Revert "Revert "More pthreads cleanup.""
This reverts commit 6f94de3ca49e4ea147b1c59e5818fa175846518f
(Doesn't try to increase the number of TLS slots; that leads to
an inability to boot. Adds more tests.)
Change-Id: Ia7d25ba3995219ed6e686463dbba80c95cc831ca
diff --git a/libc/bionic/pthread_setname_np.cpp b/libc/bionic/pthread_setname_np.cpp
new file mode 100644
index 0000000..88b86ec
--- /dev/null
+++ b/libc/bionic/pthread_setname_np.cpp
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <pthread.h>
+
+#include <fcntl.h>
+#include <stdio.h> // For snprintf.
+#include <sys/prctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "pthread_internal.h"
+#include "private/ErrnoRestorer.h"
+
+// This value is not exported by kernel headers.
+#define MAX_TASK_COMM_LEN 16
+#define TASK_COMM_FMT "/proc/self/task/%u/comm"
+
+int pthread_setname_np(pthread_t thread, const char* thread_name) {
+ ErrnoRestorer errno_restorer;
+
+ if (thread == 0 || thread_name == NULL) {
+ return EINVAL;
+ }
+
+ size_t thread_name_len = strlen(thread_name);
+ if (thread_name_len >= MAX_TASK_COMM_LEN) {
+ return ERANGE;
+ }
+
+ // Changing our own name is an easy special case.
+ if (thread == pthread_self()) {
+ return prctl(PR_SET_NAME, (unsigned long)thread_name, 0, 0, 0) ? errno : 0;
+ }
+
+ // Have to change another thread's name.
+ pthread_internal_t* t = reinterpret_cast<pthread_internal_t*>(thread);
+ char comm_name[sizeof(TASK_COMM_FMT) + 8];
+ snprintf(comm_name, sizeof(comm_name), TASK_COMM_FMT, (unsigned int) t->kernel_id);
+ int fd = open(comm_name, O_RDWR);
+ if (fd == -1) {
+ return errno;
+ }
+ ssize_t n = TEMP_FAILURE_RETRY(write(fd, thread_name, thread_name_len));
+ close(fd);
+
+ if (n < 0) {
+ return errno;
+ } else if ((size_t)n != thread_name_len) {
+ return EIO;
+ }
+ return 0;
+}