spell check languages
return candidate;
}
@Override