Revert "Use std::function instead of base::function_ref"

Revert submission 2780893

Reason for revert: breaking boot tests

Bug: 308214260

Reverted changes: /q/submissionid:2780893

Change-Id: Ibbd9bf2c9eb1389c9b8217cc75a98a3ec13b77d8

9 files changed, 42 insertions, 58 deletions

diff --git a/libs/binder/RpcState.cpp b/libs/binder/RpcState.cpp
index 09032dd4dd..aa26b91274 100644
--- a/libs/binder/RpcState.cpp
+++ b/libs/binder/RpcState.cpp
@@ -359,7 +359,7 @@ RpcState::CommandData::CommandData(size_t size) : mSize(size) {
 status_t RpcState::rpcSend(
         const sp<RpcSession::RpcConnection>& connection, const sp<RpcSession>& session,
         const char* what, iovec* iovs, int niovs,
-        const std::optional<SmallFunction<status_t()>>& altPoll,
+        const std::optional<android::base::function_ref<status_t()>>& altPoll,
         const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) {
     for (int i = 0; i < niovs; i++) {
         LOG_RPC_DETAIL("Sending %s (part %d of %d) on RpcTransport %p: %s",
@@ -604,24 +604,25 @@ status_t RpcState::transactAddress(const sp<RpcSession::RpcConnection>& connecti
             {const_cast<uint8_t*>(data.data()), data.dataSize()},
             objectTableSpan.toIovec(),
     };
-    auto altPoll = [&] {
-        if (waitUs > kWaitLogUs) {
-            ALOGE("Cannot send command, trying to process pending refcounts. Waiting "
-                  "%zuus. Too many oneway calls?",
-                  waitUs);
-        }
+    if (status_t status = rpcSend(
+                connection, session, "transaction", iovs, arraysize(iovs),
+                [&] {
+                    if (waitUs > kWaitLogUs) {
+                        ALOGE("Cannot send command, trying to process pending refcounts. Waiting "
+                              "%zuus. Too many oneway calls?",
+                              waitUs);
+                    }
 
-        if (waitUs > 0) {
-            usleep(waitUs);
-            waitUs = std::min(kWaitMaxUs, waitUs * 2);
-        } else {
-            waitUs = 1;
-        }
+                    if (waitUs > 0) {
+                        usleep(waitUs);
+                        waitUs = std::min(kWaitMaxUs, waitUs * 2);
+                    } else {
+                        waitUs = 1;
+                    }
 
-        return drainCommands(connection, session, CommandType::CONTROL_ONLY);
-    };
-    if (status_t status = rpcSend(connection, session, "transaction", iovs, arraysize(iovs),
-                                  std::ref(altPoll), rpcFields->mFds.get());
+                    return drainCommands(connection, session, CommandType::CONTROL_ONLY);
+                },
+                rpcFields->mFds.get());
         status != OK) {
         // rpcSend calls shutdownAndWait, so all refcounts should be reset. If we ever tolerate
         // errors here, then we may need to undo the binder-sent counts for the transaction as
diff --git a/libs/binder/RpcState.h b/libs/binder/RpcState.h
index 2a954e632b..1fe71a5a78 100644
--- a/libs/binder/RpcState.h
+++ b/libs/binder/RpcState.h
@@ -16,7 +16,6 @@
 #pragma once
 
 #include <android-base/unique_fd.h>
-#include <binder/Functional.h>
 #include <binder/IBinder.h>
 #include <binder/Parcel.h>
 #include <binder/RpcSession.h>
@@ -191,7 +190,7 @@ private:
     [[nodiscard]] status_t rpcSend(
             const sp<RpcSession::RpcConnection>& connection, const sp<RpcSession>& session,
             const char* what, iovec* iovs, int niovs,
-            const std::optional<binder::impl::SmallFunction<status_t()>>& altPoll,
+            const std::optional<android::base::function_ref<status_t()>>& altPoll,
             const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds =
                     nullptr);
     [[nodiscard]] status_t rpcRec(
diff --git a/libs/binder/RpcTransportRaw.cpp b/libs/binder/RpcTransportRaw.cpp
index ffa315191d..c089811561 100644
--- a/libs/binder/RpcTransportRaw.cpp
+++ b/libs/binder/RpcTransportRaw.cpp
@@ -29,8 +29,6 @@
 
 namespace android {
 
-using namespace android::binder::impl;
-
 // RpcTransport with TLS disabled.
 class RpcTransportRaw : public RpcTransport {
 public:
@@ -56,7 +54,7 @@ public:
 
     status_t interruptableWriteFully(
             FdTrigger* fdTrigger, iovec* iovs, int niovs,
-            const std::optional<SmallFunction<status_t()>>& altPoll,
+            const std::optional<android::base::function_ref<status_t()>>& altPoll,
             const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds)
             override {
         bool sentFds = false;
@@ -72,7 +70,7 @@ public:
 
     status_t interruptableReadFully(
             FdTrigger* fdTrigger, iovec* iovs, int niovs,
-            const std::optional<SmallFunction<status_t()>>& altPoll,
+            const std::optional<android::base::function_ref<status_t()>>& altPoll,
             std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) override {
         auto recv = [&](iovec* iovs, int niovs) -> ssize_t {
             return binder::os::receiveMessageFromSocket(mSocket, iovs, niovs, ancillaryFds);
diff --git a/libs/binder/RpcTransportTipcAndroid.cpp b/libs/binder/RpcTransportTipcAndroid.cpp
index cf0360f28b..0c81d83032 100644
--- a/libs/binder/RpcTransportTipcAndroid.cpp
+++ b/libs/binder/RpcTransportTipcAndroid.cpp
@@ -26,7 +26,6 @@
 #include "RpcState.h"
 #include "RpcTransportUtils.h"
 
-using namespace android::binder::impl;
 using android::base::Error;
 using android::base::Result;
 
@@ -76,7 +75,7 @@ public:
 
     status_t interruptableWriteFully(
             FdTrigger* fdTrigger, iovec* iovs, int niovs,
-            const std::optional<SmallFunction<status_t()>>& altPoll,
+            const std::optional<android::base::function_ref<status_t()>>& altPoll,
             const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds)
             override {
         auto writeFn = [&](iovec* iovs, size_t niovs) -> ssize_t {
@@ -94,7 +93,7 @@ public:
 
     status_t interruptableReadFully(
             FdTrigger* fdTrigger, iovec* iovs, int niovs,
-            const std::optional<SmallFunction<status_t()>>& altPoll,
+            const std::optional<android::base::function_ref<status_t()>>& altPoll,
             std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* /*ancillaryFds*/)
             override {
         auto readFn = [&](iovec* iovs, size_t niovs) -> ssize_t {
diff --git a/libs/binder/RpcTransportTls.cpp b/libs/binder/RpcTransportTls.cpp
index 2cbfd8d7e3..efb09e9004 100644
--- a/libs/binder/RpcTransportTls.cpp
+++ b/libs/binder/RpcTransportTls.cpp
@@ -38,9 +38,6 @@
 #endif
 
 namespace android {
-
-using namespace android::binder::impl;
-
 namespace {
 
 // Implement BIO for socket that ignores SIGPIPE.
@@ -184,9 +181,10 @@ public:
     // |sslError| should be from Ssl::getError().
     // If |sslError| is WANT_READ / WANT_WRITE, poll for POLLIN / POLLOUT respectively. Otherwise
     // return error. Also return error if |fdTrigger| is triggered before or during poll().
-    status_t pollForSslError(const android::RpcTransportFd& fd, int sslError, FdTrigger* fdTrigger,
-                             const char* fnString, int additionalEvent,
-                             const std::optional<SmallFunction<status_t()>>& altPoll) {
+    status_t pollForSslError(
+            const android::RpcTransportFd& fd, int sslError, FdTrigger* fdTrigger,
+            const char* fnString, int additionalEvent,
+            const std::optional<android::base::function_ref<status_t()>>& altPoll) {
         switch (sslError) {
             case SSL_ERROR_WANT_READ:
                 return handlePoll(POLLIN | additionalEvent, fd, fdTrigger, fnString, altPoll);
@@ -202,7 +200,7 @@ private:
 
     status_t handlePoll(int event, const android::RpcTransportFd& fd, FdTrigger* fdTrigger,
                         const char* fnString,
-                        const std::optional<SmallFunction<status_t()>>& altPoll) {
+                        const std::optional<android::base::function_ref<status_t()>>& altPoll) {
         status_t ret;
         if (altPoll) {
             ret = (*altPoll)();
@@ -286,12 +284,12 @@ public:
     status_t pollRead(void) override;
     status_t interruptableWriteFully(
             FdTrigger* fdTrigger, iovec* iovs, int niovs,
-            const std::optional<SmallFunction<status_t()>>& altPoll,
+            const std::optional<android::base::function_ref<status_t()>>& altPoll,
             const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds)
             override;
     status_t interruptableReadFully(
             FdTrigger* fdTrigger, iovec* iovs, int niovs,
-            const std::optional<SmallFunction<status_t()>>& altPoll,
+            const std::optional<android::base::function_ref<status_t()>>& altPoll,
             std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) override;
 
     bool isWaiting() override { return mSocket.isInPollingState(); };
@@ -322,7 +320,7 @@ status_t RpcTransportTls::pollRead(void) {
 
 status_t RpcTransportTls::interruptableWriteFully(
         FdTrigger* fdTrigger, iovec* iovs, int niovs,
-        const std::optional<SmallFunction<status_t()>>& altPoll,
+        const std::optional<android::base::function_ref<status_t()>>& altPoll,
         const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) {
     (void)ancillaryFds;
 
@@ -368,7 +366,7 @@ status_t RpcTransportTls::interruptableWriteFully(
 
 status_t RpcTransportTls::interruptableReadFully(
         FdTrigger* fdTrigger, iovec* iovs, int niovs,
-        const std::optional<SmallFunction<status_t()>>& altPoll,
+        const std::optional<android::base::function_ref<status_t()>>& altPoll,
         std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) {
     (void)ancillaryFds;
 
diff --git a/libs/binder/RpcTransportUtils.h b/libs/binder/RpcTransportUtils.h
index a0e502e92a..32f0db805d 100644
--- a/libs/binder/RpcTransportUtils.h
+++ b/libs/binder/RpcTransportUtils.h
@@ -27,7 +27,7 @@ template <typename SendOrReceive>
 status_t interruptableReadOrWrite(
         const android::RpcTransportFd& socket, FdTrigger* fdTrigger, iovec* iovs, int niovs,
         SendOrReceive sendOrReceiveFun, const char* funName, int16_t event,
-        const std::optional<binder::impl::SmallFunction<status_t()>>& altPoll) {
+        const std::optional<android::base::function_ref<status_t()>>& altPoll) {
     MAYBE_WAIT_IN_FLAKE_MODE;
 
     if (niovs < 0) {
diff --git a/libs/binder/include/binder/Functional.h b/libs/binder/include/binder/Functional.h
index 08e3b214da..058f8339c9 100644
--- a/libs/binder/include/binder/Functional.h
+++ b/libs/binder/include/binder/Functional.h
@@ -38,13 +38,4 @@ std::unique_ptr<void, std::function<void(void*)>> make_scope_guard(F&& f) {
     return {reinterpret_cast<void*>(true), std::bind(f)};
 }
 
-template <typename T>
-class SmallFunction : public std::function<T> {
-public:
-    template <typename F>
-    SmallFunction(F&& f) : std::function<T>(f) {
-        assert_small_callable<F>();
-    }
-};
-
 } // namespace android::binder::impl
diff --git a/libs/binder/include/binder/RpcTransport.h b/libs/binder/include/binder/RpcTransport.h
index 115a1732d7..6db9ad983c 100644
--- a/libs/binder/include/binder/RpcTransport.h
+++ b/libs/binder/include/binder/RpcTransport.h
@@ -25,10 +25,10 @@
 #include <variant>
 #include <vector>
 
+#include <android-base/function_ref.h>
 #include <android-base/unique_fd.h>
 #include <utils/Errors.h>
 
-#include <binder/Functional.h>
 #include <binder/RpcCertificateFormat.h>
 #include <binder/RpcThreads.h>
 
@@ -85,13 +85,13 @@ public:
      *   error - interrupted (failure or trigger)
      */
     [[nodiscard]] virtual status_t interruptableWriteFully(
-            FdTrigger* fdTrigger, iovec* iovs, int niovs,
-            const std::optional<binder::impl::SmallFunction<status_t()>>& altPoll,
-            const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) = 0;
+            FdTrigger *fdTrigger, iovec *iovs, int niovs,
+            const std::optional<android::base::function_ref<status_t()>> &altPoll,
+            const std::vector<std::variant<base::unique_fd, base::borrowed_fd>> *ancillaryFds) = 0;
     [[nodiscard]] virtual status_t interruptableReadFully(
-            FdTrigger* fdTrigger, iovec* iovs, int niovs,
-            const std::optional<binder::impl::SmallFunction<status_t()>>& altPoll,
-            std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) = 0;
+            FdTrigger *fdTrigger, iovec *iovs, int niovs,
+            const std::optional<android::base::function_ref<status_t()>> &altPoll,
+            std::vector<std::variant<base::unique_fd, base::borrowed_fd>> *ancillaryFds) = 0;
 
     /**
      *  Check whether any threads are blocked while polling the transport
diff --git a/libs/binder/trusty/RpcTransportTipcTrusty.cpp b/libs/binder/trusty/RpcTransportTipcTrusty.cpp
index 6bb45e2e11..692f82d6cd 100644
--- a/libs/binder/trusty/RpcTransportTipcTrusty.cpp
+++ b/libs/binder/trusty/RpcTransportTipcTrusty.cpp
@@ -29,8 +29,6 @@
 
 namespace android {
 
-using namespace android::binder::impl;
-
 // RpcTransport for Trusty.
 class RpcTransportTipcTrusty : public RpcTransport {
 public:
@@ -47,7 +45,7 @@ public:
 
     status_t interruptableWriteFully(
             FdTrigger* /*fdTrigger*/, iovec* iovs, int niovs,
-            const std::optional<SmallFunction<status_t()>>& /*altPoll*/,
+            const std::optional<android::base::function_ref<status_t()>>& /*altPoll*/,
             const std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds)
             override {
         if (niovs < 0) {
@@ -117,7 +115,7 @@ public:
 
     status_t interruptableReadFully(
             FdTrigger* /*fdTrigger*/, iovec* iovs, int niovs,
-            const std::optional<SmallFunction<status_t()>>& /*altPoll*/,
+            const std::optional<android::base::function_ref<status_t()>>& /*altPoll*/,
             std::vector<std::variant<base::unique_fd, base::borrowed_fd>>* ancillaryFds) override {
         if (niovs < 0) {
             return BAD_VALUE;