This will be used to include the thread name in error reports in a later patch. It returns a const string stored in a thread local to avoid memory allocation when it is called repeatedly in a single thread. The thread name should be set at the very start of the thread execution, which is the case when using qemu_thread_create. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> --- include/qemu/thread.h | 1 + meson.build | 21 +++++++++++++++++ util/qemu-thread-posix.c | 33 ++++++++++++++++++++++++++- util/qemu-thread-win32.c | 49 ++++++++++++++++++++++++++++++++++++---- 4 files changed, 99 insertions(+), 5 deletions(-) diff --git a/include/qemu/thread.h b/include/qemu/thread.h index 27b888ab0a..98cc5c41ac 100644 --- a/include/qemu/thread.h +++ b/include/qemu/thread.h @@ -216,6 +216,7 @@ void qemu_thread_get_self(QemuThread *thread); bool qemu_thread_is_self(QemuThread *thread); G_NORETURN void qemu_thread_exit(void *retval); void qemu_thread_set_name(const char *name); +const char *qemu_thread_get_name(void); struct Notifier; /** diff --git a/meson.build b/meson.build index db87358d62..eb27aca329 100644 --- a/meson.build +++ b/meson.build @@ -2874,6 +2874,27 @@ config_host_data.set('CONFIG_PTHREAD_SET_NAME_NP', cc.links(osdep_prefix + ''' pthread_set_name_np(thread, "QEMU"); return 0; }''', dependencies: threads)) + +config_host_data.set('CONFIG_PTHREAD_GETNAME_NP', cc.links(osdep_prefix + ''' + #include <pthread.h> + + int main(void) + { + char buf[16]; + pthread_getname_np(pthread_self(), buf, sizeof(buf)); + return 0; + }''', dependencies: threads)) +config_host_data.set('CONFIG_PTHREAD_GET_NAME_NP', cc.links(osdep_prefix + ''' + #include <pthread.h> + #include <pthread_np.h> + + int main(void) + { + char buf[16]; + pthread_get_name_np(pthread_self(), buf, sizeof(buf)); + return 0; + }''', dependencies: threads)) + config_host_data.set('CONFIG_PTHREAD_CONDATTR_SETCLOCK', cc.links(osdep_prefix + ''' #include <pthread.h> diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c index afeac9ecad..47156b60ce 100644 --- a/util/qemu-thread-posix.c +++ b/util/qemu-thread-posix.c @@ -18,7 +18,7 @@ #include "qemu/tsan.h" #include "qemu/bitmap.h" -#ifdef CONFIG_PTHREAD_SET_NAME_NP +#if defined(CONFIG_PTHREAD_SET_NAME_NP) || defined(CONFIG_PTHREAD_GET_NAME_NP) #include <pthread_np.h> #endif @@ -532,3 +532,34 @@ void *qemu_thread_join(QemuThread *thread) } return ret; } + +/* + * This is not defined on Linux, but the man page indicates + * the buffer must be at least 16 bytes, including the NUL + * terminator + */ +#ifndef PTHREAD_MAX_NAMELEN_NP +#define PTHREAD_MAX_NAMELEN_NP 16 +#endif + +static __thread char namebuf[PTHREAD_MAX_NAMELEN_NP]; + +const char *qemu_thread_get_name(void) +{ + int rv; + if (namebuf[0] != '\0') { + return namebuf; + } + +# if defined(CONFIG_PTHREAD_GETNAME_NP) + rv = pthread_getname_np(pthread_self(), namebuf, sizeof(namebuf)); +# elif defined(CONFIG_PTHREAD_GET_NAME_NP) + rv = pthread_get_name_np(pthread_self(), namebuf, sizeof(namebuf)); +# else + rv = -1; +# endif + if (rv != 0) { + g_strlcpy(namebuf, "unnamed", G_N_ELEMENTS(namebuf)); + } + return namebuf; +} diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c index 8ca6429ad3..082a38c7d5 100644 --- a/util/qemu-thread-win32.c +++ b/util/qemu-thread-win32.c @@ -19,7 +19,10 @@ typedef HRESULT (WINAPI *pSetThreadDescription) (HANDLE hThread, PCWSTR lpThreadDescription); +typedef HRESULT (WINAPI *pGetThreadDescription) (HANDLE hThread, + PWSTR *lpThreadDescription); static pSetThreadDescription SetThreadDescriptionFunc; +static pGetThreadDescription GetThreadDescriptionFunc; static HMODULE kernel32_module; static void __attribute__((__constructor__(QEMU_CONSTRUCTOR_EARLY))) @@ -28,7 +31,7 @@ qemu_thread_init(void) qemu_thread_set_name("main"); } -static bool load_set_thread_description(void) +static bool load_thread_description(void) { static gsize _init_once = 0; @@ -38,14 +41,17 @@ static bool load_set_thread_description(void) SetThreadDescriptionFunc = (pSetThreadDescription)GetProcAddress(kernel32_module, "SetThreadDescription"); - if (!SetThreadDescriptionFunc) { + GetThreadDescriptionFunc = + (pGetThreadDescription)GetProcAddress(kernel32_module, + "GetThreadDescription"); + if (!SetThreadDescriptionFunc || !GetThreadDescriptionFunc) { FreeLibrary(kernel32_module); } } g_once_init_leave(&_init_once, 1); } - return !!SetThreadDescriptionFunc; + return (SetThreadDescriptionFunc && GetThreadDescriptionFunc); } static void error_exit(int err, const char *msg) @@ -331,7 +337,7 @@ void qemu_thread_set_name(const char *name) { g_autofree wchar_t *namew = NULL; - if (!load_set_thread_description()) { + if (!load_thread_description()) { return; } @@ -415,3 +421,38 @@ bool qemu_thread_is_self(QemuThread *thread) { return GetCurrentThreadId() == thread->tid; } + +static __thread char namebuf[64]; + +const char *qemu_thread_get_name(void) +{ + HRESULT hr; + wchar_t *namew = NULL; + g_autofree char *name = NULL; + + if (namebuf[0] != '\0') { + return namebuf; + } + + if (!load_thread_description()) { + goto error; + } + + hr = GetThreadDescriptionFunc(GetCurrentThread(), &namew); + if (!SUCCEEDED(hr)) { + goto error; + } + + name = g_utf16_to_utf8(namew, -1, NULL, NULL, NULL); + LocalFree(namew); + if (!name) { + goto error; + } + + g_strlcpy(namebuf, name, G_N_ELEMENTS(namebuf)); + return namebuf; + + error: + g_strlcpy(namebuf, "unnamed", G_N_ELEMENTS(namebuf)); + return namebuf; +} -- 2.52.0