<p>laforge <strong>submitted</strong> this change.</p><p><a href="https://gerrit.osmocom.org/c/libosmocore/+/17853">View Change</a></p><div style="white-space:pre-wrap">Approvals:
Jenkins Builder: Verified
laforge: Looks good to me, approved
</div><pre style="font-family: monospace,monospace; white-space: pre-wrap;">select.c: Introduce support for signalfd<br><br>The signalfd(2) mechanism of Linux allows signals to be delivered<br>and processed via normal file descriptor I/O. This avoids any of the<br>usual problems about re-entrancy of signal processing, as signals can<br>be processed from the osmocom select() loop abstraction just like any<br>other event.<br><br>Change-Id: If8d89dd1f6989e1cd9b9367fad954d65f91ada30<br>---<br>M configure.ac<br>M include/osmocom/core/select.h<br>M src/select.c<br>3 files changed, 78 insertions(+), 1 deletion(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/configure.ac b/configure.ac</span><br><span>index 92457f1..352648b 100644</span><br><span>--- a/configure.ac</span><br><span>+++ b/configure.ac</span><br><span>@@ -62,7 +62,7 @@</span><br><span> </span><br><span> dnl checks for header files</span><br><span> AC_HEADER_STDC</span><br><span style="color: hsl(0, 100%, 40%);">-AC_CHECK_HEADERS(execinfo.h sys/select.h sys/socket.h sys/timerfd.h syslog.h ctype.h netinet/tcp.h netinet/in.h)</span><br><span style="color: hsl(120, 100%, 40%);">+AC_CHECK_HEADERS(execinfo.h sys/select.h sys/socket.h sys/signalfd.h sys/timerfd.h syslog.h ctype.h netinet/tcp.h netinet/in.h)</span><br><span> # for src/conv.c</span><br><span> AC_FUNC_ALLOCA</span><br><span> AC_SEARCH_LIBS([dlopen], [dl dld], [LIBRARY_DLOPEN="$LIBS";LIBS=""])</span><br><span>diff --git a/include/osmocom/core/select.h b/include/osmocom/core/select.h</span><br><span>index 92904e2..bc60198 100644</span><br><span>--- a/include/osmocom/core/select.h</span><br><span>+++ b/include/osmocom/core/select.h</span><br><span>@@ -7,6 +7,7 @@</span><br><span> #include <osmocom/core/linuxlist.h></span><br><span> #include <stdbool.h></span><br><span> #include <time.h></span><br><span style="color: hsl(120, 100%, 40%);">+#include <signal.h></span><br><span> </span><br><span> /*! \defgroup select Select loop abstraction</span><br><span> * @{</span><br><span>@@ -68,4 +69,21 @@</span><br><span> const struct timespec *interval);</span><br><span> int osmo_timerfd_setup(struct osmo_fd *ofd, int (*cb)(struct osmo_fd *, unsigned int), void *data);</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+/* signalfd integration */</span><br><span style="color: hsl(120, 100%, 40%);">+struct osmo_signalfd;</span><br><span style="color: hsl(120, 100%, 40%);">+struct signalfd_siginfo;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+typedef void osmo_signalfd_cb(struct osmo_signalfd *osfd, const struct signalfd_siginfo *fdsi);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+struct osmo_signalfd {</span><br><span style="color: hsl(120, 100%, 40%);">+ struct osmo_fd ofd;</span><br><span style="color: hsl(120, 100%, 40%);">+ sigset_t sigset;</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_signalfd_cb *cb;</span><br><span style="color: hsl(120, 100%, 40%);">+ void *data;</span><br><span style="color: hsl(120, 100%, 40%);">+};</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+struct osmo_signalfd *</span><br><span style="color: hsl(120, 100%, 40%);">+osmo_signalfd_setup(void *ctx, sigset_t set, osmo_signalfd_cb *cb, void *data);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /*! @} */</span><br><span>diff --git a/src/select.c b/src/select.c</span><br><span>index b997122..f0c814b 100644</span><br><span>--- a/src/select.c</span><br><span>+++ b/src/select.c</span><br><span>@@ -392,6 +392,65 @@</span><br><span> </span><br><span> #endif /* HAVE_SYS_TIMERFD_H */</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+#ifdef HAVE_SYS_SIGNALFD_H</span><br><span style="color: hsl(120, 100%, 40%);">+#include <sys/signalfd.h></span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+static int signalfd_callback(struct osmo_fd *ofd, unsigned int what)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct osmo_signalfd *osfd = ofd->data;</span><br><span style="color: hsl(120, 100%, 40%);">+ struct signalfd_siginfo fdsi;</span><br><span style="color: hsl(120, 100%, 40%);">+ int rc;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ rc = read(ofd->fd, &fdsi, sizeof(fdsi));</span><br><span style="color: hsl(120, 100%, 40%);">+ if (rc < 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_fd_unregister(ofd);</span><br><span style="color: hsl(120, 100%, 40%);">+ close(ofd->fd);</span><br><span style="color: hsl(120, 100%, 40%);">+ ofd->fd = -1;</span><br><span style="color: hsl(120, 100%, 40%);">+ return rc;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ osfd->cb(osfd, &fdsi);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+};</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+/*! create a signalfd and register it with osmocom select loop.</span><br><span style="color: hsl(120, 100%, 40%);">+ * \param[in] ctx talloc context from which osmo_signalfd is to be allocated</span><br><span style="color: hsl(120, 100%, 40%);">+ * \param[in] set of signals to be accept via this file descriptor</span><br><span style="color: hsl(120, 100%, 40%);">+ * \param[in] cb call-back function to be called for each arriving signal</span><br><span style="color: hsl(120, 100%, 40%);">+ * \param[in] data opaque user-provided data to pass to callback</span><br><span style="color: hsl(120, 100%, 40%);">+ * \returns pointer to newly-allocated + registered osmo_signalfd; NULL on error */</span><br><span style="color: hsl(120, 100%, 40%);">+struct osmo_signalfd *</span><br><span style="color: hsl(120, 100%, 40%);">+osmo_signalfd_setup(void *ctx, sigset_t set, osmo_signalfd_cb *cb, void *data)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct osmo_signalfd *osfd = talloc_size(ctx, sizeof(*osfd));</span><br><span style="color: hsl(120, 100%, 40%);">+ int fd, rc;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!osfd)</span><br><span style="color: hsl(120, 100%, 40%);">+ return NULL;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ osfd->data = data;</span><br><span style="color: hsl(120, 100%, 40%);">+ osfd->sigset = set;</span><br><span style="color: hsl(120, 100%, 40%);">+ osfd->cb = cb;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ fd = signalfd(-1, &osfd->sigset, SFD_NONBLOCK);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (fd < 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ talloc_free(osfd);</span><br><span style="color: hsl(120, 100%, 40%);">+ return NULL;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_fd_setup(&osfd->ofd, fd, OSMO_FD_READ, signalfd_callback, osfd, 0);</span><br><span style="color: hsl(120, 100%, 40%);">+ rc = osmo_fd_register(&osfd->ofd);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (rc < 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ close(fd);</span><br><span style="color: hsl(120, 100%, 40%);">+ talloc_free(osfd);</span><br><span style="color: hsl(120, 100%, 40%);">+ return NULL;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ return osfd;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+#endif /* HAVE_SYS_SIGNALFD_H */</span><br><span> </span><br><span> /*! @} */</span><br><span> </span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/libosmocore/+/17853">change 17853</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/c/libosmocore/+/17853"/><meta itemprop="name" content="View Change"/></div></div>
<div style="display:none"> Gerrit-Project: libosmocore </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: If8d89dd1f6989e1cd9b9367fad954d65f91ada30 </div>
<div style="display:none"> Gerrit-Change-Number: 17853 </div>
<div style="display:none"> Gerrit-PatchSet: 3 </div>
<div style="display:none"> Gerrit-Owner: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-Reviewer: Jenkins Builder </div>
<div style="display:none"> Gerrit-Reviewer: fixeria <axilirator@gmail.com> </div>
<div style="display:none"> Gerrit-Reviewer: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-CC: pespin <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: merged </div>