From a9579ba60cd2fd72179dfd8c2c37d389db5ec402 Mon Sep 17 00:00:00 2001 From: Thomas Wolf Date: Tue, 4 May 2021 23:48:56 +0200 Subject: [PATCH] LockFile: create OutputStream only when needed Don't create the stream eagerly in lock(); that may cause JGit to exceed OS or JVM limits on open file descriptors if many locks need to be created, for instance when creating many refs. Instead create the output stream only when one really needs to write something. Bug: 573328 Change-Id: If9441ed40494d46f594a896d34a5c4f56f91ebf4 Signed-off-by: Thomas Wolf --- .../internal/storage/file/LockFileTest.java | 153 +++++++++++++++++- .../eclipse/jgit/internal/JGitText.properties | 3 + .../org/eclipse/jgit/internal/JGitText.java | 3 + .../jgit/internal/storage/file/LockFile.java | 142 +++++++++++----- 4 files changed, 257 insertions(+), 44 deletions(-) diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/LockFileTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/LockFileTest.java index 0f93749d9..509935dfb 100644 --- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/LockFileTest.java +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/LockFileTest.java @@ -1,5 +1,5 @@ /* - * Copyright (C) 2012, GitHub Inc. and others + * Copyright (C) 2012, 2021 GitHub Inc. and others * * This program and the accompanying materials are made available under the * terms of the Eclipse Distribution License v. 1.0 which is available at @@ -9,10 +9,16 @@ */ package org.eclipse.jgit.internal.storage.file; +import static org.junit.Assert.assertFalse; import static org.junit.Assert.assertNotNull; +import static org.junit.Assert.assertThrows; import static org.junit.Assert.assertTrue; import static org.junit.Assert.fail; +import java.io.File; +import java.io.OutputStream; +import java.nio.charset.StandardCharsets; + import org.eclipse.jgit.api.Git; import org.eclipse.jgit.api.errors.JGitInternalException; import org.eclipse.jgit.errors.LockFailedException; @@ -49,4 +55,149 @@ public void lockFailedExceptionRecovery() throws Exception { } } } + + @Test + public void testLockTwice() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lock()); + lock.write("other".getBytes(StandardCharsets.US_ASCII)); + lock.commit(); + assertFalse(lock.isLocked()); + checkFile(f, "other"); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + try (OutputStream out = lock.getOutputStream()) { + out.write("second".getBytes(StandardCharsets.US_ASCII)); + } + lock.commit(); + assertFalse(lock.isLocked()); + checkFile(f, "second"); + } + + @Test + public void testLockTwiceUnlock() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + lock.write("other".getBytes(StandardCharsets.US_ASCII)); + lock.unlock(); + assertFalse(lock.isLocked()); + checkFile(f, "content"); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + try (OutputStream out = lock.getOutputStream()) { + out.write("second".getBytes(StandardCharsets.US_ASCII)); + } + lock.commit(); + assertFalse(lock.isLocked()); + checkFile(f, "second"); + } + + @Test + public void testLockWriteTwiceThrows1() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + lock.write("other".getBytes(StandardCharsets.US_ASCII)); + assertThrows(Exception.class, + () -> lock.write("second".getBytes(StandardCharsets.US_ASCII))); + lock.unlock(); + } + + @Test + public void testLockWriteTwiceThrows2() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + try (OutputStream out = lock.getOutputStream()) { + out.write("other".getBytes(StandardCharsets.US_ASCII)); + } + assertThrows(Exception.class, + () -> lock.write("second".getBytes(StandardCharsets.US_ASCII))); + lock.unlock(); + } + + @Test + public void testLockWriteTwiceThrows3() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + lock.write("other".getBytes(StandardCharsets.US_ASCII)); + assertThrows(Exception.class, () -> { + try (OutputStream out = lock.getOutputStream()) { + out.write("second".getBytes(StandardCharsets.US_ASCII)); + } + }); + lock.unlock(); + } + + @Test + public void testLockWriteTwiceThrows4() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + try (OutputStream out = lock.getOutputStream()) { + out.write("other".getBytes(StandardCharsets.US_ASCII)); + } + assertThrows(Exception.class, () -> { + try (OutputStream out = lock.getOutputStream()) { + out.write("second".getBytes(StandardCharsets.US_ASCII)); + } + }); + lock.unlock(); + } + + @Test + public void testLockUnclosedCommitThrows() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + try (OutputStream out = lock.getOutputStream()) { + out.write("other".getBytes(StandardCharsets.US_ASCII)); + assertThrows(Exception.class, () -> lock.commit()); + } + } + + @Test + public void testLockNested() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + assertThrows(IllegalStateException.class, () -> lock.lock()); + assertTrue(lock.isLocked()); + lock.unlock(); + } + + @Test + public void testLockHeld() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lock()); + assertTrue(lock.isLocked()); + LockFile lock2 = new LockFile(f); + assertFalse(lock2.lock()); + assertFalse(lock2.isLocked()); + assertTrue(lock.isLocked()); + lock.unlock(); + } + + @Test + public void testLockForAppend() throws Exception { + File f = writeTrashFile("somefile", "content"); + LockFile lock = new LockFile(f); + assertTrue(lock.lockForAppend()); + assertTrue(lock.isLocked()); + lock.write("other".getBytes(StandardCharsets.US_ASCII)); + lock.commit(); + assertFalse(lock.isLocked()); + checkFile(f, "contentother"); + } } diff --git a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties index feef39744..2fa8713da 100644 --- a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties +++ b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties @@ -415,11 +415,14 @@ listingPacks=Listing packs localObjectsIncomplete=Local objects incomplete. localRefIsMissingObjects=Local ref {0} is missing object(s). localRepository=local repository +lockAlreadyHeld=Lock on {0} already held lockCountMustBeGreaterOrEqual1=lockCount must be >= 1 lockError=lock error: {0} lockFailedRetry=locking {0} failed after {1} retries lockOnNotClosed=Lock on {0} not closed. lockOnNotHeld=Lock on {0} not held. +lockStreamClosed=Output to lock on {0} already closed +lockStreamMultiple=Output to lock on {0} already opened logInconsistentFiletimeDiff={}: inconsistent duration from file timestamps on {}, {}: {} > {}, but diff = {}. Aborting measurement at resolution {}. logLargerFiletimeDiff={}: inconsistent duration from file timestamps on {}, {}: diff = {} > {} (last good value). Aborting measurement. logSmallerFiletime={}: got smaller file timestamp on {}, {}: {} < {}. Aborting measurement at resolution {}. diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java index 09fe03e06..ab9fc5c9b 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java @@ -444,10 +444,13 @@ public static JGitText get() { /***/ public String localRefIsMissingObjects; /***/ public String localRepository; /***/ public String lockCountMustBeGreaterOrEqual1; + /***/ public String lockAlreadyHeld; /***/ public String lockError; /***/ public String lockFailedRetry; /***/ public String lockOnNotClosed; /***/ public String lockOnNotHeld; + /***/ public String lockStreamClosed; + /***/ public String lockStreamMultiple; /***/ public String logInconsistentFiletimeDiff; /***/ public String logLargerFiletimeDiff; /***/ public String logSmallerFiletime; diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/LockFile.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/LockFile.java index 2e0a6da3a..ab407a6ae 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/LockFile.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/LockFile.java @@ -1,6 +1,6 @@ /* * Copyright (C) 2007, Robin Rosenberg - * Copyright (C) 2006-2008, Shawn O. Pearce and others + * Copyright (C) 2006-2021, Shawn O. Pearce and others * * This program and the accompanying materials are made available under the * terms of the Eclipse Distribution License v. 1.0 which is available at @@ -96,11 +96,15 @@ static File getLockFile(File file) { private boolean haveLck; - FileOutputStream os; + private FileOutputStream os; private boolean needSnapshot; - boolean fsync; + private boolean fsync; + + private boolean isAppend; + + private boolean written; private FileSnapshot commitSnapshot; @@ -127,6 +131,10 @@ public LockFile(File f) { * does not hold the lock. */ public boolean lock() throws IOException { + if (haveLck) { + throw new IllegalStateException( + MessageFormat.format(JGitText.get().lockAlreadyHeld, ref)); + } FileUtils.mkdirs(lck.getParentFile(), true); try { token = FS.DETECTED.createNewFileAtomic(lck); @@ -134,18 +142,15 @@ public boolean lock() throws IOException { LOG.error(JGitText.get().failedCreateLockFile, lck, e); throw e; } - if (token.isCreated()) { + boolean obtainedLock = token.isCreated(); + if (obtainedLock) { haveLck = true; - try { - os = new FileOutputStream(lck); - } catch (IOException ioe) { - unlock(); - throw ioe; - } + isAppend = false; + written = false; } else { closeToken(); } - return haveLck; + return obtainedLock; } /** @@ -158,12 +163,24 @@ public boolean lock() throws IOException { * does not hold the lock. */ public boolean lockForAppend() throws IOException { - if (!lock()) + if (!lock()) { return false; + } copyCurrentContent(); + isAppend = true; + written = false; return true; } + // For tests only + boolean isLocked() { + return haveLck; + } + + private FileOutputStream getStream() throws IOException { + return new FileOutputStream(lck, isAppend); + } + /** * Copy the current file content into the temporary file. *

@@ -185,32 +202,31 @@ public boolean lockForAppend() throws IOException { */ public void copyCurrentContent() throws IOException { requireLock(); - try { + try (FileOutputStream out = getStream()) { try (FileInputStream fis = new FileInputStream(ref)) { if (fsync) { FileChannel in = fis.getChannel(); long pos = 0; long cnt = in.size(); while (0 < cnt) { - long r = os.getChannel().transferFrom(in, pos, cnt); + long r = out.getChannel().transferFrom(in, pos, cnt); pos += r; cnt -= r; } } else { final byte[] buf = new byte[2048]; int r; - while ((r = fis.read(buf)) >= 0) - os.write(buf, 0, r); + while ((r = fis.read(buf)) >= 0) { + out.write(buf, 0, r); + } } + } catch (FileNotFoundException fnfe) { + if (ref.exists()) { + throw fnfe; + } + // Don't worry about a file that doesn't exist yet, it + // conceptually has no current content to copy. } - } catch (FileNotFoundException fnfe) { - if (ref.exists()) { - unlock(); - throw fnfe; - } - // Don't worry about a file that doesn't exist yet, it - // conceptually has no current content to copy. - // } catch (IOException | RuntimeException | Error ioe) { unlock(); throw ioe; @@ -253,18 +269,22 @@ public void write(ObjectId id) throws IOException { */ public void write(byte[] content) throws IOException { requireLock(); - try { + try (FileOutputStream out = getStream()) { + if (written) { + throw new IOException(MessageFormat + .format(JGitText.get().lockStreamClosed, ref)); + } if (fsync) { - FileChannel fc = os.getChannel(); + FileChannel fc = out.getChannel(); ByteBuffer buf = ByteBuffer.wrap(content); - while (0 < buf.remaining()) + while (0 < buf.remaining()) { fc.write(buf); + } fc.force(true); } else { - os.write(content); + out.write(content); } - os.close(); - os = null; + written = true; } catch (IOException | RuntimeException | Error ioe) { unlock(); throw ioe; @@ -283,36 +303,68 @@ public void write(byte[] content) throws IOException { public OutputStream getOutputStream() { requireLock(); - final OutputStream out; - if (fsync) - out = Channels.newOutputStream(os.getChannel()); - else - out = os; + if (written || os != null) { + throw new IllegalStateException(MessageFormat + .format(JGitText.get().lockStreamMultiple, ref)); + } return new OutputStream() { + + private OutputStream out; + + private boolean closed; + + private OutputStream get() throws IOException { + if (written) { + throw new IOException(MessageFormat + .format(JGitText.get().lockStreamMultiple, ref)); + } + if (out == null) { + os = getStream(); + if (fsync) { + out = Channels.newOutputStream(os.getChannel()); + } else { + out = os; + } + } + return out; + } + @Override public void write(byte[] b, int o, int n) throws IOException { - out.write(b, o, n); + get().write(b, o, n); } @Override public void write(byte[] b) throws IOException { - out.write(b); + get().write(b); } @Override public void write(int b) throws IOException { - out.write(b); + get().write(b); } @Override public void close() throws IOException { + if (closed) { + return; + } + closed = true; try { - if (fsync) - os.getChannel().force(true); - out.close(); - os = null; + if (written) { + throw new IOException(MessageFormat + .format(JGitText.get().lockStreamClosed, ref)); + } + if (out != null) { + if (fsync) { + os.getChannel().force(true); + } + out.close(); + os = null; + } + written = true; } catch (IOException | RuntimeException | Error ioe) { unlock(); throw ioe; @@ -322,7 +374,7 @@ public void close() throws IOException { } void requireLock() { - if (os == null) { + if (!haveLck) { unlock(); throw new IllegalStateException(MessageFormat.format(JGitText.get().lockOnNotHeld, ref)); } @@ -411,6 +463,8 @@ public boolean commit() { try { FileUtils.rename(lck, ref, StandardCopyOption.ATOMIC_MOVE); haveLck = false; + isAppend = false; + written = false; closeToken(); return true; } catch (IOException e) { @@ -497,6 +551,8 @@ public void unlock() { closeToken(); } } + isAppend = false; + written = false; } /** {@inheritDoc} */